maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/test/CodeGen/X86/elf-associated.ll

45 lines
1.4 KiB
LLVM
Raw Normal View History

Add !associated metadata. This is an ELF-specific thing that adds SHF_LINK_ORDER to the global's section pointing to the metadata argument's section. The effect of that is a reverse dependency between sections for the linker GC. !associated does not change the behavior of global-dce. The global may also need to be added to llvm.compiler.used. Since SHF_LINK_ORDER is per-section, !associated effectively enables fdata-sections for the affected globals, the same as comdats do. Differential Revision: https://reviews.llvm.org/D29104 llvm-svn: 298157
2017-03-18 06:17:24 +08:00
; RUN: llc -data-sections=1 -mtriple x86_64-pc-linux-gnu < %s | FileCheck %s
; RUN: llc -data-sections=0 -mtriple x86_64-pc-linux-gnu < %s | FileCheck %s
@a = global i32 1
@b = global i32 2, !associated !0
!0 = !{i32* @a}
Change section flag character for SHF_LINK_ORDER to "o". GAS uses "m" as a compatibility alias for "M" (SHF_MERGE). "o" is free, except on ia64, where it already means SHF_LINK_ORDER. llvm-svn: 299479
2017-04-05 06:35:08 +08:00
; CHECK-DAG: .section .data.b,"awo",@progbits,a
Add !associated metadata. This is an ELF-specific thing that adds SHF_LINK_ORDER to the global's section pointing to the metadata argument's section. The effect of that is a reverse dependency between sections for the linker GC. !associated does not change the behavior of global-dce. The global may also need to be added to llvm.compiler.used. Since SHF_LINK_ORDER is per-section, !associated effectively enables fdata-sections for the affected globals, the same as comdats do. Differential Revision: https://reviews.llvm.org/D29104 llvm-svn: 298157
2017-03-18 06:17:24 +08:00
; Loop is OK. Also, normally -data-sections=0 would place @c and @d in the same section. !associated prevents that.
@c = global i32 2, !associated !2
@d = global i32 2, !associated !1
!1 = !{i32* @c}
!2 = !{i32* @d}
Change section flag character for SHF_LINK_ORDER to "o". GAS uses "m" as a compatibility alias for "M" (SHF_MERGE). "o" is free, except on ia64, where it already means SHF_LINK_ORDER. llvm-svn: 299479
2017-04-05 06:35:08 +08:00
; CHECK-DAG: .section .data.c,"awo",@progbits,d
; CHECK-DAG: .section .data.d,"awo",@progbits,c
Add !associated metadata. This is an ELF-specific thing that adds SHF_LINK_ORDER to the global's section pointing to the metadata argument's section. The effect of that is a reverse dependency between sections for the linker GC. !associated does not change the behavior of global-dce. The global may also need to be added to llvm.compiler.used. Since SHF_LINK_ORDER is per-section, !associated effectively enables fdata-sections for the affected globals, the same as comdats do. Differential Revision: https://reviews.llvm.org/D29104 llvm-svn: 298157
2017-03-18 06:17:24 +08:00
; BSS is OK.
@e = global i32 0
@f = global i32 0, !associated !3
@g = global i32 1, !associated !3
!3 = !{i32* @e}
Change section flag character for SHF_LINK_ORDER to "o". GAS uses "m" as a compatibility alias for "M" (SHF_MERGE). "o" is free, except on ia64, where it already means SHF_LINK_ORDER. llvm-svn: 299479
2017-04-05 06:35:08 +08:00
; CHECK-DAG: .section .bss.f,"awo",@nobits,e
; CHECK-DAG: .section .data.g,"awo",@progbits,e
Add !associated metadata. This is an ELF-specific thing that adds SHF_LINK_ORDER to the global's section pointing to the metadata argument's section. The effect of that is a reverse dependency between sections for the linker GC. !associated does not change the behavior of global-dce. The global may also need to be added to llvm.compiler.used. Since SHF_LINK_ORDER is per-section, !associated effectively enables fdata-sections for the affected globals, the same as comdats do. Differential Revision: https://reviews.llvm.org/D29104 llvm-svn: 298157
2017-03-18 06:17:24 +08:00
; Explicit sections.
@h = global i32 1, section "aaa"
@i = global i32 1, section "bbb", !associated !4
@j = global i32 1, section "bbb", !associated !4
@k = global i32 1, !associated !4
!4 = !{i32* @h}
; CHECK-DAG: .section aaa,"aw",@progbits
Change section flag character for SHF_LINK_ORDER to "o". GAS uses "m" as a compatibility alias for "M" (SHF_MERGE). "o" is free, except on ia64, where it already means SHF_LINK_ORDER. llvm-svn: 299479
2017-04-05 06:35:08 +08:00
; CHECK-DAG: .section bbb,"awo",@progbits,h,unique,1
; CHECK-DAG: .section bbb,"awo",@progbits,h,unique,2
; CHECK-DAG: .section .data.k,"awo",@progbits,h
Add !associated metadata. This is an ELF-specific thing that adds SHF_LINK_ORDER to the global's section pointing to the metadata argument's section. The effect of that is a reverse dependency between sections for the linker GC. !associated does not change the behavior of global-dce. The global may also need to be added to llvm.compiler.used. Since SHF_LINK_ORDER is per-section, !associated effectively enables fdata-sections for the affected globals, the same as comdats do. Differential Revision: https://reviews.llvm.org/D29104 llvm-svn: 298157
2017-03-18 06:17:24 +08:00
; Non-GlobalObject metadata.
@l = global i32 1, section "ccc", !associated !5
!5 = !{i32* null}
; CHECK-DAG: .section ccc,"aw",@progbits
Ignore !associated metadata with null argument. Fixes PR32577 (comment 10). Such metadata may legitimately appear in LTO. llvm-svn: 302485
2017-05-09 07:46:20 +08:00
; Null metadata.
@m = global i32 1, section "ddd", !associated !6
!6 = distinct !{null}
; CHECK-DAG: .section ddd,"aw",@progbits