From 43ac721e3b35341e7cf59d5982ad702ca8d27433 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 13 Apr 2010 00:36:43 +0000 Subject: [PATCH] add llvm codegen support for -ffunction-sections and -fdata-sections, patch by Sylvere Teissier! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101106 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Target/TargetMachine.h | 15 ++++++++ lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 38 ++++++++++++++++++-- lib/Target/TargetMachine.cpp | 25 ++++++++++++- test/CodeGen/X86/global-sections.ll | 10 ++++++ 4 files changed, 85 insertions(+), 3 deletions(-) diff --git a/include/llvm/Target/TargetMachine.h b/include/llvm/Target/TargetMachine.h index d1d665f870f..6697b73f49f 100644 --- a/include/llvm/Target/TargetMachine.h +++ b/include/llvm/Target/TargetMachine.h @@ -171,6 +171,21 @@ public: /// is false. static void setAsmVerbosityDefault(bool); + /// getDataSections - Return true if data objects should be emitted into their + /// own section, corresponds to -fdata-sections. + static bool getDataSections(); + + /// getFunctionSections - Return true if functions should be emitted into + /// their own section, corresponding to -ffunction-sections. + static bool getFunctionSections(); + + /// setDataSections - Set if the data are emit into separate sections. + static void setDataSections(bool); + + /// setFunctionSections - Set if the functions are emit into separate + /// sections. + static void setFunctionSections(bool); + /// CodeGenFileType - These enums are meant to be passed into /// addPassesToEmitFile to indicate what type of file to emit, and returned by /// it to indicate what type of file could actually be made. diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp index dc08cadaaa9..9f959932e6d 100644 --- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp +++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp @@ -279,14 +279,48 @@ static const char *getSectionPrefixForUniqueGlobal(SectionKind Kind) { return ".gnu.linkonce.d.rel.ro."; } +/// getSectionPrefixForGlobal - Return the section prefix name used by options +/// FunctionsSections and DataSections. +static const char *getSectionPrefixForGlobal(SectionKind Kind) { + if (Kind.isText()) return ".text."; + if (Kind.isReadOnly()) return ".rodata."; + + if (Kind.isThreadData()) return ".tdata."; + if (Kind.isThreadBSS()) return ".tbss."; + + if (Kind.isDataNoRel()) return ".data."; + if (Kind.isDataRelLocal()) return ".data.rel.local."; + if (Kind.isDataRel()) return ".data.rel."; + if (Kind.isReadOnlyWithRelLocal()) return ".data.rel.ro.local."; + + assert(Kind.isReadOnlyWithRel() && "Unknown section kind"); + return ".data.rel.ro."; +} + + const MCSection *TargetLoweringObjectFileELF:: SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, Mangler *Mang, const TargetMachine &TM) const { + // If we have -ffunction-section or -fdata-section then we should emit the + // global value to a uniqued section specifically for it. + 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() && !Kind.isCommon() && !Kind.isBSS()) { - const char *Prefix = getSectionPrefixForUniqueGlobal(Kind); + if ((GV->isWeakForLinker() || EmitUniquedSection) && + !Kind.isCommon() && !Kind.isBSS()) { + const char *Prefix; + if (GV->isWeakForLinker()) + Prefix = getSectionPrefixForUniqueGlobal(Kind); + else { + assert(EmitUniquedSection); + Prefix = getSectionPrefixForGlobal(Kind); + } + SmallString<128> Name(Prefix, Prefix+strlen(Prefix)); MCSymbol *Sym = Mang->getSymbol(GV); Name.append(Sym->getName().begin(), Sym->getName().end()); diff --git a/lib/Target/TargetMachine.cpp b/lib/Target/TargetMachine.cpp index 88871e3580c..871b148adb3 100644 --- a/lib/Target/TargetMachine.cpp +++ b/lib/Target/TargetMachine.cpp @@ -197,7 +197,14 @@ EnableStrongPHIElim(cl::Hidden, "strong-phi-elim", cl::desc("Use strong PHI elimination."), cl::location(StrongPHIElim), cl::init(false)); - +static cl::opt +DataSections("fdata-sections", + cl::desc("Emit data into separate sections"), + cl::init(false)); +static cl::opt +FunctionSections("ffunction-sections", + cl::desc("Emit functions into separate sections"), + cl::init(false)); //--------------------------------------------------------------------------- // TargetMachine Class // @@ -244,6 +251,22 @@ void TargetMachine::setAsmVerbosityDefault(bool V) { AsmVerbosityDefault = V; } +bool TargetMachine::getFunctionSections() { + return FunctionSections; +} + +bool TargetMachine::getDataSections() { + return DataSections; +} + +void TargetMachine::setFunctionSections(bool V) { + FunctionSections = V; +} + +void TargetMachine::setDataSections(bool V) { + DataSections = V; +} + namespace llvm { /// LessPreciseFPMAD - This flag return true when -enable-fp-mad option /// is specified on the command line. When this flag is off(default), the diff --git a/test/CodeGen/X86/global-sections.ll b/test/CodeGen/X86/global-sections.ll index d79c56bc463..732d764dbde 100644 --- a/test/CodeGen/X86/global-sections.ll +++ b/test/CodeGen/X86/global-sections.ll @@ -1,5 +1,6 @@ ; RUN: llc < %s -mtriple=i386-unknown-linux-gnu | FileCheck %s -check-prefix=LINUX ; RUN: llc < %s -mtriple=i386-apple-darwin9.7 | FileCheck %s -check-prefix=DARWIN +; RUN: llc < %s -mtriple=i386-unknown-linux-gnu -fdata-sections | FileCheck %s -check-prefix=LINUX-SECTIONS ; int G1; @@ -32,6 +33,12 @@ ; DARWIN: _G3: ; DARWIN: .long _G1 +; LINUX: .section .rodata,"a",@progbits +; LINUX: .globl G3 + +; LINUX-SECTIONS: .section .rodata.G3,"a",@progbits +; LINUX-SECTIONS: .globl G3 + ; _Complex long long const G4 = 34; @G4 = constant {i64,i64} { i64 34, i64 0 } @@ -97,6 +104,9 @@ ; LINUX: G7: ; LINUX: .asciz "abcdefghi" +; LINUX-SECTIONS: .section .rodata.G7,"aMS",@progbits,1 +; LINUX-SECTIONS: .globl G7 + @G8 = constant [4 x i16] [ i16 1, i16 2, i16 3, i16 0 ]