[PATCH] D120164: [SelectionDAGBuilder] Simplify visitShift. NFC
Craig Topper via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Sat Feb 19 12:41:12 PST 2022
This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG24bfa2435510: [SelectionDAGBuilder] Simplify visitShift. NFC (authored by craig.topper).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D120164/new/
https://reviews.llvm.org/D120164
Files:
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3150,26 +3150,12 @@
EVT ShiftTy = DAG.getTargetLoweringInfo().getShiftAmountTy(
Op1.getValueType(), DAG.getDataLayout());
- // Coerce the shift amount to the right type if we can.
+ // Coerce the shift amount to the right type if we can. This exposes the
+ // truncate or zext to optimization early.
if (!I.getType()->isVectorTy() && Op2.getValueType() != ShiftTy) {
- unsigned ShiftSize = ShiftTy.getSizeInBits();
- unsigned Op2Size = Op2.getValueSizeInBits();
- SDLoc DL = getCurSDLoc();
-
- // If the operand is smaller than the shift count type, promote it.
- if (ShiftSize > Op2Size)
- Op2 = DAG.getNode(ISD::ZERO_EXTEND, DL, ShiftTy, Op2);
-
- // If the operand is larger than the shift count type but the shift
- // count type has enough bits to represent any shift value, truncate
- // it now. This is a common case and it exposes the truncate to
- // optimization early.
- else if (ShiftSize >= Log2_32_Ceil(Op1.getValueSizeInBits()))
- Op2 = DAG.getNode(ISD::TRUNCATE, DL, ShiftTy, Op2);
- // Otherwise we'll need to temporarily settle for some other convenient
- // type. Type legalization will make adjustments once the shiftee is split.
- else
- Op2 = DAG.getZExtOrTrunc(Op2, DL, MVT::i32);
+ assert(ShiftTy.getSizeInBits() >= Log2_32_Ceil(Op1.getValueSizeInBits()) &&
+ "Unexpected shift type");
+ Op2 = DAG.getZExtOrTrunc(Op2, getCurSDLoc(), ShiftTy);
}
bool nuw = false;
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