Corner case in LVN for src and dst

gkluczek · igcbot · commit 9aabce6b595e · 2025-11-25T10:09:21.000+01:00
Corner case in LVN for src and dst.
diff --git a/visa/Passes/LVN.cpp b/visa/Passes/LVN.cpp
@@ -219,6 +219,12 @@ bool LVN::canReplaceUses(INST_LIST_ITER inst_it, UseList &uses,
       }
     }
 
+    if (useInst->getNumDst() && useInst->getDst() && !useInst->hasNULLDst() &&
+        useInst->getDst()->getTopDcl() == lvnDstTopDcl) {
+      canReplace = false;
+      break;
+    }
+
     // Compute a single positive stride if exists.
     unsigned int use_hs = 0;
     {

Original file line number	Diff line number	Diff line change
`@@ -219,6 +219,12 @@ bool LVN::canReplaceUses(INST_LIST_ITER inst_it, UseList &uses,`
`219`	`219`	`}`
`220`	`220`	`}`
`221`	`221`
	`222`	`+ if (useInst->getNumDst() && useInst->getDst() && !useInst->hasNULLDst() &&`
	`223`	`+ useInst->getDst()->getTopDcl() == lvnDstTopDcl) {`
	`224`	`+ canReplace = false;`
	`225`	`+ break;`
	`226`	`+ }`
	`227`	`+`
`222`	`228`	`// Compute a single positive stride if exists.`
`223`	`229`	`unsigned int use_hs = 0;`
`224`	`230`	`{`