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[mesa.git] / src / gallium / auxiliary / util / u_math.c

diff --git a/src/gallium/auxiliary/util/u_math.c b/src/gallium/auxiliary/util/u_math.c
index 0729114d6a16ba433cad55979d4209c3470a6d14..c58af911be7400b043c7a3d38a94eaadfacb5e2a 100644 (file)
--- a/src/gallium/auxiliary/util/u_math.c
+++ b/src/gallium/auxiliary/util/u_math.c
@@ -1,6 +1,6 @@
 /**************************************************************************
  * 
- * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * Copyright 2008 VMware, Inc.
  * All Rights Reserved.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a
@@ -18,7 +18,7 @@
  * 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 NON-INFRINGEMENT.
- * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS 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.
@@ -27,10 +27,19 @@
 
 
 
+#include "pipe/p_config.h"
 #include "util/u_math.h"
+#include "util/u_cpu_detect.h"
 
+#if defined(PIPE_ARCH_SSE)
+#include <xmmintrin.h>
+/* This is defined in pmmintrin.h, but it can only be included when -msse3 is
+ * used, so just define it here to avoid further. */
+#define _MM_DENORMALS_ZERO_MASK        0x0040
+#endif
 
 
+/** 2^x, for x in [-1.0, 1.0) */
 float pow2_table[POW2_TABLE_SIZE];
 
 
@@ -38,9 +47,21 @@ static void
 init_pow2_table(void)
 {
    int i;
-   for (i = 0; i < POW2_TABLE_SIZE; i++) {
-      pow2_table[i] = (float) pow(2.0, i / POW2_TABLE_SCALE);
-   }
+   for (i = 0; i < POW2_TABLE_SIZE; i++)
+      pow2_table[i] = exp2f((i - POW2_TABLE_OFFSET) / POW2_TABLE_SCALE);
+}
+
+
+/** log2(x), for x in [1.0, 2.0) */
+float log2_table[LOG2_TABLE_SIZE];
+
+
+static void 
+init_log2_table(void)
+{
+   unsigned i;
+   for (i = 0; i < LOG2_TABLE_SIZE; i++)
+      log2_table[i] = (float) log2(1.0 + i * (1.0 / LOG2_TABLE_SCALE));
 }
 
 
@@ -53,8 +74,64 @@ util_init_math(void)
    static boolean initialized = FALSE;
    if (!initialized) {
       init_pow2_table();
+      init_log2_table();
       initialized = TRUE;
    }
 }
 
+/**
+ * Fetches the contents of the fpstate (mxcsr on x86) register.
+ *
+ * On platforms without support for it just returns 0.
+ */
+unsigned
+util_fpstate_get(void)
+{
+   unsigned mxcsr = 0;
+
+#if defined(PIPE_ARCH_SSE)
+   if (util_cpu_caps.has_sse) {
+      mxcsr = _mm_getcsr();
+   }
+#endif
+
+   return mxcsr;
+}
+
+/**
+ * Make sure that the fp treats the denormalized floating
+ * point numbers as zero.
+ *
+ * This is the behavior required by D3D10. OpenGL doesn't care.
+ */
+unsigned
+util_fpstate_set_denorms_to_zero(unsigned current_mxcsr)
+{
+#if defined(PIPE_ARCH_SSE)
+   if (util_cpu_caps.has_sse) {
+      /* Enable flush to zero mode */
+      current_mxcsr |= _MM_FLUSH_ZERO_MASK;
+      if (util_cpu_caps.has_daz) {
+         /* Enable denormals are zero mode */
+         current_mxcsr |= _MM_DENORMALS_ZERO_MASK;
+      }
+      util_fpstate_set(current_mxcsr);
+   }
+#endif
+   return current_mxcsr;
+}
 
+/**
+ * Set the state of the fpstate (mxcsr on x86) register.
+ *
+ * On platforms without support for it's a noop.
+ */
+void
+util_fpstate_set(unsigned mxcsr)
+{
+#if defined(PIPE_ARCH_SSE)
+   if (util_cpu_caps.has_sse) {
+      _mm_setcsr(mxcsr);
+   }
+#endif
+}