gallium: use new util_fast_exp2(), _log2(), pow() functions

New code surrounded with #if FAST_MATH to allow comparing against original
code if we need to debug.

1 files changed, 19 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/tgsi/tgsi_sse2.c b/src/gallium/auxiliary/tgsi/tgsi_sse2.c
index 485e5a0e6f..e390607023 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_sse2.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_sse2.c
@@ -27,6 +27,7 @@
 
 #include "pipe/p_util.h"
 #include "pipe/p_shader_tokens.h"
+#include "util/u_math.h"
 #include "tgsi/tgsi_parse.h"
 #include "tgsi/tgsi_util.h"
 #include "tgsi_exec.h"
@@ -42,6 +43,8 @@
  */
 #define HIGH_PRECISION 1
 
+#define FAST_MATH 1
+
 
 #define FOR_EACH_CHANNEL( CHAN )\
    for (CHAN = 0; CHAN < NUM_CHANNELS; CHAN++)
@@ -623,10 +626,17 @@ ex24f(
 {
    const unsigned X = 0;
 
+#if FAST_MATH
+   store[X + 0] = util_fast_exp2( store[X + 0] );
+   store[X + 1] = util_fast_exp2( store[X + 1] );
+   store[X + 2] = util_fast_exp2( store[X + 2] );
+   store[X + 3] = util_fast_exp2( store[X + 3] );
+#else
    store[X + 0] = powf( 2.0f, store[X + 0] );
    store[X + 1] = powf( 2.0f, store[X + 1] );
    store[X + 2] = powf( 2.0f, store[X + 2] );
    store[X + 3] = powf( 2.0f, store[X + 3] );
+#endif
 }
 
 static void
@@ -762,10 +772,17 @@ pow4f(
 {
    const unsigned X = 0;
 
+#if FAST_MATH
+   store[X + 0] = util_fast_pow( store[X + 0], store[X + 4] );
+   store[X + 1] = util_fast_pow( store[X + 1], store[X + 5] );
+   store[X + 2] = util_fast_pow( store[X + 2], store[X + 6] );
+   store[X + 3] = util_fast_pow( store[X + 3], store[X + 7] );
+#else
    store[X + 0] = powf( store[X + 0], store[X + 4] );
    store[X + 1] = powf( store[X + 1], store[X + 5] );
    store[X + 2] = powf( store[X + 2], store[X + 6] );
    store[X + 3] = powf( store[X + 3], store[X + 7] );
+#endif
 }
 
 static void
@@ -2235,6 +2252,8 @@ tgsi_emit_sse2(
    unsigned ok = 1;
    uint num_immediates = 0;
 
+   util_init_math();
+
    func->csr = func->store;
 
    tgsi_parse_init( &parse, tokens );