Add a special ARM trap encoding for NaCl.

More details in this thread: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130128/163783.html

Patch by JF Bastien



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173943 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eli Bendersky 2013-01-30 16:30:19 +00:00
parent 620d5bd8e4
commit 0f156af831
10 changed files with 104 additions and 9 deletions

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@ -110,6 +110,11 @@ def FeatureMP : SubtargetFeature<"mp", "HasMPExtension", "true",
def FeatureMClass : SubtargetFeature<"mclass", "IsMClass", "true",
"Is microcontroller profile ('M' series)">;
// Special TRAP encoding for NaCl, which looks like a TRAP in Thumb too.
// See ARMInstrInfo.td for details.
def FeatureNaClTrap : SubtargetFeature<"nacl-trap", "UseNaClTrap", "true",
"NaCl trap">;
// ARM ISAs.
def HasV4TOps : SubtargetFeature<"v4t", "HasV4TOps", "true",
"Support ARM v4T instructions">;

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@ -1693,6 +1693,13 @@ void ARMAsmPrinter::EmitInstruction(const MachineInstr *MI) {
}
break;
}
case ARM::TRAPNaCl: {
//.long 0xe7fedef0 @ trap
uint32_t Val = 0xe7fedef0UL;
OutStreamer.AddComment("trap");
OutStreamer.EmitIntValue(Val, 4);
return;
}
case ARM::tTRAP: {
// Non-Darwin binutils don't yet support the "trap" mnemonic.
// FIXME: Remove this special case when they do.

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@ -2562,7 +2562,8 @@ bool ARMFastISel::SelectIntrinsicCall(const IntrinsicInst &I) {
return SelectCall(&I, "memset");
}
case Intrinsic::trap: {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(ARM::TRAP));
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(
Subtarget->useNaClTrap() ? ARM::TRAPNaCl : ARM::TRAP));
return true;
}
}

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@ -6303,7 +6303,16 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const {
DispatchBB->setIsLandingPad();
MachineBasicBlock *TrapBB = MF->CreateMachineBasicBlock();
BuildMI(TrapBB, dl, TII->get(Subtarget->isThumb() ? ARM::tTRAP : ARM::TRAP));
unsigned trap_opcode;
if (Subtarget->isThumb()) {
trap_opcode = ARM::tTRAP;
} else {
if (Subtarget->useNaClTrap())
trap_opcode = ARM::TRAPNaCl;
else
trap_opcode = ARM::TRAP;
}
BuildMI(TrapBB, dl, TII->get(trap_opcode));
DispatchBB->addSuccessor(TrapBB);
MachineBasicBlock *DispContBB = MF->CreateMachineBasicBlock();
@ -10317,4 +10326,3 @@ bool ARMTargetLowering::getTgtMemIntrinsic(IntrinsicInfo &Info,
return false;
}

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@ -239,6 +239,9 @@ def IsARM : Predicate<"!Subtarget->isThumb()">,
def IsIOS : Predicate<"Subtarget->isTargetIOS()">;
def IsNotIOS : Predicate<"!Subtarget->isTargetIOS()">;
def IsNaCl : Predicate<"Subtarget->isTargetNaCl()">;
def UseNaClTrap : Predicate<"Subtarget->useNaClTrap()">,
AssemblerPredicate<"FeatureNaClTrap", "NaCl">;
def DontUseNaClTrap : Predicate<"!Subtarget->useNaClTrap()">;
// FIXME: Eventually this will be just "hasV6T2Ops".
def UseMovt : Predicate<"Subtarget->useMovt()">;
@ -1762,11 +1765,32 @@ def DBG : AI<(outs), (ins imm0_15:$opt), MiscFrm, NoItinerary, "dbg", "\t$opt",
let Inst{3-0} = opt;
}
// A5.4 Permanently UNDEFINED instructions.
/*
* A5.4 Permanently UNDEFINED instructions.
*
* For most targets use UDF #65006, for which the OS will generate SIGTRAP.
* Other UDF encodings generate SIGILL.
*
* NaCl's OS instead chooses an ARM UDF encoding that's also a UDF in Thumb.
* Encoding A1:
* 1110 0111 1111 iiii iiii iiii 1111 iiii
* Encoding T1:
* 1101 1110 iiii iiii
* It uses the following encoding:
* 1110 0111 1111 1110 1101 1110 1111 0000
* - In ARM: UDF #60896;
* - In Thumb: UDF #254 followed by a branch-to-self.
*/
let isBarrier = 1, isTerminator = 1 in
def TRAPNaCl : AXI<(outs), (ins), MiscFrm, NoItinerary,
"trap", [(trap)]>,
Requires<[IsARM,UseNaClTrap]> {
let Inst = 0xe7fedef0;
}
let isBarrier = 1, isTerminator = 1 in
def TRAP : AXI<(outs), (ins), MiscFrm, NoItinerary,
"trap", [(trap)]>,
Requires<[IsARM]> {
Requires<[IsARM,DontUseNaClTrap]> {
let Inst = 0xe7ffdefe;
}

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@ -80,6 +80,7 @@ ARMSubtarget::ARMSubtarget(const std::string &TT, const std::string &CPU,
, FPOnlySP(false)
, AllowsUnalignedMem(false)
, Thumb2DSP(false)
, UseNaClTrap(false)
, stackAlignment(4)
, CPUString(CPU)
, TargetTriple(TT)

