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ARM: Remove the saturating (Q) condition code from the renamed register.

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Move the saturating bit (which is also saturating) from the renamed register
that holds the flags to the CPSR miscreg and adds a allows setting it in a
similar way to the FP saturating registers. This removes a dependency in
instructions that don't write, but need to preserve the Q bit.
This commit is contained in:
Ali Saidi 2011-05-13 17:27:01 -05:00
parent 2178859b76
commit e097c4fb18
11 changed files with 28 additions and 32 deletions
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1
src/arch/arm/faults.cc
View file

@ -108,7 +108,6 @@ ArmFault::invoke(ThreadContext *tc, StaticInstPtr inst)
CPSR cpsr = tc->readMiscReg(MISCREG_CPSR);
CPSR saved_cpsr = tc->readMiscReg(MISCREG_CPSR) |
tc->readIntReg(INTREG_CONDCODES_F) |
tc->readIntReg(INTREG_CONDCODES_Q) |
tc->readIntReg(INTREG_CONDCODES_GE);
Addr curPc M5_VAR_USED = tc->pcState().pc();
ITSTATE it = tc->pcState().itstate();

1
src/arch/arm/intregs.hh
View file

@ -113,7 +113,6 @@ enum IntRegIndex
INTREG_UREG1,
INTREG_UREG2,
INTREG_CONDCODES_F,
INTREG_CONDCODES_Q,
INTREG_CONDCODES_GE,
INTREG_FPCONDCODES,

9
src/arch/arm/isa.cc
View file

@ -216,6 +216,8 @@ ISA::readMiscReg(int misc_reg, ThreadContext *tc)
warn("Not doing anything for read to miscreg %s\n",
miscRegName[misc_reg]);
break;
case MISCREG_CPSR_Q:
panic("shouldn't be reading this register seperately\n");
case MISCREG_FPSCR_QC:
return readMiscRegNoEffect(MISCREG_FPSCR) & ~FpscrQcMask;
case MISCREG_FPSCR_EXC:
@ -316,6 +318,13 @@ ISA::setMiscReg(int misc_reg, const MiscReg &val, ThreadContext *tc)
(miscRegs[MISCREG_FPSCR] & ~(uint32_t)fpscrMask);
}
break;
case MISCREG_CPSR_Q:
{
assert(!(newVal & ~CpsrMaskQ));
newVal = miscRegs[MISCREG_CPSR] | newVal;
misc_reg = MISCREG_CPSR;
}
break;
case MISCREG_FPSCR_QC:
{
newVal = miscRegs[MISCREG_FPSCR] | (newVal & FpscrQcMask);

5
src/arch/arm/isa/insts/data.isa
View file

@ -48,7 +48,7 @@ let {{
'''
calcQCode = '''
CondCodesQ = CondCodesQ | ((resTemp & 1) << 27);
CpsrQ = (resTemp & 1) << 27;
'''
calcCcCode = '''
@ -239,11 +239,10 @@ let {{
code += '''
SCTLR sctlr = Sctlr;
uint32_t newCpsr =
cpsrWriteByInstr(Cpsr | CondCodesF | CondCodesQ | CondCodesGE,
cpsrWriteByInstr(Cpsr | CondCodesF | CondCodesGE,
Spsr, 0xF, true, sctlr.nmfi);
Cpsr = ~CondCodesMask & newCpsr;
CondCodesF = CondCodesMaskF & newCpsr;
CondCodesQ = CondCodesMaskQ & newCpsr;
CondCodesGE = CondCodesMaskGE & newCpsr;
NextThumb = ((CPSR)newCpsr).t;
NextJazelle = ((CPSR)newCpsr).j;

2
src/arch/arm/isa/insts/ldr.isa
View file

@ -106,7 +106,7 @@ let {{
wbDiff = 8
accCode = '''
CPSR cpsr = Cpsr;
URc = cpsr | CondCodesF | CondCodesQ | CondCodesGE;
URc = cpsr | CondCodesF | CondCodesGE;
URa = cSwap<uint32_t>(Mem.ud, cpsr.e);
URb = cSwap<uint32_t>(Mem.ud >> 32, cpsr.e);
'''

