[PowerPC] Use mtocrf when available

Just as with mfocrf, it is also preferable to use mtocrf instead of
mtcrf when only a single CR register is to be written.

Current code however always emits mtcrf.  This probably does not matter
when using an external assembler, since the GNU assembler will in fact
automatically replace mtcrf with mtocrf when possible.  It does create
inefficient code with the integrated assembler, however.

To fix this, this patch adds MTOCRF/MTOCRF8 instruction patterns and
uses those instead of MTCRF/MTCRF8 everything.  Just as done in the
MFOCRF patch committed as 185556, these patterns will be converted
back to MTCRF if MTOCRF is not available on the machine.

As a side effect, this allows to modify the MTCRF pattern to accept
the full range of mask operands for the benefit of the asm parser.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185561 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Ulrich Weigand 2013-07-03 17:59:07 +00:00
parent 965b20e39c
commit 33efedc048
10 changed files with 54 additions and 25 deletions

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@ -228,7 +228,7 @@ unsigned PPCMCCodeEmitter::
get_crbitm_encoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpNo);
assert((MI.getOpcode() == PPC::MTCRF || MI.getOpcode() == PPC::MTCRF8 ||
assert((MI.getOpcode() == PPC::MTOCRF || MI.getOpcode() == PPC::MTOCRF8 ||
MI.getOpcode() == PPC::MFOCRF || MI.getOpcode() == PPC::MFOCRF8) &&
(MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7));
return 0x80 >> CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
@ -239,9 +239,9 @@ unsigned PPCMCCodeEmitter::
getMachineOpValue(const MCInst &MI, const MCOperand &MO,
SmallVectorImpl<MCFixup> &Fixups) const {
if (MO.isReg()) {
// MTCRF/MFOCRF should go through get_crbitm_encoding for the CR operand.
// MTOCRF/MFOCRF should go through get_crbitm_encoding for the CR operand.
// The GPR operand should come through here though.
assert((MI.getOpcode() != PPC::MTCRF && MI.getOpcode() != PPC::MTCRF8 &&
assert((MI.getOpcode() != PPC::MTOCRF && MI.getOpcode() != PPC::MTOCRF8 &&
MI.getOpcode() != PPC::MFOCRF && MI.getOpcode() != PPC::MFOCRF8) ||
MO.getReg() < PPC::CR0 || MO.getReg() > PPC::CR7);
return CTX.getRegisterInfo()->getEncodingValue(MO.getReg());

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@ -676,6 +676,23 @@ void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
return;
}
break;
case PPC::MTOCRF:
case PPC::MTOCRF8:
if (!Subtarget.hasMFOCRF()) {
// Transform: %CR7 = MTOCRF %R3
// Into: MTCRF mask, %R3 ;; cr7
unsigned NewOpcode =
MI->getOpcode() == PPC::MTOCRF ? PPC::MTCRF : PPC::MTCRF8;
unsigned Mask = 0x80 >> OutContext.getRegisterInfo()
->getEncodingValue(MI->getOperand(0).getReg());
OutStreamer.AddComment(PPCInstPrinter::
getRegisterName(MI->getOperand(0).getReg()));
OutStreamer.EmitInstruction(MCInstBuilder(NewOpcode)
.addImm(Mask)
.addReg(MI->getOperand(1).getReg()));
return;
}
break;
case PPC::SYNC:
// In Book E sync is called msync, handle this special case here...
if (Subtarget.isBookE()) {

