[Mlir-commits] [mlir] 8a43bc2 - [MLIR][LLVMIR] Import: fix llvm.call attribute inheritance (#130221)

[llvmlistbot at llvm.org]

Author: Bruno Cardoso Lopes
Date: 2025-03-07T10:59:03-08:00
New Revision: 8a43bc2c0989864f2635b4f79bb2d453a15cfd9a

URL: https://github.com/llvm/llvm-project/commit/8a43bc2c0989864f2635b4f79bb2d453a15cfd9a
DIFF: https://github.com/llvm/llvm-project/commit/8a43bc2c0989864f2635b4f79bb2d453a15cfd9a.diff

LOG: [MLIR][LLVMIR] Import: fix llvm.call attribute inheritance (#130221)

`inst->getFnAttr(Kind)` fallbacks to check if the parent has an
attribute, which breaks roundtriping the LLVM IR. This change actually
checks only in the call attribute list (no fallback to parent queries).

It's possible to argue that this small optimization isn't harmful, but
seems too early if it's breaking roundtrip behavior.

Added: 
    

Modified: 
    mlir/lib/Target/LLVMIR/ModuleImport.cpp
    mlir/test/Target/LLVMIR/Import/call-argument-attributes.ll

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Target/LLVMIR/ModuleImport.cpp b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
index cff5a1940e77e..f24c2777cbbb8 100644
--- a/mlir/lib/Target/LLVMIR/ModuleImport.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
@@ -2263,10 +2263,15 @@ LogicalResult ModuleImport::convertInvokeAttributes(llvm::InvokeInst *inst,
 LogicalResult ModuleImport::convertCallAttributes(llvm::CallInst *inst,
                                                   CallOp op) {
   setFastmathFlagsAttr(inst, op.getOperation());
+  // Query the attributes directly instead of using `inst->getFnAttr(Kind)`, the
+  // latter does additional lookup to the parent and inherits, changing the
+  // semantics too early.
+  llvm::AttributeList callAttrs = inst->getAttributes();
+
   op.setTailCallKind(convertTailCallKindFromLLVM(inst->getTailCallKind()));
-  op.setConvergent(inst->isConvergent());
-  op.setNoUnwind(inst->doesNotThrow());
-  op.setWillReturn(inst->hasFnAttr(llvm::Attribute::WillReturn));
+  op.setConvergent(callAttrs.getFnAttr(llvm::Attribute::Convergent).isValid());
+  op.setNoUnwind(callAttrs.getFnAttr(llvm::Attribute::NoUnwind).isValid());
+  op.setWillReturn(callAttrs.getFnAttr(llvm::Attribute::WillReturn).isValid());
 
   llvm::MemoryEffects memEffects = inst->getMemoryEffects();
   ModRefInfo othermem = convertModRefInfoFromLLVM(

diff  --git a/mlir/test/Target/LLVMIR/Import/call-argument-attributes.ll b/mlir/test/Target/LLVMIR/Import/call-argument-attributes.ll
index fa39c79bf0859..842639df0d44b 100644
--- a/mlir/test/Target/LLVMIR/Import/call-argument-attributes.ll
+++ b/mlir/test/Target/LLVMIR/Import/call-argument-attributes.ll
@@ -1,4 +1,4 @@
-; RUN: mlir-translate -import-llvm %s | FileCheck %s
+; RUN: mlir-translate -import-llvm -split-input-file %s | FileCheck %s
 
 ; CHECK-LABEL: llvm.func @somefunc(i32, !llvm.ptr)
 declare void @somefunc(i32, ptr)
@@ -20,3 +20,22 @@ define i16 @test_call_arg_attrs_indirect(i16 %0, ptr %1) {
   %3 = tail call signext i16 %1(i16 noundef signext %0)
   ret i16 %3
 }
+
+; // -----
+
+%struct.S = type { i8 }
+
+; CHECK-LABEL: @t
+define void @t(i1 %0) #0 {
+  %3 = alloca %struct.S, align 1
+  ; CHECK-NOT: llvm.call @z(%1) {no_unwind} : (!llvm.ptr) -> ()
+  ; CHECK: llvm.call @z(%1) : (!llvm.ptr) -> ()
+  call void @z(ptr %3)
+  ret void
+}
+
+define linkonce_odr void @z(ptr %0) #0 {
+  ret void
+}
+
+attributes #0 = { nounwind }