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android / toolchain / rustc / 89a0a0cd9cbd0a0138a09bd877bbc73859a8c330 / . / vendor / cranelift-codegen / src / isa / x64 / inst / emit.rs
blob: 1a793365695a497543bb87dd16bd0a4e45bc9868 [file] [log] [blame]
use crate::binemit::{Addend, Reloc};
use crate::ir::immediates::{Ieee32, Ieee64};
use crate::ir::TrapCode;
use crate::ir::{KnownSymbol, LibCall};
use crate::isa::x64::encoding::evex::{EvexInstruction, EvexVectorLength};
use crate::isa::x64::encoding::rex::{
emit_simm, emit_std_enc_enc, emit_std_enc_mem, emit_std_reg_mem, emit_std_reg_reg, int_reg_enc,
low8_will_sign_extend_to_32, low8_will_sign_extend_to_64, reg_enc, LegacyPrefixes, OpcodeMap,
RexFlags,
};
use crate::isa::x64::encoding::vex::{VexInstruction, VexVectorLength};
use crate::isa::x64::inst::args::*;
use crate::isa::x64::inst::*;
use crate::machinst::{inst_common, MachBuffer, MachInstEmit, MachLabel, Reg, Writable};
use core::convert::TryInto;
/// A small helper to generate a signed conversion instruction.
fn emit_signed_cvt(
sink: &mut MachBuffer<Inst>,
info: &EmitInfo,
state: &mut EmitState,
// Required to be RealRegs.
src: Reg,
dst: Writable<Reg>,
to_f64: bool,
) {
// Handle an unsigned int, which is the "easy" case: a signed conversion will do the
// right thing.
let op = if to_f64 {
SseOpcode::Cvtsi2sd
} else {
SseOpcode::Cvtsi2ss
};
let inst = Inst::gpr_to_xmm(op, RegMem::reg(src), OperandSize::Size64, dst);
inst.emit(&[], sink, info, state);
}
/// Emits a one way conditional jump if CC is set (true).
fn one_way_jmp(sink: &mut MachBuffer<Inst>, cc: CC, label: MachLabel) {
let cond_start = sink.cur_offset();
let cond_disp_off = cond_start + 2;
sink.use_label_at_offset(cond_disp_off, label, LabelUse::JmpRel32);
sink.put1(0x0F);
sink.put1(0x80 + cc.get_enc());
sink.put4(0x0);
}
/// Emits a relocation, attaching the current source location as well.
fn emit_reloc(sink: &mut MachBuffer<Inst>, kind: Reloc, name: &ExternalName, addend: Addend) {
sink.add_reloc(kind, name, addend);
}
/// The top-level emit function.
///
/// Important! Do not add improved (shortened) encoding cases to existing
/// instructions without also adding tests for those improved encodings. That
/// is a dangerous game that leads to hard-to-track-down errors in the emitted
/// code.
///
/// For all instructions, make sure to have test coverage for all of the
/// following situations. Do this by creating the cross product resulting from
/// applying the following rules to each operand:
///
/// (1) for any insn that mentions a register: one test using a register from
/// the group [rax, rcx, rdx, rbx, rsp, rbp, rsi, rdi] and a second one
/// using a register from the group [r8, r9, r10, r11, r12, r13, r14, r15].
/// This helps detect incorrect REX prefix construction.
///
/// (2) for any insn that mentions a byte register: one test for each of the
/// four encoding groups [al, cl, dl, bl], [spl, bpl, sil, dil],
/// [r8b .. r11b] and [r12b .. r15b]. This checks that
/// apparently-redundant REX prefixes are retained when required.
///
/// (3) for any insn that contains an immediate field, check the following
/// cases: field is zero, field is in simm8 range (-128 .. 127), field is
/// in simm32 range (-0x8000_0000 .. 0x7FFF_FFFF). This is because some
/// instructions that require a 32-bit immediate have a short-form encoding
/// when the imm is in simm8 range.
///
/// Rules (1), (2) and (3) don't apply for registers within address expressions
/// (`Addr`s). Those are already pretty well tested, and the registers in them
/// don't have any effect on the containing instruction (apart from possibly
/// require REX prefix bits).
///
/// When choosing registers for a test, avoid using registers with the same
/// offset within a given group. For example, don't use rax and r8, since they
/// both have the lowest 3 bits as 000, and so the test won't detect errors
/// where those 3-bit register sub-fields are confused by the emitter. Instead
/// use (eg) rax (lo3 = 000) and r9 (lo3 = 001). Similarly, don't use (eg) cl
/// and bpl since they have the same offset in their group; use instead (eg) cl
/// and sil.
///
/// For all instructions, also add a test that uses only low-half registers
/// (rax .. rdi, xmm0 .. xmm7) etc, so as to check that any redundant REX
/// prefixes are correctly omitted. This low-half restriction must apply to
/// _all_ registers in the insn, even those in address expressions.
///
/// Following these rules creates large numbers of test cases, but it's the
/// only way to make the emitter reliable.
///
/// Known possible improvements:
///
/// * there's a shorter encoding for shl/shr/sar by a 1-bit immediate. (Do we
/// care?)
pub(crate) fn emit(
inst: &Inst,
allocs: &mut AllocationConsumer<'_>,
sink: &mut MachBuffer<Inst>,
info: &EmitInfo,
state: &mut EmitState,
) {
let matches_isa_flags = |iset_requirement: &InstructionSet| -> bool {
match iset_requirement {
// Cranelift assumes SSE2 at least.
InstructionSet::SSE | InstructionSet::SSE2 => true,
InstructionSet::SSSE3 => info.isa_flags.use_ssse3(),
InstructionSet::SSE41 => info.isa_flags.use_sse41(),
InstructionSet::SSE42 => info.isa_flags.use_sse42(),
InstructionSet::Popcnt => info.isa_flags.use_popcnt(),
InstructionSet::Lzcnt => info.isa_flags.use_lzcnt(),
InstructionSet::BMI1 => info.isa_flags.use_bmi1(),
InstructionSet::BMI2 => info.isa_flags.has_bmi2(),
InstructionSet::FMA => info.isa_flags.has_fma(),
InstructionSet::AVX512BITALG => info.isa_flags.has_avx512bitalg(),
InstructionSet::AVX512DQ => info.isa_flags.has_avx512dq(),
InstructionSet::AVX512F => info.isa_flags.has_avx512f(),
InstructionSet::AVX512VBMI => info.isa_flags.has_avx512vbmi(),
InstructionSet::AVX512VL => info.isa_flags.has_avx512vl(),
}
};
// Certain instructions may be present in more than one ISA feature set; we must at least match
// one of them in the target CPU.
let isa_requirements = inst.available_in_any_isa();
if !isa_requirements.is_empty() && !isa_requirements.iter().all(matches_isa_flags) {
panic!(
"Cannot emit inst '{:?}' for target; failed to match ISA requirements: {:?}",
inst, isa_requirements
)
}
match inst {
Inst::AluRmiR {
size,
op,
src1,
src2,
dst: reg_g,
} => {
let (reg_g, src2) = if inst.produces_const() {
let reg_g = allocs.next(reg_g.to_reg().to_reg());
(reg_g, RegMemImm::reg(reg_g))
} else {
let src1 = allocs.next(src1.to_reg());
let reg_g = allocs.next(reg_g.to_reg().to_reg());
debug_assert_eq!(src1, reg_g);
let src2 = src2.clone().to_reg_mem_imm().with_allocs(allocs);
(reg_g, src2)
};
let rex = RexFlags::from(*size);
if *op == AluRmiROpcode::Mul {
// We kinda freeloaded Mul into RMI_R_Op, but it doesn't fit the usual pattern, so
// we have to special-case it.
match src2 {
RegMemImm::Reg { reg: reg_e } => {
emit_std_reg_reg(sink, LegacyPrefixes::None, 0x0FAF, 2, reg_g, reg_e, rex);
}
RegMemImm::Mem { addr } => {
let amode = addr.finalize(state, sink);
emit_std_reg_mem(
sink,
info,
LegacyPrefixes::None,
0x0FAF,
2,
reg_g,
&amode,
rex,
0,
);
}
RegMemImm::Imm { simm32 } => {
let use_imm8 = low8_will_sign_extend_to_32(simm32);
let opcode = if use_imm8 { 0x6B } else { 0x69 };
// Yes, really, reg_g twice.
emit_std_reg_reg(sink, LegacyPrefixes::None, opcode, 1, reg_g, reg_g, rex);
emit_simm(sink, if use_imm8 { 1 } else { 4 }, simm32);
}
}
} else {
let (opcode_r, opcode_m, subopcode_i) = match op {
AluRmiROpcode::Add => (0x01, 0x03, 0),
AluRmiROpcode::Adc => (0x11, 0x03, 0),
AluRmiROpcode::Sub => (0x29, 0x2B, 5),
AluRmiROpcode::Sbb => (0x19, 0x2B, 5),
AluRmiROpcode::And => (0x21, 0x23, 4),
AluRmiROpcode::Or => (0x09, 0x0B, 1),
AluRmiROpcode::Xor => (0x31, 0x33, 6),
AluRmiROpcode::Mul => panic!("unreachable"),
};
match src2 {
RegMemImm::Reg { reg: reg_e } => {
// GCC/llvm use the swapped operand encoding (viz., the R/RM vs RM/R
// duality). Do this too, so as to be able to compare generated machine
// code easily.
emit_std_reg_reg(
sink,
LegacyPrefixes::None,
opcode_r,
1,
reg_e,
reg_g,
rex,
);
}
RegMemImm::Mem { addr } => {
let amode = addr.finalize(state, sink);
// Here we revert to the "normal" G-E ordering.
emit_std_reg_mem(
sink,
info,
LegacyPrefixes::None,
opcode_m,
1,
reg_g,
&amode,
rex,
0,
);
}
RegMemImm::Imm { simm32 } => {
let use_imm8 = low8_will_sign_extend_to_32(simm32);
let opcode = if use_imm8 { 0x83 } else { 0x81 };
// And also here we use the "normal" G-E ordering.
