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sh2 drc, fix optimized standard division

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still turned off, needs testing and performance checks
This commit is contained in:
kub 2021-04-07 22:24:03 +02:00
parent a95da16ae1
commit 5f97951865
1 changed files with 46 additions and 28 deletions
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74
cpu/sh2/compiler.c
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@ -3014,12 +3014,21 @@ static void emit_do_static_regs(int is_write, int tmpr)
// divide operation replacement functions, called by compiled code. Only the
// 32:16 cases and the 64:32 cases described in the SH2 prog man are replaced.
static uint32_t REGPARM(2) sh2_drc_divu32(uint32_t dv, uint32_t ds)
// This is surprisingly difficult since the SH2 division operation is generating// the result in the dividend during the operation, leaving some remainder-like
// stuff in the bits unused for the result, and leaving the T and Q status bits
// in a state depending on the operands and the result. Q always reflects the
// last result bit generated (i.e. bit 0 of the result). For T:
// 32:16 T = top bit of the 16 bit remainder-like
// 64:32 T = resulting T of the DIV0U/S operation
// The remainder-like depends on outcome of the last generated result bit.
static uint32_t REGPARM(3) sh2_drc_divu32(uint32_t dv, uint32_t *dt, uint32_t ds)
{
if (ds && ds >= dv) {
// good case: no divide by 0, and no result overflow
if (ds > dv && (uint16_t)ds == 0) {
// good case: no overflow, divisor not 0, lower 16 bits 0
uint32_t quot = dv / (ds>>16), rem = dv - (quot * (ds>>16));
if (~quot&1) rem -= ds>>16;
*dt = (rem>>15) & 1;
return (uint16_t)quot | ((2*rem + (quot>>31)) << 16);
} else {
// bad case: use the sh2 algo to get the right result
@ -3029,20 +3038,21 @@ static uint32_t REGPARM(2) sh2_drc_divu32(uint32_t dv, uint32_t ds)
dv = (dv<<1) | t;
t = v;
v = dv;
if (q) dv += ds, q = dv < v;
else dv -= ds, q = !(dv < v);
if (q) dv += ds, q = dv < v;
else dv -= ds, q = dv > v;
q ^= t, t = !q;
}
*dt = dv>>31;
return (dv<<1) | t;
}
}
static uint32_t REGPARM(3) sh2_drc_divu64(uint32_t dh, uint32_t *dl, uint32_t ds)
{
if (ds > 1 && ds >= dh) {
// good case: no divide by 0, and no result overflow
if (ds > dh) {
// good case: no overflow, divisor not 0
uint64_t dv = *dl | ((uint64_t)dh << 32);
uint32_t quot = dv / ds, rem = dv - (quot * ds);
uint32_t quot = dv / ds, rem = dv - ((uint64_t)quot * ds);
if (~quot&1) rem -= ds;
*dl = quot;
return rem;
@ -3055,8 +3065,8 @@ static uint32_t REGPARM(3) sh2_drc_divu64(uint32_t dh, uint32_t *dl, uint32_t ds
dv = (dv<<1) | t;
t = v;
v = dv;
if (q) dv += ((uint64_t)ds << 32), q = dv < v;
else dv -= ((uint64_t)ds << 32), q = !(dv < v);
if (q) dv += ((uint64_t)ds << 32), q = dv < v;
