WinCOFF: Add support for -fdata-sections

This is a pretty straight forward translation for COFF, we just need to
stick the data in a COMDAT section marked as
IMAGE_COMDAT_SELECT_NODUPLICATES.

N.B. We must be careful to avoid sticking entities with private linkage
in COMDAT groups.  COFF is pretty hostile to the renaming of entities so
we must be careful to disallow GlobalVariables with unstable names.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204703 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Majnemer 2014-03-25 06:14:26 +00:00
parent 9d5961d0d8
commit 4fd5cd06c8
2 changed files with 25 additions and 9 deletions

View File

@ -770,12 +770,18 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler &Mang, const TargetMachine &TM) const {
// If we have -ffunction-sections then we should emit the global value to a
// uniqued section specifically for it.
// TODO: Implement -fdata-sections.
bool EmitUniquedSection = Kind.isText() && TM.getFunctionSections();
bool EmitUniquedSection;
if (Kind.isText())
EmitUniquedSection = TM.getFunctionSections();
else
EmitUniquedSection = TM.getDataSections();
// If this global is linkonce/weak and the target handles this by emitting it
// into a 'uniqued' section name, create and return the section now.
if (GV->isWeakForLinker() || EmitUniquedSection) {
// Section names depend on the name of the symbol which is not feasible if the
// symbol has private linkage.
if ((GV->isWeakForLinker() || EmitUniquedSection) &&
!GV->hasPrivateLinkage()) {
const char *Name = getCOFFSectionNameForUniqueGlobal(Kind);
unsigned Characteristics = getCOFFSectionFlags(Kind);

View File

@ -3,8 +3,14 @@
; RUN: llc < %s -mtriple=i386-apple-darwin10 -relocation-model=static | FileCheck %s -check-prefix=DARWIN-STATIC
; RUN: llc < %s -mtriple=x86_64-apple-darwin10 | FileCheck %s -check-prefix=DARWIN64
; RUN: llc < %s -mtriple=i386-unknown-linux-gnu -fdata-sections | FileCheck %s -check-prefix=LINUX-SECTIONS
; RUN: llc < %s -mtriple=i686-pc-win32 -ffunction-sections | FileCheck %s -check-prefix=WIN32-SECTIONS
; RUN: llc < %s -mtriple=i686-pc-win32 -fdata-sections -ffunction-sections | FileCheck %s -check-prefix=WIN32-SECTIONS
define void @F1() {
ret void
}
; WIN32-SECTIONS: .section .text,"xr",one_only,_F1
; WIN32-SECTIONS: .globl _F1
; int G1;
@G1 = common global i32 0
@ -42,6 +48,9 @@
; LINUX-SECTIONS: .section .rodata.G3,"a",@progbits
; LINUX-SECTIONS: .globl G3
; WIN32-SECTIONS: .section .rdata,"r",one_only,_G3
; WIN32-SECTIONS: .globl _G3
; _Complex long long const G4 = 34;
@G4 = unnamed_addr constant {i64,i64} { i64 34, i64 0 }
@ -118,6 +127,9 @@
; LINUX-SECTIONS: .section .rodata.G7,"aMS",@progbits,1
; LINUX-SECTIONS: .globl G7
; WIN32-SECTIONS: .section .rdata,"r",one_only,_G7
; WIN32-SECTIONS: .globl _G7
@G8 = unnamed_addr constant [4 x i16] [ i16 1, i16 2, i16 3, i16 0 ]
@ -178,9 +190,7 @@
; LINUX-SECTIONS: .asciz "foo"
; LINUX-SECTIONS: .size .LG14, 4
define void @G15() {
ret void
}
; WIN32-SECTIONS: .section .rdata,"r"
; WIN32-SECTIONS: L_G14:
; WIN32-SECTIONS: .asciz "foo"
; WIN32-SECTIONS: .section .text,"xr",one_only,_G15
; WIN32-SECTIONS: .globl _G15