[llvm] 7013638 - [DAG] Add support for `nneg` flag with `uitofp`

[Noah Goldstein via llvm-commits]

Author: Noah Goldstein
Date: 2024-04-09T23:06:55-05:00
New Revision: 70136389788b90c2e6bbaef5ad8bb0285d460068

URL: https://github.com/llvm/llvm-project/commit/70136389788b90c2e6bbaef5ad8bb0285d460068
DIFF: https://github.com/llvm/llvm-project/commit/70136389788b90c2e6bbaef5ad8bb0285d460068.diff

LOG: [DAG] Add support for `nneg` flag with `uitofp`

Copy `nneg` flag when building `UINT_TO_FP` from `uitofp` and use
`nneg` flag in the one place we transform `UINT_TO_FP` -> `SINT_TO_FP`
if the operand is non-negative.

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 4ba27157ec1c6e..3f69f7ad54477e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3882,7 +3882,11 @@ void SelectionDAGBuilder::visitUIToFP(const User &I) {
   SDValue N = getValue(I.getOperand(0));
   EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
                                                         I.getType());
-  setValue(&I, DAG.getNode(ISD::UINT_TO_FP, getCurSDLoc(), DestVT, N));
+  SDNodeFlags Flags;
+  if (auto *PNI = dyn_cast<PossiblyNonNegInst>(&I))
+    Flags.setNonNeg(PNI->hasNonNeg());
+
+  setValue(&I, DAG.getNode(ISD::UINT_TO_FP, getCurSDLoc(), DestVT, N, Flags));
 }
 
 void SelectionDAGBuilder::visitSIToFP(const User &I) {