else dv -= ((uint64_t)ds << 32), q = dv > v;
q ^= t, t = !q;
}
*dl = (dv<<1) | t;
@ -3064,16 +3074,17 @@ static uint32_t REGPARM(3) sh2_drc_divu64(uint32_t dh, uint32_t *dl, uint32_t ds
}
}
static uint32_t REGPARM(2) sh2_drc_divs32(int32_t dv, int32_t ds)
static uint32_t REGPARM(3) sh2_drc_divs32(int32_t dv, uint32_t *dt, int32_t ds)
{
uint32_t adv = abs(dv), ads = abs(ds)>>16;
if (ads > 1 && ads > adv>>16 && (int32_t)ads > 0 && !(uint16_t)ds) {
// good case: no divide by 0, and no result overflow
if (ads > adv>>16 && ds != 0x80000000 && (int16_t)ds == 0) {
// good case: no overflow, divisor not 0 and not MIN_INT, lower 16 bits 0
uint32_t quot = adv / ads, rem = adv - (quot * ads);
int m1 = (rem ? dv^ds : ds) < 0;
if (rem && dv < 0) rem = (quot&1 ? -rem : +ads-rem);
else rem = (quot&1 ? +rem : -ads+rem);
quot = ((dv^ds)<0 ? -quot : +quot) - m1;
*dt = (rem>>15) & 1;
return (uint16_t)quot | ((2*rem + (quot>>31)) << 16);
} else {
// bad case: use the sh2 algo to get the right result
@ -3083,10 +3094,11 @@ static uint32_t REGPARM(2) sh2_drc_divs32(int32_t dv, int32_t ds)
dv = (dv<<1) | t;
t = v;
v = dv;
if (m^q) dv += ds, q = (uint32_t)dv < v;
else dv -= ds, q = !((uint32_t)dv < v);
if (m^q) dv += ds, q = (uint32_t)dv < v;
else dv -= ds, q = (uint32_t)dv > v;
q ^= m^t, t = !(m^q);
}
*dt = (uint32_t)dv>>31;
return (dv<<1) | t;
}
}
@ -3096,8 +3108,8 @@ static uint32_t REGPARM(3) sh2_drc_divs64(int32_t dh, uint32_t *dl, int32_t ds)
int64_t _dv = *dl | ((int64_t)dh << 32);
uint64_t adv = (_dv < 0 ? -_dv : _dv); // llabs isn't in older toolchains
uint32_t ads = abs(ds);
if (ads > 1 && ads > adv>>32 && (int64_t)adv > 0) {
// good case: no divide by 0, and no result overflow
if (ads > adv>>32 && ds != 0x80000000) {
// good case: no overflow, divisor not 0 and not MIN_INT
uint32_t quot = adv / ads, rem = adv - ((uint64_t)quot * ads);
int m1 = (rem ? dh^ds : ds) < 0;
if (rem && dh < 0) rem = (quot&1 ? -rem : +ads-rem);
@ -3110,12 +3122,12 @@ static uint32_t REGPARM(3) sh2_drc_divs64(int32_t dh, uint32_t *dl, int32_t ds)
uint64_t dv = *dl | ((uint64_t)dh << 32);
int m = (uint32_t)ds>>31, q = (uint64_t)dv>>63, t = m^q, s = 32;
while (s--) {
int64_t v = (uint64_t)dv>>63;
uint64_t v = (uint64_t)dv>>63;
dv = (dv<<1) | t;
t = v;
v = dv;
if (m^q) dv += ((uint64_t)ds << 32), q = dv < v;
else dv -= ((uint64_t)ds << 32), q = !(dv < v);
if (m^q) dv += ((uint64_t)ds << 32), q = dv < v;
else dv -= ((uint64_t)ds << 32), q = dv > v;
q ^= m^t, t = !(m^q);
}
*dl = (dv<<1) | t;
@ -3921,8 +3933,10 @@ static void REGPARM(2) *sh2_translate(SH2 *sh2, int tcache_id)
#if DIV_OPTIMIZER
if (div(opd).div1 == 16 && div(opd).ro == div(opd).rn) {
// divide 32/16
tmp = rcache_get_tmp_arg(1);
emith_add_r_r_ptr_imm(tmp, CONTEXT_REG, offsetof(SH2, drc_tmp));
rcache_get_reg_arg(0, div(opd).rn, NULL);
