diff options
| -rw-r--r-- | src/gallium/auxiliary/util/u_format_rgb9e5.h | 35 |
1 files changed, 17 insertions, 18 deletions
diff --git a/src/gallium/auxiliary/util/u_format_rgb9e5.h b/src/gallium/auxiliary/util/u_format_rgb9e5.h index 59fc291e917..d11bfa833f1 100644 --- a/src/gallium/auxiliary/util/u_format_rgb9e5.h +++ b/src/gallium/auxiliary/util/u_format_rgb9e5.h @@ -21,7 +21,8 @@ * DEALINGS IN THE SOFTWARE. */ -/* Copied from EXT_texture_shared_exponent and edited. */ +/* Copied from EXT_texture_shared_exponent and edited, getting rid of + * expensive float math bits too. */ #ifndef RGB9E5_H #define RGB9E5_H @@ -39,7 +40,6 @@ #define RGB9E5_MANTISSA_VALUES (1<<RGB9E5_MANTISSA_BITS) #define MAX_RGB9E5_MANTISSA (RGB9E5_MANTISSA_VALUES-1) #define MAX_RGB9E5 (((float)MAX_RGB9E5_MANTISSA)/RGB9E5_MANTISSA_VALUES * (1<<MAX_RGB9E5_EXP)) -#define EPSILON_RGB9E5 ((1.0/RGB9E5_MANTISSA_VALUES) / (1<<RGB9E5_EXP_BIAS)) typedef union { unsigned int raw; @@ -84,7 +84,7 @@ static inline float rgb9e5_ClampRange(float x) } } else { /* NaN gets here too since comparisons with NaN always fail! */ - return 0.0; + return 0.0f; } } @@ -106,31 +106,30 @@ static inline unsigned float3_to_rgb9e5(const float rgb[3]) int rm, gm, bm; float rc, gc, bc; int exp_shared, maxm; - double denom; + float754 revdenom = {0}; rc = rgb9e5_ClampRange(rgb[0]); gc = rgb9e5_ClampRange(rgb[1]); bc = rgb9e5_ClampRange(rgb[2]); maxrgb = MAX3(rc, gc, bc); - exp_shared = MAX2(-RGB9E5_EXP_BIAS-1, rgb9e5_FloorLog2(maxrgb)) + 1 + RGB9E5_EXP_BIAS; + exp_shared = MAX2(-RGB9E5_EXP_BIAS - 1, rgb9e5_FloorLog2(maxrgb)) + 1 + RGB9E5_EXP_BIAS; assert(exp_shared <= RGB9E5_MAX_VALID_BIASED_EXP); assert(exp_shared >= 0); - /* This exp2 function could be replaced by a table. */ - denom = exp2(exp_shared - RGB9E5_EXP_BIAS - RGB9E5_MANTISSA_BITS); + revdenom.field.biasedexponent = 127 - (exp_shared - RGB9E5_EXP_BIAS - RGB9E5_MANTISSA_BITS); - maxm = (int) floor(maxrgb / denom + 0.5); - if (maxm == MAX_RGB9E5_MANTISSA+1) { - denom *= 2; + maxm = (int) (maxrgb * revdenom.value + 0.5); + if (maxm == MAX_RGB9E5_MANTISSA + 1) { + revdenom.value *= 0.5f; exp_shared += 1; assert(exp_shared <= RGB9E5_MAX_VALID_BIASED_EXP); } else { assert(maxm <= MAX_RGB9E5_MANTISSA); } - rm = (int) floor(rc / denom + 0.5); - gm = (int) floor(gc / denom + 0.5); - bm = (int) floor(bc / denom + 0.5); + rm = (int) (rc * revdenom.value + 0.5); + gm = (int) (gc * revdenom.value + 0.5); + bm = (int) (bc * revdenom.value + 0.5); assert(rm <= MAX_RGB9E5_MANTISSA); assert(gm <= MAX_RGB9E5_MANTISSA); @@ -151,15 +150,15 @@ static inline void rgb9e5_to_float3(unsigned rgb, float retval[3]) { rgb9e5 v; int exponent; - float scale; + float754 scale = {0}; v.raw = rgb; exponent = v.field.biasedexponent - RGB9E5_EXP_BIAS - RGB9E5_MANTISSA_BITS; - scale = exp2f(exponent); + scale.field.biasedexponent = exponent + 127; - retval[0] = v.field.r * scale; - retval[1] = v.field.g * scale; - retval[2] = v.field.b * scale; + retval[0] = v.field.r * scale.value; + retval[1] = v.field.g * scale.value; + retval[2] = v.field.b * scale.value; } #endif |