let enc_g = int_reg_enc(reg_g);
emit_std_enc_enc(
sink,
LegacyPrefixes::None,
opcode,
1,
subopcode_i,
enc_g,
rex,
);
emit_simm(sink, if use_imm8 { 1 } else { 4 }, simm32);
}
}
}
}
Inst::AluRM {
size,
src1_dst,
src2,
op,
} => {
let src2 = allocs.next(src2.to_reg());
let src1_dst = src1_dst.finalize(state, sink).with_allocs(allocs);
assert!(*size == OperandSize::Size32 || *size == OperandSize::Size64);
let opcode = match op {
AluRmiROpcode::Add => 0x01,
AluRmiROpcode::Sub => 0x29,
AluRmiROpcode::And => 0x21,
AluRmiROpcode::Or => 0x09,
AluRmiROpcode::Xor => 0x31,
_ => panic!("Unsupported read-modify-write ALU opcode"),
};
let enc_g = int_reg_enc(src2);
emit_std_enc_mem(
sink,
info,
LegacyPrefixes::None,
opcode,
1,
enc_g,
&src1_dst,
RexFlags::from(*size),
0,
);
}
Inst::UnaryRmR { size, op, src, dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
let rex_flags = RexFlags::from(*size);
use UnaryRmROpcode::*;
let prefix = match size {
OperandSize::Size16 => match op {
Bsr | Bsf => LegacyPrefixes::_66,
Lzcnt | Tzcnt | Popcnt => LegacyPrefixes::_66F3,
},
OperandSize::Size32 | OperandSize::Size64 => match op {
Bsr | Bsf => LegacyPrefixes::None,
Lzcnt | Tzcnt | Popcnt => LegacyPrefixes::_F3,
},
_ => unreachable!(),
};
let (opcode, num_opcodes) = match op {
Bsr => (0x0fbd, 2),
Bsf => (0x0fbc, 2),
Lzcnt => (0x0fbd, 2),
Tzcnt => (0x0fbc, 2),
Popcnt => (0x0fb8, 2),
};
match src.clone().into() {
RegMem::Reg { reg: src } => {
let src = allocs.next(src);
emit_std_reg_reg(sink, prefix, opcode, num_opcodes, dst, src, rex_flags);
}
RegMem::Mem { addr: src } => {
let amode = src.finalize(state, sink).with_allocs(allocs);
emit_std_reg_mem(
sink,
info,
prefix,
opcode,
num_opcodes,
dst,
&amode,
rex_flags,
0,
);
}
}
}
Inst::Not { size, src, dst } => {
let src = allocs.next(src.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(src, dst);
let rex_flags = RexFlags::from((*size, dst));
let (opcode, prefix) = match size {
OperandSize::Size8 => (0xF6, LegacyPrefixes::None),
OperandSize::Size16 => (0xF7, LegacyPrefixes::_66),
OperandSize::Size32 => (0xF7, LegacyPrefixes::None),
OperandSize::Size64 => (0xF7, LegacyPrefixes::None),
};
let subopcode = 2;
let enc_src = int_reg_enc(dst);
emit_std_enc_enc(sink, prefix, opcode, 1, subopcode, enc_src, rex_flags)
}
Inst::Neg { size, src, dst } => {
let src = allocs.next(src.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(src, dst);
let rex_flags = RexFlags::from((*size, dst));
let (opcode, prefix) = match size {
OperandSize::Size8 => (0xF6, LegacyPrefixes::None),
OperandSize::Size16 => (0xF7, LegacyPrefixes::_66),
OperandSize::Size32 => (0xF7, LegacyPrefixes::None),
OperandSize::Size64 => (0xF7, LegacyPrefixes::None),
};
let subopcode = 3;
let enc_src = int_reg_enc(dst);
emit_std_enc_enc(sink, prefix, opcode, 1, subopcode, enc_src, rex_flags)
}
Inst::Div {
size,
signed,
dividend_lo,
dividend_hi,
divisor,
dst_quotient,
dst_remainder,
} => {
let dividend_lo = allocs.next(dividend_lo.to_reg());
let dst_quotient = allocs.next(dst_quotient.to_reg().to_reg());
debug_assert_eq!(dividend_lo, regs::rax());
debug_assert_eq!(dst_quotient, regs::rax());
if size.to_bits() > 8 {
let dst_remainder = allocs.next(dst_remainder.to_reg().to_reg());
debug_assert_eq!(dst_remainder, regs::rdx());
let dividend_hi = allocs.next(dividend_hi.to_reg());
debug_assert_eq!(dividend_hi, regs::rdx());
}
let (opcode, prefix) = match size {
OperandSize::Size8 => (0xF6, LegacyPrefixes::None),
OperandSize::Size16 => (0xF7, LegacyPrefixes::_66),
OperandSize::Size32 => (0xF7, LegacyPrefixes::None),
OperandSize::Size64 => (0xF7, LegacyPrefixes::None),
};
sink.add_trap(TrapCode::IntegerDivisionByZero);
let subopcode = if *signed { 7 } else { 6 };
match divisor.clone().to_reg_mem() {
RegMem::Reg { reg } => {
let reg = allocs.next(reg);
let src = int_reg_enc(reg);
emit_std_enc_enc(
sink,
prefix,
opcode,
1,
subopcode,
src,
RexFlags::from((*size, reg)),
)
}
RegMem::Mem { addr: src } => {
let amode = src.finalize(state, sink).with_allocs(allocs);
emit_std_enc_mem(
sink,
info,
prefix,
opcode,
1,
subopcode,
&amode,
RexFlags::from(*size),
0,
);
}
}
}
Inst::MulHi {
size,
signed,
src1,
src2,
dst_lo,
dst_hi,
} => {
let src1 = allocs.next(src1.to_reg());
let dst_lo = allocs.next(dst_lo.to_reg().to_reg());
let dst_hi = allocs.next(dst_hi.to_reg().to_reg());
debug_assert_eq!(src1, regs::rax());
debug_assert_eq!(dst_lo, regs::rax());
debug_assert_eq!(dst_hi, regs::rdx());
let rex_flags = RexFlags::from(*size);
let prefix = match size {
OperandSize::Size16 => LegacyPrefixes::_66,
OperandSize::Size32 => LegacyPrefixes::None,
OperandSize::Size64 => LegacyPrefixes::None,
_ => unreachable!(),
};
let subopcode = if *signed { 5 } else { 4 };
match src2.clone().to_reg_mem() {
RegMem::Reg { reg } => {
let reg = allocs.next(reg);
let src = int_reg_enc(reg);
emit_std_enc_enc(sink, prefix, 0xF7, 1, subopcode, src, rex_flags)
}
RegMem::Mem { addr: src } => {
let amode = src.finalize(state, sink).with_allocs(allocs);
emit_std_enc_mem(sink, info, prefix, 0xF7, 1, subopcode, &amode, rex_flags, 0);
}
}
}
Inst::SignExtendData { size, src, dst } => {
let src = allocs.next(src.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(src, regs::rax());
if *size == OperandSize::Size8 {
debug_assert_eq!(dst, regs::rax());
} else {
debug_assert_eq!(dst, regs::rdx());
}
match size {
OperandSize::Size8 => {
sink.put1(0x66);
sink.put1(0x98);
}
OperandSize::Size16 => {
sink.put1(0x66);
sink.put1(0x99);
}
OperandSize::Size32 => sink.put1(0x99),
OperandSize::Size64 => {
sink.put1(0x48);
sink.put1(0x99);
}
}
}
Inst::CheckedDivOrRemSeq {
kind,
size,
dividend_lo,
dividend_hi,
divisor,
tmp,
dst_quotient,
dst_remainder,
} => {
let dividend_lo = allocs.next(dividend_lo.to_reg());
let dividend_hi = allocs.next(dividend_hi.to_reg());
let divisor = allocs.next(divisor.to_reg());
let dst_quotient = allocs.next(dst_quotient.to_reg().to_reg());
let dst_remainder = allocs.next(dst_remainder.to_reg().to_reg());
let tmp = tmp.map(|tmp| allocs.next(tmp.to_reg().to_reg()));
debug_assert_eq!(dividend_lo, regs::rax());
debug_assert_eq!(dividend_hi, regs::rdx());
debug_assert_eq!(dst_quotient, regs::rax());
debug_assert_eq!(dst_remainder, regs::rdx());
// Generates the following code sequence:
//
// ;; check divide by zero:
// cmp 0 %divisor
// jnz $after_trap
// ud2
// $after_trap:
//
// ;; for signed modulo/div:
// cmp -1 %divisor
// jnz $do_op
// ;; for signed modulo, result is 0
// mov #0, %rdx
// j $done
// ;; for signed div, check for integer overflow against INT_MIN of the right size
// cmp INT_MIN, %rax
// jnz $do_op
// ud2
//
// $do_op:
// ;; if signed
// cdq ;; sign-extend from rax into rdx
// ;; else
// mov #0, %rdx
// idiv %divisor
//
// $done:
// Check if the divisor is zero, first.
let inst = Inst::cmp_rmi_r(*size, RegMemImm::imm(0), divisor);
inst.emit(&[], sink, info, state);
let inst = Inst::trap_if(CC::Z, TrapCode::IntegerDivisionByZero);
inst.emit(&[], sink, info, state);
let (do_op, done_label) = if kind.is_signed() {
// Now check if the divisor is -1.
let inst = Inst::cmp_rmi_r(*size, RegMemImm::imm(0xffffffff), divisor);
inst.emit(&[], sink, info, state);
let do_op = sink.get_label();
// If not equal, jump to do-op.
one_way_jmp(sink, CC::NZ, do_op);
// Here, divisor == -1.
if !kind.is_div() {
// x % -1 = 0; put the result into the destination, $rdx.
let done_label = sink.get_label();
let inst = Inst::imm(OperandSize::Size64, 0, Writable::from_reg(regs::rdx()));
inst.emit(&[], sink, info, state);
let inst = Inst::jmp_known(done_label);
inst.emit(&[], sink, info, state);
(Some(do_op), Some(done_label))
} else {
// Check for integer overflow.
if *size == OperandSize::Size64 {
let tmp = tmp.expect("temporary for i64 sdiv");
let inst = Inst::imm(
OperandSize::Size64,
0x8000000000000000,
Writable::from_reg(tmp),
);
inst.emit(&[], sink, info, state);
let inst =
Inst::cmp_rmi_r(OperandSize::Size64, RegMemImm::reg(tmp), regs::rax());
inst.emit(&[], sink, info, state);
} else {
let inst = Inst::cmp_rmi_r(*size, RegMemImm::imm(0x80000000), regs::rax());
inst.emit(&[], sink, info, state);
}
// If not equal, jump over the trap.
let inst = Inst::trap_if(CC::Z, TrapCode::IntegerOverflow);
inst.emit(&[], sink, info, state);
(Some(do_op), None)
}
} else {
(None, None)
};
if let Some(do_op) = do_op {
sink.bind_label(do_op);
}
let dividend_lo = Gpr::new(regs::rax()).unwrap();
let dst_quotient = WritableGpr::from_reg(Gpr::new(regs::rax()).unwrap());
let (dividend_hi, dst_remainder) = if *size == OperandSize::Size8 {
(
Gpr::new(regs::rax()).unwrap(),
Writable::from_reg(Gpr::new(regs::rax()).unwrap()),
)
} else {
(
Gpr::new(regs::rdx()).unwrap(),
Writable::from_reg(Gpr::new(regs::rdx()).unwrap()),
)
};
// Fill in the high parts:
if kind.is_signed() {
// sign-extend the sign-bit of rax into rdx, for signed opcodes.
let inst =
Inst::sign_extend_data(*size, dividend_lo, WritableGpr::from_reg(dividend_hi));
inst.emit(&[], sink, info, state);
} else if *size != OperandSize::Size8 {
// zero for unsigned opcodes.
let inst = Inst::imm(
OperandSize::Size64,
0,
Writable::from_reg(dividend_hi.to_reg()),
);
inst.emit(&[], sink, info, state);
}
let inst = Inst::div(
*size,
kind.is_signed(),
RegMem::reg(divisor),
dividend_lo,
dividend_hi,
dst_quotient,
dst_remainder,
);
inst.emit(&[], sink, info, state);
// Lowering takes care of moving the result back into the right register, see comment
// there.
if let Some(done) = done_label {
sink.bind_label(done);
}
}
Inst::Imm {
dst_size,
simm64,
dst,
} => {
let dst = allocs.next(dst.to_reg().to_reg());
let enc_dst = int_reg_enc(dst);
if *dst_size == OperandSize::Size64 {
if low32_will_sign_extend_to_64(*simm64) {
// Sign-extended move imm32.
emit_std_enc_enc(
sink,
LegacyPrefixes::None,
0xC7,
1,
/* subopcode */ 0,
enc_dst,
RexFlags::set_w(),
);
sink.put4(*simm64 as u32);
} else {
sink.put1(0x48 | ((enc_dst >> 3) & 1));
sink.put1(0xB8 | (enc_dst & 7));
sink.put8(*simm64);
}
} else {
if ((enc_dst >> 3) & 1) == 1 {
sink.put1(0x41);
}
sink.put1(0xB8 | (enc_dst & 7));
sink.put4(*simm64 as u32);
}
}
Inst::MovRR { size, src, dst } => {
let src = allocs.next(src.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
emit_std_reg_reg(
sink,
LegacyPrefixes::None,
0x89,
1,
src,
dst,
RexFlags::from(*size),
);
}
Inst::MovPReg { src, dst } => {
let src: Reg = (*src).into();
debug_assert!([regs::rsp(), regs::rbp()].contains(&src));
let src = Gpr::new(src).unwrap();
let size = OperandSize::Size64;
let dst = allocs.next(dst.to_reg().to_reg());
let dst = WritableGpr::from_writable_reg(Writable::from_reg(dst)).unwrap();
Inst::MovRR { size, src, dst }.emit(&[], sink, info, state);
}
Inst::MovzxRmR { ext_mode, src, dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
let (opcodes, num_opcodes, mut rex_flags) = match ext_mode {
ExtMode::BL => {
// MOVZBL is (REX.W==0) 0F B6 /r
(0x0FB6, 2, RexFlags::clear_w())
}
ExtMode::BQ => {
// MOVZBQ is (REX.W==1) 0F B6 /r
// I'm not sure why the Intel manual offers different
// encodings for MOVZBQ than for MOVZBL. AIUI they should
// achieve the same, since MOVZBL is just going to zero out
// the upper half of the destination anyway.
(0x0FB6, 2, RexFlags::set_w())
}
ExtMode::WL => {
// MOVZWL is (REX.W==0) 0F B7 /r
(0x0FB7, 2, RexFlags::clear_w())
}
ExtMode::WQ => {
// MOVZWQ is (REX.W==1) 0F B7 /r
(0x0FB7, 2, RexFlags::set_w())
}
ExtMode::LQ => {
// This is just a standard 32 bit load, and we rely on the
// default zero-extension rule to perform the extension.
// Note that in reg/reg mode, gcc seems to use the swapped form R/RM, which we
// don't do here, since it's the same encoding size.
// MOV r/m32, r32 is (REX.W==0) 8B /r
(0x8B, 1, RexFlags::clear_w())
}
};
match src.clone().to_reg_mem() {
RegMem::Reg { reg: src } => {
let src = allocs.next(src);
match ext_mode {
ExtMode::BL | ExtMode::BQ => {
// A redundant REX prefix must be emitted for certain register inputs.
rex_flags.always_emit_if_8bit_needed(src);
}
_ => {}
}
emit_std_reg_reg(
sink,
LegacyPrefixes::None,
opcodes,
num_opcodes,
dst,
src,
rex_flags,
)
}
RegMem::Mem { addr: src } => {
let src = &src.finalize(state, sink).with_allocs(allocs);
emit_std_reg_mem(
sink,
info,
LegacyPrefixes::None,
opcodes,
num_opcodes,
dst,
src,
rex_flags,
0,
)
}
}
}
Inst::Mov64MR { src, dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
let src = &src.finalize(state, sink).with_allocs(allocs);
emit_std_reg_mem(
sink,
info,
LegacyPrefixes::None,
0x8B,
1,
dst,
src,
RexFlags::set_w(),
0,
)
}
Inst::LoadEffectiveAddress { addr, dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
let amode = addr.finalize(state, sink).with_allocs(allocs);
emit_std_reg_mem(
sink,
info,
LegacyPrefixes::None,
0x8D,
1,
dst,
&amode,
RexFlags::set_w(),
0,
);
}
Inst::MovsxRmR { ext_mode, src, dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
let (opcodes, num_opcodes, mut rex_flags) = match ext_mode {
ExtMode::BL => {
// MOVSBL is (REX.W==0) 0F BE /r
(0x0FBE, 2, RexFlags::clear_w())
}
ExtMode::BQ => {
// MOVSBQ is (REX.W==1) 0F BE /r
(0x0FBE, 2, RexFlags::set_w())
}
ExtMode::WL => {
// MOVSWL is (REX.W==0) 0F BF /r
(0x0FBF, 2, RexFlags::clear_w())
}
ExtMode::WQ => {
// MOVSWQ is (REX.W==1) 0F BF /r
(0x0FBF, 2, RexFlags::set_w())
}
ExtMode::LQ => {
// MOVSLQ is (REX.W==1) 63 /r
(0x63, 1, RexFlags::set_w())
}
};
match src.clone().to_reg_mem() {
RegMem::Reg { reg: src } => {
let src = allocs.next(src);
match ext_mode {
ExtMode::BL | ExtMode::BQ => {
// A redundant REX prefix must be emitted for certain register inputs.
rex_flags.always_emit_if_8bit_needed(src);
}
_ => {}
}
emit_std_reg_reg(
sink,
LegacyPrefixes::None,
opcodes,
num_opcodes,
dst,
src,
rex_flags,
)
}
RegMem::Mem { addr: src } => {
let src = &src.finalize(state, sink).with_allocs(allocs);
emit_std_reg_mem(
sink,
info,
LegacyPrefixes::None,
opcodes,
num_opcodes,
dst,
src,
rex_flags,
0,
)
}
}
}
Inst::MovRM { size, src, dst } => {
let src = allocs.next(src.to_reg());
let dst = &dst.finalize(state, sink).with_allocs(allocs);
let prefix = match size {
OperandSize::Size16 => LegacyPrefixes::_66,
_ => LegacyPrefixes::None,
};
let opcode = match size {
OperandSize::Size8 => 0x88,
_ => 0x89,
};
// This is one of the few places where the presence of a
// redundant REX prefix changes the meaning of the
// instruction.
