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/******************************************************************************\
* Authors: Iconoclast *
* Release: 2013.11.26 *
* License: CC0 Public Domain Dedication *
* *
* To the extent possible under law, the author(s) have dedicated all copyright *
* and related and neighboring rights to this software to the public domain *
* worldwide. This software is distributed without any warranty. *
* *
* You should have received a copy of the CC0 Public Domain Dedication along *
* with this software. *
* If not, see <http://creativecommons.org/publicdomain/zero/1.0/>. *
\******************************************************************************/
#include "vu.h"
#ifdef VU_EMULATE_SCALAR_ACCUMULATOR_READ
static void VSAR(usf_state_t * state, int vd, int vs, int vt, int e)
{
ALIGNED short oldval[N];
register int i;
for (i = 0; i < N; i++)
oldval[i] = state->VR[vs][i];
vt = 0;
/* Even though VT is ignored in VSAR, according to official sources as well
* as reversing, lots of games seem to specify it as non-zero, possibly to
* avoid register stalling or other VU hazards. Not really certain why yet.
*/
e ^= 0x8;
/* Or, for exception overrides, should this be `e &= 0x7;` ?
* Currently this code is safer because &= is less likely to catch oddities.
* Either way, documentation shows that the switch range is 0:2, not 8:A.
*/
if (e > 2)
{
message(state, "VSAR\nInvalid mask.", 2);
#if ARCH_MIN_ARM_NEON
int16x8_t zero = vdupq_n_s16(0);
vst1q_s16(VR[vd], zero);
#else
for (i = 0; i < N; i++)
state->VR[vd][i] = 0x0000; /* override behavior (zilmar) */
#endif
}
else
{
#if ARCH_MIN_ARM_NEON
vector_copy(VR[vd], VACC[e]);
#else
for (i = 0; i < N; i++)
state->VR[vd][i] = state->VACC[e][i];
#endif
}
for (i = 0; i < N; i++)
state->VACC[e][i] = oldval[i]; /* ... = VS */
return;
}
#endif
static void VSAW(usf_state_t * state, int vd, int vs, int vt, int e)
{
register int i;
vs = 0; /* unused--old VSAR algorithm */
vt = 0; /* unused but mysteriously set many times */
if (vs | vt)
return;
e ^= 0x8; /* &= 7 */
if (e > 0x2)
{ /* branch very unlikely...never seen a game do VSAW illegally */
message(state, "VSAW\nIllegal mask.", 2);
#if ARCH_MIN_ARM_NEON
int16x8_t zero = vdupq_n_s16(0);
vst1q_s16(state->VR[vd], zero);
#else
for (i = 0; i < N; i++)
state->VR[vd][i] = 0x0000; /* override behavior (zilmar) */
return;
#endif
}
vector_copy(state->VR[vd], state->VACC[e]);
return;
}