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add FORCE_EVAL macro to evaluate float expr for their side effect

updated nextafter* to use FORCE_EVAL, it can be used in many other
places in the math code to improve readability.
rs-1.0
nsz 14 years ago
parent
commit
6ab8136b44
  1. 13
      src/internal/libm.h
  2. 6
      src/math/nextafter.c
  3. 6
      src/math/nextafterf.c
  4. 12
      src/math/nextafterl.c
  5. 6
      src/math/nexttoward.c
  6. 6
      src/math/nexttowardf.c

13
src/internal/libm.h

@ -32,6 +32,19 @@ union dshape {
uint64_t bits;
};
#define FORCE_EVAL(x) do { \
if (sizeof(x) == sizeof(float)) { \
volatile float __x; \
__x = (x); \
} else if (sizeof(x) == sizeof(double)) { \
volatile double __x; \
__x = (x); \
} else { \
volatile long double __x; \
__x = (x); \
} \
} while(0)
/* Get two 32 bit ints from a double. */
#define EXTRACT_WORDS(hi,lo,d) \
do { \

6
src/math/nextafter.c

@ -29,9 +29,7 @@ double nextafter(double x, double y)
if (e == 0x7ff)
return x + x;
/* raise underflow if ux.value is subnormal or zero */
if (e == 0) {
volatile double z;
z = x*x + ux.value*ux.value;
}
if (e == 0)
FORCE_EVAL(x*x + ux.value*ux.value);
return ux.value;
}

6
src/math/nextafterf.c

@ -28,9 +28,7 @@ float nextafterf(float x, float y)
if (e == 0x7f800000)
return x + x;
/* raise underflow if ux.value is subnormal or zero */
if (e == 0) {
volatile float z;
z = x*x + ux.value*ux.value;
}
if (e == 0)
FORCE_EVAL(x*x + ux.value*ux.value);
return ux.value;
}

12
src/math/nextafterl.c

@ -38,10 +38,8 @@ long double nextafterl(long double x, long double y)
if (ux.bits.exp == 0x7fff)
return x + x;
/* raise underflow if ux.value is subnormal or zero */
if (ux.bits.exp == 0) {
volatile float z;
z = x*x + ux.value*ux.value;
}
if (ux.bits.exp == 0)
FORCE_EVAL(x*x + ux.value*ux.value);
return ux.value;
}
#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
@ -77,10 +75,8 @@ long double nextafterl(long double x, long double y)
if (ux.bits.exp == 0x7fff)
return x + x;
/* raise underflow if ux.value is subnormal or zero */
if (ux.bits.exp == 0) {
volatile float z;
z = x*x + ux.value*ux.value;
}
if (ux.bits.exp == 0)
FORCE_EVAL(x*x + ux.value*ux.value);
return ux.value;
}
#endif

6
src/math/nexttoward.c

@ -38,10 +38,8 @@ double nexttoward(double x, long double y)
if (e == 0x7ff)
return x + x;
/* raise underflow if ux.value is subnormal or zero */
if (e == 0) {
volatile float z;
z = x*x + ux.value*ux.value;
}
if (e == 0)
FORCE_EVAL(x*x + ux.value*ux.value);
return ux.value;
}
#endif

6
src/math/nexttowardf.c

@ -30,9 +30,7 @@ float nexttowardf(float x, long double y)
if (e == 0x7f800000)
return x + x;
/* raise underflow if ux.value is subnormal or zero */
if (e == 0) {
volatile float z;
z = x*x + ux.value*ux.value;
}
if (e == 0)
FORCE_EVAL(x*x + ux.value*ux.value);
return ux.value;
}

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