let rex = RexFlags::from((*size, src));
// 8-bit: MOV r8, r/m8 is (REX.W==0) 88 /r
// 16-bit: MOV r16, r/m16 is 66 (REX.W==0) 89 /r
// 32-bit: MOV r32, r/m32 is (REX.W==0) 89 /r
// 64-bit: MOV r64, r/m64 is (REX.W==1) 89 /r
emit_std_reg_mem(sink, info, prefix, opcode, 1, src, dst, rex, 0);
}
Inst::ShiftR {
size,
kind,
src,
num_bits,
dst,
} => {
let src = allocs.next(src.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(src, dst);
let subopcode = match kind {
ShiftKind::RotateLeft => 0,
ShiftKind::RotateRight => 1,
ShiftKind::ShiftLeft => 4,
ShiftKind::ShiftRightLogical => 5,
ShiftKind::ShiftRightArithmetic => 7,
};
let enc_dst = int_reg_enc(dst);
let rex_flags = RexFlags::from((*size, dst));
match num_bits.clone().to_imm8_reg() {
Imm8Reg::Reg { reg } => {
let reg = allocs.next(reg);
debug_assert_eq!(reg, regs::rcx());
let (opcode, prefix) = match size {
OperandSize::Size8 => (0xD2, LegacyPrefixes::None),
OperandSize::Size16 => (0xD3, LegacyPrefixes::_66),
OperandSize::Size32 => (0xD3, LegacyPrefixes::None),
OperandSize::Size64 => (0xD3, LegacyPrefixes::None),
};
// SHL/SHR/SAR %cl, reg8 is (REX.W==0) D2 /subopcode
// SHL/SHR/SAR %cl, reg16 is 66 (REX.W==0) D3 /subopcode
// SHL/SHR/SAR %cl, reg32 is (REX.W==0) D3 /subopcode
// SHL/SHR/SAR %cl, reg64 is (REX.W==1) D3 /subopcode
emit_std_enc_enc(sink, prefix, opcode, 1, subopcode, enc_dst, rex_flags);
}
Imm8Reg::Imm8 { imm: num_bits } => {
let (opcode, prefix) = match size {
OperandSize::Size8 => (0xC0, LegacyPrefixes::None),
OperandSize::Size16 => (0xC1, LegacyPrefixes::_66),
OperandSize::Size32 => (0xC1, LegacyPrefixes::None),
OperandSize::Size64 => (0xC1, LegacyPrefixes::None),
};
// SHL/SHR/SAR $ib, reg8 is (REX.W==0) C0 /subopcode
// SHL/SHR/SAR $ib, reg16 is 66 (REX.W==0) C1 /subopcode
// SHL/SHR/SAR $ib, reg32 is (REX.W==0) C1 /subopcode ib
// SHL/SHR/SAR $ib, reg64 is (REX.W==1) C1 /subopcode ib
// When the shift amount is 1, there's an even shorter encoding, but we don't
// bother with that nicety here.
emit_std_enc_enc(sink, prefix, opcode, 1, subopcode, enc_dst, rex_flags);
sink.put1(num_bits);
}
}
}
Inst::XmmRmiReg {
opcode,
src1,
src2,
dst,
} => {
let src1 = allocs.next(src1.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(src1, dst);
let rex = RexFlags::clear_w();
let prefix = LegacyPrefixes::_66;
let src2 = src2.clone().to_reg_mem_imm();
if let RegMemImm::Imm { simm32 } = src2 {
let (opcode_bytes, reg_digit) = match opcode {
SseOpcode::Psllw => (0x0F71, 6),
SseOpcode::Pslld => (0x0F72, 6),
SseOpcode::Psllq => (0x0F73, 6),
SseOpcode::Psraw => (0x0F71, 4),
SseOpcode::Psrad => (0x0F72, 4),
SseOpcode::Psrlw => (0x0F71, 2),
SseOpcode::Psrld => (0x0F72, 2),
SseOpcode::Psrlq => (0x0F73, 2),
_ => panic!("invalid opcode: {}", opcode),
};
let dst_enc = reg_enc(dst);
emit_std_enc_enc(sink, prefix, opcode_bytes, 2, reg_digit, dst_enc, rex);
let imm = (simm32)
.try_into()
.expect("the immediate must be convertible to a u8");
sink.put1(imm);
} else {
let opcode_bytes = match opcode {
SseOpcode::Psllw => 0x0FF1,
SseOpcode::Pslld => 0x0FF2,
SseOpcode::Psllq => 0x0FF3,
SseOpcode::Psraw => 0x0FE1,
SseOpcode::Psrad => 0x0FE2,
SseOpcode::Psrlw => 0x0FD1,
SseOpcode::Psrld => 0x0FD2,
SseOpcode::Psrlq => 0x0FD3,
_ => panic!("invalid opcode: {}", opcode),
};
match src2 {
RegMemImm::Reg { reg } => {
let reg = allocs.next(reg);
emit_std_reg_reg(sink, prefix, opcode_bytes, 2, dst, reg, rex);
}
RegMemImm::Mem { addr } => {
let addr = &addr.finalize(state, sink).with_allocs(allocs);
emit_std_reg_mem(sink, info, prefix, opcode_bytes, 2, dst, addr, rex, 0);
}
RegMemImm::Imm { .. } => unreachable!(),
}
};
}
Inst::CmpRmiR {
size,
src: src_e,
dst: reg_g,
opcode,
} => {
let reg_g = allocs.next(reg_g.to_reg());
let is_cmp = match opcode {
CmpOpcode::Cmp => true,
CmpOpcode::Test => false,
};
let mut prefix = LegacyPrefixes::None;
if *size == OperandSize::Size16 {
prefix = LegacyPrefixes::_66;
}
// A redundant REX prefix can change the meaning of this instruction.
let mut rex = RexFlags::from((*size, reg_g));
match src_e.clone().to_reg_mem_imm() {
RegMemImm::Reg { reg: reg_e } => {
let reg_e = allocs.next(reg_e);
if *size == OperandSize::Size8 {
// Check whether the E register forces the use of a redundant REX.
rex.always_emit_if_8bit_needed(reg_e);
}
// Use the swapped operands encoding for CMP, to stay consistent with the output of
// gcc/llvm.
let opcode = match (*size, is_cmp) {
(OperandSize::Size8, true) => 0x38,
(_, true) => 0x39,
(OperandSize::Size8, false) => 0x84,
(_, false) => 0x85,
};
emit_std_reg_reg(sink, prefix, opcode, 1, reg_e, reg_g, rex);
}
RegMemImm::Mem { addr } => {
let addr = &addr.finalize(state, sink).with_allocs(allocs);
// Whereas here we revert to the "normal" G-E ordering for CMP.
let opcode = match (*size, is_cmp) {
(OperandSize::Size8, true) => 0x3A,
(_, true) => 0x3B,
(OperandSize::Size8, false) => 0x84,
(_, false) => 0x85,
};
emit_std_reg_mem(sink, info, prefix, opcode, 1, reg_g, addr, rex, 0);
}
RegMemImm::Imm { simm32 } => {
// FIXME JRS 2020Feb11: there are shorter encodings for
// cmp $imm, rax/eax/ax/al.
let use_imm8 = is_cmp && low8_will_sign_extend_to_32(simm32);
// And also here we use the "normal" G-E ordering.
let opcode = if is_cmp {
if *size == OperandSize::Size8 {
0x80
} else if use_imm8 {
0x83
} else {
0x81
}
} else {
if *size == OperandSize::Size8 {
0xF6
} else {
0xF7
}
};
let subopcode = if is_cmp { 7 } else { 0 };
let enc_g = int_reg_enc(reg_g);
emit_std_enc_enc(sink, prefix, opcode, 1, subopcode, enc_g, rex);
emit_simm(sink, if use_imm8 { 1 } else { size.to_bytes() }, simm32);
}
}
}
Inst::Setcc { cc, dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
let opcode = 0x0f90 + cc.get_enc() as u32;
let mut rex_flags = RexFlags::clear_w();
rex_flags.always_emit();
emit_std_enc_enc(
sink,
LegacyPrefixes::None,
opcode,
2,
0,
reg_enc(dst),
rex_flags,
);
}
Inst::Cmove {
size,
cc,
consequent,
alternative,
dst,
} => {
let alternative = allocs.next(alternative.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(alternative, dst);
let rex_flags = RexFlags::from(*size);
let prefix = match size {
OperandSize::Size16 => LegacyPrefixes::_66,
OperandSize::Size32 => LegacyPrefixes::None,
OperandSize::Size64 => LegacyPrefixes::None,
_ => unreachable!("invalid size spec for cmove"),
};
let opcode = 0x0F40 + cc.get_enc() as u32;
match consequent.clone().to_reg_mem() {
RegMem::Reg { reg } => {
let reg = allocs.next(reg);
emit_std_reg_reg(sink, prefix, opcode, 2, dst, reg, rex_flags);
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink).with_allocs(allocs);
emit_std_reg_mem(sink, info, prefix, opcode, 2, dst, addr, rex_flags, 0);
}
}
}
Inst::XmmCmove {
ty,
cc,
consequent,
alternative,
dst,
} => {
let alternative = allocs.next(alternative.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(alternative, dst);
let consequent = consequent.clone().to_reg_mem().with_allocs(allocs);
// Lowering of the Select IR opcode when the input is an fcmp relies on the fact that
// this doesn't clobber flags. Make sure to not do so here.
let next = sink.get_label();
// Jump if cc is *not* set.
one_way_jmp(sink, cc.invert(), next);
let op = match *ty {
types::F64 => SseOpcode::Movsd,
types::F32 => SseOpcode::Movsd,
types::F32X4 => SseOpcode::Movaps,
types::F64X2 => SseOpcode::Movapd,
ty => {
debug_assert!(ty.is_vector() && ty.bytes() == 16);
SseOpcode::Movdqa
}
};
let inst = Inst::xmm_unary_rm_r(op, consequent, Writable::from_reg(dst));
inst.emit(&[], sink, info, state);
sink.bind_label(next);
}
Inst::Push64 { src } => {
let src = src.clone().to_reg_mem_imm().with_allocs(allocs);
if info.flags.enable_probestack() {
sink.add_trap(TrapCode::StackOverflow);
}
match src {
RegMemImm::Reg { reg } => {
let enc_reg = int_reg_enc(reg);
let rex = 0x40 | ((enc_reg >> 3) & 1);
if rex != 0x40 {
sink.put1(rex);
}
sink.put1(0x50 | (enc_reg & 7));
}
RegMemImm::Mem { addr } => {
let addr = &addr.finalize(state, sink);
emit_std_enc_mem(
sink,
info,
LegacyPrefixes::None,
0xFF,
1,
6, /*subopcode*/
addr,
RexFlags::clear_w(),
0,
);
}
RegMemImm::Imm { simm32 } => {
if low8_will_sign_extend_to_64(simm32) {
sink.put1(0x6A);
sink.put1(simm32 as u8);
} else {
sink.put1(0x68);
sink.put4(simm32);
}
}
}
}
Inst::Pop64 { dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
let enc_dst = int_reg_enc(dst);
if enc_dst >= 8 {
// 0x41 == REX.{W=0, B=1}. It seems that REX.W is irrelevant here.
sink.put1(0x41);
}
sink.put1(0x58 + (enc_dst & 7));
}
Inst::StackProbeLoop {
tmp,
frame_size,
guard_size,
} => {
assert!(info.flags.enable_probestack());
assert!(guard_size.is_power_of_two());
let tmp = allocs.next_writable(*tmp);
// Number of probes that we need to perform
let probe_count = align_to(*frame_size, *guard_size) / guard_size;
// The inline stack probe loop has 3 phases:
//
// We generate the "guard area" register which is essentially the frame_size aligned to
// guard_size. We copy the stack pointer and subtract the guard area from it. This
// gets us a register that we can use to compare when looping.
//
// After that we emit the loop. Essentially we just adjust the stack pointer one guard_size'd
// distance at a time and then touch the stack by writing anything to it. We use the previously
// created "guard area" register to know when to stop looping.
//
// When we have touched all the pages that we need, we have to restore the stack pointer
// to where it was before.
//
// Generate the following code:
// mov tmp_reg, rsp
// sub tmp_reg, guard_size * probe_count
// .loop_start:
// sub rsp, guard_size
// mov [rsp], rsp
// cmp rsp, tmp_reg
// jne .loop_start
// add rsp, guard_size * probe_count
// Create the guard bound register
// mov tmp_reg, rsp
let inst = Inst::gen_move(tmp, regs::rsp(), types::I64);
inst.emit(&[], sink, info, state);
// sub tmp_reg, GUARD_SIZE * probe_count
let inst = Inst::alu_rmi_r(
OperandSize::Size64,
AluRmiROpcode::Sub,
RegMemImm::imm(guard_size * probe_count),
tmp,
);
inst.emit(&[], sink, info, state);
// Emit the main loop!
let loop_start = sink.get_label();
sink.bind_label(loop_start);
// sub rsp, GUARD_SIZE
let inst = Inst::alu_rmi_r(
OperandSize::Size64,
AluRmiROpcode::Sub,
RegMemImm::imm(*guard_size),
Writable::from_reg(regs::rsp()),
);
inst.emit(&[], sink, info, state);
// TODO: `mov [rsp], 0` would be better, but we don't have that instruction
// Probe the stack! We don't use Inst::gen_store_stack here because we need a predictable
// instruction size.
