41
42 #include "libm.h" /* for isgreaterequal macro */
43 #include <fenv.h>
44
45 double
46 __fmax(double x, double y) {
47 union {
48 unsigned i[2];
49 double d;
50 } xx, yy;
51 unsigned s;
52
53 /* if y is nan, replace it by x */
54 if (y != y)
55 y = x;
56
57 /* if x is nan, replace it by y */
58 if (x != x)
59 x = y;
60
61 /* if x is less than y or x and y are unordered, replace x by y */
62 #if defined(COMPARISON_MACRO_BUG)
63 if (x < y)
64 #else
65 if (!isgreaterequal(x, y))
66 #endif
67 x = y;
68
69 /*
70 * now x and y are either both NaN or both numeric; clear the
71 * sign of the result if either x or y has its sign clear
72 */
73 xx.d = x;
74 yy.d = y;
75 #if defined(__sparc)
76 s = ~(xx.i[0] & yy.i[0]) & 0x80000000;
77 xx.i[0] &= ~s;
78 #elif defined(__x86)
79 s = ~(xx.i[1] & yy.i[1]) & 0x80000000;
80 xx.i[1] &= ~s;
81 #else
82 #error Unknown architecture
83 #endif
84
85 return (xx.d);
86 }
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41
42 #include "libm.h" /* for isgreaterequal macro */
43 #include <fenv.h>
44
45 double
46 __fmax(double x, double y) {
47 union {
48 unsigned i[2];
49 double d;
50 } xx, yy;
51 unsigned s;
52
53 /* if y is nan, replace it by x */
54 if (y != y)
55 y = x;
56
57 /* if x is nan, replace it by y */
58 if (x != x)
59 x = y;
60
61 /* At this point, x and y are either both numeric, or both NaN */
62 if (!isnan(x) && !isgreaterequal(x, y))
63 x = y;
64
65 /*
66 * clear the sign of the result if either x or y has its sign clear
67 */
68 xx.d = x;
69 yy.d = y;
70 #if defined(__sparc)
71 s = ~(xx.i[0] & yy.i[0]) & 0x80000000;
72 xx.i[0] &= ~s;
73 #elif defined(__x86)
74 s = ~(xx.i[1] & yy.i[1]) & 0x80000000;
75 xx.i[1] &= ~s;
76 #else
77 #error Unknown architecture
78 #endif
79
80 return (xx.d);
81 }
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