diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/Makefile.sources | 1 | ||||
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_packed_float.c | 75 | ||||
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_reg.h | 4 |
3 files changed, 80 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/Makefile.sources b/src/mesa/drivers/dri/i965/Makefile.sources index 711aabe462a..26bf458e183 100644 --- a/src/mesa/drivers/dri/i965/Makefile.sources +++ b/src/mesa/drivers/dri/i965/Makefile.sources @@ -79,6 +79,7 @@ i965_FILES = \ brw_meta_fast_clear.c \ brw_misc_state.c \ brw_object_purgeable.c \ + brw_packed_float.c \ brw_performance_monitor.c \ brw_program.c \ brw_primitive_restart.c \ diff --git a/src/mesa/drivers/dri/i965/brw_packed_float.c b/src/mesa/drivers/dri/i965/brw_packed_float.c new file mode 100644 index 00000000000..329ba15a8d2 --- /dev/null +++ b/src/mesa/drivers/dri/i965/brw_packed_float.c @@ -0,0 +1,75 @@ +/* + * Copyright © 2014 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ +#include "brw_reg.h" + +union fu { + float f; + unsigned u; + struct { + unsigned mantissa:23; + unsigned exponent:8; + unsigned sign:1; + }; +}; + +int +brw_float_to_vf(float f) +{ + union fu fu = { .f = f }; + + /* ±0.0f is special cased. */ + if (f == 0.0f) + return fu.sign << 7; + + unsigned mantissa = fu.mantissa >> (23 - 4); + unsigned exponent = fu.exponent - (127 - 3); + unsigned vf = (fu.sign << 7) | (exponent << 4) | mantissa; + + /* 0.125 would have had the same representation as 0.0, so reject it. */ + if ((vf & 0x7f) == 0) + return -1; + + /* Make sure the mantissa fits in 4-bits and the exponent in 3-bits. */ + if (fu.u & 0x7ffff || exponent > 7) + return -1; + + return vf; +} + +float +brw_vf_to_float(unsigned char vf) +{ + union fu fu; + + /* ±0.0f is special cased. */ + if (vf == 0x00 || vf == 0x80) { + fu.u = vf << 24; + return fu.f; + } + + fu.sign = vf >> 7; + fu.exponent = ((vf & 0x70) >> 4) + (127 - 3); + fu.mantissa = (vf & 0xf) << (23 - 4); + + return fu.f; +} diff --git a/src/mesa/drivers/dri/i965/brw_reg.h b/src/mesa/drivers/dri/i965/brw_reg.h index 19af0ae09fc..175554b9877 100644 --- a/src/mesa/drivers/dri/i965/brw_reg.h +++ b/src/mesa/drivers/dri/i965/brw_reg.h @@ -881,6 +881,10 @@ brw_indirect(unsigned addr_subnr, int offset) return ptr; } +/* brw_packed_float.c */ +int brw_float_to_vf(float f); +float brw_vf_to_float(unsigned char vf); + #ifdef __cplusplus } #endif |