Changeset 109 for mppenc/trunk/src/fastmath.h

Timestamp:

11/10/06 22:04:46 (17 years ago)

Author:

zorg

Message:

Remove math aliasing issues which were breaking gcc

File:

• mppenc/trunk/src/fastmath.h (modified) (5 diffs)

mppenc/trunk/src/fastmath.h

@@ -18 +18 @@
  */
 
-#if 1
-# define ROUND32(x)   ( floattmp = (x) + (int)0x00FD8000L, *(int*)(&floattmp) - (int)0x4B7D8000L )
-#else
-# define ROUND32(x)   ( (int) floor ((x) + 0.5) )
-#endif
+typedef union mpc_floatint
+{
+    float   f;
+    Int32_t n;
+} mpc_floatint;
+
+static __inline Int32_t mpc_nearbyintf(float fVal)
+{
+    mpc_floatint tmp;
+    tmp.f = fVal  + 0x00FF8000;
+    tmp.n = tmp.n - 0x4B7F8000;
+    return tmp.n;
+}
+#define mpc_lrintf mpc_nearbyintf
+static __inline Int32_t mpc_round32(float fVal)
+{
+    mpc_floatint tmp;
+    tmp.f = fVal  + 0x00FD8000;
+    tmp.n = tmp.n - 0x4B7D8000;
+    return tmp.n;
+}
 
 #ifdef FAST_MATH
@@ -29 +45 @@
 my_atan2 ( float x, float y )
 {
-    float  t;
-    int    i;
-    float  ret;
-    float  floattmp;
+    float t, ret; int i; mpc_floatint mx, my;
 
-    if ( (*(int*)&x & 0x7FFFFFFF) < (*(int*)&y & 0x7FFFFFFF) ) {
-        i   = ROUND32 (t = TABSTEP * (x / y));
+    mx.f = x;
+    my.f = y;
+    if ( (mx.n & 0x7FFFFFFF) < (my.n & 0x7FFFFFFF) ) {
+        i   = mpc_round32 (t = TABSTEP * (mx.f / my.f));
         ret = tabatan2 [1*TABSTEP+i][0] + tabatan2 [1*TABSTEP+i][1] * (t-i);
-        if ( *(int*)&y < 0 )
+        if ( my.n < 0 )
            ret = (float)(ret - M_PI);
     }
-    else if ( *(int*)&x < 0) {
-        i   = ROUND32 (t = TABSTEP * (y / x));
+    else if ( mx.n < 0 ) {
+        i   = mpc_round32 (t = TABSTEP * (my.f / mx.f));
         ret = - M_PI/2 - tabatan2 [1*TABSTEP+i][0] + tabatan2 [1*TABSTEP+i][1] * (i-t);
     }
-    else if ( *(int*)&x > 0) {
-        i   = ROUND32 (t = TABSTEP * (y / x));
+    else if ( mx.n > 0 ) {
+        i   = mpc_round32 (t = TABSTEP * (my.f / mx.f));
         ret = + M_PI/2 - tabatan2 [1*TABSTEP+i][0] + tabatan2 [1*TABSTEP+i][1] * (i-t);
     }
@@ -58 +73 @@
 my_cos ( float x )
 {
-    float  t;
-    int    i;
-    float  ret;
-    float  floattmp;
-
-    i   = ROUND32 (t = TABSTEP * x);
+    float t, ret; int i;
+    i   = mpc_round32 (t = TABSTEP * x);
     ret = tabcos [13*TABSTEP+i][0] + tabcos [13*TABSTEP+i][1] * (t-i);
     return ret;
@@ -72 +83 @@
 my_ifloor ( float x )
 {
-    x = x + (0x0C00000L + 0.500000001);
-    return *(int*)&x - 1262485505;
+    mpc_floatint mx;
+    mx.f = (float) (x + (0x0C00000L + 0.500000001));
+    return mx.n - 1262485505;
 }
 
@@ -80 +92 @@
 my_sqrt ( float x )
 {
-    float  ret;
-    int    i;
-    int    ex = *(int*)&x >> 23;                                // get the exponent
-    float  floattmp;
-
-    *(int*)&x = (*(int*)&x & 0x7FFFFF) | 0x42800000;            // delete the exponent
-    i    = ROUND32 (x);                                         // Integer-part of the mantissa  (round ????????????)
-    ret  = tabsqrt_m [i-TABSTEP][0] + tabsqrt_m [i-TABSTEP][1] * (x-i); // calculate value
+    float  ret; int i, ex; mpc_floatint mx;
+    mx.f = x;
+    ex   = mx.n >> 23;                     // get the exponent
+    mx.n = (mx.n & 0x7FFFFF) | 0x42800000; // delete the exponent
+    i    = mpc_round32 (mx.f);             // Integer-part of the mantissa  (round ????????????)
+    ret  = tabsqrt_m [i-TABSTEP][0] + tabsqrt_m [i-TABSTEP][1] * (mx.f-i); // calculate value
     ret *= tabsqrt_ex [ex];
     return ret;