[llvm] r268106 - Differential Revision: http://reviews.llvm.org/D19733

Thu May 5 07:30:38 PDT 2016

Ping.

Do you expect LTO to set this flag? I find it a pretty nice feature
that currently we can just build everything with -flto -fPIC but get
better codegen if LTO detects that we are producing an executable.

Cheers,
Rafael

On 29 April 2016 at 17:30, Rafael Espíndola <rafael.espindola at gmail.com> wrote:
> How should LTO handle this?
>
> This is of interest to me when bootstrapping clang. We build
> everything with -fPIC, but the linker knows it is producing a PIE,
> position dependent executable or shared library.
>
> Right now the gold plugin and lld just pass that information down to
> codegen. Should them be mutating the merged module before codegen too?
>
> Cheers,
> Rafael
>
>
>
>
> On 29 April 2016 at 17:19, Sriraman Tallam via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
>> Author: tmsriram
>> Date: Fri Apr 29 16:19:16 2016
>> New Revision: 268106
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=268106&view=rev
>> Log:
>> Differential Revision: http://reviews.llvm.org/D19733
>>
>> Modified:
>>     llvm/trunk/include/llvm/CodeGen/CommandFlags.h
>>     llvm/trunk/lib/Target/TargetMachine.cpp
>>     llvm/trunk/lib/Target/X86/X86Subtarget.cpp
>>     llvm/trunk/lib/Target/X86/X86Subtarget.h
>>     llvm/trunk/test/CodeGen/X86/emutls-pie.ll
>>     llvm/trunk/test/CodeGen/X86/global-access-pie.ll
>>     llvm/trunk/test/CodeGen/X86/pie.ll
>>     llvm/trunk/test/CodeGen/X86/tls-pie.ll
>>
>> Modified: llvm/trunk/include/llvm/CodeGen/CommandFlags.h
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/CommandFlags.h?rev=268106&r1=268105&r2=268106&view=diff
>> ==============================================================================
>> --- llvm/trunk/include/llvm/CodeGen/CommandFlags.h (original)
>> +++ llvm/trunk/include/llvm/CodeGen/CommandFlags.h Fri Apr 29 16:19:16 2016
>> @@ -198,11 +198,6 @@ TrapFuncName("trap-func", cl::Hidden,
>>          cl::init(""));
>>
>>  cl::opt<bool>
>> -EnablePIE("enable-pie",
>> -          cl::desc("Assume the creation of a position independent executable."),
>> -          cl::init(false));
>> -
>> -cl::opt<bool>
>>  UseCtors("use-ctors",
>>               cl::desc("Use .ctors instead of .init_array."),
>>               cl::init(false));
>> @@ -290,7 +285,6 @@ static inline TargetOptions InitTargetOp
>>    Options.GuaranteedTailCallOpt = EnableGuaranteedTailCallOpt;
>>    Options.StackAlignmentOverride = OverrideStackAlignment;
>>    Options.StackSymbolOrdering = StackSymbolOrdering;
>> -  Options.PositionIndependentExecutable = EnablePIE;
>>    Options.UseInitArray = !UseCtors;
>>    Options.DataSections = DataSections;
>>    Options.FunctionSections = FunctionSections;
>>
>> Modified: llvm/trunk/lib/Target/TargetMachine.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/TargetMachine.cpp?rev=268106&r1=268105&r2=268106&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/Target/TargetMachine.cpp (original)
>> +++ llvm/trunk/lib/Target/TargetMachine.cpp Fri Apr 29 16:19:16 2016
>> @@ -109,7 +109,7 @@ TLSModel::Model TargetMachine::getTLSMod
>>    bool isLocal = GV->hasLocalLinkage();
>>    bool isDeclaration = GV->isDeclaration();
>>    bool isPIC = getRelocationModel() == Reloc::PIC_;
>> -  bool isPIE = Options.PositionIndependentExecutable;
>> +  bool isPIE = GV->getParent()->getPIELevel() != PIELevel::Default;
>>    // FIXME: what should we do for protected and internal visibility?
>>    // For variables, is internal different from hidden?
>>    bool isHidden = GV->hasHiddenVisibility();
>>