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@ -156,6 +156,9 @@ protected:
/// and such) instructions in Thumb2 code.
bool Thumb2DSP;
/// NaCl TRAP instruction is generated instead of the regular TRAP.
bool UseNaClTrap;
/// stackAlignment - The minimum alignment known to hold of the stack frame on
/// entry to the function and which must be maintained by every function.
unsigned stackAlignment;
@ -241,6 +244,7 @@ protected:
bool hasRAS() const { return HasRAS; }
bool hasMPExtension() const { return HasMPExtension; }
bool hasThumb2DSP() const { return Thumb2DSP; }
bool useNaClTrap() const { return UseNaClTrap; }
bool hasFP16() const { return HasFP16; }
bool hasD16() const { return HasD16; }

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@ -11,11 +11,12 @@
//
//===----------------------------------------------------------------------===//
#include "ARMMCTargetDesc.h"
#include "ARMBaseInfo.h"
#include "ARMELFStreamer.h"
#include "ARMMCAsmInfo.h"
#include "ARMMCTargetDesc.h"
#include "InstPrinter/ARMInstPrinter.h"
#include "llvm/ADT/Triple.h"
#include "llvm/MC/MCCodeGenInfo.h"
#include "llvm/MC/MCInstrAnalysis.h"
#include "llvm/MC/MCInstrInfo.h"
@ -37,6 +38,8 @@
using namespace llvm;
std::string ARM_MC::ParseARMTriple(StringRef TT, StringRef CPU) {
Triple triple(TT);
// Set the boolean corresponding to the current target triple, or the default
// if one cannot be determined, to true.
unsigned Len = TT.size();
@ -119,6 +122,13 @@ std::string ARM_MC::ParseARMTriple(StringRef TT, StringRef CPU) {
ARMArchFeature += ",+thumb-mode";
}
if (triple.isOSNaCl()) {
if (ARMArchFeature.empty())
ARMArchFeature = "+nacl-trap";
else
ARMArchFeature += ",+nacl-trap";
}
return ARMArchFeature;
}

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@ -1,5 +1,23 @@
; RUN: llc < %s -mtriple=arm-apple-darwin | FileCheck %s -check-prefix=INSTR
; RUN: llc < %s -mtriple=arm-apple-darwin -trap-func=_trap | FileCheck %s -check-prefix=FUNC
; RUN: llc -mtriple=armv7-unknown-nacl -filetype=obj %s -o - \
; RUN: | llvm-objdump -disassemble -triple armv7-unknown-nacl - \
; RUN: | FileCheck %s -check-prefix=ENCODING-NACL
; RUN: llc -mtriple=armv7-unknown-nacl -filetype=obj %s -o - \
; RUN: | llvm-objdump -disassemble -triple armv7 -mattr=+nacl-trap - \
; RUN: | FileCheck %s -check-prefix=ENCODING-NACL
; RUN: llc -mtriple=armv7 -mattr=+nacl-trap -filetype=obj %s -o - \
; RUN: | llvm-objdump -disassemble -triple armv7 -mattr=+nacl-trap - \
; RUN: | FileCheck %s -check-prefix=ENCODING-NACL
; RUN: llc -fast-isel -mtriple=armv7-unknown-nacl -filetype=obj %s -o - \
; RUN: | llvm-objdump -disassemble -triple armv7-unknown-nacl - \
; RUN: | FileCheck %s -check-prefix=ENCODING-NACL
; RUN: llc -mtriple=armv7 -filetype=obj %s -o - \
; RUN: | llvm-objdump -disassemble -triple armv7 - \
; RUN: | FileCheck %s -check-prefix=ENCODING-ALL
; RUN: llc -fast-isel -mtriple=armv7 -filetype=obj %s -o - \
; RUN: | llvm-objdump -disassemble -triple armv7 - \
; RUN: | FileCheck %s -check-prefix=ENCODING-ALL
; rdar://7961298
; rdar://9249183
@ -10,6 +28,11 @@ entry:
; FUNC: t:
; FUNC: bl __trap
; ENCODING-NACL: f0 de fe e7
; ENCODING-ALL: fe de ff e7
call void @llvm.trap()
unreachable
}
@ -21,6 +44,11 @@ entry:
; FUNC: t2:
; FUNC: bl __trap
; ENCODING-NACL: f0 de fe e7
; ENCODING-ALL: fe de ff e7
call void @llvm.debugtrap()
unreachable
}

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@ -1,7 +1,14 @@
@ RUN: llvm-mc -mcpu=cortex-a8 -triple arm-unknown-unknown -show-encoding %s | FileCheck %s
@ RUN: llvm-mc -mcpu=cortex-a8 -triple arm-unknown-unknown -show-encoding %s \
@ RUN: | FileCheck %s -check-prefix=ALL
@ RUN: llvm-mc -mcpu=cortex-a9-mp -triple armv7-unknown-nacl -show-encoding %s \
@ RUN: | FileCheck %s -check-prefix=NACL
@ RUN: llvm-mc -mcpu=cortex-a8 -mattr=+nacl-trap -triple armv7 -show-encoding %s \
@ RUN: | FileCheck %s -check-prefix=NACL
@ CHECK: trap
@ CHECK: encoding: [0xfe,0xde,0xff,0xe7]
@ ALL: trap
@ ALL: encoding: [0xfe,0xde,0xff,0xe7]
@ NACL: trap
@ NACL: encoding: [0xf0,0xde,0xfe,0xe7]
trap
@ CHECK: bx lr