// mov [rsp], rsp
let inst = Inst::mov_r_m(
OperandSize::Size32, // Use Size32 since it saves us one byte
regs::rsp(),
SyntheticAmode::Real(Amode::imm_reg(0, regs::rsp())),
);
inst.emit(&[], sink, info, state);
// Compare and jump if we are not done yet
// cmp rsp, tmp_reg
let inst = Inst::cmp_rmi_r(
OperandSize::Size64,
RegMemImm::reg(regs::rsp()),
tmp.to_reg(),
);
inst.emit(&[], sink, info, state);
// jne .loop_start
// TODO: Encoding the JmpIf as a short jump saves us 4 bytes here.
one_way_jmp(sink, CC::NZ, loop_start);
// The regular prologue code is going to emit a `sub` after this, so we need to
// reset the stack pointer
//
// TODO: It would be better if we could avoid the `add` + `sub` that is generated here
// and in the stack adj portion of the prologue
//
// add rsp, GUARD_SIZE * probe_count
let inst = Inst::alu_rmi_r(
OperandSize::Size64,
AluRmiROpcode::Add,
RegMemImm::imm(guard_size * probe_count),
Writable::from_reg(regs::rsp()),
);
inst.emit(&[], sink, info, state);
}
Inst::CallKnown {
dest,
info: call_info,
..
} => {
if info.flags.enable_probestack() {
sink.add_trap(TrapCode::StackOverflow);
}
if let Some(s) = state.take_stack_map() {
sink.add_stack_map(StackMapExtent::UpcomingBytes(5), s);
}
sink.put1(0xE8);
// The addend adjusts for the difference between the end of the instruction and the
// beginning of the immediate field.
emit_reloc(sink, Reloc::X86CallPCRel4, &dest, -4);
sink.put4(0);
if call_info.opcode.is_call() {
sink.add_call_site(call_info.opcode);
}
}
Inst::CallUnknown {
dest,
info: call_info,
..
} => {
let dest = dest.with_allocs(allocs);
if info.flags.enable_probestack() {
sink.add_trap(TrapCode::StackOverflow);
}
let start_offset = sink.cur_offset();
match dest {
RegMem::Reg { reg } => {
let reg_enc = int_reg_enc(reg);
emit_std_enc_enc(
sink,
LegacyPrefixes::None,
0xFF,
1,
2, /*subopcode*/
reg_enc,
RexFlags::clear_w(),
);
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink);
emit_std_enc_mem(
sink,
info,
LegacyPrefixes::None,
0xFF,
1,
2, /*subopcode*/
addr,
RexFlags::clear_w(),
0,
);
}
}
if let Some(s) = state.take_stack_map() {
sink.add_stack_map(StackMapExtent::StartedAtOffset(start_offset), s);
}
if call_info.opcode.is_call() {
sink.add_call_site(call_info.opcode);
}
}
Inst::Ret { .. } => sink.put1(0xC3),
Inst::JmpKnown { dst } => {
let br_start = sink.cur_offset();
let br_disp_off = br_start + 1;
let br_end = br_start + 5;
sink.use_label_at_offset(br_disp_off, *dst, LabelUse::JmpRel32);
sink.add_uncond_branch(br_start, br_end, *dst);
sink.put1(0xE9);
// Placeholder for the label value.
sink.put4(0x0);
}
Inst::JmpIf { cc, taken } => {
let cond_start = sink.cur_offset();
let cond_disp_off = cond_start + 2;
sink.use_label_at_offset(cond_disp_off, *taken, LabelUse::JmpRel32);
// Since this is not a terminator, don't enroll in the branch inversion mechanism.
sink.put1(0x0F);
sink.put1(0x80 + cc.get_enc());
// Placeholder for the label value.
sink.put4(0x0);
}
Inst::JmpCond {
cc,
taken,
not_taken,
} => {
// If taken.
let cond_start = sink.cur_offset();
let cond_disp_off = cond_start + 2;
let cond_end = cond_start + 6;
sink.use_label_at_offset(cond_disp_off, *taken, LabelUse::JmpRel32);
let inverted: [u8; 6] = [0x0F, 0x80 + (cc.invert().get_enc()), 0x00, 0x00, 0x00, 0x00];
sink.add_cond_branch(cond_start, cond_end, *taken, &inverted[..]);
sink.put1(0x0F);
sink.put1(0x80 + cc.get_enc());
// Placeholder for the label value.
sink.put4(0x0);
// If not taken.
let uncond_start = sink.cur_offset();
let uncond_disp_off = uncond_start + 1;
let uncond_end = uncond_start + 5;
sink.use_label_at_offset(uncond_disp_off, *not_taken, LabelUse::JmpRel32);
sink.add_uncond_branch(uncond_start, uncond_end, *not_taken);
sink.put1(0xE9);
// Placeholder for the label value.
sink.put4(0x0);
}
Inst::JmpUnknown { target } => {
let target = target.with_allocs(allocs);
match target {
RegMem::Reg { reg } => {
let reg_enc = int_reg_enc(reg);
emit_std_enc_enc(
sink,
LegacyPrefixes::None,
0xFF,
1,
4, /*subopcode*/
reg_enc,
RexFlags::clear_w(),
);
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink);
emit_std_enc_mem(
sink,
info,
LegacyPrefixes::None,
0xFF,
1,
4, /*subopcode*/
addr,
RexFlags::clear_w(),
0,
);
}
}
}
Inst::JmpTableSeq {
idx,
tmp1,
tmp2,
ref targets,
default_target,
..
} => {
let idx = allocs.next(*idx);
let tmp1 = Writable::from_reg(allocs.next(tmp1.to_reg()));
let tmp2 = Writable::from_reg(allocs.next(tmp2.to_reg()));
// This sequence is *one* instruction in the vcode, and is expanded only here at
// emission time, because we cannot allow the regalloc to insert spills/reloads in
// the middle; we depend on hardcoded PC-rel addressing below.
//
// We don't have to worry about emitting islands, because the only label-use type has a
// maximum range of 2 GB. If we later consider using shorter-range label references,
// this will need to be revisited.
// Save index in a tmp (the live range of ridx only goes to start of this
// sequence; rtmp1 or rtmp2 may overwrite it).
// We generate the following sequence:
// ;; generated by lowering: cmp #jmp_table_size, %idx
// jnb $default_target
// movl %idx, %tmp2
// mov $0, %tmp1
// cmovnb %tmp1, %tmp2 ;; Spectre mitigation.
// lea start_of_jump_table_offset(%rip), %tmp1
// movslq [%tmp1, %tmp2, 4], %tmp2 ;; shift of 2, viz. multiply index by 4
// addq %tmp2, %tmp1
// j *%tmp1
// $start_of_jump_table:
// -- jump table entries
one_way_jmp(sink, CC::NB, *default_target); // idx unsigned >= jmp table size
// Copy the index (and make sure to clear the high 32-bits lane of tmp2).
let inst = Inst::movzx_rm_r(ExtMode::LQ, RegMem::reg(idx), tmp2);
inst.emit(&[], sink, info, state);
// Zero `tmp1` to overwrite `tmp2` with zeroes on the
// out-of-bounds case (Spectre mitigation using CMOV).
// Note that we need to do this with a move-immediate
// form, because we cannot clobber the flags.
let inst = Inst::imm(OperandSize::Size32, 0, tmp1);
inst.emit(&[], sink, info, state);
// Spectre mitigation: CMOV to zero the index if the out-of-bounds branch above misspeculated.
let inst = Inst::cmove(
OperandSize::Size64,
CC::NB,
RegMem::reg(tmp1.to_reg()),
tmp2,
);
inst.emit(&[], sink, info, state);
// Load base address of jump table.
let start_of_jumptable = sink.get_label();
let inst = Inst::lea(Amode::rip_relative(start_of_jumptable), tmp1);
inst.emit(&[], sink, info, state);
// Load value out of the jump table. It's a relative offset to the target block, so it
// might be negative; use a sign-extension.
let inst = Inst::movsx_rm_r(
ExtMode::LQ,
RegMem::mem(Amode::imm_reg_reg_shift(
0,
Gpr::new(tmp1.to_reg()).unwrap(),
Gpr::new(tmp2.to_reg()).unwrap(),
2,
)),
tmp2,
);
inst.emit(&[], sink, info, state);
// Add base of jump table to jump-table-sourced block offset.
let inst = Inst::alu_rmi_r(
OperandSize::Size64,
AluRmiROpcode::Add,
RegMemImm::reg(tmp2.to_reg()),
tmp1,
);
inst.emit(&[], sink, info, state);
// Branch to computed address.
let inst = Inst::jmp_unknown(RegMem::reg(tmp1.to_reg()));
inst.emit(&[], sink, info, state);
// Emit jump table (table of 32-bit offsets).
sink.bind_label(start_of_jumptable);
let jt_off = sink.cur_offset();
for &target in targets.iter() {
let word_off = sink.cur_offset();
// off_into_table is an addend here embedded in the label to be later patched at
// the end of codegen. The offset is initially relative to this jump table entry;
// with the extra addend, it'll be relative to the jump table's start, after
// patching.
let off_into_table = word_off - jt_off;
sink.use_label_at_offset(word_off, target, LabelUse::PCRel32);
sink.put4(off_into_table);
}
}
Inst::TrapIf { cc, trap_code } => {
let else_label = sink.get_label();
// Jump over if the invert of CC is set (i.e. CC is not set).
one_way_jmp(sink, cc.invert(), else_label);
// Trap!
let inst = Inst::trap(*trap_code);
inst.emit(&[], sink, info, state);
sink.bind_label(else_label);
}
Inst::TrapIfAnd {
cc1,
cc2,
trap_code,
} => {
let else_label = sink.get_label();
// Jump over if either condition code is not set.
one_way_jmp(sink, cc1.invert(), else_label);
one_way_jmp(sink, cc2.invert(), else_label);
// Trap!
let inst = Inst::trap(*trap_code);
inst.emit(&[], sink, info, state);
sink.bind_label(else_label);
}
Inst::TrapIfOr {
cc1,
cc2,
trap_code,
} => {
let trap_label = sink.get_label();
let else_label = sink.get_label();
// trap immediately if cc1 is set, otherwise jump over the trap if cc2 is not.
one_way_jmp(sink, *cc1, trap_label);
one_way_jmp(sink, cc2.invert(), else_label);
// Trap!
sink.bind_label(trap_label);
let inst = Inst::trap(*trap_code);
inst.emit(&[], sink, info, state);
sink.bind_label(else_label);
}
Inst::XmmUnaryRmR {
op,
src: src_e,
dst: reg_g,
} => {
let reg_g = allocs.next(reg_g.to_reg().to_reg());
let src_e = src_e.clone().to_reg_mem().with_allocs(allocs);
let rex = RexFlags::clear_w();
let (prefix, opcode, num_opcodes) = match op {
SseOpcode::Cvtdq2pd => (LegacyPrefixes::_F3, 0x0FE6, 2),
SseOpcode::Cvtpd2ps => (LegacyPrefixes::_66, 0x0F5A, 2),
SseOpcode::Cvtps2pd => (LegacyPrefixes::None, 0x0F5A, 2),
SseOpcode::Cvtdq2ps => (LegacyPrefixes::None, 0x0F5B, 2),
SseOpcode::Cvtss2sd => (LegacyPrefixes::_F3, 0x0F5A, 2),
SseOpcode::Cvtsd2ss => (LegacyPrefixes::_F2, 0x0F5A, 2),
SseOpcode::Cvttpd2dq => (LegacyPrefixes::_66, 0x0FE6, 2),
SseOpcode::Cvttps2dq => (LegacyPrefixes::_F3, 0x0F5B, 2),
SseOpcode::Movaps => (LegacyPrefixes::None, 0x0F28, 2),
SseOpcode::Movapd => (LegacyPrefixes::_66, 0x0F28, 2),
SseOpcode::Movdqa => (LegacyPrefixes::_66, 0x0F6F, 2),
SseOpcode::Movdqu => (LegacyPrefixes::_F3, 0x0F6F, 2),
SseOpcode::Movsd => (LegacyPrefixes::_F2, 0x0F10, 2),
SseOpcode::Movss => (LegacyPrefixes::_F3, 0x0F10, 2),
SseOpcode::Movups => (LegacyPrefixes::None, 0x0F10, 2),
SseOpcode::Movupd => (LegacyPrefixes::_66, 0x0F10, 2),
SseOpcode::Pabsb => (LegacyPrefixes::_66, 0x0F381C, 3),
SseOpcode::Pabsw => (LegacyPrefixes::_66, 0x0F381D, 3),
SseOpcode::Pabsd => (LegacyPrefixes::_66, 0x0F381E, 3),
SseOpcode::Pmovsxbd => (LegacyPrefixes::_66, 0x0F3821, 3),
SseOpcode::Pmovsxbw => (LegacyPrefixes::_66, 0x0F3820, 3),
SseOpcode::Pmovsxbq => (LegacyPrefixes::_66, 0x0F3822, 3),
SseOpcode::Pmovsxwd => (LegacyPrefixes::_66, 0x0F3823, 3),
SseOpcode::Pmovsxwq => (LegacyPrefixes::_66, 0x0F3824, 3),
SseOpcode::Pmovsxdq => (LegacyPrefixes::_66, 0x0F3825, 3),
SseOpcode::Pmovzxbd => (LegacyPrefixes::_66, 0x0F3831, 3),
SseOpcode::Pmovzxbw => (LegacyPrefixes::_66, 0x0F3830, 3),
SseOpcode::Pmovzxbq => (LegacyPrefixes::_66, 0x0F3832, 3),
SseOpcode::Pmovzxwd => (LegacyPrefixes::_66, 0x0F3833, 3),
SseOpcode::Pmovzxwq => (LegacyPrefixes::_66, 0x0F3834, 3),
SseOpcode::Pmovzxdq => (LegacyPrefixes::_66, 0x0F3835, 3),
SseOpcode::Sqrtps => (LegacyPrefixes::None, 0x0F51, 2),
SseOpcode::Sqrtpd => (LegacyPrefixes::_66, 0x0F51, 2),
SseOpcode::Sqrtss => (LegacyPrefixes::_F3, 0x0F51, 2),
SseOpcode::Sqrtsd => (LegacyPrefixes::_F2, 0x0F51, 2),
_ => unimplemented!("Opcode {:?} not implemented", op),
};
match src_e {
RegMem::Reg { reg: reg_e } => {
emit_std_reg_reg(sink, prefix, opcode, num_opcodes, reg_g, reg_e, rex);
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink);
emit_std_reg_mem(sink, info, prefix, opcode, num_opcodes, reg_g, addr, rex, 0);
}
};
}
Inst::XmmUnaryRmRImm { op, src, dst, imm } => {
debug_assert!(!op.uses_src1());
let dst = allocs.next(dst.to_reg().to_reg());
let src = src.clone().to_reg_mem().with_allocs(allocs);
let rex = RexFlags::clear_w();
let (prefix, opcode, len) = match op {
SseOpcode::Roundps => (LegacyPrefixes::_66, 0x0F3A08, 3),
SseOpcode::Roundss => (LegacyPrefixes::_66, 0x0F3A0A, 3),
SseOpcode::Roundpd => (LegacyPrefixes::_66, 0x0F3A09, 3),
SseOpcode::Roundsd => (LegacyPrefixes::_66, 0x0F3A0B, 3),
_ => unimplemented!("Opcode {:?} not implemented", op),
};
match src {
RegMem::Reg { reg } => {
emit_std_reg_reg(sink, prefix, opcode, len, dst, reg, rex);
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink);
// N.B.: bytes_at_end == 1, because of the `imm` byte below.
