From 47d4b958cfaac080a97bf0ba21d78b3ce37b62a9 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Fri, 22 Aug 2008 15:14:36 -0600 Subject: mesa: glsl: implement exp() functions in terms of EXP asm instruction, not pow --- .../shader/slang/library/slang_common_builtin.gc | 29 +++++++++++----------- 1 file changed, 15 insertions(+), 14 deletions(-) (limited to 'src/mesa/shader/slang/library') diff --git a/src/mesa/shader/slang/library/slang_common_builtin.gc b/src/mesa/shader/slang/library/slang_common_builtin.gc index e908e6c940..561e94f6ba 100644 --- a/src/mesa/shader/slang/library/slang_common_builtin.gc +++ b/src/mesa/shader/slang/library/slang_common_builtin.gc @@ -473,32 +473,33 @@ vec4 pow(const vec4 a, const vec4 b) float exp(const float a) { - const float e = 2.71828; - __asm float_power __retVal, e, a; + // NOTE: log2(e) = 1.44269502 + float t = a * 1.44269502; + __asm float_exp2 __retVal, t; } vec2 exp(const vec2 a) { - const float e = 2.71828; - __asm float_power __retVal.x, e, a.x; - __asm float_power __retVal.y, e, a.y; + vec2 t = a * 1.44269502; + __asm float_exp2 __retVal.x, t.x; + __asm float_exp2 __retVal.y, t.y; } vec3 exp(const vec3 a) { - const float e = 2.71828; - __asm float_power __retVal.x, e, a.x; - __asm float_power __retVal.y, e, a.y; - __asm float_power __retVal.z, e, a.z; + vec3 t = a * 1.44269502; + __asm float_exp2 __retVal.x, t.x; + __asm float_exp2 __retVal.y, t.y; + __asm float_exp2 __retVal.z, t.z; } vec4 exp(const vec4 a) { - const float e = 2.71828; - __asm float_power __retVal.x, e, a.x; - __asm float_power __retVal.y, e, a.y; - __asm float_power __retVal.z, e, a.z; - __asm float_power __retVal.w, e, a.w; + vec4 t = a * 1.44269502; + __asm float_exp2 __retVal.x, t.x; + __asm float_exp2 __retVal.y, t.y; + __asm float_exp2 __retVal.z, t.z; + __asm float_exp2 __retVal.w, t.w; } -- cgit v1.2.3