rcache_get_reg_arg(1, div(opd).rm, NULL);
rcache_get_reg_arg(2, div(opd).rm, NULL);
rcache_invalidate_tmp();
emith_abicall(sh2_drc_divu32);
tmp = rcache_get_tmp_ret();
@ -3934,8 +3948,9 @@ static void REGPARM(2) *sh2_translate(SH2 *sh2, int tcache_id)
emith_and_r_r_imm(tmp3, tmp2, 1); // Q = !Rn[0]
emith_eor_r_r_imm(tmp3, tmp3, 1);
emith_or_r_r_lsl(sr, tmp3, Q_SHIFT);
emith_ctx_read(tmp3, offsetof(SH2, drc_tmp));
emith_or_r_r_r(sr, sr, tmp3); // T
rcache_free_tmp(tmp3);
emith_or_r_r_r_lsr(sr, sr, tmp2, 31); // T = Rn[31]
skip_op = div(opd).div1 + div(opd).rotcl;
}
else if (div(opd).div1 == 32 && div(opd).ro != div(opd).rn) {
@ -3960,7 +3975,6 @@ static void REGPARM(2) *sh2_translate(SH2 *sh2, int tcache_id)
emith_eor_r_r_imm(tmp3, tmp3, 1);
emith_or_r_r_lsl(sr, tmp3, Q_SHIFT);
rcache_free_tmp(tmp3);
emith_or_r_r_r_lsr(sr, sr, tmp4, 31); // T = Ro[31]
skip_op = div(opd).div1 + div(opd).rotcl;
}
#endif
@ -4035,8 +4049,10 @@ static void REGPARM(2) *sh2_translate(SH2 *sh2, int tcache_id)
#if DIV_OPTIMIZER
if (div(opd).div1 == 16 && div(opd).ro == div(opd).rn) {
// divide 32/16
tmp = rcache_get_tmp_arg(1);
emith_add_r_r_ptr_imm(tmp, CONTEXT_REG, offsetof(SH2, drc_tmp));
rcache_get_reg_arg(0, div(opd).rn, NULL);
tmp2 = rcache_get_reg_arg(1, div(opd).rm, NULL);
tmp2 = rcache_get_reg_arg(2, div(opd).rm, NULL);
tmp3 = rcache_get_tmp();
emith_lsr(tmp3, tmp2, 31);
emith_or_r_r_lsl(sr, tmp3, M_SHIFT); // M = Rm[31]
@ -4052,19 +4068,22 @@ static void REGPARM(2) *sh2_translate(SH2 *sh2, int tcache_id)
emith_and_r_r_imm(tmp3, tmp3, 1);
emith_eor_r_r_imm(tmp3, tmp3, 1);
emith_or_r_r_lsl(sr, tmp3, Q_SHIFT); // Q = !Rn[0]^M
emith_ctx_read(tmp3, offsetof(SH2, drc_tmp));
emith_or_r_r_r(sr, sr, tmp3); // T
rcache_free_tmp(tmp3);
emith_or_r_r_r_lsr(sr, sr, tmp2, 31); // T = Rn[31]
skip_op = div(opd).div1 + div(opd).rotcl;
}
else if (div(opd).div1 == 32 && div(opd).ro != div(opd).rn) {
// divide 64/32
tmp4 = rcache_get_reg(div(opd).ro, RC_GR_READ, NULL);
emith_ctx_write(tmp4, offsetof(SH2, drc_tmp));
rcache_get_reg_arg(0, div(opd).rn, NULL);
tmp = rcache_get_reg_arg(0, div(opd).rn, NULL);
tmp2 = rcache_get_reg_arg(2, div(opd).rm, NULL);
tmp3 = rcache_get_tmp_arg(1);
emith_lsr(tmp3, tmp2, 31);
emith_or_r_r_lsl(sr, tmp3, M_SHIFT); // M = Rm[31]
emith_or_r_r_lsl(sr, tmp3, M_SHIFT); // M = Rm[31]
emith_eor_r_r_lsr(tmp3, tmp, 31);
emith_or_r_r(sr, tmp3); // T = Rn[31]^M
emith_add_r_r_ptr_imm(tmp3, CONTEXT_REG, offsetof(SH2, drc_tmp));
rcache_invalidate_tmp();
emith_abicall(sh2_drc_divs64);
@ -4081,7 +4100,6 @@ static void REGPARM(2) *sh2_translate(SH2 *sh2, int tcache_id)
emith_eor_r_r_imm(tmp3, tmp3, 1);
emith_or_r_r_lsl(sr, tmp3, Q_SHIFT); // Q = !Ro[0]^M
rcache_free_tmp(tmp3);
emith_or_r_r_r_lsr(sr, sr, tmp4, 31); // T = Ro[31]
skip_op = div(opd).div1 + div(opd).rotcl;
} else
#endif