[llvm] [LV] Fix crash when vectorizing function calls with linear args. (PR #76274)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Alexandros Lamprineas (labrinea)

<details>
<summary>Changes</summary>

llvm/lib/IR/Type.cpp:694:
    Assertion `isValidElementType(ElementType) && "Element type of a
    VectorType must be an integer, floating point, or pointer type."'
    failed.
Stack dump:
    llvm::FixedVectorType::get(llvm::Type*, unsigned int)
    llvm::VPWidenCallRecipe::execute(llvm::VPTransformState&)
    llvm::VPBasicBlock::execute(llvm::VPTransformState*)
    llvm::VPRegionBlock::execute(llvm::VPTransformState*)
    llvm::VPlan::execute(llvm::VPTransformState*)
    ...

Happens with function calls of void return type.

---
Full diff: https://github.com/llvm/llvm-project/pull/76274.diff


2 Files Affected:

- (modified) llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp (+2-1) 
- (added) llvm/test/Transforms/LoopVectorize/vector-call-linear-args.ll (+31) 


``````````diff
diff --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index 02e400d590bed4..1ca9556adad6ac 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -504,7 +504,8 @@ void VPWidenCallRecipe::execute(VPTransformState &State) {
   for (unsigned Part = 0; Part < State.UF; ++Part) {
     SmallVector<Type *, 2> TysForDecl;
     // Add return type if intrinsic is overloaded on it.
-    if (isVectorIntrinsicWithOverloadTypeAtArg(VectorIntrinsicID, -1)) {
+    if (isVectorIntrinsicWithOverloadTypeAtArg(VectorIntrinsicID, -1) &&
+        VectorIntrinsicID != Intrinsic::not_intrinsic) {
       TysForDecl.push_back(
           VectorType::get(CI.getType()->getScalarType(), State.VF));
     }
diff --git a/llvm/test/Transforms/LoopVectorize/vector-call-linear-args.ll b/llvm/test/Transforms/LoopVectorize/vector-call-linear-args.ll
new file mode 100644
index 00000000000000..e84326d5d402aa
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/vector-call-linear-args.ll
@@ -0,0 +1,31 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --filter "call.*foo" --version 4
+; RUN: opt -passes=loop-vectorize,simplifycfg -force-vector-interleave=1 -force-vector-width=2 -S < %s | FileCheck %s
+
+; Make sure the vectorizer does not crash.
+
+define void @test_foo(ptr noalias %in, ptr noalias %out) {
+; CHECK-LABEL: define void @test_foo(
+; CHECK-SAME: ptr noalias [[IN:%.*]], ptr noalias [[OUT:%.*]]) {
+; CHECK:    call void @vec_foo(<2 x i64> [[WIDE_LOAD:%.*]], ptr [[TMP4:%.*]])
+;
+entry:
+  br label %for.body
+
+for.body:
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %gep.in = getelementptr i64, ptr %in, i64 %indvars.iv
+  %num = load i64, ptr %gep.in, align 8
+  %gep.out = getelementptr i64, ptr %out, i64 %indvars.iv
+  call void @foo(i64 %num, ptr %gep.out) #0
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, 1000
+  br i1 %exitcond, label %for.cond.cleanup, label %for.body
+
+for.cond.cleanup:
+  ret void
+}
+
+declare void @foo(i64, ptr)
+declare void @vec_foo(<2 x i64>, ptr)
+
+attributes #0 = { "vector-function-abi-variant"="_ZGV_LLVM_N2vl8_foo(vec_foo)" }

``````````

</details>


https://github.com/llvm/llvm-project/pull/76274