Add hasOneUse check

Pierre-vh · Pierre-vh · commit 239c6ef32392 · 2025-03-21T15:48:35.000+01:00
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -13947,7 +13947,7 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
       }
 
       // If the trunc wasn't legal, try to fold to (sext_inreg (anyext x))
-      if ((!LegalTypes || TLI.isTypeLegal(VT))) {
+      if ((!LegalTypes || TLI.isTypeLegal(VT)) && N0.hasOneUse()) {
         SDValue ExtSrc = DAG.getAnyExtOrTrunc(N00, DL, VT);
         return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, ExtSrc,
                            N0->getOperand(1));

Original file line number	Diff line number	Diff line change
`@@ -13947,7 +13947,7 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {`
`13947`	`13947`	`}`
`13948`	`13948`
`13949`	`13949`	`// If the trunc wasn't legal, try to fold to (sext_inreg (anyext x))`
`13950`		`- if ((!LegalTypes \|\| TLI.isTypeLegal(VT))) {`
	`13950`	`+ if ((!LegalTypes \|\| TLI.isTypeLegal(VT)) && N0.hasOneUse()) {`
`13951`	`13951`	`SDValue ExtSrc = DAG.getAnyExtOrTrunc(N00, DL, VT);`
`13952`	`13952`	`return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, ExtSrc,`
`13953`	`13953`	`N0->getOperand(1));`