2930d7662e
Summary: This change avoids the overhead of storing, and later crawling, an initializer list of all zeros for arrays. When LLVM visits this (llvm/IR/Constants.cpp) ConstantArray::getImpl() it will scan the list looking for an array of all zero. We can avoid the store, and short-cut the scan, by detecting all zeros when clang builds-up the initialization representation. This was brought to my attention when investigating PR36030 Reviewers: majnemer, rjmccall Reviewed By: rjmccall Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D42549 llvm-svn: 324776
13 lines
431 B
C
13 lines
431 B
C
// RUN: %clang_cc1 %s -O0 -triple x86_64-unknown-linux-gnu -emit-llvm -o - | FileCheck %s
|
|
|
|
// CHECK: @{{.*}}.a1 = internal constant [5 x i32] [i32 0, i32 1, i32 2, i32 0, i32 0]
|
|
// CHECK: @{{.*}}.a2 = internal constant [5 x i32] zeroinitializer
|
|
// CHECK: @{{.*}}.a3 = internal constant [5 x i32] zeroinitializer
|
|
|
|
void testConstArrayInits(void)
|
|
{
|
|
const int a1[5] = {0,1,2};
|
|
const int a2[5] = {0,0,0};
|
|
const int a3[5] = {0};
|
|
}
|