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JIT: optimize crclr special case of crxor

This commit is contained in:
Fiora 2014-10-27 04:11:46 -07:00
parent 97fba41860
commit 1ec1a9c33a
2 changed files with 44 additions and 0 deletions
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1
Source/Core/Core/PowerPC/Jit64/Jit.h
View File

@ -137,6 +137,7 @@ public:
void GetCRFieldBit(int field, int bit, Gen::X64Reg out, bool negate = false);
// Clobbers RDX.
void SetCRFieldBit(int field, int bit, Gen::X64Reg in);
void ClearCRFieldBit(int field, int bit);
// Generates a branch that will check if a given bit of a CR register part
// is set or not.

43
Source/Core/Core/PowerPC/Jit64/Jit_SystemRegisters.cpp
View File

@ -89,6 +89,42 @@ void Jit64::SetCRFieldBit(int field, int bit, Gen::X64Reg in)
MOV(64, PPCSTATE(cr_val[field]), R(RSCRATCH2));
}
void Jit64::ClearCRFieldBit(int field, int bit)
{
MOV(64, R(RSCRATCH2), PPCSTATE(cr_val[field]));
if (bit != CR_GT_BIT)
{
TEST(64, R(RSCRATCH2), R(RSCRATCH2));
FixupBranch dont_clear_gt = J_CC(CC_NZ);
BTS(64, R(RSCRATCH2), Imm8(63));
SetJumpTarget(dont_clear_gt);
}
switch (bit)
{
case CR_SO_BIT: // set bit 61 to input
BTR(64, R(RSCRATCH2), Imm8(61));
break;
case CR_EQ_BIT: // clear low 32 bits, set bit 0 to !input
SHR(64, R(RSCRATCH2), Imm8(32));
SHL(64, R(RSCRATCH2), Imm8(32));
break;
case CR_GT_BIT: // set bit 63 to !input
BTR(64, R(RSCRATCH2), Imm8(63));
break;
case CR_LT_BIT: // set bit 62 to input
BTR(64, R(RSCRATCH2), Imm8(62));
break;
}
BTS(64, R(RSCRATCH2), Imm8(32));
MOV(64, PPCSTATE(cr_val[field]), R(RSCRATCH2));
}
FixupBranch Jit64::JumpIfCRFieldBit(int field, int bit, bool jump_if_set)
{
switch (bit)
@ -476,6 +512,13 @@ void Jit64::crXXX(UGeckoInstruction inst)
JITDISABLE(bJITSystemRegistersOff);
_dbg_assert_msg_(DYNA_REC, inst.OPCD == 19, "Invalid crXXX");
// Special case: crclr
if (inst.CRBA == inst.CRBB && inst.CRBA == inst.CRBD && inst.SUBOP10 == 193)
{
ClearCRFieldBit(inst.CRBD >> 2, 3 - (inst.CRBD & 3));
return;
}
// TODO(delroth): Potential optimizations could be applied here. For
// instance, if the two CR bits being loaded are the same, two loads are
// not required.