1 files changed, 20 insertions, 10 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 3df448d..8f60e50 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Analysis/AssumptionCache.h"
 #include "llvm/Analysis/CmpInstAnalysis.h"
 #include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/Loads.h"
 #include "llvm/Analysis/OverflowInstAnalysis.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/Analysis/VectorUtils.h"
@@ -42,6 +43,7 @@
 #include "llvm/Support/KnownBits.h"
 #include "llvm/Transforms/InstCombine/InstCombiner.h"
 #include <cassert>
+#include <optional>
 #include <utility>
 
 #define DEBUG_TYPE "instcombine"
@@ -1451,10 +1453,16 @@ Instruction *InstCombinerImpl::foldSelectValueEquivalence(SelectInst &Sel,
     return nullptr;
   };
 
-  if (Instruction *R = ReplaceOldOpWithNewOp(CmpLHS, CmpRHS))
-    return R;
-  if (Instruction *R = ReplaceOldOpWithNewOp(CmpRHS, CmpLHS))
-    return R;
+  bool CanReplaceCmpLHSWithRHS = canReplacePointersIfEqual(CmpLHS, CmpRHS, DL);
+  if (CanReplaceCmpLHSWithRHS) {
+    if (Instruction *R = ReplaceOldOpWithNewOp(CmpLHS, CmpRHS))
+      return R;
+  }
+  bool CanReplaceCmpRHSWithLHS = canReplacePointersIfEqual(CmpRHS, CmpLHS, DL);
+  if (CanReplaceCmpRHSWithLHS) {
+    if (Instruction *R = ReplaceOldOpWithNewOp(CmpRHS, CmpLHS))
+      return R;
+  }
 
   auto *FalseInst = dyn_cast<Instruction>(FalseVal);
   if (!FalseInst)
@@ -1469,12 +1477,14 @@ Instruction *InstCombinerImpl::foldSelectValueEquivalence(SelectInst &Sel,
   // Example:
   // (X == 42) ? 43 : (X + 1) --> (X == 42) ? (X + 1) : (X + 1) --> X + 1
   SmallVector<Instruction *> DropFlags;
-  if (simplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, SQ,
-                             /* AllowRefinement */ false,
-                             &DropFlags) == TrueVal ||
-      simplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, SQ,
-                             /* AllowRefinement */ false,
-                             &DropFlags) == TrueVal) {
+  if ((CanReplaceCmpLHSWithRHS &&
+       simplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, SQ,
+                              /* AllowRefinement */ false,
+                              &DropFlags) == TrueVal) ||
+      (CanReplaceCmpRHSWithLHS &&
+       simplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, SQ,
+                              /* AllowRefinement */ false,
+                              &DropFlags) == TrueVal)) {
     for (Instruction *I : DropFlags) {
       I->dropPoisonGeneratingAnnotations();
       Worklist.add(I);