emit_std_reg_mem(sink, info, prefix, opcode, len, dst, addr, rex, 1);
}
}
sink.put1(*imm);
}
Inst::XmmUnaryRmREvex { op, src, dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
let src = src.clone().to_reg_mem().with_allocs(allocs);
let (prefix, map, w, opcode) = match op {
Avx512Opcode::Vcvtudq2ps => (LegacyPrefixes::_F2, OpcodeMap::_0F, false, 0x7a),
Avx512Opcode::Vpabsq => (LegacyPrefixes::_66, OpcodeMap::_0F38, true, 0x1f),
Avx512Opcode::Vpopcntb => (LegacyPrefixes::_66, OpcodeMap::_0F38, false, 0x54),
_ => unimplemented!("Opcode {:?} not implemented", op),
};
match src {
RegMem::Reg { reg: src } => EvexInstruction::new()
.length(EvexVectorLength::V128)
.prefix(prefix)
.map(map)
.w(w)
.opcode(opcode)
.reg(dst.to_real_reg().unwrap().hw_enc())
.rm(src.to_real_reg().unwrap().hw_enc())
.encode(sink),
_ => todo!(),
};
}
Inst::XmmRmR {
op,
src1,
src2: src_e,
dst: reg_g,
} => {
let (src_e, reg_g) = if inst.produces_const() {
let reg_g = allocs.next(reg_g.to_reg().to_reg());
(RegMem::Reg { reg: reg_g }, reg_g)
} else {
let src1 = allocs.next(src1.to_reg());
let reg_g = allocs.next(reg_g.to_reg().to_reg());
let src_e = src_e.clone().to_reg_mem().with_allocs(allocs);
debug_assert_eq!(src1, reg_g);
(src_e, reg_g)
};
let rex = RexFlags::clear_w();
let (prefix, opcode, length) = match op {
SseOpcode::Addps => (LegacyPrefixes::None, 0x0F58, 2),
SseOpcode::Addpd => (LegacyPrefixes::_66, 0x0F58, 2),
SseOpcode::Addss => (LegacyPrefixes::_F3, 0x0F58, 2),
SseOpcode::Addsd => (LegacyPrefixes::_F2, 0x0F58, 2),
SseOpcode::Andps => (LegacyPrefixes::None, 0x0F54, 2),
SseOpcode::Andpd => (LegacyPrefixes::_66, 0x0F54, 2),
SseOpcode::Andnps => (LegacyPrefixes::None, 0x0F55, 2),
SseOpcode::Andnpd => (LegacyPrefixes::_66, 0x0F55, 2),
SseOpcode::Blendvps => (LegacyPrefixes::_66, 0x0F3814, 3),
SseOpcode::Blendvpd => (LegacyPrefixes::_66, 0x0F3815, 3),
SseOpcode::Divps => (LegacyPrefixes::None, 0x0F5E, 2),
SseOpcode::Divpd => (LegacyPrefixes::_66, 0x0F5E, 2),
SseOpcode::Divss => (LegacyPrefixes::_F3, 0x0F5E, 2),
SseOpcode::Divsd => (LegacyPrefixes::_F2, 0x0F5E, 2),
SseOpcode::Maxps => (LegacyPrefixes::None, 0x0F5F, 2),
SseOpcode::Maxpd => (LegacyPrefixes::_66, 0x0F5F, 2),
SseOpcode::Maxss => (LegacyPrefixes::_F3, 0x0F5F, 2),
SseOpcode::Maxsd => (LegacyPrefixes::_F2, 0x0F5F, 2),
SseOpcode::Minps => (LegacyPrefixes::None, 0x0F5D, 2),
SseOpcode::Minpd => (LegacyPrefixes::_66, 0x0F5D, 2),
SseOpcode::Minss => (LegacyPrefixes::_F3, 0x0F5D, 2),
SseOpcode::Minsd => (LegacyPrefixes::_F2, 0x0F5D, 2),
SseOpcode::Movlhps => (LegacyPrefixes::None, 0x0F16, 2),
SseOpcode::Movsd => (LegacyPrefixes::_F2, 0x0F10, 2),
SseOpcode::Mulps => (LegacyPrefixes::None, 0x0F59, 2),
SseOpcode::Mulpd => (LegacyPrefixes::_66, 0x0F59, 2),
SseOpcode::Mulss => (LegacyPrefixes::_F3, 0x0F59, 2),
SseOpcode::Mulsd => (LegacyPrefixes::_F2, 0x0F59, 2),
SseOpcode::Orpd => (LegacyPrefixes::_66, 0x0F56, 2),
SseOpcode::Orps => (LegacyPrefixes::None, 0x0F56, 2),
SseOpcode::Packssdw => (LegacyPrefixes::_66, 0x0F6B, 2),
SseOpcode::Packsswb => (LegacyPrefixes::_66, 0x0F63, 2),
SseOpcode::Packusdw => (LegacyPrefixes::_66, 0x0F382B, 3),
SseOpcode::Packuswb => (LegacyPrefixes::_66, 0x0F67, 2),
SseOpcode::Paddb => (LegacyPrefixes::_66, 0x0FFC, 2),
SseOpcode::Paddd => (LegacyPrefixes::_66, 0x0FFE, 2),
SseOpcode::Paddq => (LegacyPrefixes::_66, 0x0FD4, 2),
SseOpcode::Paddw => (LegacyPrefixes::_66, 0x0FFD, 2),
SseOpcode::Paddsb => (LegacyPrefixes::_66, 0x0FEC, 2),
SseOpcode::Paddsw => (LegacyPrefixes::_66, 0x0FED, 2),
SseOpcode::Paddusb => (LegacyPrefixes::_66, 0x0FDC, 2),
SseOpcode::Paddusw => (LegacyPrefixes::_66, 0x0FDD, 2),
SseOpcode::Pmaddubsw => (LegacyPrefixes::_66, 0x0F3804, 3),
SseOpcode::Pand => (LegacyPrefixes::_66, 0x0FDB, 2),
SseOpcode::Pandn => (LegacyPrefixes::_66, 0x0FDF, 2),
SseOpcode::Pavgb => (LegacyPrefixes::_66, 0x0FE0, 2),
SseOpcode::Pavgw => (LegacyPrefixes::_66, 0x0FE3, 2),
SseOpcode::Pblendvb => (LegacyPrefixes::_66, 0x0F3810, 3),
SseOpcode::Pcmpeqb => (LegacyPrefixes::_66, 0x0F74, 2),
SseOpcode::Pcmpeqw => (LegacyPrefixes::_66, 0x0F75, 2),
SseOpcode::Pcmpeqd => (LegacyPrefixes::_66, 0x0F76, 2),
SseOpcode::Pcmpeqq => (LegacyPrefixes::_66, 0x0F3829, 3),
SseOpcode::Pcmpgtb => (LegacyPrefixes::_66, 0x0F64, 2),
SseOpcode::Pcmpgtw => (LegacyPrefixes::_66, 0x0F65, 2),
SseOpcode::Pcmpgtd => (LegacyPrefixes::_66, 0x0F66, 2),
SseOpcode::Pcmpgtq => (LegacyPrefixes::_66, 0x0F3837, 3),
SseOpcode::Pmaddwd => (LegacyPrefixes::_66, 0x0FF5, 2),
SseOpcode::Pmaxsb => (LegacyPrefixes::_66, 0x0F383C, 3),
SseOpcode::Pmaxsw => (LegacyPrefixes::_66, 0x0FEE, 2),
SseOpcode::Pmaxsd => (LegacyPrefixes::_66, 0x0F383D, 3),
SseOpcode::Pmaxub => (LegacyPrefixes::_66, 0x0FDE, 2),
SseOpcode::Pmaxuw => (LegacyPrefixes::_66, 0x0F383E, 3),
SseOpcode::Pmaxud => (LegacyPrefixes::_66, 0x0F383F, 3),
SseOpcode::Pminsb => (LegacyPrefixes::_66, 0x0F3838, 3),
SseOpcode::Pminsw => (LegacyPrefixes::_66, 0x0FEA, 2),
SseOpcode::Pminsd => (LegacyPrefixes::_66, 0x0F3839, 3),
SseOpcode::Pminub => (LegacyPrefixes::_66, 0x0FDA, 2),
SseOpcode::Pminuw => (LegacyPrefixes::_66, 0x0F383A, 3),
SseOpcode::Pminud => (LegacyPrefixes::_66, 0x0F383B, 3),
SseOpcode::Pmuldq => (LegacyPrefixes::_66, 0x0F3828, 3),
SseOpcode::Pmulhw => (LegacyPrefixes::_66, 0x0FE5, 2),
SseOpcode::Pmulhrsw => (LegacyPrefixes::_66, 0x0F380B, 3),
SseOpcode::Pmulhuw => (LegacyPrefixes::_66, 0x0FE4, 2),
SseOpcode::Pmulld => (LegacyPrefixes::_66, 0x0F3840, 3),
SseOpcode::Pmullw => (LegacyPrefixes::_66, 0x0FD5, 2),
SseOpcode::Pmuludq => (LegacyPrefixes::_66, 0x0FF4, 2),
SseOpcode::Por => (LegacyPrefixes::_66, 0x0FEB, 2),
SseOpcode::Pshufb => (LegacyPrefixes::_66, 0x0F3800, 3),
SseOpcode::Psubb => (LegacyPrefixes::_66, 0x0FF8, 2),
SseOpcode::Psubd => (LegacyPrefixes::_66, 0x0FFA, 2),
SseOpcode::Psubq => (LegacyPrefixes::_66, 0x0FFB, 2),
SseOpcode::Psubw => (LegacyPrefixes::_66, 0x0FF9, 2),
SseOpcode::Psubsb => (LegacyPrefixes::_66, 0x0FE8, 2),
SseOpcode::Psubsw => (LegacyPrefixes::_66, 0x0FE9, 2),
SseOpcode::Psubusb => (LegacyPrefixes::_66, 0x0FD8, 2),
SseOpcode::Psubusw => (LegacyPrefixes::_66, 0x0FD9, 2),
SseOpcode::Punpckhbw => (LegacyPrefixes::_66, 0x0F68, 2),
SseOpcode::Punpckhwd => (LegacyPrefixes::_66, 0x0F69, 2),
SseOpcode::Punpcklbw => (LegacyPrefixes::_66, 0x0F60, 2),
SseOpcode::Punpcklwd => (LegacyPrefixes::_66, 0x0F61, 2),
SseOpcode::Pxor => (LegacyPrefixes::_66, 0x0FEF, 2),
SseOpcode::Subps => (LegacyPrefixes::None, 0x0F5C, 2),
SseOpcode::Subpd => (LegacyPrefixes::_66, 0x0F5C, 2),
SseOpcode::Subss => (LegacyPrefixes::_F3, 0x0F5C, 2),
SseOpcode::Subsd => (LegacyPrefixes::_F2, 0x0F5C, 2),
SseOpcode::Unpcklps => (LegacyPrefixes::None, 0x0F14, 2),
SseOpcode::Xorps => (LegacyPrefixes::None, 0x0F57, 2),
SseOpcode::Xorpd => (LegacyPrefixes::_66, 0x0F57, 2),
_ => unimplemented!("Opcode {:?} not implemented", op),
};
match src_e {
RegMem::Reg { reg: reg_e } => {
emit_std_reg_reg(sink, prefix, opcode, length, reg_g, reg_e, rex);
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink);
emit_std_reg_mem(sink, info, prefix, opcode, length, reg_g, addr, rex, 0);
}
}
}
Inst::XmmRmRVex {
op,
src1,
src2,
src3,
dst,
} => {
let src1 = allocs.next(src1.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(src1, dst);
let src2 = allocs.next(src2.to_reg());
let src3 = src3.clone().to_reg_mem().with_allocs(allocs);
let (w, opcode) = match op {
AvxOpcode::Vfmadd213ss => (false, 0xA9),
AvxOpcode::Vfmadd213sd => (true, 0xA9),
AvxOpcode::Vfmadd213ps => (false, 0xA8),
AvxOpcode::Vfmadd213pd => (true, 0xA8),
};
match src3 {
RegMem::Reg { reg: src } => VexInstruction::new()
.length(VexVectorLength::V128)
.prefix(LegacyPrefixes::_66)
.map(OpcodeMap::_0F38)
.w(w)
.opcode(opcode)
.reg(dst.to_real_reg().unwrap().hw_enc())
.rm(src.to_real_reg().unwrap().hw_enc())
.vvvv(src2.to_real_reg().unwrap().hw_enc())
.encode(sink),
_ => todo!(),
};
}
Inst::XmmRmREvex {
op,
src1,
src2,
dst,
}
| Inst::XmmRmREvex3 {
op,
src1,
src2,
dst,
// `dst` reuses `src3`.
..
