aco: add NUW flag
This (combined with a pass to actually set the corresponding NIR flags)
should help fix a lot of the regressions from the SMEM addition combining
change.
fossil-db (Navi):
Totals from 12 (0.01% of 135946) affected shaders:
CodeSize: 12376 -> 12304 (-0.58%)
Instrs: 2436 -> 2422 (-0.57%)
VMEM: 1105 -> 1096 (-0.81%)
SClause: 133 -> 130 (-2.26%)
Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2720>
diff --git a/src/amd/compiler/aco_builder_h.py b/src/amd/compiler/aco_builder_h.py
index e10358a..b3adb14 100644
--- a/src/amd/compiler/aco_builder_h.py
+++ b/src/amd/compiler/aco_builder_h.py
@@ -176,6 +176,7 @@
std::vector<aco_ptr<Instruction>> *instructions;
std::vector<aco_ptr<Instruction>>::iterator it;
bool is_precise = false;
+ bool is_nuw = false;
Builder(Program *pgm) : program(pgm), use_iterator(false), start(false), lm(pgm->lane_mask), instructions(NULL) {}
Builder(Program *pgm, Block *block) : program(pgm), use_iterator(false), start(false), lm(pgm ? pgm->lane_mask : s2), instructions(&block->instructions) {}
@@ -187,6 +188,12 @@
return res;
};
+ Builder nuw() const {
+ Builder res = *this;
+ res.is_nuw = true;
+ return res;
+ }
+
void moveEnd(Block *block) {
instructions = &block->instructions;
}
@@ -572,6 +579,7 @@
% for i in range(num_definitions):
instr->definitions[${i}] = def${i};
instr->definitions[${i}].setPrecise(is_precise);
+ instr->definitions[${i}].setNUW(is_nuw);
% endfor
% for i in range(num_operands):
instr->operands[${i}] = op${i}.op;
diff --git a/src/amd/compiler/aco_instruction_selection.cpp b/src/amd/compiler/aco_instruction_selection.cpp
index 0af1f1f..34887f2 100644
--- a/src/amd/compiler/aco_instruction_selection.cpp
+++ b/src/amd/compiler/aco_instruction_selection.cpp
@@ -614,6 +614,8 @@
sop2->operands[0] = Operand(get_alu_src(ctx, instr->src[0]));
sop2->operands[1] = Operand(get_alu_src(ctx, instr->src[1]));
sop2->definitions[0] = Definition(dst);
+ if (instr->no_unsigned_wrap)
+ sop2->definitions[0].setNUW(true);
if (writes_scc)
sop2->definitions[1] = Definition(ctx->program->allocateId(), scc, s1);
ctx->block->instructions.emplace_back(std::move(sop2));
@@ -5287,7 +5289,7 @@
Temp index = bld.as_uniform(get_ssa_temp(ctx, instr->src[0].ssa));
if (offset != 0) // TODO check if index != 0 as well
- index = bld.sop2(aco_opcode::s_add_i32, bld.def(s1), bld.def(s1, scc), Operand(offset), index);
+ index = bld.nuw().sop2(aco_opcode::s_add_i32, bld.def(s1), bld.def(s1, scc), Operand(offset), index);
Temp ptr = convert_pointer_to_64_bit(ctx, get_arg(ctx, ctx->args->ac.push_constants));
Temp vec = dst;
bool trim = false;
@@ -5373,7 +5375,7 @@
Temp offset = get_ssa_temp(ctx, instr->src[0].ssa);
if (base && offset.type() == RegType::sgpr)
- offset = bld.sop2(aco_opcode::s_add_u32, bld.def(s1), bld.def(s1, scc), offset, Operand(base));
+ offset = bld.nuw().sop2(aco_opcode::s_add_u32, bld.def(s1), bld.def(s1, scc), offset, Operand(base));
else if (base && offset.type() == RegType::vgpr)
offset = bld.vadd32(bld.def(v1), Operand(base), offset);
@@ -6255,8 +6257,8 @@
aco_ptr<SMEM_instruction> store{create_instruction<SMEM_instruction>(op, Format::SMEM, 3, 0)};
store->operands[0] = Operand(rsrc);
if (offsets[i]) {
- Temp off = bld.sop2(aco_opcode::s_add_i32, bld.def(s1), bld.def(s1, scc),
- offset, Operand(offsets[i]));
+ Temp off = bld.nuw().sop2(aco_opcode::s_add_i32, bld.def(s1), bld.def(s1, scc),
+ offset, Operand(offsets[i]));
store->operands[1] = Operand(off);
} else {
store->operands[1] = Operand(offset);
@@ -7273,6 +7275,7 @@
Temp addr = get_ssa_temp(ctx, instr->src[0].ssa);
nir_const_value* const_addr = nir_src_as_const_value(instr->src[0]);
Temp private_segment_buffer = ctx->program->private_segment_buffer;
+ //TODO: bounds checking?
