https://github.com/mmha created https://github.com/llvm/llvm-project/pull/151073
This implements support for structured bindings on a function scope level. It
does not add support for global structured bindings.
>From 1a77ffaa97180947a4bfb5c09d801f7feb9b173b Mon Sep 17 00:00:00 2001
From: Morris Hafner <mhaf...@nvidia.com>
Date: Tue, 29 Jul 2025 04:23:46 +0200
Subject: [PATCH] [CIR] Upstream support for function-level variable
decompositions
This implements support for structured bindings on a function scope level. It
does not add support for global structured bindings.
---
clang/include/clang/CIR/MissingFeatures.h | 1 +
clang/lib/CIR/CodeGen/CIRGenDecl.cpp | 8 ++-
clang/lib/CIR/CodeGen/CIRGenExpr.cpp | 5 ++
clang/lib/CIR/CodeGen/CIRGenModule.cpp | 7 ++-
.../CIR/CodeGen/variable-decomposition.cpp | 55 +++++++++++++++++++
5 files changed, 73 insertions(+), 3 deletions(-)
create mode 100644 clang/test/CIR/CodeGen/variable-decomposition.cpp
diff --git a/clang/include/clang/CIR/MissingFeatures.h
b/clang/include/clang/CIR/MissingFeatures.h
index e1a5c3d9ca337..d6501961dbe95 100644
--- a/clang/include/clang/CIR/MissingFeatures.h
+++ b/clang/include/clang/CIR/MissingFeatures.h
@@ -215,6 +215,7 @@ struct MissingFeatures {
static bool intrinsics() { return false; }
static bool isMemcpyEquivalentSpecialMember() { return false; }
static bool isTrivialCtorOrDtor() { return false; }
+ static bool lambdaCaptures() { return false; }
static bool lambdaFieldToName() { return false; }
static bool loopInfoStack() { return false; }
static bool lowerAggregateLoadStore() { return false; }
diff --git a/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
b/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
index a28ac3c16ce59..97cfec5475dfe 100644
--- a/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
@@ -608,11 +608,16 @@ void CIRGenFunction::emitDecl(const Decl &d) {
case Decl::UsingDirective: // using namespace X; [C++]
assert(!cir::MissingFeatures::generateDebugInfo());
return;
- case Decl::Var: {
+ case Decl::Var:
+ case Decl::Decomposition: {
const VarDecl &vd = cast<VarDecl>(d);
assert(vd.isLocalVarDecl() &&
"Should not see file-scope variables inside a function!");
emitVarDecl(vd);
+ if (auto *dd = dyn_cast<DecompositionDecl>(&vd))
+ for (BindingDecl *b : dd->bindings())
+ if (VarDecl *hd = b->getHoldingVar())
+ emitVarDecl(*hd);
return;
}
case Decl::OpenACCDeclare:
@@ -632,7 +637,6 @@ void CIRGenFunction::emitDecl(const Decl &d) {
case Decl::ImplicitConceptSpecialization:
case Decl::TopLevelStmt:
case Decl::UsingPack:
- case Decl::Decomposition: // This could be moved to join Decl::Var
case Decl::OMPDeclareReduction:
case Decl::OMPDeclareMapper:
cgm.errorNYI(d.getSourceRange(),
diff --git a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
index 7ff5f26be21b4..a2a9e719861f2 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
@@ -584,6 +584,11 @@ LValue CIRGenFunction::emitDeclRefLValue(const DeclRefExpr
*e) {
return lv;
}
+ if (const auto *bd = dyn_cast<BindingDecl>(nd)) {
+ assert(!e->refersToEnclosingVariableOrCapture() &&
!cir::MissingFeatures::lambdaCaptures());
+ return emitLValue(bd->getBinding());
+ }
+
cgm.errorNYI(e->getSourceRange(), "emitDeclRefLValue: unhandled decl type");
return LValue();
}
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.cpp
b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
index 350270518156e..2f750153f5ee3 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
@@ -1244,8 +1244,13 @@ void CIRGenModule::emitTopLevelDecl(Decl *decl) {
break;
}
- case Decl::Var: {
+ case Decl::Var:
+ case Decl::Decomposition: {