} => {
let dst = allocs.next(dst.to_reg().to_reg());
let src2 = allocs.next(src2.to_reg());
if let Inst::XmmRmREvex3 { src3, .. } = inst {
let src3 = allocs.next(src3.to_reg());
debug_assert_eq!(src3, dst);
}
let src1 = src1.clone().to_reg_mem().with_allocs(allocs);
let (w, opcode) = match op {
Avx512Opcode::Vpermi2b => (false, 0x75),
Avx512Opcode::Vpmullq => (true, 0x40),
_ => unimplemented!("Opcode {:?} not implemented", op),
};
match src1 {
RegMem::Reg { reg: src } => EvexInstruction::new()
.length(EvexVectorLength::V128)
.prefix(LegacyPrefixes::_66)
.map(OpcodeMap::_0F38)
.w(w)
.opcode(opcode)
.reg(dst.to_real_reg().unwrap().hw_enc())
.rm(src.to_real_reg().unwrap().hw_enc())
.vvvvv(src2.to_real_reg().unwrap().hw_enc())
.encode(sink),
_ => todo!(),
};
}
Inst::XmmMinMaxSeq {
size,
is_min,
lhs,
rhs,
dst,
} => {
let rhs = allocs.next(rhs.to_reg());
let lhs = allocs.next(lhs.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(rhs, dst);
// Generates the following sequence:
// cmpss/cmpsd %lhs, %rhs_dst
// jnz do_min_max
// jp propagate_nan
//
// ;; ordered and equal: propagate the sign bit (for -0 vs 0):
// {and,or}{ss,sd} %lhs, %rhs_dst
// j done
//
// ;; to get the desired NaN behavior (signalling NaN transformed into a quiet NaN, the
// ;; NaN value is returned), we add both inputs.
// propagate_nan:
// add{ss,sd} %lhs, %rhs_dst
// j done
//
// do_min_max:
// {min,max}{ss,sd} %lhs, %rhs_dst
//
// done:
let done = sink.get_label();
let propagate_nan = sink.get_label();
let do_min_max = sink.get_label();
let (add_op, cmp_op, and_op, or_op, min_max_op) = match size {
OperandSize::Size32 => (
SseOpcode::Addss,
SseOpcode::Ucomiss,
SseOpcode::Andps,
SseOpcode::Orps,
if *is_min {
SseOpcode::Minss
} else {
SseOpcode::Maxss
},
),
OperandSize::Size64 => (
SseOpcode::Addsd,
SseOpcode::Ucomisd,
SseOpcode::Andpd,
SseOpcode::Orpd,
if *is_min {
SseOpcode::Minsd
} else {
SseOpcode::Maxsd
},
),
_ => unreachable!(),
};
let inst = Inst::xmm_cmp_rm_r(cmp_op, RegMem::reg(lhs), dst);
inst.emit(&[], sink, info, state);
one_way_jmp(sink, CC::NZ, do_min_max);
one_way_jmp(sink, CC::P, propagate_nan);
// Ordered and equal. The operands are bit-identical unless they are zero
// and negative zero. These instructions merge the sign bits in that
// case, and are no-ops otherwise.
let op = if *is_min { or_op } else { and_op };
let inst = Inst::xmm_rm_r(op, RegMem::reg(lhs), Writable::from_reg(dst));
inst.emit(&[], sink, info, state);
let inst = Inst::jmp_known(done);
inst.emit(&[], sink, info, state);
// x86's min/max are not symmetric; if either operand is a NaN, they return the
// read-only operand: perform an addition between the two operands, which has the
// desired NaN propagation effects.
sink.bind_label(propagate_nan);
let inst = Inst::xmm_rm_r(add_op, RegMem::reg(lhs), Writable::from_reg(dst));
inst.emit(&[], sink, info, state);
one_way_jmp(sink, CC::P, done);
sink.bind_label(do_min_max);
let inst = Inst::xmm_rm_r(min_max_op, RegMem::reg(lhs), Writable::from_reg(dst));
inst.emit(&[], sink, info, state);
sink.bind_label(done);
}
Inst::XmmRmRImm {
op,
src1,
src2,
dst,
imm,
size,
} => {
let (src2, dst) = if inst.produces_const() {
let dst = allocs.next(dst.to_reg());
(RegMem::Reg { reg: dst }, dst)
} else if !op.uses_src1() {
let dst = allocs.next(dst.to_reg());
let src2 = src2.with_allocs(allocs);
(src2, dst)
} else {
let src1 = allocs.next(*src1);
let dst = allocs.next(dst.to_reg());
let src2 = src2.with_allocs(allocs);
debug_assert_eq!(src1, dst);
(src2, dst)
};
let (prefix, opcode, len) = match op {
SseOpcode::Cmpps => (LegacyPrefixes::None, 0x0FC2, 2),
SseOpcode::Cmppd => (LegacyPrefixes::_66, 0x0FC2, 2),
SseOpcode::Cmpss => (LegacyPrefixes::_F3, 0x0FC2, 2),
SseOpcode::Cmpsd => (LegacyPrefixes::_F2, 0x0FC2, 2),
SseOpcode::Insertps => (LegacyPrefixes::_66, 0x0F3A21, 3),
SseOpcode::Palignr => (LegacyPrefixes::_66, 0x0F3A0F, 3),
SseOpcode::Pinsrb => (LegacyPrefixes::_66, 0x0F3A20, 3),
SseOpcode::Pinsrw => (LegacyPrefixes::_66, 0x0FC4, 2),
SseOpcode::Pinsrd => (LegacyPrefixes::_66, 0x0F3A22, 3),
SseOpcode::Pextrb => (LegacyPrefixes::_66, 0x0F3A14, 3),
SseOpcode::Pextrw => (LegacyPrefixes::_66, 0x0FC5, 2),
SseOpcode::Pextrd => (LegacyPrefixes::_66, 0x0F3A16, 3),
SseOpcode::Pshufd => (LegacyPrefixes::_66, 0x0F70, 2),
SseOpcode::Shufps => (LegacyPrefixes::None, 0x0FC6, 2),
_ => unimplemented!("Opcode {:?} not implemented", op),
};
let rex = RexFlags::from(*size);
let regs_swapped = match *op {
// These opcodes (and not the SSE2 version of PEXTRW) flip the operand
// encoding: `dst` in ModRM's r/m, `src` in ModRM's reg field.
SseOpcode::Pextrb | SseOpcode::Pextrd => true,
// The rest of the opcodes have the customary encoding: `dst` in ModRM's reg,
// `src` in ModRM's r/m field.
_ => false,
};
match src2 {
RegMem::Reg { reg } => {
if regs_swapped {
emit_std_reg_reg(sink, prefix, opcode, len, reg, dst, rex);
} else {
emit_std_reg_reg(sink, prefix, opcode, len, dst, reg, rex);
}
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink);
assert!(
!regs_swapped,
"No existing way to encode a mem argument in the ModRM r/m field."
);
// N.B.: bytes_at_end == 1, because of the `imm` byte below.
emit_std_reg_mem(sink, info, prefix, opcode, len, dst, addr, rex, 1);
}
}
sink.put1(*imm);
}
Inst::XmmLoadConst { src, dst, ty } => {
let dst = allocs.next(dst.to_reg());
let load_offset = Amode::rip_relative(sink.get_label_for_constant(*src));
let load = Inst::load(*ty, load_offset, Writable::from_reg(dst), ExtKind::None);
load.emit(&[], sink, info, state);
}
Inst::XmmUninitializedValue { .. } => {
// This instruction format only exists to declare a register as a `def`; no code is
// emitted.
}
Inst::XmmMovRM { op, src, dst } => {
let src = allocs.next(*src);
let dst = dst.with_allocs(allocs);
let (prefix, opcode) = match op {
SseOpcode::Movaps => (LegacyPrefixes::None, 0x0F29),
SseOpcode::Movapd => (LegacyPrefixes::_66, 0x0F29),
SseOpcode::Movdqu => (LegacyPrefixes::_F3, 0x0F7F),
SseOpcode::Movss => (LegacyPrefixes::_F3, 0x0F11),
SseOpcode::Movsd => (LegacyPrefixes::_F2, 0x0F11),
SseOpcode::Movups => (LegacyPrefixes::None, 0x0F11),
SseOpcode::Movupd => (LegacyPrefixes::_66, 0x0F11),
_ => unimplemented!("Opcode {:?} not implemented", op),
};
let dst = &dst.finalize(state, sink);
emit_std_reg_mem(
sink,
info,
prefix,
opcode,
2,
src,
dst,
RexFlags::clear_w(),
0,
);
}
Inst::XmmToGpr {
op,
src,
dst,
dst_size,
} => {
let src = allocs.next(src.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
let (prefix, opcode, dst_first) = match op {
SseOpcode::Cvttss2si => (LegacyPrefixes::_F3, 0x0F2C, true),
SseOpcode::Cvttsd2si => (LegacyPrefixes::_F2, 0x0F2C, true),
// Movd and movq use the same opcode; the presence of the REX prefix (set below)
// actually determines which is used.
SseOpcode::Movd | SseOpcode::Movq => (LegacyPrefixes::_66, 0x0F7E, false),
SseOpcode::Movmskps => (LegacyPrefixes::None, 0x0F50, true),
SseOpcode::Movmskpd => (LegacyPrefixes::_66, 0x0F50, true),
SseOpcode::Pmovmskb => (LegacyPrefixes::_66, 0x0FD7, true),
_ => panic!("unexpected opcode {:?}", op),
};
let rex = RexFlags::from(*dst_size);
let (src, dst) = if dst_first { (dst, src) } else { (src, dst) };
emit_std_reg_reg(sink, prefix, opcode, 2, src, dst, rex);
}
Inst::GprToXmm {
op,
src: src_e,
dst: reg_g,
src_size,
} => {
let reg_g = allocs.next(reg_g.to_reg().to_reg());
let src_e = src_e.clone().to_reg_mem().with_allocs(allocs);
let (prefix, opcode) = match op {
// Movd and movq use the same opcode; the presence of the REX prefix (set below)
// actually determines which is used.
SseOpcode::Movd | SseOpcode::Movq => (LegacyPrefixes::_66, 0x0F6E),
SseOpcode::Cvtsi2ss => (LegacyPrefixes::_F3, 0x0F2A),
SseOpcode::Cvtsi2sd => (LegacyPrefixes::_F2, 0x0F2A),
_ => panic!("unexpected opcode {:?}", op),
};
let rex = RexFlags::from(*src_size);
match src_e {
RegMem::Reg { reg: reg_e } => {
emit_std_reg_reg(sink, prefix, opcode, 2, reg_g, reg_e, rex);
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink);
emit_std_reg_mem(sink, info, prefix, opcode, 2, reg_g, addr, rex, 0);
}
}
}
Inst::XmmCmpRmR { op, src, dst } => {
let dst = allocs.next(dst.to_reg());
let src = src.clone().to_reg_mem().with_allocs(allocs);
let rex = RexFlags::clear_w();
let (prefix, opcode, len) = match op {
SseOpcode::Ptest => (LegacyPrefixes::_66, 0x0F3817, 3),
SseOpcode::Ucomisd => (LegacyPrefixes::_66, 0x0F2E, 2),
SseOpcode::Ucomiss => (LegacyPrefixes::None, 0x0F2E, 2),
_ => unimplemented!("Emit xmm cmp rm r"),
};
match src {
RegMem::Reg { reg } => {
emit_std_reg_reg(sink, prefix, opcode, len, dst, reg, rex);
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink);
emit_std_reg_mem(sink, info, prefix, opcode, len, dst, addr, rex, 0);
}
}
}
Inst::CvtUint64ToFloatSeq {
dst_size,
src,
dst,
tmp_gpr1,
tmp_gpr2,
} => {
let src = allocs.next(src.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
let tmp_gpr1 = allocs.next(tmp_gpr1.to_reg().to_reg());
let tmp_gpr2 = allocs.next(tmp_gpr2.to_reg().to_reg());
// Note: this sequence is specific to 64-bit mode; a 32-bit mode would require a
// different sequence.
//
// Emit the following sequence:
//
// cmp 0, %src
// jl handle_negative
//
// ;; handle positive, which can't overflow
// cvtsi2sd/cvtsi2ss %src, %dst
// j done
//
// ;; handle negative: see below for an explanation of what it's doing.
// handle_negative:
// mov %src, %tmp_gpr1
// shr $1, %tmp_gpr1
// mov %src, %tmp_gpr2
// and $1, %tmp_gpr2
// or %tmp_gpr1, %tmp_gpr2
// cvtsi2sd/cvtsi2ss %tmp_gpr2, %dst
// addsd/addss %dst, %dst
//
// done:
assert_ne!(src, tmp_gpr1);
assert_ne!(src, tmp_gpr2);
assert_ne!(tmp_gpr1, tmp_gpr2);
let handle_negative = sink.get_label();
let done = sink.get_label();
// If x seen as a signed int64 is not negative, a signed-conversion will do the right
// thing.
