math: cosmetic cleanup (use explicit union instead of fshape and dshape)
authorSzabolcs Nagy <nsz@port70.net>
Wed, 4 Sep 2013 17:36:00 +0000 (17:36 +0000)
committerSzabolcs Nagy <nsz@port70.net>
Thu, 5 Sep 2013 11:30:09 +0000 (11:30 +0000)
src/internal/libm.h
src/math/__fpclassify.c
src/math/__fpclassifyf.c
src/math/copysign.c
src/math/copysignf.c
src/math/fabs.c
src/math/fabsf.c
src/math/nextafter.c
src/math/nextafterf.c
src/math/nexttoward.c
src/math/nexttowardf.c

index 99448a0..946c310 100644 (file)
 
 #include "libc.h"
 
-union fshape {
-       float value;
-       uint32_t bits;
-};
-
-union dshape {
-       double value;
-       uint64_t bits;
-};
-
 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
 #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 && __BYTE_ORDER == __LITTLE_ENDIAN
 union ldshape {
@@ -58,86 +48,86 @@ union ldshape {
 #error Unsupported long double representation
 #endif
 
-#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);                          \
-       }                                           \
+#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 {                                                            \
-  union dshape __u;                                             \
-  __u.value = (d);                                              \
-  (hi) = __u.bits >> 32;                                        \
-  (lo) = (uint32_t)__u.bits;                                    \
+#define EXTRACT_WORDS(hi,lo,d)                    \
+do {                                              \
+  union {double f; uint64_t i;} __u;              \
+  __u.f = (d);                                    \
+  (hi) = __u.i >> 32;                             \
+  (lo) = (uint32_t)__u.i;                         \
 } while (0)
 
 /* Get the more significant 32 bit int from a double.  */
-#define GET_HIGH_WORD(i,d)                                      \
-do {                                                            \
-  union dshape __u;                                             \
-  __u.value = (d);                                              \
-  (i) = __u.bits >> 32;                                         \
+#define GET_HIGH_WORD(hi,d)                       \
+do {                                              \
+  union {double f; uint64_t i;} __u;              \
+  __u.f = (d);                                    \
+  (hi) = __u.i >> 32;                             \
 } while (0)
 
 /* Get the less significant 32 bit int from a double.  */
-#define GET_LOW_WORD(i,d)                                       \
-do {                                                            \
-  union dshape __u;                                             \
-  __u.value = (d);                                              \
-  (i) = (uint32_t)__u.bits;                                     \
+#define GET_LOW_WORD(lo,d)                        \
+do {                                              \
+  union {double f; uint64_t i;} __u;              \
+  __u.f = (d);                                    \
+  (lo) = (uint32_t)__u.i;                         \
 } while (0)
 
 /* Set a double from two 32 bit ints.  */
-#define INSERT_WORDS(d,hi,lo)                                   \
-do {                                                            \
-  union dshape __u;                                             \
-  __u.bits = ((uint64_t)(hi) << 32) | (uint32_t)(lo);           \
-  (d) = __u.value;                                              \
+#define INSERT_WORDS(d,hi,lo)                     \
+do {                                              \
+  union {double f; uint64_t i;} __u;              \
+  __u.i = ((uint64_t)(hi)<<32) | (uint32_t)(lo);  \
+  (d) = __u.f;                                    \
 } while (0)
 
 /* Set the more significant 32 bits of a double from an int.  */
-#define SET_HIGH_WORD(d,hi)                                     \
-do {                                                            \
-  union dshape __u;                                             \
-  __u.value = (d);                                              \
-  __u.bits &= 0xffffffff;                                       \
-  __u.bits |= (uint64_t)(hi) << 32;                             \
-  (d) = __u.value;                                              \
+#define SET_HIGH_WORD(d,hi)                       \
+do {                                              \
+  union {double f; uint64_t i;} __u;              \
+  __u.f = (d);                                    \
+  __u.i &= 0xffffffff;                            \
+  __u.i |= (uint64_t)(hi) << 32;                  \
+  (d) = __u.f;                                    \
 } while (0)
 
