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Bring back r323297.
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It was reverted because it broke the grub build. The reason the grub
build broke is because grub does its own relocation processing and was
not handing R_386_PLT32. Since grub has no dynamic linker, the fix is
trivial: handle R_386_PLT32 exactly like R_386_PC32.

On the report it was noted that they are using
-fno-integrated-assembler. The upstream GAS (starting with
451875b4f976a527395e9303224c7881b65e12ed) will already be producing a
R_386_PLT32 anyway, so they have to update their code one way or the
other

Original message:

Don't assume a null GV is local for ELF and MachO.

This is already a simplification, and should help with avoiding a plt
reference when calling an intrinsic with -fno-plt.

With this change we return false for null GVs, so the caller only
needs to check the new metadata to decide if it should use foo@plt or
*foo@got.

llvm-svn: 325514
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@espindola
espindola committed Feb 19, 2018
1 parent 9c5ac63 commit c7e5180
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Showing 7 changed files with 34 additions and 27 deletions.
21 changes: 14 additions & 7 deletions llvm/lib/Target/TargetMachine.cpp
View file
Expand Up @@ -137,20 +137,27 @@ bool TargetMachine::shouldAssumeDSOLocal(const Module &M,
if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
return true;

// If GV is null we know that this is a call to an intrinsic. For ELF and
// MachO we don't need to assume those are local since the liker can trivially
// convert a call to a PLT to a direct call if the target (in the runtime
// library) turns out to be local.
if (!GV)
return false;

// Most PIC code sequences that assume that a symbol is local cannot
// produce a 0 if it turns out the symbol is undefined. While this
// is ABI and relocation depended, it seems worth it to handle it
// here.
if (GV && isPositionIndependent() && GV->hasExternalWeakLinkage())
if (isPositionIndependent() && GV->hasExternalWeakLinkage())
return false;

if (GV && !GV->hasDefaultVisibility())
if (!GV->hasDefaultVisibility())
return true;

if (TT.isOSBinFormatMachO()) {
if (RM == Reloc::Static)
return true;
return GV && GV->isStrongDefinitionForLinker();
return GV->isStrongDefinitionForLinker();
}

assert(TT.isOSBinFormatELF());
Expand All @@ -160,19 +167,19 @@ bool TargetMachine::shouldAssumeDSOLocal(const Module &M,
RM == Reloc::Static || M.getPIELevel() != PIELevel::Default;
if (IsExecutable) {
// If the symbol is defined, it cannot be preempted.
if (GV && !GV->isDeclarationForLinker())
if (!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);
const Function *F = dyn_cast<Function>(GV);
if (F && F->hasFnAttribute(Attribute::NonLazyBind))
return false;

