[llvm-branch-commits] [llvm] release/22.x: [SLP] Fix a very long loads offset, being stored in DenseMap (PR #193589)

[via llvm-branch-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: llvmbot

<details>
<summary>Changes</summary>

Backport 7ec7907b80f8137f06bfb84b47f4a9b4805402ba

Requested by: @<!-- -->nikic

---
Full diff: https://github.com/llvm/llvm-project/pull/193589.diff


2 Files Affected:

- (modified) llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp (+4) 
- (added) llvm/test/Transforms/SLPVectorizer/loads-with-large-distance.ll (+21) 


``````````diff
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 0a6b2545bc461..37385bc245ffe 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -7199,6 +7199,10 @@ bool BoUpSLP::analyzeRtStrideCandidate(ArrayRef<Value *> PointerOps,
         if (!SC)
           continue;
         Offset = SC->getAPInt().getSExtValue();
+        if (Offset >= std::numeric_limits<int64_t>::max() - 1) {
+          Offset = 0;
+          continue;
+        }
         break;
       }
     }
diff --git a/llvm/test/Transforms/SLPVectorizer/loads-with-large-distance.ll b/llvm/test/Transforms/SLPVectorizer/loads-with-large-distance.ll
new file mode 100644
index 0000000000000..77cad89ac88ac
--- /dev/null
+++ b/llvm/test/Transforms/SLPVectorizer/loads-with-large-distance.ll
@@ -0,0 +1,21 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -passes=slp-vectorizer -S < %s | FileCheck %s
+
+define void @test() {
+; CHECK-LABEL: define void @test() {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr i8, ptr addrspace(1) null, i64 9223372036854775807
+; CHECK-NEXT:    [[A:%.*]] = load float, ptr addrspace(1) [[TMP0]], align 4
+; CHECK-NEXT:    [[B:%.*]] = load float, ptr addrspace(1) null, align 4
+; CHECK-NEXT:    [[C:%.*]] = fadd float [[A]], [[B]]
+; CHECK-NEXT:    store float [[C]], ptr addrspace(1) null, align 4
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = getelementptr i8, ptr addrspace(1) null, i64 9223372036854775807
+  %a = load float, ptr addrspace(1) %0, align 4
+  %b = load float, ptr addrspace(1) null, align 4
+  %c = fadd float %a, %b
+  store float %c, ptr addrspace(1) null, align 4
+  ret void
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/193589