[llvm] b2837bf - [ScalarEvolution] Add bailout to avoid zext of pointer.

[Eli Friedman via llvm-commits]

Author: Eli Friedman
Date: 2022-01-31T11:41:39-08:00
New Revision: b2837bf2f22a9198d636e2d5755c119d1fc4329a

URL: https://github.com/llvm/llvm-project/commit/b2837bf2f22a9198d636e2d5755c119d1fc4329a
DIFF: https://github.com/llvm/llvm-project/commit/b2837bf2f22a9198d636e2d5755c119d1fc4329a.diff

LOG: [ScalarEvolution] Add bailout to avoid zext of pointer.

The RHS of an isImpliedCond call can be a pointer even if the LHS is
not. This is similar to bfa2a81e.

Not going to include a testcase; an IR testcase would be extremely
complicated and fragile.

Fixes https://github.com/llvm/llvm-project/issues/51936 .

Differential Revision: https://reviews.llvm.org/D114555

Added: 
    

Modified: 
    llvm/lib/Analysis/ScalarEvolution.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 402d6311f2288..977fc09113550 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -10919,7 +10919,8 @@ bool ScalarEvolution::isImpliedCond(ICmpInst::Predicate Pred, const SCEV *LHS,
     // For unsigned and equality predicates, try to prove that both found
     // operands fit into narrow unsigned range. If so, try to prove facts in
     // narrow types.
-    if (!CmpInst::isSigned(FoundPred) && !FoundLHS->getType()->isPointerTy()) {
+    if (!CmpInst::isSigned(FoundPred) && !FoundLHS->getType()->isPointerTy() &&
+        !FoundRHS->getType()->isPointerTy()) {
       auto *NarrowType = LHS->getType();
       auto *WideType = FoundLHS->getType();
       auto BitWidth = getTypeSizeInBits(NarrowType);
@@ -10937,7 +10938,7 @@ bool ScalarEvolution::isImpliedCond(ICmpInst::Predicate Pred, const SCEV *LHS,
       }
     }
 
-    if (LHS->getType()->isPointerTy())
+    if (LHS->getType()->isPointerTy() || RHS->getType()->isPointerTy())
       return false;
     if (CmpInst::isSigned(Pred)) {
       LHS = getSignExtendExpr(LHS, FoundLHS->getType());
@@ -10948,7 +10949,7 @@ bool ScalarEvolution::isImpliedCond(ICmpInst::Predicate Pred, const SCEV *LHS,
     }
   } else if (getTypeSizeInBits(LHS->getType()) >
       getTypeSizeInBits(FoundLHS->getType())) {
-    if (FoundLHS->getType()->isPointerTy())
+    if (FoundLHS->getType()->isPointerTy() || FoundRHS->getType()->isPointerTy())
       return false;
     if (CmpInst::isSigned(FoundPred)) {
       FoundLHS = getSignExtendExpr(FoundLHS, LHS->getType());