// TODO use tst src, src here.
let inst = Inst::cmp_rmi_r(OperandSize::Size64, RegMemImm::imm(0), src);
inst.emit(&[], sink, info, state);
one_way_jmp(sink, CC::L, handle_negative);
// Handle a positive int64, which is the "easy" case: a signed conversion will do the
// right thing.
emit_signed_cvt(
sink,
info,
state,
src,
Writable::from_reg(dst),
*dst_size == OperandSize::Size64,
);
let inst = Inst::jmp_known(done);
inst.emit(&[], sink, info, state);
sink.bind_label(handle_negative);
// Divide x by two to get it in range for the signed conversion, keep the LSB, and
// scale it back up on the FP side.
let inst = Inst::gen_move(Writable::from_reg(tmp_gpr1), src, types::I64);
inst.emit(&[], sink, info, state);
// tmp_gpr1 := src >> 1
let inst = Inst::shift_r(
OperandSize::Size64,
ShiftKind::ShiftRightLogical,
Imm8Gpr::new(Imm8Reg::Imm8 { imm: 1 }).unwrap(),
Writable::from_reg(tmp_gpr1),
);
inst.emit(&[], sink, info, state);
let inst = Inst::gen_move(Writable::from_reg(tmp_gpr2), src, types::I64);
inst.emit(&[], sink, info, state);
let inst = Inst::alu_rmi_r(
OperandSize::Size64,
AluRmiROpcode::And,
RegMemImm::imm(1),
Writable::from_reg(tmp_gpr2),
);
inst.emit(&[], sink, info, state);
let inst = Inst::alu_rmi_r(
OperandSize::Size64,
AluRmiROpcode::Or,
RegMemImm::reg(tmp_gpr1),
Writable::from_reg(tmp_gpr2),
);
inst.emit(&[], sink, info, state);
emit_signed_cvt(
sink,
info,
state,
tmp_gpr2,
Writable::from_reg(dst),
*dst_size == OperandSize::Size64,
);
let add_op = if *dst_size == OperandSize::Size64 {
SseOpcode::Addsd
} else {
SseOpcode::Addss
};
let inst = Inst::xmm_rm_r(add_op, RegMem::reg(dst), Writable::from_reg(dst));
inst.emit(&[], sink, info, state);
sink.bind_label(done);
}
Inst::CvtFloatToSintSeq {
src_size,
dst_size,
is_saturating,
src,
dst,
tmp_gpr,
tmp_xmm,
} => {
let src = allocs.next(src.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
let tmp_gpr = allocs.next(tmp_gpr.to_reg().to_reg());
let tmp_xmm = allocs.next(tmp_xmm.to_reg().to_reg());
// Emits the following common sequence:
//
// cvttss2si/cvttsd2si %src, %dst
// cmp %dst, 1
// jno done
//
// Then, for saturating conversions:
//
// ;; check for NaN
// cmpss/cmpsd %src, %src
// jnp not_nan
// xor %dst, %dst
//
// ;; positive inputs get saturated to INT_MAX; negative ones to INT_MIN, which is
// ;; already in %dst.
// xorpd %tmp_xmm, %tmp_xmm
// cmpss/cmpsd %src, %tmp_xmm
// jnb done
// mov/movaps $INT_MAX, %dst
//
// done:
//
// Then, for non-saturating conversions:
//
// ;; check for NaN
// cmpss/cmpsd %src, %src
// jnp not_nan
// ud2 trap BadConversionToInteger
//
// ;; check if INT_MIN was the correct result, against a magic constant:
// not_nan:
// movaps/mov $magic, %tmp_gpr
// movq/movd %tmp_gpr, %tmp_xmm
// cmpss/cmpsd %tmp_xmm, %src
// jnb/jnbe $check_positive
// ud2 trap IntegerOverflow
//
// ;; if positive, it was a real overflow
// check_positive:
// xorpd %tmp_xmm, %tmp_xmm
// cmpss/cmpsd %src, %tmp_xmm
// jnb done
// ud2 trap IntegerOverflow
//
// done:
let (cast_op, cmp_op, trunc_op) = match src_size {
OperandSize::Size64 => (SseOpcode::Movq, SseOpcode::Ucomisd, SseOpcode::Cvttsd2si),
OperandSize::Size32 => (SseOpcode::Movd, SseOpcode::Ucomiss, SseOpcode::Cvttss2si),
_ => unreachable!(),
};
let done = sink.get_label();
let not_nan = sink.get_label();
// The truncation.
let inst = Inst::xmm_to_gpr(trunc_op, src, Writable::from_reg(dst), *dst_size);
inst.emit(&[], sink, info, state);
// Compare against 1, in case of overflow the dst operand was INT_MIN.
let inst = Inst::cmp_rmi_r(*dst_size, RegMemImm::imm(1), dst);
inst.emit(&[], sink, info, state);
one_way_jmp(sink, CC::NO, done); // no overflow => done
// Check for NaN.
let inst = Inst::xmm_cmp_rm_r(cmp_op, RegMem::reg(src), src);
inst.emit(&[], sink, info, state);
one_way_jmp(sink, CC::NP, not_nan); // go to not_nan if not a NaN
if *is_saturating {
// For NaN, emit 0.
let inst = Inst::alu_rmi_r(
*dst_size,
AluRmiROpcode::Xor,
RegMemImm::reg(dst),
Writable::from_reg(dst),
);
inst.emit(&[], sink, info, state);
let inst = Inst::jmp_known(done);
inst.emit(&[], sink, info, state);
sink.bind_label(not_nan);
// If the input was positive, saturate to INT_MAX.
// Zero out tmp_xmm.
let inst = Inst::xmm_rm_r(
SseOpcode::Xorpd,
RegMem::reg(tmp_xmm),
Writable::from_reg(tmp_xmm),
);
inst.emit(&[], sink, info, state);
let inst = Inst::xmm_cmp_rm_r(cmp_op, RegMem::reg(src), tmp_xmm);
inst.emit(&[], sink, info, state);
// Jump if >= to done.
one_way_jmp(sink, CC::NB, done);
// Otherwise, put INT_MAX.
if *dst_size == OperandSize::Size64 {
let inst = Inst::imm(
OperandSize::Size64,
0x7fffffffffffffff,
Writable::from_reg(dst),
);
inst.emit(&[], sink, info, state);
} else {
let inst = Inst::imm(OperandSize::Size32, 0x7fffffff, Writable::from_reg(dst));
inst.emit(&[], sink, info, state);
}
} else {
let check_positive = sink.get_label();
let inst = Inst::trap(TrapCode::BadConversionToInteger);
inst.emit(&[], sink, info, state);
// Check if INT_MIN was the correct result: determine the smallest floating point
// number that would convert to INT_MIN, put it in a temporary register, and compare
// against the src register.
// If the src register is less (or in some cases, less-or-equal) than the threshold,
// trap!
sink.bind_label(not_nan);
let mut no_overflow_cc = CC::NB; // >=
let output_bits = dst_size.to_bits();
match *src_size {
OperandSize::Size32 => {
let cst = Ieee32::pow2(output_bits - 1).neg().bits();
let inst =
Inst::imm(OperandSize::Size32, cst as u64, Writable::from_reg(tmp_gpr));
inst.emit(&[], sink, info, state);
}
OperandSize::Size64 => {
// An f64 can represent `i32::min_value() - 1` exactly with precision to spare,
// so there are values less than -2^(N-1) that convert correctly to INT_MIN.
let cst = if output_bits < 64 {
no_overflow_cc = CC::NBE; // >
Ieee64::fcvt_to_sint_negative_overflow(output_bits)
} else {
Ieee64::pow2(output_bits - 1).neg()
};
let inst =
Inst::imm(OperandSize::Size64, cst.bits(), Writable::from_reg(tmp_gpr));
inst.emit(&[], sink, info, state);
}
_ => unreachable!(),
}
let inst = Inst::gpr_to_xmm(
cast_op,
RegMem::reg(tmp_gpr),
*src_size,
Writable::from_reg(tmp_xmm),
);
inst.emit(&[], sink, info, state);
let inst = Inst::xmm_cmp_rm_r(cmp_op, RegMem::reg(tmp_xmm), src);
inst.emit(&[], sink, info, state);
// jump over trap if src >= or > threshold
one_way_jmp(sink, no_overflow_cc, check_positive);
let inst = Inst::trap(TrapCode::IntegerOverflow);
inst.emit(&[], sink, info, state);
// If positive, it was a real overflow.
sink.bind_label(check_positive);
// Zero out the tmp_xmm register.
let inst = Inst::xmm_rm_r(
SseOpcode::Xorpd,
RegMem::reg(tmp_xmm),
Writable::from_reg(tmp_xmm),
);
inst.emit(&[], sink, info, state);
let inst = Inst::xmm_cmp_rm_r(cmp_op, RegMem::reg(src), tmp_xmm);
inst.emit(&[], sink, info, state);
one_way_jmp(sink, CC::NB, done); // jump over trap if 0 >= src
let inst = Inst::trap(TrapCode::IntegerOverflow);
inst.emit(&[], sink, info, state);
}
sink.bind_label(done);
}
Inst::CvtFloatToUintSeq {
src_size,
dst_size,
is_saturating,
src,
dst,
tmp_gpr,
tmp_xmm,
tmp_xmm2,
} => {
let src = allocs.next(src.to_reg());
let dst = allocs.next(dst.to_reg().to_reg());
let tmp_gpr = allocs.next(tmp_gpr.to_reg().to_reg());
let tmp_xmm = allocs.next(tmp_xmm.to_reg().to_reg());
let tmp_xmm2 = allocs.next(tmp_xmm2.to_reg().to_reg());
// The only difference in behavior between saturating and non-saturating is how we
// handle errors. Emits the following sequence:
//
// movaps/mov 2**(int_width - 1), %tmp_gpr
// movq/movd %tmp_gpr, %tmp_xmm
// cmpss/cmpsd %tmp_xmm, %src
// jnb is_large
//
// ;; check for NaN inputs
// jnp not_nan
// -- non-saturating: ud2 trap BadConversionToInteger
// -- saturating: xor %dst, %dst; j done
//
// not_nan:
// cvttss2si/cvttsd2si %src, %dst
// cmp 0, %dst
// jnl done
// -- non-saturating: ud2 trap IntegerOverflow
// -- saturating: xor %dst, %dst; j done
//
// is_large:
// mov %src, %tmp_xmm2
// subss/subsd %tmp_xmm, %tmp_xmm2
// cvttss2si/cvttss2sd %tmp_x, %dst
// cmp 0, %dst
// jnl next_is_large
// -- non-saturating: ud2 trap IntegerOverflow
// -- saturating: movaps $UINT_MAX, %dst; j done
//
// next_is_large:
// add 2**(int_width -1), %dst ;; 2 instructions for 64-bits integers
//
// done:
assert_ne!(tmp_xmm, src, "tmp_xmm clobbers src!");
let (sub_op, cast_op, cmp_op, trunc_op) = match src_size {
OperandSize::Size32 => (
SseOpcode::Subss,
SseOpcode::Movd,
SseOpcode::Ucomiss,
SseOpcode::Cvttss2si,
),
OperandSize::Size64 => (
SseOpcode::Subsd,
SseOpcode::Movq,
SseOpcode::Ucomisd,
SseOpcode::Cvttsd2si,
),
_ => unreachable!(),
};
let done = sink.get_label();
let cst = match src_size {
OperandSize::Size32 => Ieee32::pow2(dst_size.to_bits() - 1).bits() as u64,
OperandSize::Size64 => Ieee64::pow2(dst_size.to_bits() - 1).bits(),
_ => unreachable!(),
};
let inst = Inst::imm(*src_size, cst, Writable::from_reg(tmp_gpr));
inst.emit(&[], sink, info, state);
let inst = Inst::gpr_to_xmm(
cast_op,
RegMem::reg(tmp_gpr),
*src_size,
Writable::from_reg(tmp_xmm),
);
inst.emit(&[], sink, info, state);
let inst = Inst::xmm_cmp_rm_r(cmp_op, RegMem::reg(tmp_xmm), src);
inst.emit(&[], sink, info, state);
let handle_large = sink.get_label();
one_way_jmp(sink, CC::NB, handle_large); // jump to handle_large if src >= large_threshold
let not_nan = sink.get_label();
one_way_jmp(sink, CC::NP, not_nan); // jump over trap if not NaN
if *is_saturating {
// Emit 0.
let inst = Inst::alu_rmi_r(
*dst_size,
AluRmiROpcode::Xor,
RegMemImm::reg(dst),
Writable::from_reg(dst),
);
inst.emit(&[], sink, info, state);
let inst = Inst::jmp_known(done);
inst.emit(&[], sink, info, state);
} else {
// Trap.
let inst = Inst::trap(TrapCode::BadConversionToInteger);
inst.emit(&[], sink, info, state);
}
sink.bind_label(not_nan);
// Actual truncation for small inputs: if the result is not positive, then we had an
// overflow.
let inst = Inst::xmm_to_gpr(trunc_op, src, Writable::from_reg(dst), *dst_size);
inst.emit(&[], sink, info, state);
let inst = Inst::cmp_rmi_r(*dst_size, RegMemImm::imm(0), dst);
inst.emit(&[], sink, info, state);
one_way_jmp(sink, CC::NL, done); // if dst >= 0, jump to done
if *is_saturating {
// The input was "small" (< 2**(width -1)), so the only way to get an integer
// overflow is because the input was too small: saturate to the min value, i.e. 0.
let inst = Inst::alu_rmi_r(
*dst_size,
AluRmiROpcode::Xor,
RegMemImm::reg(dst),
Writable::from_reg(dst),
);
inst.emit(&[], sink, info, state);
let inst = Inst::jmp_known(done);
inst.emit(&[], sink, info, state);
} else {
// Trap.
let inst = Inst::trap(TrapCode::IntegerOverflow);
inst.emit(&[], sink, info, state);
}
// Now handle large inputs.
sink.bind_label(handle_large);
let inst = Inst::gen_move(Writable::from_reg(tmp_xmm2), src, types::F64);
inst.emit(&[], sink, info, state);
let inst = Inst::xmm_rm_r(sub_op, RegMem::reg(tmp_xmm), Writable::from_reg(tmp_xmm2));
inst.emit(&[], sink, info, state);
let inst = Inst::xmm_to_gpr(trunc_op, tmp_xmm2, Writable::from_reg(dst), *dst_size);
inst.emit(&[], sink, info, state);
let inst = Inst::cmp_rmi_r(*dst_size, RegMemImm::imm(0), dst);
inst.emit(&[], sink, info, state);
let next_is_large = sink.get_label();
one_way_jmp(sink, CC::NL, next_is_large); // if dst >= 0, jump to next_is_large
if *is_saturating {
// The input was "large" (>= 2**(width -1)), so the only way to get an integer
// overflow is because the input was too large: saturate to the max value.
let inst = Inst::imm(
OperandSize::Size64,
if *dst_size == OperandSize::Size64 {
u64::max_value()
} else {
u32::max_value() as u64
},
Writable::from_reg(dst),
);
inst.emit(&[], sink, info, state);
let inst = Inst::jmp_known(done);
inst.emit(&[], sink, info, state);
} else {
let inst = Inst::trap(TrapCode::IntegerOverflow);
inst.emit(&[], sink, info, state);
}
sink.bind_label(next_is_large);
if *dst_size == OperandSize::Size64 {
let inst = Inst::imm(OperandSize::Size64, 1 << 63, Writable::from_reg(tmp_gpr));
inst.emit(&[], sink, info, state);
let inst = Inst::alu_rmi_r(
OperandSize::Size64,
AluRmiROpcode::Add,
RegMemImm::reg(tmp_gpr),
Writable::from_reg(dst),
);
inst.emit(&[], sink, info, state);
} else {
let inst = Inst::alu_rmi_r(
OperandSize::Size32,
AluRmiROpcode::Add,
RegMemImm::imm(1 << 31),
Writable::from_reg(dst),
);
inst.emit(&[], sink, info, state);
}
sink.bind_label(done);
}
Inst::LoadExtName { dst, name, offset } => {
let dst = allocs.next(dst.to_reg());
if info.flags.is_pic() {
// Generates: movq symbol@GOTPCREL(%rip), %dst
let enc_dst = int_reg_enc(dst);
sink.put1(0x48 | ((enc_dst >> 3) & 1) << 2);
sink.put1(0x8B);
sink.put1(0x05 | ((enc_dst & 7) << 3));
emit_reloc(sink, Reloc::X86GOTPCRel4, name, -4);
sink.put4(0);
// Offset in the relocation above applies to the address of the *GOT entry*, not
// the loaded address; so we emit a separate add or sub instruction if needed.
if *offset < 0 {
assert!(*offset >= -i32::MAX as i64);
sink.put1(0x48 | ((enc_dst >> 3) & 1));
sink.put1(0x81);
sink.put1(0xe8 | (enc_dst & 7));
sink.put4((-*offset) as u32);
} else if *offset > 0 {
assert!(*offset <= i32::MAX as i64);
sink.put1(0x48 | ((enc_dst >> 3) & 1));
sink.put1(0x81);
sink.put1(0xc0 | (enc_dst & 7));
sink.put4(*offset as u32);
}
} else {
// The full address can be encoded in the register, with a relocation.
