core: start implementing optimised trigonometry functions for PS3 and x86.

src/Makefile.am

@@ -10,7 +10,7 @@ liblol_a_SOURCES = \
     world.cpp world.h sample.cpp sample.h sampler.cpp sampler.h \
     text.cpp text.h emitter.cpp emitter.h numeric.h hash.cpp hash.h \
     worldentity.cpp worldentity.h gradient.cpp gradient.h half.cpp half.h \
-    platform.cpp platform.h sprite.cpp sprite.h \
+    platform.cpp platform.h sprite.cpp sprite.h trig.cpp trig.h \
     \
     eglapp.cpp eglapp.h \
     \

src/core.h

@@ -17,6 +17,7 @@
 #define __LOL_CORE_H__
 
 // Base types
+#include "trig.h"
 #include "half.h"
 #include "matrix.h"
 #include "numeric.h"

src/trig.cpp

@@ -0,0 +1,194 @@
+//
+// Lol Engine
+//
+// Copyright: (c) 2010-2011 Sam Hocevar <sam@hocevar.net>
+//   This program is free software; you can redistribute it and/or
+//   modify it under the terms of the Do What The Fuck You Want To
+//   Public License, Version 2, as published by Sam Hocevar. See
+//   http://sam.zoy.org/projects/COPYING.WTFPL for more details.
+//
+
+#if defined HAVE_CONFIG_H
+#   include "config.h"
+#endif
+
+#if defined HAVE_FASTMATH_H
+#   include <fastmath.h>
+#endif
+
+#include "core.h"
+
+using namespace std;
+
+namespace lol
+{
+
+static const double PI     = 3.14159265358979323846;
+static const double PI_2   = PI / 2.0;
+static const double PI_4   = PI / 4.0;
+static const double INV_PI = 1.0 / PI;
+static const double ROOT3  = 1.732050807568877293527;
+
+static const double ZERO    = 0.0;
+static const double ONE     = 1.0;
+static const double NEG_ONE = -1.0;
+static const double HALF    = 0.5;
+static const double TWO     = 2.0;
+static const double VERY_SMALL_NUMBER = 0x1.0p-128;
+static const double VERY_LARGE_NUMBER = 4503599627370496.0;
+
+/** sin Taylor series coefficients. */
+static const double SC[]    =
+{
+    -1.6666666666666666666667e-01, // 1/3!
+    +8.3333333333333333333333e-03, // 1/5!
+    -1.9841269841269841269841e-04, // 1/7!
+    +2.7557319223985890652557e-06, // 1/9!
+    -2.5052108385441718775052e-08, // 1/11!
+    +1.6059043836821614599392e-10, // 1/13!
+    -7.6471637318198164759011e-13, // 1/15!
+    +2.8114572543455207631989e-15, // 1/17!
+};
+
+/* Custom intrinsics */
+#define INLINEATTR __attribute__((always_inline))
+
+#if defined __CELLOS_LV2__
+static inline double lol_fctid(double x) INLINEATTR;
+static inline double lol_fctidz(double x) INLINEATTR;
+static inline double lol_fcfid(double x) INLINEATTR;
+static inline double lol_frsqrte(double x) INLINEATTR;
+#endif
+static inline double lol_fsel(double c, double gte, double lt) INLINEATTR;
+static inline double lol_fabs(double x) INLINEATTR;
+static inline double lol_round(double x) INLINEATTR;
+static inline double lol_trunc(double x) INLINEATTR;
+static inline double lol_round(double x) INLINEATTR;
+static inline double lol_trunc(double x) INLINEATTR;
+
+#if defined __CELLOS_LV2__
+static inline double lol_fctid(double x)
+{
+    double r;
+#if defined __SNC__
+    r = __builtin_fctid(x);
+#else
+    __asm__ ("fctid %0, %1"
+             : "=f"(r) : "f"(x));
+#endif
+    return r;
+}
+
+static double lol_fctidz(double x)
+{
+    double r;
+#if defined __SNC__
+    r = __builtin_fctidz(x);
+#else
+    __asm__ ("fctidz %0, %1"
+             : "=f"(r) : "f"(x));
+#endif
+    return r;
+}
+