4
src/arch/arm/isa/insts/macromem.isa
View file

@ -90,11 +90,10 @@ let {{
CPSR cpsr = Cpsr;
SCTLR sctlr = Sctlr;
uint32_t newCpsr =
cpsrWriteByInstr(cpsr | CondCodesF | CondCodesQ | CondCodesGE,
cpsrWriteByInstr(cpsr | CondCodesF | CondCodesGE,
Spsr, 0xF, true, sctlr.nmfi);
Cpsr = ~CondCodesMask & newCpsr;
CondCodesF = CondCodesMaskF & newCpsr;
CondCodesQ = CondCodesMaskQ & newCpsr;
CondCodesGE = CondCodesMaskGE & newCpsr;
IWNPC = cSwap(%s, cpsr.e) | ((Spsr & 0x20) ? 1 : 0);
NextItState = ((((CPSR)Spsr).it2 << 2) & 0xFC)
@ -635,7 +634,6 @@ let {{
NextItState = ((((CPSR)URb).it2 << 2) & 0xFC)
| (((CPSR)URb).it1 & 0x3);
CondCodesF = CondCodesMaskF & newCpsr;
CondCodesQ = CondCodesMaskQ & newCpsr;
CondCodesGE = CondCodesMaskGE & newCpsr;
'''

26
src/arch/arm/isa/insts/misc.isa
View file

@ -61,7 +61,7 @@ let {{
header_output = decoder_output = exec_output = ""
mrsCpsrCode = '''
Dest = (Cpsr | CondCodesF | CondCodesQ | CondCodesGE) & 0xF8FF03DF
Dest = (Cpsr | CondCodesF | CondCodesGE) & 0xF8FF03DF
'''
mrsCpsrIop = InstObjParams("mrs", "MrsCpsr", "MrsOp",
@ -84,11 +84,10 @@ let {{
msrCpsrRegCode = '''
SCTLR sctlr = Sctlr;
uint32_t newCpsr =
cpsrWriteByInstr(Cpsr | CondCodesF | CondCodesQ | CondCodesGE, Op1,
cpsrWriteByInstr(Cpsr | CondCodesF | CondCodesGE, Op1,
byteMask, false, sctlr.nmfi);
Cpsr = ~CondCodesMask & newCpsr;
CondCodesF = CondCodesMaskF & newCpsr;
CondCodesQ = CondCodesMaskQ & newCpsr;
CondCodesGE = CondCodesMaskGE & newCpsr;
'''
msrCpsrRegIop = InstObjParams("msr", "MsrCpsrReg", "MsrRegOp",
@ -111,11 +110,10 @@ let {{
msrCpsrImmCode = '''
SCTLR sctlr = Sctlr;
uint32_t newCpsr =
cpsrWriteByInstr(Cpsr | CondCodesF | CondCodesQ | CondCodesGE, imm,
cpsrWriteByInstr(Cpsr | CondCodesF | CondCodesGE, imm,
byteMask, false, sctlr.nmfi);
Cpsr = ~CondCodesMask & newCpsr;
CondCodesF = CondCodesMaskF & newCpsr;
CondCodesQ = CondCodesMaskQ & newCpsr;
CondCodesGE = CondCodesMaskGE & newCpsr;
'''
msrCpsrImmIop = InstObjParams("msr", "MsrCpsrImm", "MsrImmOp",
@ -205,9 +203,7 @@ let {{
int32_t operand = shift_rm_imm(Op1, shiftAmt, shiftType, 0);
int32_t res;
if (satInt(res, operand, imm))
CondCodesQ = CondCodesQ | (1 << 27);
else
CondCodesQ = CondCodesQ;
CpsrQ = 1 << 27;
Dest = res;
'''
ssatIop = InstObjParams("ssat", "Ssat", "RegImmRegShiftOp",
@ -221,9 +217,7 @@ let {{
int32_t operand = shift_rm_imm(Op1, shiftAmt, shiftType, 0);
int32_t res;
if (uSatInt(res, operand, imm))
CondCodesQ = CondCodesQ | (1 << 27);
else
CondCodesQ = CondCodesQ;
CpsrQ = 1 << 27;
Dest = res;
'''
usatIop = InstObjParams("usat", "Usat", "RegImmRegShiftOp",
@ -236,14 +230,13 @@ let {{
ssat16Code = '''
int32_t res;
uint32_t resTemp = 0;
CondCodesQ = CondCodesQ;
int32_t argLow = sext<16>(bits(Op1, 15, 0));
int32_t argHigh = sext<16>(bits(Op1, 31, 16));
if (satInt(res, argLow, imm))
CondCodesQ = CondCodesQ | (1 << 27);
CpsrQ = 1 << 27;
replaceBits(resTemp, 15, 0, res);
if (satInt(res, argHigh, imm))
CondCodesQ = CondCodesQ | (1 << 27);
CpsrQ = 1 << 27;
replaceBits(resTemp, 31, 16, res);
Dest = resTemp;
'''
@ -257,14 +250,13 @@ let {{
usat16Code = '''
int32_t res;
uint32_t resTemp = 0;
CondCodesQ = CondCodesQ;
int32_t argLow = sext<16>(bits(Op1, 15, 0));
int32_t argHigh = sext<16>(bits(Op1, 31, 16));
if (uSatInt(res, argLow, imm))
CondCodesQ = CondCodesQ | (1 << 27);
CpsrQ = 1 << 27;
replaceBits(resTemp, 15, 0, res);
if (uSatInt(res, argHigh, imm))
CondCodesQ = CondCodesQ | (1 << 27);
CpsrQ = 1 << 27;
replaceBits(resTemp, 31, 16, res);
Dest = resTemp;
'''

