diff options
Diffstat (limited to 'src/gallium/auxiliary')
-rw-r--r-- | src/gallium/auxiliary/rtasm/rtasm_ppc_spe.c | 41 | ||||
-rw-r--r-- | src/gallium/auxiliary/rtasm/rtasm_ppc_spe.h | 8 |
2 files changed, 48 insertions, 1 deletions
diff --git a/src/gallium/auxiliary/rtasm/rtasm_ppc_spe.c b/src/gallium/auxiliary/rtasm/rtasm_ppc_spe.c index 870ae802c5..12e0826fb9 100644 --- a/src/gallium/auxiliary/rtasm/rtasm_ppc_spe.c +++ b/src/gallium/auxiliary/rtasm/rtasm_ppc_spe.c @@ -384,7 +384,7 @@ void spe_release_func(struct spe_function *p) /** - * Alloate a SPE register. + * Allocate a SPE register. * \return register index or -1 if none left. */ int spe_allocate_available_register(struct spe_function *p) @@ -646,5 +646,44 @@ spe_splat_word(struct spe_function *p, unsigned rT, unsigned rA, int word) } } +/* For each 32-bit float element of rA and rB, choose the smaller of the + * two, compositing them into the rT register. + * + * The Float Compare Greater Than (fcgt) instruction will put 1s into + * compare_reg where rA > rB, and 0s where rA <= rB. + * + * Then the Select Bits (selb) instruction will take bits from rA where + * compare_reg is 0, and from rB where compare_reg is 1; i.e., from rA + * where rA <= rB and from rB where rB > rA, which is exactly the + * "min" operation. + * + * The compare_reg could in many cases be the same as rT, unless + * rT == rA || rt == rB. But since this is common in constructions + * like "x = min(x, a)", we always allocate a new register to be safe. + */ +void +spe_float_min(struct spe_function *p, unsigned int rT, unsigned int rA, unsigned int rB) +{ + unsigned int compare_reg = spe_allocate_available_register(p); + spe_fcgt(p, compare_reg, rA, rB); + spe_selb(p, rT, rA, rB, compare_reg); + spe_release_register(p, compare_reg); +} + +/* For each 32-bit float element of rA and rB, choose the greater of the + * two, compositing them into the rT register. + * + * The logic is similar to that of spe_float_min() above; the only + * difference is that the registers on spe_selb() have been reversed, + * so that the larger of the two is selected instead of the smaller. + */ +void +spe_float_max(struct spe_function *p, unsigned int rT, unsigned int rA, unsigned int rB) +{ + unsigned int compare_reg = spe_allocate_available_register(p); + spe_fcgt(p, compare_reg, rA, rB); + spe_selb(p, rT, rB, rA, compare_reg); + spe_release_register(p, compare_reg); +} #endif /* GALLIUM_CELL */ diff --git a/src/gallium/auxiliary/rtasm/rtasm_ppc_spe.h b/src/gallium/auxiliary/rtasm/rtasm_ppc_spe.h index 2579045232..4ef05ea27d 100644 --- a/src/gallium/auxiliary/rtasm/rtasm_ppc_spe.h +++ b/src/gallium/auxiliary/rtasm/rtasm_ppc_spe.h @@ -322,6 +322,14 @@ spe_zero(struct spe_function *p, unsigned rT); extern void spe_splat_word(struct spe_function *p, unsigned rT, unsigned rA, int word); +/** rT = float min(rA, rB) */ +extern void +spe_float_min(struct spe_function *p, unsigned rT, unsigned rA, unsigned rB); + +/** rT = float max(rA, rB) */ +extern void +spe_float_max(struct spe_function *p, unsigned rT, unsigned rA, unsigned rB); + /* Floating-point instructions */ |