6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-23 01:24:30 +00:00
Code Issues Projects Releases Wiki Activity

Add a small gep optimization I noticed was missing while reading some IL.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136585 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rafael Espindola
2011-07-31 04:43:41 +00:00
parent c47690264a
commit 592ad6a82f
2 changed files with 33 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
lib/Transforms/InstCombine/InstructionCombining.cpp
View File

@ -737,7 +737,15 @@ Type *InstCombiner::FindElementAtOffset(Type *Ty, int64_t Offset,
return Ty;
}
static bool shouldMergeGEPs(GEPOperator &GEP, GEPOperator &Src) {
// If this GEP has only 0 indices, it is the same pointer as
// Src. If Src is not a trivial GEP too, don't combine
// the indices.
if (GEP.hasAllZeroIndices() && !Src.hasAllZeroIndices() &&
!Src.hasOneUse())
return false;
return true;
}
Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
SmallVector<Value*, 8> Ops(GEP.op_begin(), GEP.op_end());
@ -785,21 +793,15 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
// getelementptr instructions into a single instruction.
//
if (GEPOperator *Src = dyn_cast<GEPOperator>(PtrOp)) {
// If this GEP has only 0 indices, it is the same pointer as
// Src. If Src is not a trivial GEP too, don't combine
// the indices.
if (GEP.hasAllZeroIndices() && !Src->hasAllZeroIndices() &&
!Src->hasOneUse())
if (!shouldMergeGEPs(*cast<GEPOperator>(&GEP), *Src))
return 0;
// Note that if our source is a gep chain itself that we wait for that
// chain to be resolved before we perform this transformation. This
// avoids us creating a TON of code in some cases.
//
if (GetElementPtrInst *SrcGEP =
dyn_cast<GetElementPtrInst>(Src->getOperand(0)))
if (SrcGEP->getNumOperands() == 2)
if (GEPOperator *SrcGEP =
dyn_cast<GEPOperator>(Src->getOperand(0)))
if (SrcGEP->getNumOperands() == 2 && shouldMergeGEPs(*Src, *SrcGEP))
return 0; // Wait until our source is folded to completion.
SmallVector<Value*, 8> Indices;