[MC] Use LShr for constant evaluation of ">>" on ELF/arm64--darwin.

This matches other assemblers and is less unexpected (e.g. PR23227).
On ELF, I tried binutils gas v2.24 and nasm 2.10.09, and they both
agree on LShr.  On COFF, I couldn't get my hands on an assembler yet,
so don't change the behavior.  For now, don't change it on non-AArch64
Darwin either, as the other assembler is gas v1.38, which does an AShr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235963 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Ahmed Bougacha 2015-04-28 01:37:11 +00:00
parent fef483667f
commit e1f835ab59
8 changed files with 37 additions and 3 deletions

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@ -90,7 +90,7 @@ MCAsmInfo::MCAsmInfo() {
DwarfRegNumForCFI = false;
NeedsDwarfSectionOffsetDirective = false;
UseParensForSymbolVariant = false;
UseLogicalShr = false;
UseLogicalShr = true;
// FIXME: Clang's logic should be synced with the logic used to initialize
// this member and the two implementations should be merged.

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@ -36,6 +36,10 @@ MCAsmInfoCOFF::MCAsmInfoCOFF() {
NeedsDwarfSectionOffsetDirective = true;
UseIntegratedAssembler = true;
// FIXME: For now keep the previous behavior, AShr. Need to double-check
// other COFF-targeting assemblers and change this if necessary.
UseLogicalShr = false;
}
void MCAsmInfoMicrosoft::anchor() { }

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@ -93,4 +93,9 @@ MCAsmInfoDarwin::MCAsmInfoDarwin() {
UseIntegratedAssembler = true;
SetDirectiveSuppressesReloc = true;
// FIXME: For now keep the previous behavior, AShr, matching the previous
// behavior of as(1) (both -q and -Q: resp. LLVM and gas v1.38).
// If/when this changes, the AArch64 Darwin special case can go away.
UseLogicalShr = false;
}

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@ -48,6 +48,10 @@ AArch64MCAsmInfoDarwin::AArch64MCAsmInfoDarwin() {
UseDataRegionDirectives = true;
ExceptionsType = ExceptionHandling::DwarfCFI;
// AArch64 Darwin doesn't have the baggage of X86/ARM, so it's fine to use
// LShr instead of AShr.
UseLogicalShr = true;
}
const MCExpr *AArch64MCAsmInfoDarwin::getExprForPersonalitySymbol(

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@ -0,0 +1,8 @@
// RUN: llvm-mc -triple aarch64-unknown-unknown-elf %s | FileCheck %s --check-prefix=ELF
// RUN: llvm-mc -triple aarch64-unknown-darwin %s | FileCheck %s --check-prefix=DARWIN
.data
// ELF: .xword 3
// DARWIN: .quad 3
.quad (~0 >> 62)

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@ -1,7 +1,7 @@
// RUN: llvm-mc -triple arm-unknown-linux %s | FileCheck %s
// CHECK: .byte 1
.if [~0 >> 1] == -1
.if [~0 >> 63] == 1
.byte 1
.else
.byte 2

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@ -0,0 +1,13 @@
// RUN: llvm-mc -triple x86_64-unknown-unknown-elf %s | FileCheck %s --check-prefix=CHECK
// RUN: llvm-mc -triple x86_64-pc-windows-msvc %s | FileCheck %s --check-prefix=MSVC
// RUN: llvm-mc -triple x86_64-unknown-darwin %s | FileCheck %s --check-prefix=DARWIN
.data
// CHECK: .quad 3
// Both COFF and Darwin still use AShr.
// MSVC: .quad -1
// DARWIN: .quad -1
.quad (~0 >> 62)

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@ -1,7 +1,7 @@
// RUN: llvm-mc -triple i386-unknown-unknown %s | FileCheck %s
// CHECK: .byte 1
.if [~0 >> 1] == -1
.if [~0 >> 63] == 1
.byte 1
.else
.byte 2