[FastISel][X86] Add MachineMemOperand to load/store instructions.
This commit adds MachineMemOperands to load and store instructions. This allows
the peephole optimizer to fold load instructions. Unfortunatelly the peephole
optimizer currently doesn't run at -O0.
llvm-svn: 210858
diff --git a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
index 94d3be9..21fcbd6 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -1737,3 +1737,47 @@
return isa<ConstantInt>(cast<AddOperator>(Add)->getOperand(1));
}
+MachineMemOperand *
+FastISel::createMachineMemOperandFor(const Instruction *I) const {
+ const Value *Ptr;
+ Type *ValTy;
+ unsigned Alignment;
+ unsigned Flags;
+ bool IsVolatile;
+
+ if (const auto *LI = dyn_cast<LoadInst>(I)) {
+ Alignment = LI->getAlignment();
+ IsVolatile = LI->isVolatile();
+ Flags = MachineMemOperand::MOLoad;
+ Ptr = LI->getPointerOperand();
+ ValTy = LI->getType();
+ } else if (const auto *SI = dyn_cast<StoreInst>(I)) {
+ Alignment = SI->getAlignment();
+ IsVolatile = SI->isVolatile();
+ Flags = MachineMemOperand::MOStore;
+ Ptr = SI->getPointerOperand();
+ ValTy = SI->getValueOperand()->getType();
+ } else {
+ return nullptr;
+ }
+
+ bool IsNonTemporal = I->getMetadata("nontemporal") != nullptr;
+ bool IsInvariant = I->getMetadata("invariant.load") != nullptr;
+ const MDNode *TBAAInfo = I->getMetadata(LLVMContext::MD_tbaa);
+ const MDNode *Ranges = I->getMetadata(LLVMContext::MD_range);
+
+ if (Alignment == 0) // Ensure that codegen never sees alignment 0.
+ Alignment = DL.getABITypeAlignment(ValTy);
+
+ unsigned Size = TM.getDataLayout()->getTypeStoreSize(ValTy);
+
+ if (IsVolatile)
+ Flags |= MachineMemOperand::MOVolatile;
+ if (IsNonTemporal)
+ Flags |= MachineMemOperand::MONonTemporal;
+ if (IsInvariant)
+ Flags |= MachineMemOperand::MOInvariant;
+
+ return FuncInfo.MF->getMachineMemOperand(MachinePointerInfo(Ptr), Flags, Size,
+ Alignment, TBAAInfo, Ranges);
+}