 /* Set the less significant 32 bits of a double from an int.  */
-#define SET_LOW_WORD(d,lo)                                      \
-do {                                                            \
-  union dshape __u;                                             \
-  __u.value = (d);                                              \
-  __u.bits &= 0xffffffff00000000ull;                            \
-  __u.bits |= (uint32_t)(lo);                                   \
-  (d) = __u.value;                                              \
+#define SET_LOW_WORD(d,lo)                        \
+do {                                              \
+  union {double f; uint64_t i;} __u;              \
+  __u.f = (d);                                    \
+  __u.i &= 0xffffffff00000000ull;                 \
+  __u.i |= (uint32_t)(lo);                        \
+  (d) = __u.f;                                    \
 } while (0)
 
 /* Get a 32 bit int from a float.  */
-#define GET_FLOAT_WORD(i,d)                                     \
-do {                                                            \
-  union fshape __u;                                             \
-  __u.value = (d);                                              \
-  (i) = __u.bits;                                               \
+#define GET_FLOAT_WORD(w,d)                       \
+do {                                              \
+  union {float f; uint32_t i;} __u;               \
+  __u.f = (d);                                    \
+  (w) = __u.i;                                    \
 } while (0)
 
 /* Set a float from a 32 bit int.  */
-#define SET_FLOAT_WORD(d,i)                                     \
-do {                                                            \
-  union fshape __u;                                             \
-  __u.bits = (i);                                               \
-  (d) = __u.value;                                              \
+#define SET_FLOAT_WORD(d,w)                       \
+do {                                              \
+  union {float f; uint32_t i;} __u;               \
+  __u.i = (w);                                    \
+  (d) = __u.f;                                    \
 } while (0)
 
 /* fdlibm kernel functions */
index c9dd027..f7c0e2d 100644 (file)
@@ -1,10 +1,11 @@
-#include "libm.h"
+#include <math.h>
+#include <stdint.h>
 
 int __fpclassify(double x)
 {
-       union dshape u = { x };
-       int e = u.bits>>52 & 0x7ff;
-       if (!e) return u.bits<<1 ? FP_SUBNORMAL : FP_ZERO;
-       if (e==0x7ff) return u.bits<<12 ? FP_NAN : FP_INFINITE;
+       union {double f; uint64_t i;} u = {x};
+       int e = u.i>>52 & 0x7ff;
+       if (!e) return u.i<<1 ? FP_SUBNORMAL : FP_ZERO;
+       if (e==0x7ff) return u.i<<12 ? FP_NAN : FP_INFINITE;
        return FP_NORMAL;
 }
index 8149087..fd00eb1 100644 (file)
@@ -1,10 +1,11 @@
-#include "libm.h"
+#include <math.h>
+#include <stdint.h>
 
 int __fpclassifyf(float x)
 {
-       union fshape u = { x };
-       int e = u.bits>>23 & 0xff;
-       if (!e) return u.bits<<1 ? FP_SUBNORMAL : FP_ZERO;
-       if (e==0xff) return u.bits<<9 ? FP_NAN : FP_INFINITE;
+       union {float f; uint32_t i;} u = {x};
+       int e = u.i>>23 & 0xff;
+       if (!e) return u.i<<1 ? FP_SUBNORMAL : FP_ZERO;
+       if (e==0xff) return u.i<<9 ? FP_NAN : FP_INFINITE;
        return FP_NORMAL;
 }
index 038b8b4..b09331b 100644 (file)
@@ -1,11 +1,8 @@
 #include "libm.h"
 
 double copysign(double x, double y) {
-       union dshape ux, uy;
-
-       ux.value = x;
-       uy.value = y;
-       ux.bits &= (uint64_t)-1>>1;
-       ux.bits |= uy.bits & (uint64_t)1<<63;
-       return ux.value;
+       union {double f; uint64_t i;} ux={x}, uy={y};
+       ux.i &= -1ULL/2;
+       ux.i |= uy.i & 1ULL<<63;
+       return ux.f;
 }
index 47ab37e..0af6ae9 100644 (file)
@@ -1,11 +1,10 @@
-#include "libm.h"
+#include <math.h>
+#include <stdint.h>
 
