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Differential D98247 Diff 329531 llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp

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llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp

Show First 20 Lines • Show All 2,389 Lines • ▼ Show 20 LinesInstruction *InstCombinerImpl::optimizeBitCastFromPhi(CastInst &CI,
OldPhiNodes.insert(PN); OldPhiNodes.insert(PN);
while (!PhiWorklist.empty()) { while (!PhiWorklist.empty()) {
auto *OldPN = PhiWorklist.pop_back_val(); auto *OldPN = PhiWorklist.pop_back_val();
for (Value *IncValue : OldPN->incoming_values()) { for (Value *IncValue : OldPN->incoming_values()) {
if (isa<Constant>(IncValue)) if (isa<Constant>(IncValue))
continue; continue;
if (auto *LI = dyn_cast<LoadInst>(IncValue)) { if (auto *LI = dyn_cast<LoadInst>(IncValue)) {
// Don't transform "load <256 x i32>, <256 x i32>*" to
pengfeiUnsubmitted
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Better to add a comment for the reason.

pengfei: Better to add a comment for the reason.
// "load x86_amx, x86_amx*", because we don't have a corresponding
// instruction to load x86_amx. Doing the transform causes trouble
// to lower "load x86_amx" instruction in backend.
if (DestTy->isX86_AMXTy())
return nullptr;
// If there is a sequence of one or more load instructions, each loaded // If there is a sequence of one or more load instructions, each loaded
// value is used as address of later load instruction, bitcast is // value is used as address of later load instruction, bitcast is
// necessary to change the value type, don't optimize it. For // necessary to change the value type, don't optimize it. For
// simplicity we give up if the load address comes from another load. // simplicity we give up if the load address comes from another load.
Value *Addr = LI->getOperand(0); Value *Addr = LI->getOperand(0);
if (Addr == &CI || isa<LoadInst>(Addr)) if (Addr == &CI || isa<LoadInst>(Addr))
return nullptr; return nullptr;
if (LI->hasOneUse() && LI->isSimple()) if (LI->hasOneUse() && LI->isSimple())
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