From 4a2757d80f0af48e65d90e7eaf268f78bcfa997f Mon Sep 17 00:00:00 2001
From: Hans Wennborg <hans@chromium.org>
Date: Thu, 16 Mar 2023 11:23:31 +0100
Subject: [PATCH] Make globals used for array initialization codegen constant

As pointed out in D133835 these globals will never be written to
(they're only used for trivially copyable types), so they can always be
constant.

Differential revision: https://reviews.llvm.org/D146211
---
 clang/lib/CodeGen/CGExprAgg.cpp                 | 5 ++---
 clang/test/CodeGen/init.c                       | 2 +-
 clang/test/CodeGen/label-array-aggregate-init.c | 2 +-
 3 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index 983c350129f8..33d2295fa98e 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -532,9 +532,8 @@ void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
             Emitter.tryEmitForInitializer(ExprToVisit, AS, ArrayQTy)) {
       auto GV = new llvm::GlobalVariable(
           CGM.getModule(), C->getType(),
-          CGM.isTypeConstant(ArrayQTy, /* ExcludeCtor= */ true,
-                             /* ExcludeDtor= */ false),
-          llvm::GlobalValue::PrivateLinkage, C, "constinit",
+          /* isConstant= */ true, llvm::GlobalValue::PrivateLinkage, C,
+          "constinit",
           /* InsertBefore= */ nullptr, llvm::GlobalVariable::NotThreadLocal,
           CGM.getContext().getTargetAddressSpace(AS));
       Emitter.finalize(GV);
diff --git a/clang/test/CodeGen/init.c b/clang/test/CodeGen/init.c
index 0a2d739e1a80..5ebd6853733f 100644
--- a/clang/test/CodeGen/init.c
+++ b/clang/test/CodeGen/init.c
@@ -10,7 +10,7 @@ unsigned v2[2][3] = {[0 ... 1][0 ... 1] = 2222, 3333};
 
 // CHECK-DAG: [1 x %struct.M] [%struct.M { [2 x %struct.I] [%struct.I { [3 x i32] [i32 4, i32 4, i32 0] }, %struct.I { [3 x i32] [i32 4, i32 4, i32 5] }] }],
 // CHECK-DAG: [2 x [3 x i32]] {{[[][[]}}3 x i32] [i32 2222, i32 2222, i32 0], [3 x i32] [i32 2222, i32 2222, i32 3333]],
-// CHECK-DAG: [[INIT14:.*]] = private global [16 x i32] [i32 0, i32 0, i32 0, i32 0, i32 0, i32 17, i32 17, i32 17, i32 17, i32 17, i32 17, i32 17, i32 0, i32 0, i32 0, i32 0], align 4
+// CHECK-DAG: [[INIT14:.*]] = private constant [16 x i32] [i32 0, i32 0, i32 0, i32 0, i32 0, i32 17, i32 17, i32 17, i32 17, i32 17, i32 17, i32 17, i32 0, i32 0, i32 0, i32 0], align 4
 
 void f1(void) {
   // Scalars in braces.
diff --git a/clang/test/CodeGen/label-array-aggregate-init.c b/clang/test/CodeGen/label-array-aggregate-init.c
index 00a20d5d204a..4039b925f21b 100644
--- a/clang/test/CodeGen/label-array-aggregate-init.c
+++ b/clang/test/CodeGen/label-array-aggregate-init.c
@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -triple x86_64-windows-msvc -emit-llvm %s -o - | FileCheck %s
 
-// CHECK: @constinit = private global [3 x ptr] [ptr blockaddress(@main, %L), ptr null, ptr null]
+// CHECK: @constinit = private constant [3 x ptr] [ptr blockaddress(@main, %L), ptr null, ptr null]
 
 void receivePtrs(void **);