>> Modified: llvm/trunk/lib/Target/X86/X86Subtarget.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86Subtarget.cpp?rev=268106&r1=268105&r2=268106&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/Target/X86/X86Subtarget.cpp (original)
>> +++ llvm/trunk/lib/Target/X86/X86Subtarget.cpp Fri Apr 29 16:19:16 2016
>> @@ -159,8 +159,7 @@ unsigned char X86Subtarget::classifyGlob
>>    // we don't need to use the PLT - we can directly call it.
>>    // In PIE mode, calls to global functions don't need to go through PLT
>>    if (isTargetELF() && TM.getRelocationModel() == Reloc::PIC_ &&
>> -      (!TM.Options.PositionIndependentExecutable ||
>> -       GV->isDeclarationForLinker()) &&
>> +      !isGlobalDefinedInPIE(GV, TM) &&
>>        GV->hasDefaultVisibility() && !GV->hasLocalLinkage()) {
>>      return X86II::MO_PLT;
>>    } else if (isPICStyleStubAny() && !GV->isStrongDefinitionForLinker() &&
>>
>> Modified: llvm/trunk/lib/Target/X86/X86Subtarget.h
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86Subtarget.h?rev=268106&r1=268105&r2=268106&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/Target/X86/X86Subtarget.h (original)
>> +++ llvm/trunk/lib/Target/X86/X86Subtarget.h Fri Apr 29 16:19:16 2016
>> @@ -552,7 +552,7 @@ public:
>>    /// Executable (PIE) where its definition cannot be interposed.
>>    bool isGlobalDefinedInPIE(const GlobalValue *GV,
>>                              const TargetMachine &TM) const {
>> -    return TM.Options.PositionIndependentExecutable &&
>> +    return GV->getParent()->getPIELevel() != PIELevel::Default &&
>>             !GV->isDeclarationForLinker();
>>    }
>>
>>
>> Modified: llvm/trunk/test/CodeGen/X86/emutls-pie.ll
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/emutls-pie.ll?rev=268106&r1=268105&r2=268106&view=diff
>> ==============================================================================
>> --- llvm/trunk/test/CodeGen/X86/emutls-pie.ll (original)
>> +++ llvm/trunk/test/CodeGen/X86/emutls-pie.ll Fri Apr 29 16:19:16 2016
>> @@ -1,10 +1,10 @@
>> -; RUN: llc < %s -emulated-tls -march=x86 -mcpu=generic -mtriple=i386-linux-gnu -relocation-model=pic -enable-pie \
>> +; RUN: llc < %s -emulated-tls -march=x86 -mcpu=generic -mtriple=i386-linux-gnu -relocation-model=pic \
>>  ; RUN:   | FileCheck -check-prefix=X32 %s
>> -; RUN: llc < %s -emulated-tls -march=x86-64 -mcpu=generic -mtriple=x86_64-linux-gnu -relocation-model=pic -enable-pie \
>> +; RUN: llc < %s -emulated-tls -march=x86-64 -mcpu=generic -mtriple=x86_64-linux-gnu -relocation-model=pic \
>>  ; RUN:   | FileCheck -check-prefix=X64 %s
>> -; RUN: llc < %s -emulated-tls -march=x86 -mcpu=generic -mtriple=i386-linux-android -relocation-model=pic -enable-pie \
>> +; RUN: llc < %s -emulated-tls -march=x86 -mcpu=generic -mtriple=i386-linux-android -relocation-model=pic \
>>  ; RUN:   | FileCheck -check-prefix=X32 %s
>> -; RUN: llc < %s -emulated-tls -march=x86-64 -mcpu=generic -mtriple=x86_64-linux-android -relocation-model=pic -enable-pie \
>> +; RUN: llc < %s -emulated-tls -march=x86-64 -mcpu=generic -mtriple=x86_64-linux-android -relocation-model=pic \
>>  ; RUN:   | FileCheck -check-prefix=X64 %s
>>
>>  ; Use my_emutls_get_address like __emutls_get_address.
>> @@ -129,3 +129,8 @@ entry:
>>
>>  ; X64-NOT:   __emutls_v.i2
>>  ; X64-NOT:   __emutls_t.i2
>> +
>> +
>> +!llvm.module.flags = !{!0, !1}
>> +!0 = !{i32 1, !"PIC Level", i32 1}
>> +!1 = !{i32 1, !"PIE Level", i32 1}
>>
>> Modified: llvm/trunk/test/CodeGen/X86/global-access-pie.ll
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/global-access-pie.ll?rev=268106&r1=268105&r2=268106&view=diff
>> ==============================================================================