bool IsTLS = GV && GV->isThreadLocal();
bool IsTLS = GV->isThreadLocal();
bool IsAccessViaCopyRelocs =
Options.MCOptions.MCPIECopyRelocations && GV && isa<GlobalVariable>(GV);
Options.MCOptions.MCPIECopyRelocations && isa<GlobalVariable>(GV);
Triple::ArchType Arch = TT.getArch();
bool IsPPC =
Arch == Triple::ppc || Arch == Triple::ppc64 || Arch == Triple::ppc64le;
Expand Down
24 changes: 12 additions & 12 deletions llvm/test/CodeGen/X86/finite-libcalls.ll
View file
Expand Up @@ -9,7 +9,7 @@
define float @exp_f32(float %x) #0 {
; GNU-LABEL: exp_f32:
; GNU: # %bb.0:
; GNU-NEXT: jmp __expf_finite # TAILCALL
; GNU-NEXT: jmp __expf_finite@PLT # TAILCALL
;
; WIN-LABEL: exp_f32:
; WIN: # %bb.0:
Expand All @@ -25,7 +25,7 @@ define float @exp_f32(float %x) #0 {
define double @exp_f64(double %x) #0 {
; GNU-LABEL: exp_f64:
; GNU: # %bb.0:
; GNU-NEXT: jmp __exp_finite # TAILCALL
; GNU-NEXT: jmp __exp_finite@PLT # TAILCALL
;
; WIN-LABEL: exp_f64:
; WIN: # %bb.0:
Expand Down Expand Up @@ -72,7 +72,7 @@ define x86_fp80 @exp_f80(x86_fp80 %x) #0 {
define float @exp2_f32(float %x) #0 {
; GNU-LABEL: exp2_f32:
; GNU: # %bb.0:
; GNU-NEXT: jmp __exp2f_finite # TAILCALL
; GNU-NEXT: jmp __exp2f_finite@PLT # TAILCALL
;
; WIN-LABEL: exp2_f32:
; WIN: # %bb.0:
Expand All @@ -88,7 +88,7 @@ define float @exp2_f32(float %x) #0 {
define double @exp2_f64(double %x) #0 {
; GNU-LABEL: exp2_f64:
; GNU: # %bb.0:
; GNU-NEXT: jmp __exp2_finite # TAILCALL
; GNU-NEXT: jmp __exp2_finite@PLT # TAILCALL
;
; WIN-LABEL: exp2_f64:
; WIN: # %bb.0:
Expand Down Expand Up @@ -135,7 +135,7 @@ define x86_fp80 @exp2_f80(x86_fp80 %x) #0 {
define float @log_f32(float %x) #0 {
; GNU-LABEL: log_f32:
; GNU: # %bb.0:
; GNU-NEXT: jmp __logf_finite # TAILCALL
; GNU-NEXT: jmp __logf_finite@PLT # TAILCALL
;
; WIN-LABEL: log_f32:
; WIN: # %bb.0:
Expand All @@ -151,7 +151,7 @@ define float @log_f32(float %x) #0 {
define double @log_f64(double %x) #0 {
; GNU-LABEL: log_f64:
; GNU: # %bb.0:
; GNU-NEXT: jmp __log_finite # TAILCALL
; GNU-NEXT: jmp __log_finite@PLT # TAILCALL
;
; WIN-LABEL: log_f64:
; WIN: # %bb.0:
Expand Down Expand Up @@ -198,7 +198,7 @@ define x86_fp80 @log_f80(x86_fp80 %x) #0 {
define float @log2_f32(float %x) #0 {
; GNU-LABEL: log2_f32:
; GNU: # %bb.0:
; GNU-NEXT: jmp __log2f_finite # TAILCALL
; GNU-NEXT: jmp __log2f_finite@PLT # TAILCALL
;
; WIN-LABEL: log2_f32:
; WIN: # %bb.0:
Expand All @@ -214,7 +214,7 @@ define float @log2_f32(float %x) #0 {
define double @log2_f64(double %x) #0 {
; GNU-LABEL: log2_f64:
; GNU: # %bb.0:
; GNU-NEXT: jmp __log2_finite # TAILCALL
; GNU-NEXT: jmp __log2_finite@PLT # TAILCALL
;
; WIN-LABEL: log2_f64:
; WIN: # %bb.0:
Expand Down Expand Up @@ -261,7 +261,7 @@ define x86_fp80 @log2_f80(x86_fp80 %x) #0 {
define float @log10_f32(float %x) #0 {
; GNU-LABEL: log10_f32:
; GNU: # %bb.0:
; GNU-NEXT: jmp __log10f_finite # TAILCALL
; GNU-NEXT: jmp __log10f_finite@PLT # TAILCALL
;
; WIN-LABEL: log10_f32:
; WIN: # %bb.0:
Expand All @@ -277,7 +277,7 @@ define float @log10_f32(float %x) #0 {
define double @log10_f64(double %x) #0 {
; GNU-LABEL: log10_f64:
; GNU: # %bb.0:
; GNU-NEXT: jmp __log10_finite # TAILCALL
; GNU-NEXT: jmp __log10_finite@PLT # TAILCALL
;
; WIN-LABEL: log10_f64:
; WIN: # %bb.0:
Expand Down Expand Up @@ -325,7 +325,7 @@ define float @pow_f32(float %x) #0 {
; GNU-LABEL: pow_f32:
; GNU: # %bb.0:
; GNU-NEXT: movaps %xmm0, %xmm1
; GNU-NEXT: jmp __powf_finite # TAILCALL
