[IRCE] Skip icmp ptr in InductiveRangeCheck::parseRangeCheckICmp

[dtcxzyw]

Fixes #89959.

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Yingwei Zheng (dtcxzyw)

Changes

Fixes #89959.

---

Full diff: https://github.com/llvm/llvm-project/pull/89967.diff

2 Files Affected:

• (modified) llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp (+4)
• (added) llvm/test/Transforms/IRCE/pr89959.ll (+33)

diff --git a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
index 9df28747570c4d..661d42b87cda94 100644
--- a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
@@ -279,6 +279,10 @@ bool InductiveRangeCheck::parseRangeCheckICmp(Loop *L, ICmpInst *ICI,
   Value *LHS = ICI->getOperand(0);
   Value *RHS = ICI->getOperand(1);
 
+  // ICmp with pointers are unsupported.
+  if (LHS->getType()->isPtrOrPtrVectorTy())
+    return false;
+
   // Canonicalize to the `Index Pred Invariant` comparison
   if (IsLoopInvariant(LHS)) {
     std::swap(LHS, RHS);
diff --git a/llvm/test/Transforms/IRCE/pr89959.ll b/llvm/test/Transforms/IRCE/pr89959.ll
new file mode 100644
index 00000000000000..dc7c0dfbc57a97
--- /dev/null
+++ b/llvm/test/Transforms/IRCE/pr89959.ll
@@ -0,0 +1,33 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -passes=irce -S < %s 2>&1 | FileCheck %s
+
+; Make sure we don't crash.
+define void @pr89959() {
+; CHECK-LABEL: define void @pr89959() {
+; CHECK-NEXT:  top:
+; CHECK-NEXT:    br label [[L3:%.*]]
+; CHECK:       L3:
+; CHECK-NEXT:    [[VALUE_PHI:%.*]] = phi ptr [ null, [[TOP:%.*]] ], [ [[TMP0:%.*]], [[L13:%.*]] ]
+; CHECK-NEXT:    [[TMP0]] = getelementptr i8, ptr [[VALUE_PHI]], i64 8
+; CHECK-NEXT:    [[DOTNOT:%.*]] = icmp ule ptr [[VALUE_PHI]], null
+; CHECK-NEXT:    br i1 [[DOTNOT]], label [[L13]], label [[L15:%.*]]
+; CHECK:       L13:
+; CHECK-NEXT:    br label [[L3]]
+; CHECK:       L15:
+; CHECK-NEXT:    ret void
+;
+top:
+  br label %L3
+
+L3:
+  %value_phi = phi ptr [ null, %top ], [ %0, %L13 ]
+  %0 = getelementptr i8, ptr %value_phi, i64 8
+  %.not = icmp ule ptr %value_phi, null
+  br i1 %.not, label %L13, label %L15
+
+L13:
+  br label %L3
+
+L15:
+  ret void
+}

[fhahn]

Better to use SE->isSCEVable(LHS->getType()) as it makes the intention more explicit?

[dtcxzyw]

Pointer type is SCEVable, but willNotOverflow only supports binops with integers.

[fhahn]

Ah my bad, thanks for clarifying

[nikic]

LGTM