AMDGPU: Add Assert[SZ]Ext during argument load creation
For i16 zeroext arguments when i16 was a legal type, the
known bits information from the truncate was lost. Insert
a zeroext so the known bits optimizations work with the 32-bit
loads.
Fixes code quality regressions vs. SI in min.ll test.
llvm-svn: 291461
diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index 7c83e96..9140fe6 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -711,7 +711,8 @@
SDValue SITargetLowering::LowerParameter(SelectionDAG &DAG, EVT VT, EVT MemVT,
const SDLoc &SL, SDValue Chain,
- unsigned Offset, bool Signed) const {
+ unsigned Offset, bool Signed,
+ const ISD::InputArg *Arg) const {
const DataLayout &DL = DAG.getDataLayout();
Type *Ty = MemVT.getTypeForEVT(*DAG.getContext());
PointerType *PtrTy = PointerType::get(Ty, AMDGPUAS::CONSTANT_ADDRESS);
@@ -725,20 +726,21 @@
MachineMemOperand::MODereferenceable |
MachineMemOperand::MOInvariant);
- SDValue Val;
+ SDValue Val = Load;
+ if (Arg && (Arg->Flags.isSExt() || Arg->Flags.isZExt()) &&
+ VT.bitsLT(MemVT)) {
+ unsigned Opc = Arg->Flags.isZExt() ? ISD::AssertZext : ISD::AssertSext;
+ Val = DAG.getNode(Opc, SL, MemVT, Val, DAG.getValueType(VT));
+ }
+
if (MemVT.isFloatingPoint())
- Val = getFPExtOrFPTrunc(DAG, Load, SL, VT);
+ Val = getFPExtOrFPTrunc(DAG, Val, SL, VT);
else if (Signed)
- Val = DAG.getSExtOrTrunc(Load, SL, VT);
+ Val = DAG.getSExtOrTrunc(Val, SL, VT);
else
- Val = DAG.getZExtOrTrunc(Load, SL, VT);
+ Val = DAG.getZExtOrTrunc(Val, SL, VT);
- SDValue Ops[] = {
- Val,
- Load.getValue(1)
- };
-
- return DAG.getMergeValues(Ops, SL);
+ return DAG.getMergeValues({ Val, Load.getValue(1) }, SL);
}
SDValue SITargetLowering::LowerFormalArguments(
@@ -911,7 +913,8 @@
// The first 36 bytes of the input buffer contains information about
// thread group and global sizes.
SDValue Arg = LowerParameter(DAG, VT, MemVT, DL, Chain,
- Offset, Ins[i].Flags.isSExt());
+ Offset, Ins[i].Flags.isSExt(),
+ &Ins[i]);
Chains.push_back(Arg.getValue(1));
auto *ParamTy =