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armemu: Simplify REV/REV16/SXTH/SXTAH

This commit is contained in:
Lioncash 2014-12-28 12:13:13 -05:00
parent 914ecfe04f
commit 9f5b53f9ff
1 changed files with 26 additions and 38 deletions
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52
src/core/arm/interpreter/armemu.cpp
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@ -6350,51 +6350,39 @@ L_stm_s_takeabort:
return 1; return 1;
} }
case 0x6b:
case 0x6b: // REV, REV16, SXTH, and SXTAH
{ {
ARMword Rm; const u8 op2 = BITS(5, 7);
int ror = -1;
switch (BITS(4, 11)) { // REV
case 0x07: if (op2 == 0x01) {
ror = 0;
break;
case 0x47:
ror = 8;
break;
case 0x87:
ror = 16;
break;
case 0xc7:
ror = 24;
break;
case 0xf3: // REV
DEST = ((RHS & 0xFF) << 24) | ((RHS & 0xFF00)) << 8 | ((RHS & 0xFF0000) >> 8) | ((RHS & 0xFF000000) >> 24); DEST = ((RHS & 0xFF) << 24) | ((RHS & 0xFF00)) << 8 | ((RHS & 0xFF0000) >> 8) | ((RHS & 0xFF000000) >> 24);
return 1; return 1;
case 0xfb: // REV16 }
// REV16
else if (op2 == 0x05) {
DEST = ((RHS & 0xFF) << 8) | ((RHS & 0xFF00)) >> 8 | ((RHS & 0xFF0000) << 8) | ((RHS & 0xFF000000) >> 8); DEST = ((RHS & 0xFF) << 8) | ((RHS & 0xFF00)) >> 8 | ((RHS & 0xFF0000) << 8) | ((RHS & 0xFF000000) >> 8);
return 1; return 1;
default:
break;
} }
else if (op2 == 0x03) {
const u8 rotate = BITS(10, 11) * 8;
if (ror == -1) u32 rm = ((state->Reg[BITS(0, 3)] >> rotate) & 0xFFFF) | (((state->Reg[BITS(0, 3)] << (32 - rotate)) & 0xFFFF) & 0xFFFF);
break; if (rm & 0x8000)
rm |= 0xffff0000;
Rm = ((state->Reg[BITS(0, 3)] >> ror) & 0xFFFF) | (((state->Reg[BITS(0, 3)] << (32 - ror)) & 0xFFFF) & 0xFFFF); // SXTH, otherwise SXTAH
if (Rm & 0x8000) if (BITS(16, 19) == 15)
Rm |= 0xffff0000; state->Reg[BITS(12, 15)] = rm;
if (BITS(16, 19) == 0xf)
/* SXTH */
state->Reg[BITS(12, 15)] = Rm;
else else
/* SXTAH */ state->Reg[BITS(12, 15)] = state->Reg[BITS(16, 19)] + rm;
state->Reg[BITS(12, 15)] = state->Reg[BITS(16, 19)] + Rm;
return 1; return 1;
} }
}
break;
case 0x6c: // UXTB16 and UXTAB16 case 0x6c: // UXTB16 and UXTAB16
{ {
const u8 rm_idx = BITS(0, 3); const u8 rm_idx = BITS(0, 3);