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@ -142,7 +142,7 @@ void PPCCodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
unsigned PPCCodeEmitter::get_crbitm_encoding(const MachineInstr &MI,
unsigned OpNo) const {
const MachineOperand &MO = MI.getOperand(OpNo);
assert((MI.getOpcode() == PPC::MTCRF || MI.getOpcode() == PPC::MTCRF8 ||
assert((MI.getOpcode() == PPC::MTOCRF || MI.getOpcode() == PPC::MTOCRF8 ||
MI.getOpcode() == PPC::MFOCRF || MI.getOpcode() == PPC::MFOCRF8) &&
(MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7));
return 0x80 >> TM.getRegisterInfo()->getEncodingValue(MO.getReg());
@ -274,9 +274,9 @@ unsigned PPCCodeEmitter::getMachineOpValue(const MachineInstr &MI,
const MachineOperand &MO) const {
if (MO.isReg()) {
// MTCRF/MFOCRF should go through get_crbitm_encoding for the CR operand.
// MTOCRF/MFOCRF should go through get_crbitm_encoding for the CR operand.
// The GPR operand should come through here though.
assert((MI.getOpcode() != PPC::MTCRF && MI.getOpcode() != PPC::MTCRF8 &&
assert((MI.getOpcode() != PPC::MTOCRF && MI.getOpcode() != PPC::MTOCRF8 &&
MI.getOpcode() != PPC::MFOCRF && MI.getOpcode() != PPC::MFOCRF8) ||
MO.getReg() < PPC::CR0 || MO.getReg() > PPC::CR7);
return TM.getRegisterInfo()->getEncodingValue(MO.getReg());

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@ -753,7 +753,7 @@ void PPCFrameLowering::emitEpilogue(MachineFunction &MF,
if (!MustSaveCRs.empty())
for (unsigned i = 0, e = MustSaveCRs.size(); i != e; ++i)
BuildMI(MBB, MBBI, dl, TII.get(PPC::MTCRF8), MustSaveCRs[i])
BuildMI(MBB, MBBI, dl, TII.get(PPC::MTOCRF8), MustSaveCRs[i])
.addReg(PPC::X12, getKillRegState(i == e-1));
if (MustSaveLR)
@ -1212,7 +1212,7 @@ restoreCRs(bool isPPC64, bool is31,
MBB.insert(MI, addFrameReference(BuildMI(*MF, DL, TII.get(PPC::LWZ),
PPC::R12),
CSI[CSIIndex].getFrameIdx()));
RestoreOp = PPC::MTCRF;
RestoreOp = PPC::MTOCRF;
MoveReg = PPC::R12;
}

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@ -257,7 +257,11 @@ def : Pat<(PPCtc_return CTRRC8:$dst, imm:$imm),
// 64-bit CR instructions
let Interpretation64Bit = 1 in {
let neverHasSideEffects = 1 in {
def MTCRF8 : XFXForm_5<31, 144, (outs crbitm:$FXM), (ins g8rc:$rS),
def MTOCRF8: XFXForm_5a<31, 144, (outs crbitm:$FXM), (ins g8rc:$ST),
"mtocrf $FXM, $ST", BrMCRX>,
PPC970_DGroup_First, PPC970_Unit_CRU;
def MTCRF8 : XFXForm_5<31, 144, (outs), (ins i32imm:$FXM, g8rc:$rS),
"mtcrf $FXM, $rS", BrMCRX>,
PPC970_MicroCode, PPC970_Unit_CRU;

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@ -1898,7 +1898,11 @@ def RESTORE_VRSAVE : Pseudo<(outs VRSAVERC:$vrsave), (ins memri:$F),
"#RESTORE_VRSAVE", []>;
let neverHasSideEffects = 1 in {
def MTCRF : XFXForm_5<31, 144, (outs crbitm:$FXM), (ins gprc:$rS),
def MTOCRF: XFXForm_5a<31, 144, (outs crbitm:$FXM), (ins gprc:$ST),
"mtocrf $FXM, $ST", BrMCRX>,
PPC970_DGroup_First, PPC970_Unit_CRU;
def MTCRF : XFXForm_5<31, 144, (outs), (ins i32imm:$FXM, gprc:$rS),
"mtcrf $FXM, $rS", BrMCRX>,
PPC970_MicroCode, PPC970_Unit_CRU;
@ -2322,6 +2326,8 @@ def : InstAlias<"mr. $rA, $rB", (OR8o g8rc:$rA, g8rc:$rB, g8rc:$rB)>;
def : InstAlias<"not $rA, $rB", (NOR8 g8rc:$rA, g8rc:$rB, g8rc:$rB)>;
def : InstAlias<"not. $rA, $rB", (NOR8o g8rc:$rA, g8rc:$rB, g8rc:$rB)>;
def : InstAlias<"mtcr $rA", (MTCRF8 255, g8rc:$rA)>;
def LAx : PPCAsmPseudo<"la $rA, $addr", (ins gprc:$rA, memri:$addr)>;
def SUBI : PPCAsmPseudo<"subi $rA, $rB, $imm",

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@ -403,7 +403,7 @@ void PPCRegisterInfo::lowerCRRestore(MachineBasicBlock::iterator II,
.addImm(31);
}
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTCRF8 : PPC::MTCRF), DestReg)
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTOCRF8 : PPC::MTOCRF), DestReg)
.addReg(Reg, RegState::Kill);
// Discard the pseudo instruction.

