[InstSimplify] Add additional checks when substituting pointers

Author: dtcxzyw

llvm/lib/Analysis/InstructionSimplify.cpp

@@ -27,6 +27,7 @@
 #include "llvm/Analysis/CmpInstAnalysis.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/InstSimplifyFolder.h"
+#include "llvm/Analysis/Loads.h"
 #include "llvm/Analysis/LoopAnalysisManager.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
 #include "llvm/Analysis/OverflowInstAnalysis.h"
@@ -4731,12 +4732,16 @@ static Value *simplifySelectWithICmpCond(Value *CondVal, Value *TrueVal,
   // the arms of the select. See if substituting this value into the arm and
   // simplifying the result yields the same value as the other arm.
   if (Pred == ICmpInst::ICMP_EQ) {
-    if (Value *V = simplifySelectWithEquivalence({{CmpLHS, CmpRHS}}, TrueVal,
-                                                 FalseVal, Q, MaxRecurse))
-      return V;
-    if (Value *V = simplifySelectWithEquivalence({{CmpRHS, CmpLHS}}, TrueVal,
-                                                 FalseVal, Q, MaxRecurse))
-      return V;
+    if (CmpLHS->getType()->isIntOrIntVectorTy() ||
+        canReplacePointersIfEqual(CmpLHS, CmpRHS, Q.DL))
+      if (Value *V = simplifySelectWithEquivalence({{CmpLHS, CmpRHS}}, TrueVal,
+                                                   FalseVal, Q, MaxRecurse))
+        return V;
+    if (CmpLHS->getType()->isIntOrIntVectorTy() ||
+        canReplacePointersIfEqual(CmpRHS, CmpLHS, Q.DL))
+      if (Value *V = simplifySelectWithEquivalence({{CmpRHS, CmpLHS}}, TrueVal,
+                                                   FalseVal, Q, MaxRecurse))
+        return V;
 
     Value *X;
     Value *Y;

llvm/test/Transforms/InstSimplify/select-icmp.ll

@@ -247,7 +247,9 @@ cond.end:                                         ; preds = %entry, %cond.true
 
 define ptr @icmp_ptr_eq_replace(ptr %a, ptr %b) {
 ; CHECK-LABEL: @icmp_ptr_eq_replace(
-; CHECK-NEXT:    ret ptr [[B:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq ptr [[A:%.*]], [[B1:%.*]]
+; CHECK-NEXT:    [[B:%.*]] = select i1 [[CMP]], ptr [[A]], ptr [[B1]]
+; CHECK-NEXT:    ret ptr [[B]]
 ;
   %cmp = icmp eq ptr %a, %b
   %sel = select i1 %cmp, ptr %a, ptr %b