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Damnit. LWR() is a pita.

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git-svn-id: http://pcsx2.googlecode.com/svn/trunk@603 96395faa-99c1-11dd-bbfe-3dabce05a288
This commit is contained in:
Jake.Stine 2009-02-25 19:29:32 +00:00
parent d200ab382d
commit 8d86297533
1 changed files with 9 additions and 10 deletions
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15
pcsx2/R5900OpcodeImpl.cpp
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@ -317,7 +317,6 @@ void LWU() {
static const s32 LWL_MASK[4] = { 0xffffff, 0x0000ffff, 0x000000ff, 0x00000000 }; static const s32 LWL_MASK[4] = { 0xffffff, 0x0000ffff, 0x000000ff, 0x00000000 };
static const s32 LWR_MASK[4] = { 0x000000, 0xff000000, 0xffff0000, 0xffffff00 }; static const s32 LWR_MASK[4] = { 0x000000, 0xff000000, 0xffff0000, 0xffffff00 };
static const u8 LWL_SHIFT[4] = { 24, 16, 8, 0 }; static const u8 LWL_SHIFT[4] = { 24, 16, 8, 0 };
static const u8 LWR_SHIFT[4] = { 0, 8, 16, 24 }; static const u8 LWR_SHIFT[4] = { 0, 8, 16, 24 };
@ -343,27 +342,27 @@ void LWL() {
*/ */
} }
void LWR() { void LWR() {
if (!_Rt_) return; if (!_Rt_) return;
s32 addr = cpuRegs.GPR.r[_Rs_].UL[0] + _Imm_; s32 addr = cpuRegs.GPR.r[_Rs_].UL[0] + _Imm_;
u32 shift = addr & 3; u32 shift = addr & 3;
s32 mem; // ensure the compiler does correct sign extension into 64 bits by using s32
memRead32(addr & ~3, (u32*)&mem);
mem = (cpuRegs.GPR.r[_Rt_].SL[0] & LWR_MASK[shift]) | u32 mem;
(mem >> LWR_SHIFT[shift]); memRead32(addr & ~3, &mem);
// Use unsigned math here, and conditionally sign extend below, when needed.
mem = (cpuRegs.GPR.r[_Rt_].UL[0] & LWR_MASK[shift]) | (mem >> LWR_SHIFT[shift]);
if( shift == 0 ) if( shift == 0 )
{ {
// This special case requires sign extension into the full 64 bit dest. // This special case requires sign extension into the full 64 bit dest.
cpuRegs.GPR.r[_Rt_].SD[0] = mem; cpuRegs.GPR.r[_Rt_].SD[0] = (s32)mem;
} }
else else
{ {
// This case can simply set the lower 32 bits of the target register. Upper // This case sets the lower 32 bits of the target register. Upper
// 32 bits are always preserved. // 32 bits are always preserved.
cpuRegs.GPR.r[_Rt_].UL[0] = mem; cpuRegs.GPR.r[_Rt_].UL[0] = mem;
} }