Quick: Use 16-bit Thumb2 PUSH/POP when possible.
Generate correct PUSH/POP in Gen{Entry,Exit}Sequence()
to avoid extra processing during insn fixup.
Change-Id: I396168e2a42faee6980d40779c7de9657531867b
diff --git a/compiler/dex/compiler_enums.h b/compiler/dex/compiler_enums.h
index 4d377df..3b3170e 100644
--- a/compiler/dex/compiler_enums.h
+++ b/compiler/dex/compiler_enums.h
@@ -614,7 +614,6 @@
kFixupVLoad, // FP load which *may* be pc-relative.
kFixupCBxZ, // Cbz, Cbnz.
kFixupTBxZ, // Tbz, Tbnz.
- kFixupPushPop, // Not really pc relative, but changes size based on args.
kFixupCondBranch, // Conditional branch
kFixupT1Branch, // Thumb1 Unconditional branch
kFixupT2Branch, // Thumb2 Unconditional branch
diff --git a/compiler/dex/quick/arm/assemble_arm.cc b/compiler/dex/quick/arm/assemble_arm.cc
index 4e20d76..76ec9df 100644
--- a/compiler/dex/quick/arm/assemble_arm.cc
+++ b/compiler/dex/quick/arm/assemble_arm.cc
@@ -671,12 +671,12 @@
kFmtBitBlt, 15, 0, kFmtUnused, -1, -1, kFmtUnused, -1, -1,
kFmtUnused, -1, -1,
IS_UNARY_OP | REG_DEF_SP | REG_USE_SP | REG_DEF_LIST0
- | IS_LOAD | NEEDS_FIXUP, "pop", "<!0R>", 4, kFixupPushPop),
+ | IS_LOAD, "pop", "<!0R>", 4, kFixupNone),
ENCODING_MAP(kThumb2Push, 0xe92d0000,
kFmtBitBlt, 15, 0, kFmtUnused, -1, -1, kFmtUnused, -1, -1,
kFmtUnused, -1, -1,
IS_UNARY_OP | REG_DEF_SP | REG_USE_SP | REG_USE_LIST0
- | IS_STORE | NEEDS_FIXUP, "push", "<!0R>", 4, kFixupPushPop),
+ | IS_STORE, "push", "<!0R>", 4, kFixupNone),
ENCODING_MAP(kThumb2CmpRI8M, 0xf1b00f00,
kFmtBitBlt, 19, 16, kFmtModImm, -1, -1, kFmtUnused, -1, -1,
kFmtUnused, -1, -1,
@@ -1396,31 +1396,6 @@
}
break;
}
- case kFixupPushPop: {
- if (__builtin_popcount(lir->operands[0]) == 1) {
- /*
- * The standard push/pop multiple instruction
- * requires at least two registers in the list.
- * If we've got just one, switch to the single-reg
- * encoding.
- */
- lir->opcode = (lir->opcode == kThumb2Push) ? kThumb2Push1 :
- kThumb2Pop1;
- int reg = 0;
- while (lir->operands[0]) {
- if (lir->operands[0] & 0x1) {
- break;
- } else {
- reg++;
- lir->operands[0] >>= 1;
- }
- }
- lir->operands[0] = reg;
- // This won't change again, don't bother unlinking, just reset fixup kind
- lir->flags.fixup = kFixupNone;
- }
- break;
- }
case kFixupCondBranch: {
LIR *target_lir = lir->target;
int32_t delta = 0;
diff --git a/compiler/dex/quick/arm/call_arm.cc b/compiler/dex/quick/arm/call_arm.cc
index f15d707..99b2166 100644
--- a/compiler/dex/quick/arm/call_arm.cc
+++ b/compiler/dex/quick/arm/call_arm.cc
@@ -347,7 +347,20 @@
}
}
/* Spill core callee saves */
- NewLIR1(kThumb2Push, core_spill_mask_);
+ if (core_spill_mask_ == 0u) {
+ // Nothing to spill.
+ } else if ((core_spill_mask_ & ~(0xffu | (1u << rs_rARM_LR.GetRegNum()))) == 0u) {
+ // Spilling only low regs and/or LR, use 16-bit PUSH.
+ constexpr int lr_bit_shift = rs_rARM_LR.GetRegNum() - 8;
+ NewLIR1(kThumbPush,
+ (core_spill_mask_ & ~(1u << rs_rARM_LR.GetRegNum())) |
+ ((core_spill_mask_ & (1u << rs_rARM_LR.GetRegNum())) >> lr_bit_shift));
+ } else if (IsPowerOfTwo(core_spill_mask_)) {
+ // kThumb2Push cannot be used to spill a single register.
+ NewLIR1(kThumb2Push1, CTZ(core_spill_mask_));
+ } else {
+ NewLIR1(kThumb2Push, core_spill_mask_);
+ }
/* Need to spill any FP regs? */
if (num_fp_spills_) {
/*
@@ -444,13 +457,26 @@
if (num_fp_spills_) {
NewLIR1(kThumb2VPopCS, num_fp_spills_);
}
- if (core_spill_mask_ & (1 << rs_rARM_LR.GetRegNum())) {
+ if ((core_spill_mask_ & (1 << rs_rARM_LR.GetRegNum())) != 0) {
/* Unspill rARM_LR to rARM_PC */
core_spill_mask_ &= ~(1 << rs_rARM_LR.GetRegNum());
core_spill_mask_ |= (1 << rs_rARM_PC.GetRegNum());
}
- NewLIR1(kThumb2Pop, core_spill_mask_);
- if (!(core_spill_mask_ & (1 << rs_rARM_PC.GetRegNum()))) {
+ if (core_spill_mask_ == 0u) {
+ // Nothing to unspill.
+ } else if ((core_spill_mask_ & ~(0xffu | (1u << rs_rARM_PC.GetRegNum()))) == 0u) {
+ // Unspilling only low regs and/or PC, use 16-bit POP.
+ constexpr int pc_bit_shift = rs_rARM_PC.GetRegNum() - 8;
+ NewLIR1(kThumbPop,
+ (core_spill_mask_ & ~(1u << rs_rARM_PC.GetRegNum())) |
+ ((core_spill_mask_ & (1u << rs_rARM_PC.GetRegNum())) >> pc_bit_shift));
+ } else if (IsPowerOfTwo(core_spill_mask_)) {
+ // kThumb2Pop cannot be used to unspill a single register.
+ NewLIR1(kThumb2Pop1, CTZ(core_spill_mask_));
+ } else {
+ NewLIR1(kThumb2Pop, core_spill_mask_);
+ }
+ if ((core_spill_mask_ & (1 << rs_rARM_PC.GetRegNum())) == 0) {
/* We didn't pop to rARM_PC, so must do a bv rARM_LR */
NewLIR1(kThumbBx, rs_rARM_LR.GetReg());
}
