6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-06-30 23:30:28 +00:00
Code Issues Projects Releases Wiki Activity

Put each jump table in an independent section if the function is too.

Browse Source 
This allows the linker to GC both, fixing pr22557.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228937 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rafael Espindola 2015-02-12 17:16:46 +00:00
parent a858be4291
commit 8eeedf74d3
7 changed files with 100 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
View File

@ -56,6 +56,10 @@ public:
SectionKind Kind, Mangler &Mang,
const TargetMachine &TM) const override;
const MCSection *
getSectionForJumpTable(const Function &F, Mangler &Mang,
const TargetMachine &TM) const override;
/// Return an MCExpr to use for a reference to the specified type info global
/// variable from exception handling information.
const MCExpr *

4
include/llvm/Target/TargetLoweringObjectFile.h
View File

@ -94,6 +94,10 @@ public:
return SectionForGlobal(GV, getKindForGlobal(GV, TM), Mang, TM);
}
virtual const MCSection *
getSectionForJumpTable(const Function &F, Mangler &Mang,
const TargetMachine &TM) const;
/// Targets should implement this method to assign a section to globals with
/// an explicit section specfied. The implementation of this method can
/// assume that GV->hasSection() is true.

7
lib/CodeGen/AsmPrinter/AsmPrinter.cpp
View File

@ -1177,6 +1177,7 @@ void AsmPrinter::EmitJumpTableInfo() {
// Pick the directive to use to print the jump table entries, and switch to
// the appropriate section.
const Function *F = MF->getFunction();
const TargetLoweringObjectFile &TLOF = getObjFileLowering();
bool JTInDiffSection = false;
if (// In PIC mode, we need to emit the jump table to the same section as the
// function body itself, otherwise the label differences won't make sense.
@ -1187,13 +1188,11 @@ void AsmPrinter::EmitJumpTableInfo() {
// FIXME: this isn't the right predicate, should be based on the MCSection
// for the function.
F->isWeakForLinker()) {
OutStreamer.SwitchSection(
getObjFileLowering().SectionForGlobal(F, *Mang, TM));
OutStreamer.SwitchSection(TLOF.SectionForGlobal(F, *Mang, TM));
} else {
// Otherwise, drop it in the readonly section.
const MCSection *ReadOnlySection =
getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
/*C=*/nullptr);
TLOF.getSectionForJumpTable(*F, *Mang, TM);
OutStreamer.SwitchSection(ReadOnlySection);
JTInDiffSection = true;
}

22
lib/CodeGen/TargetLoweringObjectFileImpl.cpp
View File

@ -334,6 +334,28 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
return DataRelROSection;
}
const MCSection *TargetLoweringObjectFileELF::getSectionForJumpTable(
const Function &F, Mangler &Mang, const TargetMachine &TM) const {
// If the function can be removed, produce a unique section so that
// the table doesn't prevent the removal.
const Comdat *C = F.getComdat();
bool EmitUniqueSection = TM.getFunctionSections() || C;
if (!EmitUniqueSection)
return ReadOnlySection;
SmallString<128> Name(".rodata.");
TM.getNameWithPrefix(Name, &F, Mang, true);
unsigned Flags = ELF::SHF_ALLOC;
StringRef Group = "";
if (C) {
Flags |= ELF::SHF_GROUP;
Group = C->getName();
}
return getContext().getELFSection(Name, ELF::SHT_PROGBITS, Flags, 0, Group);
}
/// getSectionForConstant - Given a mergeable constant with the
/// specified size and relocation information, return a section that it
/// should be placed in.

5
lib/Target/TargetLoweringObjectFile.cpp
View File

@ -270,6 +270,11 @@ SectionForGlobal(const GlobalValue *GV, SectionKind Kind, Mangler &Mang,
return SelectSectionForGlobal(GV, Kind, Mang, TM);
}
const MCSection *TargetLoweringObjectFile::getSectionForJumpTable(
const Function &F, Mangler &Mang, const TargetMachine &TM) const {
return getSectionForConstant(SectionKind::getReadOnly(), /*C=*/nullptr);
}
/// getSectionForConstant - Given a mergable constant with the
/// specified size and relocation information, return a section that it
/// should be placed in.

33
test/CodeGen/X86/global-sections-comdat.ll
View File

@ -1,5 +1,36 @@
; RUN: llc < %s -mtriple=i386-unknown-linux | FileCheck %s -check-prefix=LINUX
; RUN: llc < %s -mtriple=i386-unknown-linux -data-sections | FileCheck %s -check-prefix=LINUX-SECTIONS
; RUN: llc < %s -mtriple=i386-unknown-linux -data-sections -function-sections | FileCheck %s -check-prefix=LINUX-SECTIONS
$F1 = comdat any
define void @F1(i32 %y) comdat {
bb0:
switch i32 %y, label %bb5 [
i32 1, label %bb1
i32 2, label %bb2
i32 3, label %bb3
i32 4, label %bb4
]
bb1:
ret void
bb2:
ret void
bb3:
ret void
bb4:
ret void
bb5:
ret void
}
; LINUX: .section .text.F1,"axG",@progbits,F1,comdat
; LINUX: .size F1,
; LINUX-NEXT: .cfi_endproc
; LINUX-NEXT: .section .rodata.F1,"aG",@progbits,F1,comdat
; LINUX-SECTIONS: .section .text.F1,"axG",@progbits,F1,comdat
; LINUX-SECTIONS: .size F1,
; LINUX-SECTIONS-NEXT: .cfi_endproc
; LINUX-SECTIONS-NEXT: .section .rodata.F1,"aG",@progbits,F1,comdat
$G16 = comdat any
@G16 = unnamed_addr constant i32 42, comdat

31
test/CodeGen/X86/global-sections.ll
View File

@ -2,7 +2,7 @@
; RUN: llc < %s -mtriple=i386-apple-darwin9.7 | FileCheck %s -check-prefix=DARWIN
; 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 -data-sections | FileCheck %s -check-prefix=LINUX-SECTIONS
; RUN: llc < %s -mtriple=i386-unknown-linux-gnu -data-sections -function-sections | FileCheck %s -check-prefix=LINUX-SECTIONS
; RUN: llc < %s -mtriple=i686-pc-win32 -data-sections -function-sections | FileCheck %s -check-prefix=WIN32-SECTIONS
define void @F1() {
@ -12,6 +12,35 @@ define void @F1() {
; WIN32-SECTIONS: .section .text,"xr",one_only,_F1
; WIN32-SECTIONS: .globl _F1
define void @F2(i32 %y) {
bb0:
switch i32 %y, label %bb5 [
i32 1, label %bb1
i32 2, label %bb2
i32 3, label %bb3
i32 4, label %bb4
]
bb1:
ret void
bb2:
ret void
bb3:
ret void
bb4:
ret void
bb5:
ret void
}
; LINUX: .size F2,
; LINUX-NEX: .cfi_endproc
; LINUX-NEX: .section .rodata,"a",@progbits
; LINUX-SECTIONS: .section .text.F2,"ax",@progbits
; LINUX-SECTIONS: .size F2,
; LINUX-SECTIONS-NEXT: .cfi_endproc
; LINUX-SECTIONS-NEXT: .section .rodata.F2,"a",@progbits
; int G1;
@G1 = common global i32 0