2
src/arch/arm/isa/insts/mult.isa
View file

@ -44,7 +44,7 @@ let {{
exec_output = ""
calcQCode = '''
CondCodesQ = CondCodesQ | ((resTemp & 1) << 27);
CpsrQ = (resTemp & 1) << 27;
'''
calcCcCode = '''

2
src/arch/arm/isa/operands.isa
View file

@ -157,7 +157,6 @@ def operands {{
#Pseudo integer condition code registers
'CondCodesF': intRegCC('INTREG_CONDCODES_F'),
'CondCodesQ': intRegCC('INTREG_CONDCODES_Q'),
'CondCodesGE': intRegCC('INTREG_CONDCODES_GE'),
'OptCondCodesF': intRegCC(
'''(condCode == COND_AL || condCode == COND_UC) ?
@ -219,6 +218,7 @@ def operands {{
#Fixed index control regs
'Cpsr': cntrlReg('MISCREG_CPSR', srtCpsr),
'CpsrQ': cntrlReg('MISCREG_CPSR_Q', srtCpsr),
'Spsr': cntrlRegNC('MISCREG_SPSR'),
'Fpsr': cntrlRegNC('MISCREG_FPSR'),
'Fpsid': cntrlRegNC('MISCREG_FPSID'),

7
src/arch/arm/miscregs.hh
View file

@ -67,6 +67,7 @@ namespace ArmISA
enum MiscRegIndex {
MISCREG_CPSR = 0,
MISCREG_CPSR_Q,
MISCREG_SPSR,
MISCREG_SPSR_FIQ,
MISCREG_SPSR_IRQ,
@ -209,7 +210,7 @@ namespace ArmISA
unsigned crm, unsigned opc2);
const char * const miscRegName[NUM_MISCREGS] = {
"cpsr", "spsr", "spsr_fiq", "spsr_irq", "spsr_svc",
"cpsr", "cpsr_q", "spsr", "spsr_fiq", "spsr_irq", "spsr_svc",
"spsr_mon", "spsr_und", "spsr_abt",
"fpsr", "fpsid", "fpscr", "fpscr_qc", "fpscr_exc", "fpexc",
"mvfr0", "mvfr1",
@ -269,9 +270,9 @@ namespace ArmISA
// This mask selects bits of the CPSR that actually go in the CondCodes
// integer register to allow renaming.
static const uint32_t CondCodesMask = 0xF80F0000;
static const uint32_t CondCodesMask = 0xF00F0000;
static const uint32_t CondCodesMaskF = 0xF0000000;
static const uint32_t CondCodesMaskQ = 0x08000000;
static const uint32_t CpsrMaskQ = 0x08000000;
static const uint32_t CondCodesMaskGE = 0x000F0000;
BitUnion32(SCTLR)

1
src/arch/arm/nativetrace.cc
View file

@ -117,7 +117,6 @@ Trace::ArmNativeTrace::ThreadState::update(ThreadContext *tc)
//CPSR
newState[STATE_CPSR] = tc->readMiscReg(MISCREG_CPSR) |
tc->readIntReg(INTREG_CONDCODES_F) |
tc->readIntReg(INTREG_CONDCODES_Q) |
tc->readIntReg(INTREG_CONDCODES_GE);
changed[STATE_CPSR] = (newState[STATE_CPSR] != oldState[STATE_CPSR]);