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Attribute nonlazybind should not affect calls to functions with hidden visibility. 

Differential Revision: https://reviews.llvm.org/D39625

llvm-svn: 317639
This commit is contained in:
Sriraman Tallam 2017-11-08 00:01:05 +00:00
parent 0379d3f844
commit 056b3fd6fb
3 changed files with 18 additions and 9 deletions
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7
llvm/lib/Target/TargetMachine.cpp
View File

@ -167,6 +167,13 @@ bool TargetMachine::shouldAssumeDSOLocal(const Module &M,
if (GV && !GV->isDeclarationForLinker())
return true;
// A symbol marked nonlazybind should not be accessed with a plt. If the
// symbol turns out to be external, the linker will convert a direct
// access to an access via the plt, so don't assume it is local.
const Function *F = dyn_cast_or_null<Function>(GV);
if (F && F->hasFnAttribute(Attribute::NonLazyBind))
return false;
bool IsTLS = GV && GV->isThreadLocal();
bool IsAccessViaCopyRelocs =
Options.MCOptions.MCPIECopyRelocations && GV && isa<GlobalVariable>(GV);

13
llvm/lib/Target/X86/X86Subtarget.cpp
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@ -144,15 +144,6 @@ X86Subtarget::classifyGlobalFunctionReference(const GlobalValue *GV) const {
unsigned char
X86Subtarget::classifyGlobalFunctionReference(const GlobalValue *GV,
const Module &M) const {
const Function *F = dyn_cast_or_null<Function>(GV);
// Do not use the PLT when explicitly told to do so for ELF 64-bit
// target.
if (isTargetELF() && is64Bit() && F &&
F->hasFnAttribute(Attribute::NonLazyBind) &&
GV->isDeclarationForLinker())
return X86II::MO_GOTPCREL;
if (TM.shouldAssumeDSOLocal(M, GV))
return X86II::MO_NO_FLAG;
@ -162,12 +153,16 @@ X86Subtarget::classifyGlobalFunctionReference(const GlobalValue *GV,
return X86II::MO_DLLIMPORT;
}
const Function *F = dyn_cast_or_null<Function>(GV);
if (isTargetELF()) {
if (is64Bit() && F && (CallingConv::X86_RegCall == F->getCallingConv()))
// According to psABI, PLT stub clobbers XMM8-XMM15.
// In Regcall calling convention those registers are used for passing
// parameters. Thus we need to prevent lazy binding in Regcall.
return X86II::MO_GOTPCREL;
if (F && F->hasFnAttribute(Attribute::NonLazyBind) && is64Bit())
return X86II::MO_GOTPCREL;
return X86II::MO_PLT;
}

7
llvm/test/CodeGen/X86/no-plt.ll
View File

@ -6,12 +6,14 @@
define i32 @main() #0 {
; X64: callq *_Z3foov@GOTPCREL(%rip)
; X64: callq _Z3barv
; X64: callq _Z3bazv
entry:
%retval = alloca i32, align 4
store i32 0, i32* %retval, align 4
%call1 = call i32 @_Z3foov()
%call2 = call i32 @_Z3barv()
%call3 = call i32 @_Z3bazv()
ret i32 0
}
@ -20,4 +22,9 @@ declare i32 @_Z3foov() #1
declare i32 @_Z3barv() #2
; Function Attrs: nonlazybind
declare hidden i32 @_Z3bazv() #3
attributes #1 = { nonlazybind }
attributes #3 = { nonlazybind }