[MLIR][LLVM] Improve inlining debug information (#123520)

This commit improves the debug information for `alloca` and `memcpy`
operations generated by the LLVM dialect inlining interface.

When inlining by value parameters, the inliner creates `alloca` and
`memcpy` operations. This revision sets the location of these created
operations to the respective argument locations instead of the function
location. This change enables users to better identify the source code
location of the copied variables.

Author: gysit

mlir/lib/Dialect/LLVMIR/Transforms/InlinerInterfaceImpl.cpp

@@ -643,9 +643,9 @@ static Value handleByValArgument(OpBuilder &builder, Operation *callable,
       return argument;
   }
   uint64_t targetAlignment = std::max(requestedAlignment, minimumAlignment);
-  return handleByValArgumentInit(builder, func.getLoc(), argument, elementType,
-                                 dataLayout.getTypeSize(elementType),
-                                 targetAlignment);
+  return handleByValArgumentInit(
+      builder, argument.getLoc(), argument, elementType,
+      dataLayout.getTypeSize(elementType), targetAlignment);
 }
 
 namespace {

mlir/test/Dialect/LLVMIR/inlining-debuginfo.mlir

@@ -0,0 +1,21 @@
+// RUN: mlir-opt %s -inline -mlir-print-debuginfo | FileCheck %s
+
+llvm.func @foo() -> !llvm.ptr
+
+llvm.func @with_byval_arg(%ptr : !llvm.ptr { llvm.byval = f64 }) {
+  llvm.return
+}
+
+// CHECK-LABEL: llvm.func @test_byval
+llvm.func @test_byval() {
+  // CHECK: %[[COPY:.+]] = llvm.alloca %{{.+}} x f64
+  // CHECK-SAME: loc(#[[LOC:.+]])
+  // CHECK: %[[ORIG:.+]] = llvm.call @foo() : () -> !llvm.ptr loc(#[[LOC]])
+  %0 = llvm.call @foo() : () -> !llvm.ptr loc("inlining-debuginfo.mlir":14:2)
+  // CHECK: "llvm.intr.memcpy"(%[[COPY]], %[[ORIG]]
+  // CHECK-SAME: loc(#[[LOC]])
+  llvm.call @with_byval_arg(%0) : (!llvm.ptr) -> ()
+  llvm.return
+}
+
+// CHECK: #[[LOC]] = loc("inlining-debuginfo.mlir":14:2)