Added some function attributes when using GCC; these may help the optimizer a bit.

1 files changed, 32 insertions, 21 deletions

diff --git a/libfixmath/fix16.h b/libfixmath/fix16.h
index c573786..a2a49b1 100644
--- a/libfixmath/fix16.h
+++ b/libfixmath/fix16.h
@@ -6,6 +6,17 @@ extern "C"
 {

 #endif

 

+/* These options may let the optimizer to remove some calls to the functions.

+ * Refer to http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html

+ */

+#ifndef FIXMATH_FUNC_ATTRS

+# ifdef __GNUC__

+#   define FIXMATH_FUNC_ATTRS __attribute__((leaf, nothrow, pure))

+# else

+#   define FIXMATH_FUNC_ATTRS

+# endif

+#endif

+

 #include <stdint.h>

 

 typedef int32_t fix16_t;

@@ -69,84 +80,84 @@ static inline fix16_t fix16_sub(fix16_t inArg0, fix16_t inArg1) { return (inArg0
 

 #else

 

-extern fix16_t fix16_add(fix16_t a, fix16_t b);

-extern fix16_t fix16_sub(fix16_t a, fix16_t b);

+extern fix16_t fix16_add(fix16_t a, fix16_t b) FIXMATH_FUNC_ATTRS;

+extern fix16_t fix16_sub(fix16_t a, fix16_t b) FIXMATH_FUNC_ATTRS;

 

 /* Saturating arithmetic */

-extern fix16_t fix16_sadd(fix16_t a, fix16_t b);

-extern fix16_t fix16_ssub(fix16_t a, fix16_t b);

+extern fix16_t fix16_sadd(fix16_t a, fix16_t b) FIXMATH_FUNC_ATTRS;

+extern fix16_t fix16_ssub(fix16_t a, fix16_t b) FIXMATH_FUNC_ATTRS;

 

 #endif

 

 /*! Multiplies the two given fix16_t's and returns the result.

 */

-extern fix16_t fix16_mul(fix16_t inArg0, fix16_t inArg1);

+extern fix16_t fix16_mul(fix16_t inArg0, fix16_t inArg1) FIXMATH_FUNC_ATTRS;

 

 /*! Divides the first given fix16_t by the second and returns the result.

 */

-extern fix16_t fix16_div(fix16_t inArg0, fix16_t inArg1);

+extern fix16_t fix16_div(fix16_t inArg0, fix16_t inArg1) FIXMATH_FUNC_ATTRS;

 

 #ifndef FIXMATH_NO_OVERFLOW

 /*! Performs a saturated multiplication (overflow-protected) of the two given fix16_t's and returns the result.

 */

-extern fix16_t fix16_smul(fix16_t inArg0, fix16_t inArg1);

+extern fix16_t fix16_smul(fix16_t inArg0, fix16_t inArg1) FIXMATH_FUNC_ATTRS;

 

 /*! Performs a saturated division (overflow-protected) of the first fix16_t by the second and returns the result.

 */

-extern fix16_t fix16_sdiv(fix16_t inArg0, fix16_t inArg1);

+extern fix16_t fix16_sdiv(fix16_t inArg0, fix16_t inArg1) FIXMATH_FUNC_ATTRS;

 #endif

 

 /*! Returns the linear interpolation: (inArg0 * (1 - inFract)) + (inArg1 * inFract)

 */

-extern fix16_t fix16_lerp8(fix16_t inArg0, fix16_t inArg1, uint8_t inFract);

-extern fix16_t fix16_lerp16(fix16_t inArg0, fix16_t inArg1, uint16_t inFract);

+extern fix16_t fix16_lerp8(fix16_t inArg0, fix16_t inArg1, uint8_t inFract) FIXMATH_FUNC_ATTRS;

+extern fix16_t fix16_lerp16(fix16_t inArg0, fix16_t inArg1, uint16_t inFract) FIXMATH_FUNC_ATTRS;

 #ifndef FIXMATH_NO_64BIT

-extern fix16_t fix16_lerp32(fix16_t inArg0, fix16_t inArg1, uint32_t inFract);

+extern fix16_t fix16_lerp32(fix16_t inArg0, fix16_t inArg1, uint32_t inFract) FIXMATH_FUNC_ATTRS;

 #endif

 

 /*! Returns the sine of the given fix16_t.

 */

-extern fix16_t fix16_sin_parabola(fix16_t inAngle);

+extern fix16_t fix16_sin_parabola(fix16_t inAngle) FIXMATH_FUNC_ATTRS;

 

 /*! Returns the sine of the given fix16_t.

 */

-extern fix16_t fix16_sin(fix16_t inAngle);

+extern fix16_t fix16_sin(fix16_t inAngle) FIXMATH_FUNC_ATTRS;

 

 /*! Returns the cosine of the given fix16_t.

 */

-extern fix16_t fix16_cos(fix16_t inAngle);

+extern fix16_t fix16_cos(fix16_t inAngle) FIXMATH_FUNC_ATTRS;

 

 /*! Returns the tangent of the given fix16_t.

 */

-extern fix16_t fix16_tan(fix16_t inAngle);

+extern fix16_t fix16_tan(fix16_t inAngle) FIXMATH_FUNC_ATTRS;

 

 /*! Returns the arcsine of the given fix16_t.

 */

-extern fix16_t fix16_asin(fix16_t inValue);

+extern fix16_t fix16_asin(fix16_t inValue) FIXMATH_FUNC_ATTRS;

 

 /*! Returns the arccosine of the given fix16_t.

 */

-extern fix16_t fix16_acos(fix16_t inValue);

+extern fix16_t fix16_acos(fix16_t inValue) FIXMATH_FUNC_ATTRS;

 

 /*! Returns the arctangent of the given fix16_t.

 */

-extern fix16_t fix16_atan(fix16_t inValue);

+extern fix16_t fix16_atan(fix16_t inValue) FIXMATH_FUNC_ATTRS;

 

 /*! Returns the arctangent of inY/inX.

 */

-extern fix16_t fix16_atan2(fix16_t inY, fix16_t inX);

+extern fix16_t fix16_atan2(fix16_t inY, fix16_t inX) FIXMATH_FUNC_ATTRS;

 

 

 

 /*! Returns the square root of the given fix16_t.

 */

-extern fix16_t fix16_sqrt(fix16_t inValue);

+extern fix16_t fix16_sqrt(fix16_t inValue) FIXMATH_FUNC_ATTRS;

 

 

 

 /*! Returns the exponent (e^) of the given fix16_t.

 */

-extern fix16_t fix16_exp(fix16_t inValue);

+extern fix16_t fix16_exp(fix16_t inValue) FIXMATH_FUNC_ATTRS;

 

 #ifdef __cplusplus

 }