; GNU-NEXT: jmp __powf_finite@PLT # TAILCALL
;
; WIN-LABEL: pow_f32:
; WIN: # %bb.0:
Expand All @@ -344,7 +344,7 @@ define double @pow_f64(double %x) #0 {
; GNU-LABEL: pow_f64:
; GNU: # %bb.0:
; GNU-NEXT: movaps %xmm0, %xmm1
; GNU-NEXT: jmp __pow_finite # TAILCALL
; GNU-NEXT: jmp __pow_finite@PLT # TAILCALL
;
; WIN-LABEL: pow_f64:
; WIN: # %bb.0:
Expand Down
4 changes: 2 additions & 2 deletions llvm/test/CodeGen/X86/fp-intrinsics.ll
View file
Expand Up @@ -245,7 +245,7 @@ entry:
; Verify that fma(3.5) isn't simplified when the rounding mode is
; unknown.
; CHECK-LABEL: f17
; FMACALL32: jmp fmaf # TAILCALL
; FMACALL32: jmp fmaf@PLT # TAILCALL
; FMA32: vfmadd213ss
define float @f17() {
entry:
Expand All @@ -261,7 +261,7 @@ entry:
; Verify that fma(42.1) isn't simplified when the rounding mode is
; unknown.
; CHECK-LABEL: f18
; FMACALL64: jmp fma # TAILCALL
; FMACALL64: jmp fma@PLT # TAILCALL
; FMA64: vfmadd213sd
define double @f18() {
entry:
Expand Down
2 changes: 1 addition & 1 deletion llvm/test/CodeGen/X86/half.ll
View file
Expand Up @@ -75,7 +75,7 @@ define float @test_extend32(half* %addr) #0 {
; CHECK-LIBCALL-LABEL: test_extend32:
; CHECK-LIBCALL: # %bb.0:
; CHECK-LIBCALL-NEXT: movzwl (%rdi), %edi
; CHECK-LIBCALL-NEXT: jmp __gnu_h2f_ieee # TAILCALL
; CHECK-LIBCALL-NEXT: jmp __gnu_h2f_ieee@PLT # TAILCALL
;
; BWON-F16C-LABEL: test_extend32:
; BWON-F16C: # %bb.0:
Expand Down
2 changes: 1 addition & 1 deletion llvm/test/CodeGen/X86/memset-nonzero.ll
View file
Expand Up @@ -394,7 +394,7 @@ define void @memset_256_nonconst_bytes(i8* %x, i8 %c) {
; SSE-LABEL: memset_256_nonconst_bytes:
; SSE: # %bb.0:
; SSE-NEXT: movl $256, %edx # imm = 0x100
; SSE-NEXT: jmp memset # TAILCALL
; SSE-NEXT: jmp memset@PLT # TAILCALL
;
; SSE2FAST-LABEL: memset_256_nonconst_bytes:
; SSE2FAST: # %bb.0:
Expand Down
6 changes: 3 additions & 3 deletions llvm/test/CodeGen/X86/negative-sin.ll
View file
Expand Up @@ -28,7 +28,7 @@ define double @strict(double %e) nounwind {
define double @fast(double %e) nounwind {
; CHECK-LABEL: fast:
; CHECK: # %bb.0:
; CHECK-NEXT: jmp sin # TAILCALL
; CHECK-NEXT: jmp sin@PLT # TAILCALL
%f = fsub fast double 0.0, %e
%g = call double @sin(double %f) readonly
%h = fsub fast double 0.0, %g
Expand All @@ -40,7 +40,7 @@ define double @fast(double %e) nounwind {
define double @nsz(double %e) nounwind {
; CHECK-LABEL: nsz:
; CHECK: # %bb.0:
; CHECK-NEXT: jmp sin # TAILCALL
; CHECK-NEXT: jmp sin@PLT # TAILCALL
%f = fsub nsz double 0.0, %e
%g = call double @sin(double %f) readonly
%h = fsub nsz double 0.0, %g
Expand Down Expand Up @@ -88,7 +88,7 @@ define double @semi_strict2(double %e) nounwind {
define double @fn_attr(double %e) nounwind #0 {
; CHECK-LABEL: fn_attr:
; CHECK: # %bb.0:
; CHECK-NEXT: jmp sin # TAILCALL
; CHECK-NEXT: jmp sin@PLT # TAILCALL
%f = fsub double 0.0, %e
%g = call double @sin(double %f) readonly
%h = fsub double 0.0, %g
Expand Down
2 changes: 1 addition & 1 deletion llvm/test/CodeGen/X86/vector-half-conversions.ll
View file
Expand Up @@ -2953,7 +2953,7 @@ define void @store_cvt_16f32_to_16i16(<16 x float> %a0, <16 x i16>* %a1) nounwin
define i16 @cvt_f64_to_i16(double %a0) nounwind {
; ALL-LABEL: cvt_f64_to_i16:
; ALL: # %bb.0:
; ALL-NEXT: jmp __truncdfhf2 # TAILCALL
; ALL-NEXT: jmp __truncdfhf2@PLT # TAILCALL
%1 = fptrunc double %a0 to half
%2 = bitcast half %1 to i16
ret i16 %2
Expand Down

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