-float copysignf(float x, float y) {
-       union fshape ux, uy;
-
-       ux.value = x;
-       uy.value = y;
-       ux.bits &= (uint32_t)-1>>1;
-       ux.bits |= uy.bits & (uint32_t)1<<31;
-       return ux.value;
+float copysignf(float x, float y)
+{
+       union {float f; uint32_t i;} ux={x}, uy={y};
+       ux.i &= 0x7fffffff;
+       ux.i |= uy.i & 0x80000000;
+       return ux.f;
 }
index 6e28f1e..e8258cf 100644 (file)
@@ -1,10 +1,9 @@
-#include "libm.h"
+#include <math.h>
+#include <stdint.h>
 
 double fabs(double x)
 {
-       union dshape u;
-
-       u.value = x;
-       u.bits &= (uint64_t)-1 / 2;
-       return u.value;
+       union {double f; uint64_t i;} u = {x};
+       u.i &= -1ULL/2;
+       return u.f;
 }
index 516f110..4efc8d6 100644 (file)
@@ -1,10 +1,9 @@
-#include "libm.h"
+#include <math.h>
+#include <stdint.h>
 
 float fabsf(float x)
 {
-       union fshape u;
-
-       u.value = x;
-       u.bits &= (uint32_t)-1 / 2;
-       return u.value;
+       union {float f; uint32_t i;} u = {x};
+       u.i &= 0x7fffffff;
+       return u.f;
 }
index 9ee8251..ab5795a 100644 (file)
@@ -1,35 +1,31 @@
 #include "libm.h"
 
-#define SIGN ((uint64_t)1<<63)
-
 double nextafter(double x, double y)
 {
-       union dshape ux, uy;
+       union {double f; uint64_t i;} ux={x}, uy={y};
        uint64_t ax, ay;
        int e;
 
        if (isnan(x) || isnan(y))
                return x + y;
-       ux.value = x;
-       uy.value = y;
-       if (ux.bits == uy.bits)
+       if (ux.i == uy.i)
                return y;
-       ax = ux.bits & ~SIGN;
-       ay = uy.bits & ~SIGN;
+       ax = ux.i & -1ULL/2;
+       ay = uy.i & -1ULL/2;
        if (ax == 0) {
                if (ay == 0)
                        return y;
-               ux.bits = (uy.bits & SIGN) | 1;
-       } else if (ax > ay || ((ux.bits ^ uy.bits) & SIGN))
-               ux.bits--;
+               ux.i = (uy.i & 1ULL<<63) | 1;
+       } else if (ax > ay || ((ux.i ^ uy.i) & 1ULL<<63))
+               ux.i--;
        else
-               ux.bits++;
-       e = ux.bits >> 52 & 0x7ff;
-       /* raise overflow if ux.value is infinite and x is finite */
+               ux.i++;
+       e = ux.i >> 52 & 0x7ff;
+       /* raise overflow if ux.f is infinite and x is finite */
        if (e == 0x7ff)
                FORCE_EVAL(x+x);
-       /* raise underflow if ux.value is subnormal or zero */
+       /* raise underflow if ux.f is subnormal or zero */
        if (e == 0)
-               FORCE_EVAL(x*x + ux.value*ux.value);
-       return ux.value;
+               FORCE_EVAL(x*x + ux.f*ux.f);
+       return ux.f;
 }
index 22b61dc..75a09f7 100644 (file)
@@ -1,34 +1,30 @@
 #include "libm.h"
 
-#define SIGN 0x80000000
-
 float nextafterf(float x, float y)
 {
-       union fshape ux, uy;
+       union {float f; uint32_t i;} ux={x}, uy={y};
        uint32_t ax, ay, e;
 