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@ -1,5 +1,5 @@
; RUN: llc -O0 -disable-fp-elim -mtriple=powerpc-unknown-linux-gnu < %s | FileCheck %s -check-prefix=PPC32
; RUN: llc -O0 -mtriple=powerpc64-unknown-linux-gnu < %s | FileCheck %s -check-prefix=PPC64
; RUN: llc -O0 -disable-fp-elim -mtriple=powerpc-unknown-linux-gnu -mcpu=g5 < %s | FileCheck %s -check-prefix=PPC32
; RUN: llc -O0 -mtriple=powerpc64-unknown-linux-gnu -mcpu=g5 < %s | FileCheck %s -check-prefix=PPC64
declare void @foo()
@ -18,7 +18,7 @@ entry:
; PPC32: mfcr 12
; PPC32-NEXT: stw 12, 24(31)
; PPC32: lwz 12, 24(31)
; PPC32-NEXT: mtcrf 32, 12
; PPC32-NEXT: mtocrf 32, 12
; PPC64: .cfi_startproc
; PPC64: mfcr 12
@ -29,7 +29,7 @@ entry:
; PPC64: .cfi_offset cr2, 8
; PPC64: addi 1, 1, [[AMT]]
; PPC64: lwz 12, 8(1)
; PPC64: mtcrf 32, 12
; PPC64: mtocrf 32, 12
; PPC64: .cfi_endproc
define i32 @test_cr234() nounwind {
@ -47,16 +47,16 @@ entry:
; PPC32: mfcr 12
; PPC32-NEXT: stw 12, 24(31)
; PPC32: lwz 12, 24(31)
; PPC32-NEXT: mtcrf 32, 12
; PPC32-NEXT: mtcrf 16, 12
; PPC32-NEXT: mtcrf 8, 12
; PPC32-NEXT: mtocrf 32, 12
; PPC32-NEXT: mtocrf 16, 12
; PPC32-NEXT: mtocrf 8, 12
; PPC64: mfcr 12
; PPC64: stw 12, 8(1)
; PPC64: stdu 1, -[[AMT:[0-9]+]](1)
; PPC64: addi 1, 1, [[AMT]]
; PPC64: lwz 12, 8(1)
; PPC64: mtcrf 32, 12
; PPC64: mtcrf 16, 12
; PPC64: mtcrf 8, 12
; PPC64: mtocrf 32, 12
; PPC64: mtocrf 16, 12
; PPC64: mtocrf 8, 12

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@ -1986,4 +1986,6 @@
not 2, 3
# CHECK: nor. 2, 3, 3 # encoding: [0x7c,0x62,0x18,0xf9]
not. 2, 3
# CHECK: mtcrf 255, 2 # encoding: [0x7c,0x4f,0xf1,0x20]
mtcr 2

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@ -508,12 +508,12 @@
mtspr 600, 2
# CHECK: mfspr 2, 600 # encoding: [0x7c,0x58,0x92,0xa6]
mfspr 2, 600
# CHECK: mtcrf 16, 2 # encoding: [0x7c,0x41,0x01,0x20]
mtcrf 16, 2
# CHECK: mtcrf 123, 2 # encoding: [0x7c,0x47,0xb1,0x20]
mtcrf 123, 2
# CHECK: mfcr 2 # encoding: [0x7c,0x40,0x00,0x26]
mfcr 2
# FIXME: mtocrf 16, 2
# CHECK: mtocrf 16, 2 # encoding: [0x7c,0x51,0x01,0x20]
mtocrf 16, 2
# CHECK: mfocrf 16, 8 # encoding: [0x7e,0x10,0x80,0x26]
mfocrf 16, 8
# FIXME: mcrxr 2