RPCSX/llvm
1
0
Fork 0
mirror of https://github.com/RPCSX/llvm.git synced 2025-01-23 20:57:21 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Implement test/Regression/Transforms/InstCombine/getelementptr_index.ll

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12762 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-04-07 18:38:20 +00:00
parent ef09aab9ce
commit cb69a4ed64
1 changed files with 38 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
lib/Transforms/Scalar/InstructionCombining.cpp
View File

@ -2317,16 +2317,18 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
// Eliminate unneeded casts for indices. // Eliminate unneeded casts for indices.
bool MadeChange = false; bool MadeChange = false;
for (unsigned i = 1, e = GEP.getNumOperands(); i != e; ++i) gep_type_iterator GTI = gep_type_begin(GEP);
for (unsigned i = 1, e = GEP.getNumOperands(); i != e; ++i, ++GTI)
if (isa<SequentialType>(*GTI)) {
if (CastInst *CI = dyn_cast<CastInst>(GEP.getOperand(i))) { if (CastInst *CI = dyn_cast<CastInst>(GEP.getOperand(i))) {
Value *Src = CI->getOperand(0); Value *Src = CI->getOperand(0);
const Type *SrcTy = Src->getType(); const Type *SrcTy = Src->getType();
const Type *DestTy = CI->getType(); const Type *DestTy = CI->getType();
if (Src->getType()->isInteger()) { if (Src->getType()->isInteger()) {
if (SrcTy->getPrimitiveSize() == DestTy->getPrimitiveSize()) { if (SrcTy->getPrimitiveSize() == DestTy->getPrimitiveSize()) {
// We can always eliminate a cast from ulong or long to the other. We // We can always eliminate a cast from ulong or long to the other.
// can always eliminate a cast from uint to int or the other on 32-bit // We can always eliminate a cast from uint to int or the other on
// pointer platforms. // 32-bit pointer platforms.
if (DestTy->getPrimitiveSize() >= TD->getPointerSize()) { if (DestTy->getPrimitiveSize() >= TD->getPointerSize()) {
MadeChange = true; MadeChange = true;
GEP.setOperand(i, Src); GEP.setOperand(i, Src);
@ -2344,6 +2346,19 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
} }
} }
} }
// If we are using a wider index than needed for this platform, shrink it
// to what we need. If the incoming value needs a cast instruction,
// insert it. This explicit cast can make subsequent optimizations more
// obvious.
Value *Op = GEP.getOperand(i);
if (Op->getType()->getPrimitiveSize() > TD->getPointerSize())
if (!isa<Constant>(Op)) {
Op = InsertNewInstBefore(new CastInst(Op, TD->getIntPtrType(),
Op->getName()), GEP);
GEP.setOperand(i, Op);
MadeChange = true;
}
}
if (MadeChange) return &GEP; if (MadeChange) return &GEP;
// Combine Indices - If the source pointer to this getelementptr instruction // Combine Indices - If the source pointer to this getelementptr instruction