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armemu: Set the Q flag properly for SMLAD/SMUAD

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This commit is contained in:
Lioncash 2014-12-23 09:55:07 -05:00
parent d31a94f06b
commit 79a7a432c5
3 changed files with 28 additions and 13 deletions
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30
src/core/arm/interpreter/armemu.cpp
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@ -6478,22 +6478,28 @@ L_stm_s_takeabort:
const s16 rn_lo = (rn_val & 0xFFFF);
const s16 rn_hi = ((rn_val >> 16) & 0xFFFF);
// SMUAD
if ((instr & 0xf0d0) == 0xf010) {
state->Reg[rd_idx] = (rn_lo * rm_lo) + (rn_hi * rm_hi);
const u32 product1 = (rn_lo * rm_lo);
const u32 product2 = (rn_hi * rm_hi);
// SMUAD and SMLAD
if (BIT(6) == 0) {
state->Reg[rd_idx] = product1 + product2;
if (BITS(12, 15) != 15) {
state->Reg[rd_idx] += state->Reg[ra_idx];
ARMul_AddOverflowQ(state, product1 + product2, state->Reg[ra_idx]);
}
// SMUSD
else if ((instr & 0xf0d0) == 0xf050) {
state->Reg[rd_idx] = (rn_lo * rm_lo) - (rn_hi * rm_hi);
ARMul_AddOverflowQ(state, product1, product2);
}
// SMLAD
else if ((instr & 0xd0) == 0x10) {
state->Reg[rd_idx] = (rn_lo * rm_lo) + (rn_hi * rm_hi) + (s32)state->Reg[ra_idx];
}
// SMLSD
// SMUSD and SMLSD
else {
state->Reg[rd_idx] = ((rn_lo * rm_lo) - (rn_hi * rm_hi)) + (s32)state->Reg[ra_idx];
state->Reg[rd_idx] = product1 - product2;
if (BITS(12, 15) != 15)
state->Reg[rd_idx] += state->Reg[ra_idx];
}
return 1;
}
break;

8
src/core/arm/interpreter/armsupp.cpp
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@ -444,6 +444,14 @@ ARMul_AddOverflow (ARMul_State * state, ARMword a, ARMword b, ARMword result)
ASSIGNV (AddOverflow (a, b, result));
}
/* Assigns the Q flag if the given result is considered an overflow from the addition of a and b */
void ARMul_AddOverflowQ(ARMul_State* state, ARMword a, ARMword b)
{
u32 result = a + b;
if (((result ^ a) & (u32)0x80000000) && ((a ^ b) & (u32)0x80000000) == 0)
SETQ;
}
/* Assigns the C flag after an subtraction of a and b to give result. */
void

1
src/core/arm/skyeye_common/armemu.h
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@ -602,6 +602,7 @@ extern ARMword ARMul_SwitchMode (ARMul_State *, ARMword, ARMword);
extern void ARMul_MSRCpsr (ARMul_State *, ARMword, ARMword);
extern void ARMul_SubOverflow (ARMul_State *, ARMword, ARMword, ARMword);
extern void ARMul_AddOverflow (ARMul_State *, ARMword, ARMword, ARMword);
extern void ARMul_AddOverflowQ(ARMul_State*, ARMword, ARMword);
extern void ARMul_SubCarry (ARMul_State *, ARMword, ARMword, ARMword);
extern void ARMul_AddCarry (ARMul_State *, ARMword, ARMword, ARMword);
extern tdstate ARMul_ThumbDecode (ARMul_State *, ARMword, ARMword, ARMword *);