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xenia-canary
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Not sure why I thought I could do this.

This commit is contained in:
Ben Vanik 2014-01-14 00:39:31 -08:00
parent 81226db1b4
commit 50587974b5
2 changed files with 1 additions and 30 deletions
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30
src/alloy/compiler/passes/simplification_pass.cc
View File

@ -31,13 +31,7 @@ int SimplificationPass::Run(HIRBuilder* builder) {
void SimplificationPass::EliminateConversions(HIRBuilder* builder) {
// First, we check for truncates/extensions that can be skipped.
// This generates some assignments which then the second step will clean up.
// Only zero extend truncates can be skipped:
// v1.i32 = truncate v0.i64
// v2.i64 = zero_extend v1.i32
// becomes:
// v1.i32 = truncate v0.i64 (may be dead code removed later)
// v2.i64 = v0.i64
// But both zero/sign extends can be skipped:
// Both zero/sign extends can be skipped:
// v1.i64 = zero/sign_extend v0.i32
// v2.i32 = truncate v1.i64
// becomes:
@ -53,9 +47,6 @@ void SimplificationPass::EliminateConversions(HIRBuilder* builder) {
if (i->opcode == &OPCODE_TRUNCATE_info) {
// Matches zero/sign_extend + truncate.
CheckTruncate(i);
} else if (i->opcode == &OPCODE_ZERO_EXTEND_info) {
// Matches truncate + zero_extend.
CheckZeroExtend(i);
} else if (i->opcode == &OPCODE_BYTE_SWAP_info) {
// Matches byte swap + byte swap.
// This is pretty rare within the same basic block, but is in the
@ -96,25 +87,6 @@ void SimplificationPass::CheckTruncate(Instr* i) {
}
}
void SimplificationPass::CheckZeroExtend(Instr* i) {
// Walk backward up src's chain looking for a truncate. We may have
// assigns, so skip those.
auto src = i->src1.value;
Instr* def = src->def;
while (def && def->opcode == &OPCODE_ASSIGN_info) {
// Skip asignments.
def = def->src1.value->def;
}
if (def && def->opcode == &OPCODE_TRUNCATE_info) {
// Value comes from a truncate.
if (def->src1.value->type == i->dest->type) {
// Types match, use original by turning this into an assign.
i->Replace(&OPCODE_ASSIGN_info, 0);
i->set_src1(def->src1.value);
}
}
}
void SimplificationPass::CheckByteSwap(Instr* i) {
// Walk backward up src's chain looking for a byte swap. We may have
// assigns, so skip those.

1
src/alloy/compiler/passes/simplification_pass.h
View File

@ -28,7 +28,6 @@ public:
private:
void EliminateConversions(hir::HIRBuilder* builder);
void CheckTruncate(hir::Instr* i);
void CheckZeroExtend(hir::Instr* i);
void CheckByteSwap(hir::Instr* i);
void SimplifyAssignments(hir::HIRBuilder* builder);