[llvm-branch-commits] [clang] [KeyInstr][Clang] Aggregate init + copy (PR #134639)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Orlando Cazalet-Hyams (OCHyams)

<details>
<summary>Changes</summary>

[KeyInstr][Clang] Aggregate init + copy

This patch is part of a stack that teaches Clang to generate Key Instructions
metadata for C and C++.

The Key Instructions project is introduced, including a "quick summary" section
at the top which adds context for this PR, here:
https://discourse.llvm.org/t/rfc-improving-is-stmt-placement-for-better-interactive-debugging/82668

The feature is only functional in LLVM if LLVM is built with CMake flag
LLVM_EXPERIMENTAL_KEY_INSTRUCTIONs. Eventually that flag will be removed.

The Clang-side work is demoed here:
https://github.com/llvm/llvm-project/pull/130943

[KeyInstr][Clang] Agg copy atom

---
Full diff: https://github.com/llvm/llvm-project/pull/134639.diff


4 Files Affected:

- (modified) clang/lib/CodeGen/CGExprAgg.cpp (+3-1) 
- (modified) clang/lib/CodeGen/CodeGenFunction.h (+1) 
- (added) clang/test/KeyInstructions/agg.c (+17) 
- (modified) clang/test/KeyInstructions/init-agg.c (+2) 


``````````diff
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index c8bdda375d1b1..26bc2666d9759 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -1332,6 +1332,7 @@ static bool isBlockVarRef(const Expr *E) {
 }
 
 void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
+  ApplyAtomGroup Grp(CGF.getDebugInfo());
   // For an assignment to work, the value on the right has
   // to be compatible with the value on the left.
   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
@@ -2394,7 +2395,8 @@ void CodeGenFunction::EmitAggregateCopy(LValue Dest, LValue Src, QualType Ty,
     }
   }
 
-  auto Inst = Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, isVolatile);
+  auto *Inst = Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, isVolatile);
+  addInstToCurrentSourceAtom(Inst, nullptr);
 
   // Determine the metadata to describe the position of any padding in this
   // memcpy, as well as the TBAA tags for the members of the struct, in case
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index d8b1c4e4efb77..0a72784f311e5 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -3042,6 +3042,7 @@ class CodeGenFunction : public CodeGenTypeCache {
 
   /// Emit an aggregate assignment.
   void EmitAggregateAssign(LValue Dest, LValue Src, QualType EltTy) {
+    ApplyAtomGroup Grp(getDebugInfo());
     bool IsVolatile = hasVolatileMember(EltTy);
     EmitAggregateCopy(Dest, Src, EltTy, AggValueSlot::MayOverlap, IsVolatile);
   }
diff --git a/clang/test/KeyInstructions/agg.c b/clang/test/KeyInstructions/agg.c
new file mode 100644
index 0000000000000..177e1ea8b9fc1
--- /dev/null
+++ b/clang/test/KeyInstructions/agg.c
@@ -0,0 +1,17 @@
+// RUN: %clang -gkey-instructions -x c++ %s -gmlt -S -emit-llvm -o - \
+// RUN: | FileCheck %s --implicit-check-not atomGroup --implicit-check-not atomRank
+
+// RUN: %clang -gkey-instructions -x c %s -gmlt -S -emit-llvm -o -  \
+// RUN: | FileCheck %s --implicit-check-not atomGroup --implicit-check-not atomRank
+
+typedef struct { int a, b, c; } Struct;
+void fun(Struct a) {
+// CHECK: call void @llvm.memcpy{{.*}}, !dbg [[G1R1:!.*]]
+  Struct b = a;
+
+// CHECK: call void @llvm.memcpy{{.*}}, !dbg [[G2R1:!.*]]
+  b = a;
+}
+
+// CHECK: [[G1R1]] = !DILocation({{.*}}, atomGroup: 1, atomRank: 1)
+// CHECK: [[G2R1]] = !DILocation({{.*}}, atomGroup: 2, atomRank: 1)
diff --git a/clang/test/KeyInstructions/init-agg.c b/clang/test/KeyInstructions/init-agg.c
index ad298715286cd..dc3ccaedc57b5 100644
--- a/clang/test/KeyInstructions/init-agg.c
+++ b/clang/test/KeyInstructions/init-agg.c
@@ -9,6 +9,8 @@
 // store locations to be included in the atom group.
 
 int g;
+typedef struct { int a, b, c; } Struct;
+Struct g2;
 void a() {
 // CHECK: call void @llvm.memcpy{{.*}}, !dbg [[G1R1:!.*]]
     int A[] = { 1, 2, 3 };

``````````

</details>


https://github.com/llvm/llvm-project/pull/134639