+static double lol_fcfid(double x)
+{
+    double r;
+#if defined __SNC__
+    r = __builtin_fcfid(x);
+#else
+    __asm__ ("fcfid %0, %1"
+             : "=f"(r) : "f"(x));
+#endif
+    return r;
+}
+
+static double lol_frsqrte(double x)
+{
+#if defined __SNC__
+    return __builtin_frsqrte(x);
+#else
+    double r;
+    __asm__ ("frsqrte %0, %1"
+             : "=f"(r) : "f"(x));
+    return r;
+#endif
+}
+#endif /* __CELLOS_LV2__ */
+
+static inline double lol_fsel(double c, double gte, double lt)
+{
+#if defined __CELLOS_LV2__ && defined __SNC__
+    return __fsel(c, gte, lt);
+#elif defined __CELLOS_LV2__
+    double r;
+    __asm__ ("fsel %0, %1, %2, %3"
+             : "=f"(r) : "f"(c), "f"(gte), "f"(lt));
+    return r;
+#else
+    if (c >= 0) return gte; return lt;
+#endif
+}
+
+static inline double lol_fabs(double x)
+{
+#if defined __CELLOS_LV2__ && defined __SNC__
+    return __fabs(x);
+#elif defined __CELLOS_LV2__
+    double r;
+    __asm__ ("fabs %0, %1"
+             : "=f"(r) : "f"(x));
+    return r;
+#else
+    return __builtin_fabs(x);
+#endif
+}
+
+static inline double lol_round(double x)
+{
+#if defined __CELLOS_LV2__
+    return lol_fcfid(lol_fctid(x));
+#else
+    return __builtin_round(x);
+#endif
+}
+
+static inline double lol_trunc(double x)
+{
+#if defined __CELLOS_LV2__
+    return lol_fcfid(lol_fctidz(x));
+#else
+    return __builtin_trunc(x);
+#endif
+}
+
+double lol_sin(double x)
+{
+    double absx = lol_fabs(x);
+#if defined __CELLOS_LV2__
+    double num_cycles = lol_round(absx * INV_PI);
+    double is_even = lol_trunc(num_cycles * HALF) - (num_cycles * HALF);
+#else
+    double num_cycles = absx * INV_PI;
+    num_cycles += VERY_LARGE_NUMBER;
+    __asm__("" : "+m" (num_cycles));
+    num_cycles -= VERY_LARGE_NUMBER;
+    double is_even = num_cycles * HALF - HALF;
+    is_even += VERY_LARGE_NUMBER;
+    __asm__("" : "+m" (is_even));
+    is_even -= VERY_LARGE_NUMBER;
+    is_even -= num_cycles * HALF;
+#endif
+    double norm_x = absx - PI * num_cycles;
+    double y = norm_x * norm_x;
+    double taylor = ((((((((SC[7] * y + SC[6]) * y + SC[5])
+                                  * y + SC[4]) * y + SC[3])
+                                  * y + SC[2]) * y + SC[1])
+                                  * y + SC[0]) * y);
+    double sign = lol_fsel(is_even * x, ONE, NEG_ONE);
+    double result = norm_x + norm_x * taylor;
+    return result * sign;
+}
+
+} /* namespace lol */
+

src/trig.h

@@ -0,0 +1,38 @@
+//
+// Lol Engine
+//
+// Copyright: (c) 2010-2011 Sam Hocevar <sam@hocevar.net>
+//   This program is free software; you can redistribute it and/or
+//   modify it under the terms of the Do What The Fuck You Want To
+//   Public License, Version 2, as published by Sam Hocevar. See
+//   http://sam.zoy.org/projects/COPYING.WTFPL for more details.
+//
+
+//
+// Trigonometry functions
+// ----------------------
+//
+
+#if !defined __LOL_TRIG_H__
+#define __LOL_TRIG_H__
+
+#include <cstdio>
+#include <stdint.h>
+
+namespace lol
+{
+
+double lol_sin(double);
+double lol_cos(double);
+double lol_tan(double);
+void lol_sincos(double, double*, double*);
+void lol_sincos(float, float*, float*);
+double lol_asin(double);
+double lol_acos(double);
+double lol_atan(double);
+double lol_atan2(double, double);
+
+} /* namespace lol */
+
+#endif // __LOL_TRIG_H__
+