if (addr.type() == RegType::sgpr) {
Operand offset;
if (const_addr) {
diff --git a/src/amd/compiler/aco_ir.h b/src/amd/compiler/aco_ir.h
index a23ff7c..661b698 100644
--- a/src/amd/compiler/aco_ir.h
+++ b/src/amd/compiler/aco_ir.h
@@ -700,7 +700,8 @@
class Definition final
{
public:
- constexpr Definition() : temp(Temp(0, s1)), reg_(0), isFixed_(0), hasHint_(0), isKill_(0), isPrecise_(0) {}
+ constexpr Definition() : temp(Temp(0, s1)), reg_(0), isFixed_(0), hasHint_(0),
+ isKill_(0), isPrecise_(0), isNUW_(0) {}
Definition(uint32_t index, RegClass type) noexcept
: temp(index, type) {}
explicit Definition(Temp tmp) noexcept
@@ -797,6 +798,17 @@
return isPrecise_;
}
+ /* No Unsigned Wrap */
+ constexpr void setNUW(bool nuw) noexcept
+ {
+ isNUW_ = nuw;
+ }
+
+ constexpr bool isNUW() const noexcept
+ {
+ return isNUW_;
+ }
+
private:
Temp temp = Temp(0, s1);
PhysReg reg_;
@@ -806,6 +818,7 @@
uint8_t hasHint_:1;
uint8_t isKill_:1;
uint8_t isPrecise_:1;
+ uint8_t isNUW_:1;
};
/* can't initialize bit-fields in c++11, so work around using a union */
uint8_t control_ = 0;
diff --git a/src/amd/compiler/aco_opt_value_numbering.cpp b/src/amd/compiler/aco_opt_value_numbering.cpp
index 9a1972f..2fdbfaa 100644
--- a/src/amd/compiler/aco_opt_value_numbering.cpp
+++ b/src/amd/compiler/aco_opt_value_numbering.cpp
@@ -406,6 +406,12 @@
ctx.renames[instr->definitions[i].tempId()] = orig_instr->definitions[i].getTemp();
if (instr->definitions[i].isPrecise())
orig_instr->definitions[i].setPrecise(true);
+ /* SPIR_V spec says that an instruction marked with NUW wrapping
+ * around is undefined behaviour, so we can break additions in
+ * other contexts.
+ */
+ if (instr->definitions[i].isNUW())
+ orig_instr->definitions[i].setNUW(true);
}
} else {
ctx.expr_values.erase(res.first);
diff --git a/src/amd/compiler/aco_optimizer.cpp b/src/amd/compiler/aco_optimizer.cpp
index a254728..e00c8c1 100644
--- a/src/amd/compiler/aco_optimizer.cpp
+++ b/src/amd/compiler/aco_optimizer.cpp
@@ -717,9 +717,6 @@
bool parse_base_offset(opt_ctx &ctx, Instruction* instr, unsigned op_index, Temp *base, uint32_t *offset, bool prevent_overflow)
{
- if (prevent_overflow)
- return false; //TODO
-
Operand op = instr->operands[op_index];
if (!op.isTemp())
@@ -740,6 +737,8 @@
default:
return false;
}
+ if (prevent_overflow && !add_instr->definitions[0].isNUW())
+ return false;
if (add_instr->usesModifiers())
return false;
diff --git a/src/amd/compiler/aco_print_ir.cpp b/src/amd/compiler/aco_print_ir.cpp
index 3daa60b..9172fc1 100644
--- a/src/amd/compiler/aco_print_ir.cpp
+++ b/src/amd/compiler/aco_print_ir.cpp
@@ -181,6 +181,8 @@
print_reg_class(definition->regClass(), output);
if (definition->isPrecise())
fprintf(output, "(precise)");
+ if (definition->isNUW())
+ fprintf(output, "(nuw)");
fprintf(output, "%%%d", definition->tempId());
if (definition->isFixed())
