ARM implement TargetInstrInfo::getNoopForMachoTarget()

Without this hook, functions w/ a completely empty body (including no
epilogue) will cause an MCEmitter assertion failure.

For example,
define internal fastcc void @empty_function() {
  unreachable
}

rdar://10947471

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151673 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2012-02-28 23:53:30 +00:00
parent b62fbc5e46
commit c01810eeb7
9 changed files with 66 additions and 1 deletions

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@ -3003,3 +3003,7 @@ ARMBaseInstrInfo::setExecutionDomain(MachineInstr *MI, unsigned Domain) const {
// This will go before any implicit ops.
AddDefaultPred(MachineInstrBuilder(MI).addOperand(MI->getOperand(1)));
}
bool ARMBaseInstrInfo::hasNOP() const {
return (Subtarget.getFeatureBits() & ARM::HasV6T2Ops) != 0;
}

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@ -35,6 +35,9 @@ protected:
explicit ARMBaseInstrInfo(const ARMSubtarget &STI);
public:
// Return whether the target has an explicit NOP encoding.
bool hasNOP() const;
// Return the non-pre/post incrementing version of 'Opc'. Return 0
// if there is not such an opcode.
virtual unsigned getUnindexedOpcode(unsigned Opc) const =0;

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@ -21,12 +21,29 @@
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCInst.h"
using namespace llvm;
ARMInstrInfo::ARMInstrInfo(const ARMSubtarget &STI)
: ARMBaseInstrInfo(STI), RI(*this, STI) {
}
/// getNoopForMachoTarget - Return the noop instruction to use for a noop.
void ARMInstrInfo::getNoopForMachoTarget(MCInst &NopInst) const {
if (hasNOP()) {
NopInst.setOpcode(ARM::NOP);
NopInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
NopInst.addOperand(MCOperand::CreateReg(0));
} else {
NopInst.setOpcode(ARM::MOVr);
NopInst.addOperand(MCOperand::CreateReg(ARM::R0));
NopInst.addOperand(MCOperand::CreateReg(ARM::R0));
NopInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
NopInst.addOperand(MCOperand::CreateReg(0));
NopInst.addOperand(MCOperand::CreateReg(0));
}
}
unsigned ARMInstrInfo::getUnindexedOpcode(unsigned Opc) const {
switch (Opc) {
default: break;

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@ -28,6 +28,9 @@ class ARMInstrInfo : public ARMBaseInstrInfo {
public:
explicit ARMInstrInfo(const ARMSubtarget &STI);
/// getNoopForMachoTarget - Return the noop instruction to use for a noop.
void getNoopForMachoTarget(MCInst &NopInst) const;
// Return the non-pre/post incrementing version of 'Opc'. Return 0
// if there is not such an opcode.
unsigned getUnindexedOpcode(unsigned Opc) const;

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@ -19,7 +19,7 @@
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/ADT/SmallVector.h"
#include "Thumb1InstrInfo.h"
#include "llvm/MC/MCInst.h"
using namespace llvm;
@ -27,6 +27,15 @@ Thumb1InstrInfo::Thumb1InstrInfo(const ARMSubtarget &STI)
: ARMBaseInstrInfo(STI), RI(*this, STI) {
}
/// getNoopForMachoTarget - Return the noop instruction to use for a noop.
void Thumb1InstrInfo::getNoopForMachoTarget(MCInst &NopInst) const {
NopInst.setOpcode(ARM::tMOVr);
NopInst.addOperand(MCOperand::CreateReg(ARM::R8));
NopInst.addOperand(MCOperand::CreateReg(ARM::R8));
NopInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
NopInst.addOperand(MCOperand::CreateReg(0));
}
unsigned Thumb1InstrInfo::getUnindexedOpcode(unsigned Opc) const {
return 0;
}

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@ -27,6 +27,9 @@ class Thumb1InstrInfo : public ARMBaseInstrInfo {
public:
explicit Thumb1InstrInfo(const ARMSubtarget &STI);
/// getNoopForMachoTarget - Return the noop instruction to use for a noop.
void getNoopForMachoTarget(MCInst &NopInst) const;
// Return the non-pre/post incrementing version of 'Opc'. Return 0
// if there is not such an opcode.
unsigned getUnindexedOpcode(unsigned Opc) const;

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@ -21,6 +21,7 @@
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/CommandLine.h"
using namespace llvm;
@ -34,6 +35,13 @@ Thumb2InstrInfo::Thumb2InstrInfo(const ARMSubtarget &STI)
: ARMBaseInstrInfo(STI), RI(*this, STI) {
}
/// getNoopForMachoTarget - Return the noop instruction to use for a noop.
void Thumb2InstrInfo::getNoopForMachoTarget(MCInst &NopInst) const {
NopInst.setOpcode(ARM::tNOP);
NopInst.addOperand(MCOperand::CreateImm(ARMCC::AL));
NopInst.addOperand(MCOperand::CreateReg(0));
}
unsigned Thumb2InstrInfo::getUnindexedOpcode(unsigned Opc) const {
// FIXME
return 0;

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@ -28,6 +28,9 @@ class Thumb2InstrInfo : public ARMBaseInstrInfo {
public:
explicit Thumb2InstrInfo(const ARMSubtarget &STI);
/// getNoopForMachoTarget - Return the noop instruction to use for a noop.
void getNoopForMachoTarget(MCInst &NopInst) const;
// Return the non-pre/post incrementing version of 'Opc'. Return 0
// if there is not such an opcode.
unsigned getUnindexedOpcode(unsigned Opc) const;

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@ -0,0 +1,15 @@
; RUN: llc < %s -filetype=obj -mtriple=thumbv6-apple-darwin -o - | macho-dump -dump-section-data | FileCheck -prefix=T1
; RUN: llc < %s -filetype=obj -mtriple=thumbv7-apple-darwin -o - | macho-dump -dump-section-data | FileCheck -prefix=T2
; RUN: llc < %s -filetype=obj -mtriple=armv6-apple-darwin -o - | macho-dump -dump-section-data | FileCheck -prefix=ARM
; RUN: llc < %s -filetype=obj -mtriple=armv7-apple-darwin -o - | macho-dump -dump-section-data | FileCheck -prefix=ARMV7
; Empty functions need a NOP in them for MachO to prevent DWARF FDEs from
; getting all mucked up. See lib/CodeGen/AsmPrinter/AsmPrinter.cpp for
; details.
define internal fastcc void @empty_function() {
unreachable
}
; CHECK-T1: ('_section_data', 'c046')
; CHECK-T2: ('_section_data', '00bf')
; CHECK-ARM: ('_section_data', '0000a0e1')
; CHECK-ARMV7: ('_section_data', '00f020e3')