        if (isnan(x) || isnan(y))
                return x + y;
-       ux.value = x;
-       uy.value = y;
-       if (ux.bits == uy.bits)
+       if (ux.i == uy.i)
                return y;
-       ax = ux.bits & ~SIGN;
-       ay = uy.bits & ~SIGN;
+       ax = ux.i & 0x7fffffff;
+       ay = uy.i & 0x7fffffff;
        if (ax == 0) {
                if (ay == 0)
                        return y;
-               ux.bits = (uy.bits & SIGN) | 1;
-       } else if (ax > ay || ((ux.bits ^ uy.bits) & SIGN))
-               ux.bits--;
+               ux.i = (uy.i & 0x80000000) | 1;
+       } else if (ax > ay || ((ux.i ^ uy.i) & 0x80000000))
+               ux.i--;
        else
-               ux.bits++;
-       e = ux.bits & 0x7f800000;
-       /* raise overflow if ux.value is infinite and x is finite */
+               ux.i++;
+       e = ux.i & 0x7f800000;
+       /* raise overflow if ux.f is infinite and x is finite */
        if (e == 0x7f800000)
                FORCE_EVAL(x+x);
-       /* raise underflow if ux.value is subnormal or zero */
+       /* raise underflow if ux.f is subnormal or zero */
        if (e == 0)
-               FORCE_EVAL(x*x + ux.value*ux.value);
-       return ux.value;
+               FORCE_EVAL(x*x + ux.f*ux.f);
+       return ux.f;
 }
index 6f32eca..827ee5c 100644 (file)
@@ -6,40 +6,37 @@ double nexttoward(double x, long double y)
        return nextafter(x, y);
 }
 #else
-#define SIGN ((uint64_t)1<<63)
-
 double nexttoward(double x, long double y)
 {
-       union dshape ux;
+       union {double f; uint64_t i;} ux = {x};
        int e;
 
        if (isnan(x) || isnan(y))
                return x + y;
        if (x == y)
                return y;
-       ux.value = x;
        if (x == 0) {
-               ux.bits = 1;
+               ux.i = 1;
                if (signbit(y))
-                       ux.bits |= SIGN;
+                       ux.i |= 1ULL<<63;
        } else if (x < y) {
                if (signbit(x))
-                       ux.bits--;
+                       ux.i--;
                else
-                       ux.bits++;
+                       ux.i++;
        } else {
                if (signbit(x))
-                       ux.bits++;
+                       ux.i++;
                else
-                       ux.bits--;
+                       ux.i--;
        }
-       e = ux.bits>>52 & 0x7ff;
-       /* raise overflow if ux.value is infinite and x is finite */
+       e = ux.i>>52 & 0x7ff;
+       /* raise overflow if ux.f is infinite and x is finite */
        if (e == 0x7ff)
                FORCE_EVAL(x+x);
-       /* raise underflow if ux.value is subnormal or zero */
+       /* raise underflow if ux.f is subnormal or zero */
        if (e == 0)
-               FORCE_EVAL(x*x + ux.value*ux.value);
-       return ux.value;
+               FORCE_EVAL(x*x + ux.f*ux.f);
+       return ux.f;
 }
 #endif
index 9a693b1..bbf172f 100644 (file)
@@ -2,35 +2,34 @@
 
 float nexttowardf(float x, long double y)
 {
-       union fshape ux;
+       union {float f; uint32_t i;} ux = {x};
        uint32_t e;
 
        if (isnan(x) || isnan(y))
                return x + y;
        if (x == y)
                return y;
-       ux.value = x;
        if (x == 0) {
-               ux.bits = 1;
+               ux.i = 1;
                if (signbit(y))
-                       ux.bits |= 0x80000000;
+                       ux.i |= 0x80000000;
        } else if (x < y) {
                if (signbit(x))
-                       ux.bits--;
+                       ux.i--;
                else
-                       ux.bits++;
+                       ux.i++;
        } else {
                if (signbit(x))
-                       ux.bits++;
+                       ux.i++;
                else
-                       ux.bits--;
+                       ux.i--;
        }
-       e = ux.bits & 0x7f800000;
-       /* raise overflow if ux.value is infinite and x is finite */
+       e = ux.i & 0x7f800000;
+       /* raise overflow if ux.f is infinite and x is finite */
        if (e == 0x7f800000)
                FORCE_EVAL(x+x);
-       /* raise underflow if ux.value is subnormal or zero */
+       /* raise underflow if ux.f is subnormal or zero */
        if (e == 0)
-               FORCE_EVAL(x*x + ux.value*ux.value);
-       return ux.value;
+               FORCE_EVAL(x*x + ux.f*ux.f);
+       return ux.f;
 }