[Mlir-commits] [mlir] [mlir][LLVM] Preserve scalable array bit sizes (PR #236862)

[llvmlistbot at llvm.org]

llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-mlir

Author: Akimasa Watanuki (Men-cotton)

<details>
<summary>Changes</summary>

Preserve the scalable factor in LLVM array bit-size queries, including nested arrays of scalable vectors. Prevent these queries from aborting when the array size depends on `vscale`.

Assisted-by: Codex / GPT-6

---
Full diff: https://github.com/llvm/llvm-project/pull/236862.diff


2 Files Affected:

- (modified) mlir/lib/Dialect/LLVMIR/IR/LLVMTypes.cpp (+1-2) 
- (modified) mlir/unittests/Dialect/LLVMIR/LLVMTypeTest.cpp (+10) 


``````````diff
diff --git a/mlir/lib/Dialect/LLVMIR/IR/LLVMTypes.cpp b/mlir/lib/Dialect/LLVMIR/IR/LLVMTypes.cpp
index 2d99c0e4a4931d..03fe8a15c5d30c 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/LLVMTypes.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/LLVMTypes.cpp
@@ -181,8 +181,7 @@ LLVMArrayType::verify(function_ref<InFlightDiagnostic()> emitError,
 llvm::TypeSize
 LLVMArrayType::getTypeSizeInBits(const DataLayout &dataLayout,
                                  DataLayoutEntryListRef params) const {
-  return llvm::TypeSize::getFixed(kBitsInByte *
-                                  getTypeSize(dataLayout, params));
+  return getTypeSize(dataLayout, params) * kBitsInByte;
 }
 
 llvm::TypeSize LLVMArrayType::getTypeSize(const DataLayout &dataLayout,
diff --git a/mlir/unittests/Dialect/LLVMIR/LLVMTypeTest.cpp b/mlir/unittests/Dialect/LLVMIR/LLVMTypeTest.cpp
index 72d8867d232aad..7428f0fe39da76 100644
--- a/mlir/unittests/Dialect/LLVMIR/LLVMTypeTest.cpp
+++ b/mlir/unittests/Dialect/LLVMIR/LLVMTypeTest.cpp
@@ -60,3 +60,13 @@ TEST_F(LLVMIRTest, StructElementOffsets) {
   EXPECT_EQ(packedAlloc.getElementOffset(dataLayout, 1), 16u);
   EXPECT_EQ(dataLayout.getTypeSize(packedAlloc), 17u);
 }
+
+TEST_F(LLVMIRTest, ScalableVectorArrayLayout) {
+  DataLayout layout;
+  auto vector = VectorType::get({3}, IntegerType::get(&context, 32), {true});
+  auto array = LLVMArrayType::get(LLVMArrayType::get(vector, 2), 3);
+  EXPECT_EQ(layout.getTypeSizeInBits(array).getKnownMinValue(), 768u);
+  EXPECT_TRUE(layout.getTypeSizeInBits(array).isScalable());
+  EXPECT_EQ(layout.getTypeSize(array).getKnownMinValue(), 96u);
+  EXPECT_TRUE(layout.getTypeSize(array).isScalable());
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/236862