-/***
- *** START_FAST_MATH: Set x86 FPU to faster, 32-bit precision mode (and save
- *** original mode to a temporary).
- *** END_FAST_MATH: Restore x86 FPU to original mode.
- ***/
-#if defined(__GNUC__) && defined(__i386__)
-/*
- * Set the x86 FPU control word to guarentee only 32 bits of precision
- * are stored in registers. Allowing the FPU to store more introduces
- * differences between situations where numbers are pulled out of memory
- * vs. situations where the compiler is able to optimize register usage.
- *
- * In the worst case, we force the compiler to use a memory access to
- * truncate the float, by specifying the 'volatile' keyword.
- */
-/* Hardware default: All exceptions masked, extended double precision,
- * round to nearest (IEEE compliant):
- */
-#define DEFAULT_X86_FPU 0x037f
-/* All exceptions masked, single precision, round to nearest:
- */
-#define FAST_X86_FPU 0x003f
-/* The fldcw instruction will cause any pending FP exceptions to be
- * raised prior to entering the block, and we clear any pending
- * exceptions before exiting the block. Hence, asm code has free
- * reign over the FPU while in the fast math block.
- */
-#if defined(NO_FAST_MATH)
-#define START_FAST_MATH(x) \
-do { \
- static GLuint mask = DEFAULT_X86_FPU; \
- __asm__ ( "fnstcw %0" : "=m" (*&(x)) ); \
- __asm__ ( "fldcw %0" : : "m" (mask) ); \
-} while (0)
-#else
-#define START_FAST_MATH(x) \
-do { \
- static GLuint mask = FAST_X86_FPU; \
- __asm__ ( "fnstcw %0" : "=m" (*&(x)) ); \
- __asm__ ( "fldcw %0" : : "m" (mask) ); \
-} while (0)
-#endif
-/* Restore original FPU mode, and clear any exceptions that may have
- * occurred in the FAST_MATH block.
- */
-#define END_FAST_MATH(x) \
-do { \
- __asm__ ( "fnclex ; fldcw %0" : : "m" (*&(x)) ); \
-} while (0)
-
-#elif defined(__WATCOMC__) && defined(__386__)
-#define DEFAULT_X86_FPU 0x037f /* See GCC comments above */
-#define FAST_X86_FPU 0x003f /* See GCC comments above */
-void _watcom_start_fast_math(unsigned short *x,unsigned short *mask);
-#pragma aux _watcom_start_fast_math = \
- "fnstcw word ptr [eax]" \
- "fldcw word ptr [ecx]" \
- parm [eax] [ecx] \
- modify exact [];
-void _watcom_end_fast_math(unsigned short *x);
-#pragma aux _watcom_end_fast_math = \
- "fnclex" \
- "fldcw word ptr [eax]" \
- parm [eax] \
- modify exact [];
-#if defined(NO_FAST_MATH)
-#define START_FAST_MATH(x) \
-do { \
- static GLushort mask = DEFAULT_X86_FPU; \
- _watcom_start_fast_math(&x,&mask); \
-} while (0)
-#else
-#define START_FAST_MATH(x) \
-do { \
- static GLushort mask = FAST_X86_FPU; \
- _watcom_start_fast_math(&x,&mask); \
-} while (0)
-#endif
-#define END_FAST_MATH(x) _watcom_end_fast_math(&x)
-
-#elif defined(_MSC_VER) && defined(_M_IX86)
-#define DEFAULT_X86_FPU 0x037f /* See GCC comments above */
-#define FAST_X86_FPU 0x003f /* See GCC comments above */
-#if defined(NO_FAST_MATH)
-#define START_FAST_MATH(x) do {\
- static GLuint mask = DEFAULT_X86_FPU;\
- __asm fnstcw word ptr [x]\
- __asm fldcw word ptr [mask]\
-} while(0)
-#else
-#define START_FAST_MATH(x) do {\
- static GLuint mask = FAST_X86_FPU;\
- __asm fnstcw word ptr [x]\
- __asm fldcw word ptr [mask]\
-} while(0)
-#endif
-#define END_FAST_MATH(x) do {\
- __asm fnclex\
- __asm fldcw word ptr [x]\
-} while(0)
-
-#else
-#define START_FAST_MATH(x) x = 0
-#define END_FAST_MATH(x) (void)(x)
-#endif
-
-