// Generates: movabsq $name, %dst
let enc_dst = int_reg_enc(dst);
sink.put1(0x48 | ((enc_dst >> 3) & 1));
sink.put1(0xB8 | (enc_dst & 7));
emit_reloc(sink, Reloc::Abs8, name, *offset);
sink.put8(0);
}
}
Inst::LockCmpxchg {
ty,
replacement,
expected,
mem,
dst_old,
} => {
let replacement = allocs.next(*replacement);
let expected = allocs.next(*expected);
let dst_old = allocs.next(dst_old.to_reg());
let mem = mem.with_allocs(allocs);
debug_assert_eq!(expected, regs::rax());
debug_assert_eq!(dst_old, regs::rax());
// lock cmpxchg{b,w,l,q} %replacement, (mem)
// Note that 0xF0 is the Lock prefix.
let (prefix, opcodes) = match *ty {
types::I8 => (LegacyPrefixes::_F0, 0x0FB0),
types::I16 => (LegacyPrefixes::_66F0, 0x0FB1),
types::I32 => (LegacyPrefixes::_F0, 0x0FB1),
types::I64 => (LegacyPrefixes::_F0, 0x0FB1),
_ => unreachable!(),
};
let rex = RexFlags::from((OperandSize::from_ty(*ty), replacement));
let amode = mem.finalize(state, sink);
emit_std_reg_mem(sink, info, prefix, opcodes, 2, replacement, &amode, rex, 0);
}
Inst::AtomicRmwSeq {
ty,
op,
mem,
operand,
temp,
dst_old,
} => {
let operand = allocs.next(*operand);
let temp = allocs.next_writable(*temp);
let dst_old = allocs.next_writable(*dst_old);
debug_assert_eq!(dst_old.to_reg(), regs::rax());
let mem = mem.finalize(state, sink).with_allocs(allocs);
// Emit this:
// mov{zbq,zwq,zlq,q} (%r_address), %rax // rax = old value
// again:
// movq %rax, %r_temp // rax = old value, r_temp = old value
// `op`q %r_operand, %r_temp // rax = old value, r_temp = new value
// lock cmpxchg{b,w,l,q} %r_temp, (%r_address) // try to store new value
// jnz again // If this is taken, rax will have a "revised" old value
//
// Operand conventions: IN: %r_address, %r_operand OUT: %rax (old
// value), %r_temp (trashed), %rflags (trashed)
//
// In the case where the operation is 'xchg', the "`op`q"
// instruction is instead: movq %r_operand,
// %r_temp so that we simply write in the destination, the "2nd
// arg for `op`".
//
// TODO: this sequence can be significantly improved (e.g., to `lock
// <op>`) when it is known that `dst_old` is not used later, see
// https://github.com/bytecodealliance/wasmtime/issues/2153.
let again_label = sink.get_label();
// mov{zbq,zwq,zlq,q} (%r_address), %rax
// No need to call `add_trap` here, since the `i1` emit will do that.
let i1 = Inst::load(*ty, mem.clone(), dst_old, ExtKind::ZeroExtend);
i1.emit(&[], sink, info, state);
// again:
sink.bind_label(again_label);
// movq %rax, %r_temp
let i2 = Inst::mov_r_r(OperandSize::Size64, dst_old.to_reg(), temp);
i2.emit(&[], sink, info, state);
let operand_rmi = RegMemImm::reg(operand);
use inst_common::MachAtomicRmwOp as RmwOp;
match op {
RmwOp::Xchg => {
// movq %r_operand, %r_temp
let i3 = Inst::mov_r_r(OperandSize::Size64, operand, temp);
i3.emit(&[], sink, info, state);
}
RmwOp::Nand => {
// andq %r_operand, %r_temp
let i3 =
Inst::alu_rmi_r(OperandSize::Size64, AluRmiROpcode::And, operand_rmi, temp);
i3.emit(&[], sink, info, state);
// notq %r_temp
let i4 = Inst::not(OperandSize::Size64, temp);
i4.emit(&[], sink, info, state);
}
RmwOp::Umin | RmwOp::Umax | RmwOp::Smin | RmwOp::Smax => {
// cmp %r_temp, %r_operand
let i3 = Inst::cmp_rmi_r(
OperandSize::from_ty(*ty),
RegMemImm::reg(temp.to_reg()),
operand,
);
i3.emit(&[], sink, info, state);
// cmovcc %r_operand, %r_temp
let cc = match op {
RmwOp::Umin => CC::BE,
RmwOp::Umax => CC::NB,
RmwOp::Smin => CC::LE,
RmwOp::Smax => CC::NL,
_ => unreachable!(),
};
let i4 = Inst::cmove(OperandSize::Size64, cc, RegMem::reg(operand), temp);
i4.emit(&[], sink, info, state);
}
_ => {
// opq %r_operand, %r_temp
let alu_op = match op {
RmwOp::Add => AluRmiROpcode::Add,
RmwOp::Sub => AluRmiROpcode::Sub,
RmwOp::And => AluRmiROpcode::And,
RmwOp::Or => AluRmiROpcode::Or,
RmwOp::Xor => AluRmiROpcode::Xor,
RmwOp::Xchg
| RmwOp::Nand
| RmwOp::Umin
| RmwOp::Umax
| RmwOp::Smin
| RmwOp::Smax => unreachable!(),
};
let i3 = Inst::alu_rmi_r(OperandSize::Size64, alu_op, operand_rmi, temp);
i3.emit(&[], sink, info, state);
}
}
// lock cmpxchg{b,w,l,q} %r_temp, (%r_address)
// No need to call `add_trap` here, since the `i4` emit will do that.
let i4 = Inst::LockCmpxchg {
ty: *ty,
replacement: temp.to_reg(),
expected: dst_old.to_reg(),
mem: mem.into(),
dst_old,
};
i4.emit(&[], sink, info, state);
// jnz again
one_way_jmp(sink, CC::NZ, again_label);
}
Inst::Fence { kind } => {
sink.put1(0x0F);
sink.put1(0xAE);
match kind {
FenceKind::MFence => sink.put1(0xF0), // mfence = 0F AE F0
FenceKind::LFence => sink.put1(0xE8), // lfence = 0F AE E8
FenceKind::SFence => sink.put1(0xF8), // sfence = 0F AE F8
}
}
Inst::Hlt => {
sink.put1(0xcc);
}
Inst::Ud2 { trap_code } => {
sink.add_trap(*trap_code);
if let Some(s) = state.take_stack_map() {
sink.add_stack_map(StackMapExtent::UpcomingBytes(2), s);
}
sink.put1(0x0f);
sink.put1(0x0b);
}
Inst::VirtualSPOffsetAdj { offset } => {
trace!(
"virtual sp offset adjusted by {} -> {}",
offset,
state.virtual_sp_offset + offset
);
state.virtual_sp_offset += offset;
}
Inst::Nop { len } => {
// These encodings can all be found in Intel's architecture manual, at the NOP
// instruction description.
let mut len = *len;
while len != 0 {
let emitted = u8::min(len, 9);
match emitted {
0 => {}
1 => sink.put1(0x90), // NOP
2 => {
// 66 NOP
sink.put1(0x66);
sink.put1(0x90);
}
3 => {
// NOP [EAX]
sink.put1(0x0F);
sink.put1(0x1F);
sink.put1(0x00);
}
4 => {
// NOP 0(EAX), with 0 a 1-byte immediate.
sink.put1(0x0F);
sink.put1(0x1F);
sink.put1(0x40);
sink.put1(0x00);
}
5 => {
// NOP [EAX, EAX, 1]
sink.put1(0x0F);
sink.put1(0x1F);
sink.put1(0x44);
sink.put1(0x00);
sink.put1(0x00);
}
6 => {
// 66 NOP [EAX, EAX, 1]
sink.put1(0x66);
sink.put1(0x0F);
sink.put1(0x1F);
sink.put1(0x44);
sink.put1(0x00);
sink.put1(0x00);
}
7 => {
// NOP 0[EAX], but 0 is a 4 bytes immediate.
sink.put1(0x0F);
sink.put1(0x1F);
sink.put1(0x80);
sink.put1(0x00);
sink.put1(0x00);
sink.put1(0x00);
sink.put1(0x00);
}
8 => {
// NOP 0[EAX, EAX, 1], with 0 a 4 bytes immediate.
sink.put1(0x0F);
sink.put1(0x1F);
sink.put1(0x84);
sink.put1(0x00);
sink.put1(0x00);
sink.put1(0x00);
sink.put1(0x00);
sink.put1(0x00);
}
9 => {
// 66 NOP 0[EAX, EAX, 1], with 0 a 4 bytes immediate.
sink.put1(0x66);
sink.put1(0x0F);
sink.put1(0x1F);
sink.put1(0x84);
sink.put1(0x00);
sink.put1(0x00);
sink.put1(0x00);
sink.put1(0x00);
sink.put1(0x00);
}
_ => unreachable!(),
}
len -= emitted;
}
}
Inst::ElfTlsGetAddr { ref symbol, dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(dst, regs::rax());
// N.B.: Must be exactly this byte sequence; the linker requires it,
// because it must know how to rewrite the bytes.
// data16 lea gv@tlsgd(%rip),%rdi
sink.put1(0x66); // data16
sink.put1(0b01001000); // REX.W
sink.put1(0x8d); // LEA
sink.put1(0x3d); // ModRM byte
emit_reloc(sink, Reloc::ElfX86_64TlsGd, symbol, -4);
sink.put4(0); // offset
// data16 data16 callq __tls_get_addr-4
sink.put1(0x66); // data16
sink.put1(0x66); // data16
sink.put1(0b01001000); // REX.W
sink.put1(0xe8); // CALL
emit_reloc(
sink,
Reloc::X86CallPLTRel4,
&ExternalName::LibCall(LibCall::ElfTlsGetAddr),
-4,
);
sink.put4(0); // offset
}
Inst::MachOTlsGetAddr { ref symbol, dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(dst, regs::rax());
// movq gv@tlv(%rip), %rdi
sink.put1(0x48); // REX.w
sink.put1(0x8b); // MOV
sink.put1(0x3d); // ModRM byte
emit_reloc(sink, Reloc::MachOX86_64Tlv, symbol, -4);
sink.put4(0); // offset
// callq *(%rdi)
sink.put1(0xff);
sink.put1(0x17);
}
Inst::CoffTlsGetAddr { ref symbol, dst } => {
let dst = allocs.next(dst.to_reg().to_reg());
debug_assert_eq!(dst, regs::rax());
// See: https://gcc.godbolt.org/z/M8or9x6ss
// And: https://github.com/bjorn3/rustc_codegen_cranelift/issues/388#issuecomment-532930282
// Emit the following sequence
// movl (%rip), %eax ; IMAGE_REL_AMD64_REL32 _tls_index
// movq %gs:88, %rcx
// movq (%rcx,%rax,8), %rax
// leaq (%rax), %rax ; Reloc: IMAGE_REL_AMD64_SECREL symbol
// Load TLS index for current thread
// movl (%rip), %eax
sink.put1(0x8b); // mov
sink.put1(0x05);
emit_reloc(
sink,
Reloc::X86PCRel4,
&ExternalName::KnownSymbol(KnownSymbol::CoffTlsIndex),
-4,
);
sink.put4(0); // offset
// movq %gs:88, %rcx
// Load the TLS Storage Array pointer
// The gs segment register refers to the base address of the TEB on x64.
// 0x58 is the offset in the TEB for the ThreadLocalStoragePointer member on x64:
sink.put_data(&[
0x65, 0x48, // REX.W
0x8b, // MOV
0x0c, 0x25, 0x58, // 0x58 - ThreadLocalStoragePointer offset
0x00, 0x00, 0x00,
]);
// movq (%rcx,%rax,8), %rax
// Load the actual TLS entry for this thread.
// Computes ThreadLocalStoragePointer + _tls_index*8
sink.put_data(&[0x48, 0x8b, 0x04, 0xc1]);
// leaq (%rax), %rax
sink.put1(0x48);
sink.put1(0x8d);
sink.put1(0x80);
emit_reloc(sink, Reloc::X86SecRel, symbol, 0);
sink.put4(0); // offset
}
Inst::Unwind { ref inst } => {
sink.add_unwind(inst.clone());
}
Inst::DummyUse { .. } => {
// Nothing.
}
}
state.clear_post_insn();
}