>> --- llvm/trunk/test/CodeGen/X86/global-access-pie.ll (original)
>> +++ llvm/trunk/test/CodeGen/X86/global-access-pie.ll Fri Apr 29 16:19:16 2016
>> @@ -1,6 +1,6 @@
>> -; RUN: llc < %s -march=x86-64 -mcpu=generic -mtriple=x86_64-linux-gnu -relocation-model=pic -enable-pie \
>> +; RUN: llc < %s -march=x86-64 -mcpu=generic -mtriple=x86_64-linux-gnu -relocation-model=pic \
>>  ; RUN:   | FileCheck -check-prefix=X64 %s
>> -; RUN: llc < %s -emulated-tls -march=x86 -mcpu=generic -mtriple=i386-linux-gnu -relocation-model=pic -enable-pie \
>> +; RUN: llc < %s -emulated-tls -march=x86 -mcpu=generic -mtriple=i386-linux-gnu -relocation-model=pic \
>>  ; RUN:   | FileCheck -check-prefix=X32 %s
>>
>>  ; External Linkage
>> @@ -117,3 +117,7 @@ entry:
>>    %call = call i32 @access_fp(i32 ()* @bar)
>>    ret i32 %call
>>  }
>> +
>> +!llvm.module.flags = !{!0, !1}
>> +!0 = !{i32 1, !"PIC Level", i32 1}
>> +!1 = !{i32 1, !"PIE Level", i32 1}
>>
>> Modified: llvm/trunk/test/CodeGen/X86/pie.ll
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pie.ll?rev=268106&r1=268105&r2=268106&view=diff
>> ==============================================================================
>> --- llvm/trunk/test/CodeGen/X86/pie.ll (original)
>> +++ llvm/trunk/test/CodeGen/X86/pie.ll Fri Apr 29 16:19:16 2016
>> @@ -1,7 +1,7 @@
>> -; RUN: llc < %s -O0 -mcpu=generic -mtriple=i686-linux-gnu -relocation-model=pic -enable-pie | FileCheck %s
>> -; RUN: llc < %s -O0 -mcpu=generic -mtriple=i686-linux-gnu -fast-isel -relocation-model=pic -enable-pie | FileCheck %s
>> -; RUN: llc < %s -O0 -mcpu=generic -mtriple=x86_64-linux-gnu -relocation-model=pic -enable-pie | FileCheck %s
>> -; RUN: llc < %s -O0 -mcpu=generic -mtriple=x86_64-linux-gnu -fast-isel -relocation-model=pic -enable-pie | FileCheck %s
>> +; RUN: llc < %s -O0 -mcpu=generic -mtriple=i686-linux-gnu -relocation-model=pic | FileCheck %s
>> +; RUN: llc < %s -O0 -mcpu=generic -mtriple=i686-linux-gnu -fast-isel -relocation-model=pic | FileCheck %s
>> +; RUN: llc < %s -O0 -mcpu=generic -mtriple=x86_64-linux-gnu -relocation-model=pic | FileCheck %s
>> +; RUN: llc < %s -O0 -mcpu=generic -mtriple=x86_64-linux-gnu -fast-isel -relocation-model=pic | FileCheck %s
>>
>>  ; CHECK-LABEL:  bar:
>>  ; CHECK:  call{{l|q}}  foo{{$}}
>> @@ -39,3 +39,7 @@ entry:
>>  }
>>
>>  ; -fpie for local global data tests should be added here
>> +
>> +!llvm.module.flags = !{!0, !1}
>> +!0 = !{i32 1, !"PIC Level", i32 1}
>> +!1 = !{i32 1, !"PIE Level", i32 1}
>>
>> Modified: llvm/trunk/test/CodeGen/X86/tls-pie.ll
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/tls-pie.ll?rev=268106&r1=268105&r2=268106&view=diff
>> ==============================================================================
>> --- llvm/trunk/test/CodeGen/X86/tls-pie.ll (original)
>> +++ llvm/trunk/test/CodeGen/X86/tls-pie.ll Fri Apr 29 16:19:16 2016
>> @@ -1,6 +1,6 @@
>> -; RUN: llc < %s -march=x86 -mcpu=generic -mtriple=i386-linux-gnu -relocation-model=pic -enable-pie \
>> +; RUN: llc < %s -march=x86 -mcpu=generic -mtriple=i386-linux-gnu -relocation-model=pic \
>>  ; RUN:   | FileCheck -check-prefix=X32 %s
>> -; RUN: llc < %s -march=x86-64 -mcpu=generic -mtriple=x86_64-linux-gnu -relocation-model=pic -enable-pie \
>> +; RUN: llc < %s -march=x86-64 -mcpu=generic -mtriple=x86_64-linux-gnu -relocation-model=pic \
>>  ; RUN:   | FileCheck -check-prefix=X64 %s
>>
>>  @i = thread_local global i32 15
>> @@ -79,3 +79,7 @@ define i32* @f4() {
>>  entry:
>>         ret i32* @i2
>>  }
>> +
>> +!llvm.module.flags = !{!0, !1}
>> +!0 = !{i32 1, !"PIC Level", i32 1}
>> +!1 = !{i32 1, !"PIE Level", i32 1}
>>
>>
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits