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This patch handles unaligned loads and stores in Mips JIT. Mips backend

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implements unaligned loads and stores with assembler macro-instructions
ulw, usw, ulh, ulhu, ush, and this patch emits corresponding instructions
instead of these macros. Since each unaligned load/store is expanded
into two corresponding loads/stores where offset for second load/store is
modified by +3 (for words) or +1 (for halfwords).

Patch by Petar Jovanovic and Sasa Stankovic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144081 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bruno Cardoso Lopes 2011-11-08 12:47:11 +00:00
parent d63e7bf556
commit ad6eef4a65
2 changed files with 148 additions and 6 deletions
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144
lib/Target/Mips/MipsCodeEmitter.cpp
View File

@ -108,6 +108,15 @@ class MipsCodeEmitter : public MachineFunctionPass {
unsigned getMemEncoding(const MachineInstr &MI, unsigned OpNo) const;
unsigned getSizeExtEncoding(const MachineInstr &MI, unsigned OpNo) const;
unsigned getSizeInsEncoding(const MachineInstr &MI, unsigned OpNo) const;
int emitULW(const MachineInstr &MI);
int emitUSW(const MachineInstr &MI);
int emitULH(const MachineInstr &MI);
int emitULHu(const MachineInstr &MI);
int emitUSH(const MachineInstr &MI);
void emitGlobalAddressUnaligned(const GlobalValue *GV, unsigned Reloc,
int Offset) const;
};
}
@ -186,9 +195,15 @@ unsigned MipsCodeEmitter::getMachineOpValue(const MachineInstr &MI,
return MipsRegisterInfo::getRegisterNumbering(MO.getReg());
else if (MO.isImm())
return static_cast<unsigned>(MO.getImm());
else if (MO.isGlobal())
emitGlobalAddress(MO.getGlobal(), getRelocation(MI, MO), true);
else if (MO.isSymbol())
else if (MO.isGlobal()) {
if (MI.getOpcode() == Mips::ULW || MI.getOpcode() == Mips::USW ||
MI.getOpcode() == Mips::ULH || MI.getOpcode() == Mips::ULHu)
emitGlobalAddressUnaligned(MO.getGlobal(), getRelocation(MI, MO), 4);
else if (MI.getOpcode() == Mips::USH)
emitGlobalAddressUnaligned(MO.getGlobal(), getRelocation(MI, MO), 8);
else
emitGlobalAddress(MO.getGlobal(), getRelocation(MI, MO), true);
} else if (MO.isSymbol())
emitExternalSymbolAddress(MO.getSymbolName(), getRelocation(MI, MO));
else if (MO.isCPI())
emitConstPoolAddress(MO.getIndex(), getRelocation(MI, MO));
@ -207,6 +222,14 @@ void MipsCodeEmitter::emitGlobalAddress(const GlobalValue *GV, unsigned Reloc,
const_cast<GlobalValue *>(GV), 0, MayNeedFarStub));
}
void MipsCodeEmitter::emitGlobalAddressUnaligned(const GlobalValue *GV,
unsigned Reloc, int Offset) const {
MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc,
const_cast<GlobalValue *>(GV), 0, false));
MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset() + Offset,
Reloc, const_cast<GlobalValue *>(GV), 0, false));
}
void MipsCodeEmitter::
emitExternalSymbolAddress(const char *ES, unsigned Reloc) const {
MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
@ -230,6 +253,103 @@ void MipsCodeEmitter::emitMachineBasicBlock(MachineBasicBlock *BB,
Reloc, BB));
}
int MipsCodeEmitter::emitUSW(const MachineInstr &MI) {
unsigned src = getMachineOpValue(MI, MI.getOperand(0));
unsigned base = getMachineOpValue(MI, MI.getOperand(1));
unsigned offset = getMachineOpValue(MI, MI.getOperand(2));
// swr src, offset(base)
// swl src, offset+3(base)
MCE.emitWordLE(
(0x2e << 26) | (base << 21) | (src << 16) | (offset & 0xffff));
MCE.emitWordLE(
(0x2a << 26) | (base << 21) | (src << 16) | ((offset+3) & 0xffff));
return 2;
}
int MipsCodeEmitter::emitULW(const MachineInstr &MI) {
unsigned dst = getMachineOpValue(MI, MI.getOperand(0));
unsigned base = getMachineOpValue(MI, MI.getOperand(1));
unsigned offset = getMachineOpValue(MI, MI.getOperand(2));
unsigned at = 1;
if (dst != base) {
// lwr dst, offset(base)
// lwl dst, offset+3(base)
MCE.emitWordLE(
(0x26 << 26) | (base << 21) | (dst << 16) | (offset & 0xffff));
MCE.emitWordLE(
(0x22 << 26) | (base << 21) | (dst << 16) | ((offset+3) & 0xffff));
return 2;
} else {
// lwr at, offset(base)
// lwl at, offset+3(base)
// addu dst, at, $zero
MCE.emitWordLE(
(0x26 << 26) | (base << 21) | (at << 16) | (offset & 0xffff));
MCE.emitWordLE(
(0x22 << 26) | (base << 21) | (at << 16) | ((offset+3) & 0xffff));
MCE.emitWordLE(
(0x0 << 26) | (at << 21) | (0x0 << 16) | (dst << 11) | (0x0 << 6) | 0x21);
return 3;
}
}
int MipsCodeEmitter::emitUSH(const MachineInstr &MI) {
unsigned src = getMachineOpValue(MI, MI.getOperand(0));
unsigned base = getMachineOpValue(MI, MI.getOperand(1));
unsigned offset = getMachineOpValue(MI, MI.getOperand(2));
unsigned at = 1;
// sb src, offset(base)
// srl at,src,8
// sb at, offset+1(base)
MCE.emitWordLE(
(0x28 << 26) | (base << 21) | (src << 16) | (offset & 0xffff));
MCE.emitWordLE(
(0x0 << 26) | (0x0 << 21) | (src << 16) | (at << 11) | (0x8 << 6) | 0x2);
MCE.emitWordLE(
(0x28 << 26) | (base << 21) | (at << 16) | ((offset+1) & 0xffff));
return 3;
}
int MipsCodeEmitter::emitULH(const MachineInstr &MI) {
unsigned dst = getMachineOpValue(MI, MI.getOperand(0));
unsigned base = getMachineOpValue(MI, MI.getOperand(1));
unsigned offset = getMachineOpValue(MI, MI.getOperand(2));
unsigned at = 1;
// lbu at, offset(base)
// lb dst, offset+1(base)
// sll dst,dst,8
// or dst,dst,at
MCE.emitWordLE(
(0x24 << 26) | (base << 21) | (at << 16) | (offset & 0xffff));
MCE.emitWordLE(
(0x20 << 26) | (base << 21) | (dst << 16) | ((offset+1) & 0xffff));
MCE.emitWordLE(
(0x0 << 26) | (0x0 << 21) | (dst << 16) | (dst << 11) | (0x8 << 6) | 0x0);
MCE.emitWordLE(
(0x0 << 26) | (dst << 21) | (at << 16) | (dst << 11) | (0x0 << 6) | 0x25);
return 4;
}
int MipsCodeEmitter::emitULHu(const MachineInstr &MI) {
unsigned dst = getMachineOpValue(MI, MI.getOperand(0));
unsigned base = getMachineOpValue(MI, MI.getOperand(1));
unsigned offset = getMachineOpValue(MI, MI.getOperand(2));
unsigned at = 1;
// lbu at, offset(base)
// lbu dst, offset+1(base)
// sll dst,dst,8
// or dst,dst,at
MCE.emitWordLE(
(0x24 << 26) | (base << 21) | (at << 16) | (offset & 0xffff));
MCE.emitWordLE(
(0x24 << 26) | (base << 21) | (dst << 16) | ((offset+1) & 0xffff));
MCE.emitWordLE(
(0x0 << 26) | (0x0 << 21) | (dst << 16) | (dst << 11) | (0x8 << 6) | 0x0);
MCE.emitWordLE(
(0x0 << 26) | (dst << 21) | (at << 16) | (dst << 11) | (0x0 << 6) | 0x25);
return 4;
}
void MipsCodeEmitter::emitInstruction(const MachineInstr &MI) {
DEBUG(errs() << "JIT: " << (void*)MCE.getCurrentPCValue() << ":\t" << MI);
@ -239,11 +359,27 @@ void MipsCodeEmitter::emitInstruction(const MachineInstr &MI) {
if ((MI.getDesc().TSFlags & MipsII::FormMask) == MipsII::Pseudo)
return;
++NumEmitted; // Keep track of the # of mi's emitted
switch (MI.getOpcode()) {
case Mips::USW:
NumEmitted += emitUSW(MI);
break;
case Mips::ULW:
NumEmitted += emitULW(MI);
break;
case Mips::ULH:
NumEmitted += emitULH(MI);
break;
case Mips::ULHu:
NumEmitted += emitULHu(MI);
break;
case Mips::USH:
NumEmitted += emitUSH(MI);
break;
default:
emitWordLE(getBinaryCodeForInstr(MI));
++NumEmitted; // Keep track of the # of mi's emitted
break;
}

10
lib/Target/Mips/MipsJITInfo.cpp
View File

@ -218,10 +218,16 @@ void MipsJITInfo::relocate(void *Function, MachineRelocation *MR,
*((unsigned*) RelocPos) |= (unsigned) ResultPtr;
break;
case Mips::reloc_mips_lo:
ResultPtr = ResultPtr & 0xffff;
case Mips::reloc_mips_lo: {
// Addend is needed for unaligned load/store instructions, where offset
// for the second load/store in the expanded instruction sequence must
// be modified by +1 or +3. Otherwise, Addend is 0.
int Addend = *((unsigned*) RelocPos) & 0xffff;
ResultPtr = (ResultPtr + Addend) & 0xffff;
*((unsigned*) RelocPos) &= 0xffff0000;
*((unsigned*) RelocPos) |= (unsigned) ResultPtr;
break;
}
default:
llvm_unreachable("ERROR: Unknown Mips relocation.");