auto *vd = cast<VarDecl>(decl);
+ if(isa<DecompositionDecl>(decl)) {
+ errorNYI(decl->getSourceRange(), "global variable decompositions");
+ break;
+ }
emitGlobal(vd);
break;
}
diff --git a/clang/test/CIR/CodeGen/variable-decomposition.cpp
b/clang/test/CIR/CodeGen/variable-decomposition.cpp
new file mode 100644
index 0000000000000..b82e0c62424d4
--- /dev/null
+++ b/clang/test/CIR/CodeGen/variable-decomposition.cpp
@@ -0,0 +1,55 @@
+// RUN: %clang_cc1 -std=c++17 -triple x86_64-pc-linux-gnu -fclangir -emit-cir
%s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+// RUN: %clang_cc1 -std=c++17 -triple x86_64-pc-linux-gnu -fclangir -emit-llvm
%s -o %t-cir.ll
+// RUN: FileCheck --check-prefix=LLVM --input-file=%t-cir.ll %s
+// RUN: %clang_cc1 -std=c++17 -triple x86_64-pc-linux-gnu -emit-llvm %s -o
%t.ll
+// RUN: FileCheck --check-prefix=OGCG --input-file=%t.ll %s
+
+struct some_struct {
+ int a;
+ float b;
+};
+
+float function() {
+ auto[a, b] = some_struct{1, 2.f};
+
+ return a + b;
+}
+
+// CIR-LABEL: cir.func dso_local @_Z8functionv() -> !cir.float
+// CIR: %[[RETVAL:.+]] = cir.alloca !cir.float, !cir.ptr<!cir.float>,
["__retval"]
+// CIR: %[[STRUCT:.+]] = cir.alloca !rec_some_struct,
!cir.ptr<!rec_some_struct>, [""]
+// CIR: %[[MEMBER_A:.+]] = cir.get_member %[[STRUCT]][0] {name = "a"} :
!cir.ptr<!rec_some_struct> -> !cir.ptr<!s32i>
+// CIR: %[[LOAD_A:.+]] = cir.load align(4) %[[MEMBER_A]] : !cir.ptr<!s32i>,
!s32i
+// CIR: %[[CAST_A:.+]] = cir.cast(int_to_float, %[[LOAD_A]] : !s32i),
!cir.float
+// CIR: %[[MEMBER_B:.+]] = cir.get_member %[[STRUCT]][1] {name = "b"} :
!cir.ptr<!rec_some_struct> -> !cir.ptr<!cir.float>
+// CIR: %[[LOAD_B:.+]] = cir.load align(4) %[[MEMBER_B]] :
!cir.ptr<!cir.float>, !cir.float
+// CIR: %[[ADD:.+]] = cir.binop(add, %[[CAST_A]], %[[LOAD_B]]) : !cir.float
+// CIR: cir.store %[[ADD]], %[[RETVAL]] : !cir.float, !cir.ptr<!cir.float>
+// CIR: %[[RET:.+]] = cir.load %[[RETVAL]] : !cir.ptr<!cir.float>, !cir.float
+// CIR: cir.return %[[RET]] : !cir.float
+
+// LLVM-LABEL: define dso_local float @_Z8functionv()
+// LLVM: %[[RETVAL:.+]] = alloca float, i64 1
+// LLVM: %[[STRUCT:.+]] = alloca %struct.some_struct, i64 1
+// LLVM: %[[GEP_A:.+]] = getelementptr %struct.some_struct, ptr %[[STRUCT]],
i32 0, i32 0
+// LLVM: %[[LOAD_A:.+]] = load i32, ptr %[[GEP_A]]
+// LLVM: %[[CAST_A:.+]] = sitofp i32 %[[LOAD_A]] to float
+// LLVM: %[[GEP_B:.+]] = getelementptr %struct.some_struct, ptr %[[STRUCT]],
i32 0, i32 1
+// LLVM: %[[LOAD_B:.+]] = load float, ptr %[[GEP_B]]
+// LLVM: %[[ADD:.+]] = fadd float %[[CAST_A]], %[[LOAD_B]]
+// LLVM: store float %[[ADD]], ptr %[[RETVAL]]
+// LLVM: %[[RET:.+]] = load float, ptr %[[RETVAL]]
+// LLVM: ret float %[[RET]]
+
+// OGCG: @__const._Z8functionv.{{.*}} = private unnamed_addr constant
%struct.some_struct { i32 1, float 2.000000e+00 }
+// OGCG-LABEL: define dso_local noundef float @_Z8functionv()
+// OGCG: %[[STRUCT:.+]] = alloca %struct.some_struct
+// OGCG: call void @llvm.memcpy.p0.p0.i64(ptr align 4 %[[STRUCT]], ptr align
4 @__const._Z8functionv.{{.*}}, i64 8, i1 false)
+// OGCG: %[[GEP_A:.+]] = getelementptr inbounds nuw %struct.some_struct, ptr
%[[STRUCT]], i32 0, i32 0
+// OGCG: %[[LOAD_A:.+]] = load i32, ptr %[[GEP_A]]
+// OGCG: %[[CAST_A:.+]] = sitofp i32 %[[LOAD_A]] to float
+// OGCG: %[[GEP_B:.+]] = getelementptr inbounds nuw %struct.some_struct, ptr
%[[STRUCT]], i32 0, i32 1
+// OGCG: %[[LOAD_B:.+]] = load float, ptr %[[GEP_B]]
+// OGCG: %[[ADD:.+]] = fadd float %[[CAST_A]], %[[LOAD_B]]
+// OGCG: ret float %[[ADD]]
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
