mirror of
https://github.com/fluencelabs/musl
synced 2025-05-29 07:31:53 +00:00
6ab8136b44
updated nextafter* to use FORCE_EVAL, it can be used in many other places in the math code to improve readability.
83 lines
1.7 KiB
C
83 lines
1.7 KiB
C
#include "libm.h"
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#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
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long double nextafterl(long double x, long double y)
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{
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return nextafter(x, y);
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}
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#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
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#define MSB ((uint64_t)1<<63)
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long double nextafterl(long double x, long double y)
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{
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union ldshape ux, uy;
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if (isnan(x) || isnan(y))
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return x + y;
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if (x == y)
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return y;
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ux.value = x;
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if (x == 0) {
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uy.value = y;
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ux.bits.m = 1;
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ux.bits.sign = uy.bits.sign;
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} else if (x < y ^ ux.bits.sign) {
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ux.bits.m++;
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if ((ux.bits.m & ~MSB) == 0) {
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ux.bits.m = MSB;
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ux.bits.exp++;
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}
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} else {
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if ((ux.bits.m & ~MSB) == 0) {
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ux.bits.exp--;
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if (ux.bits.exp)
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ux.bits.m = 0;
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}
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ux.bits.m--;
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}
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/* raise overflow if ux.value is infinite and x is finite */
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if (ux.bits.exp == 0x7fff)
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return x + x;
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/* raise underflow if ux.value is subnormal or zero */
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if (ux.bits.exp == 0)
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FORCE_EVAL(x*x + ux.value*ux.value);
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return ux.value;
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}
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#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
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long double nextafterl(long double x, long double y)
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{
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union ldshape ux, uy;
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if (isnan(x) || isnan(y))
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return x + y;
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if (x == y)
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return y;
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ux.value = x;
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if (x == 0) {
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uy.value = y;
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ux.bits.mlo = 1;
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ux.bits.sign = uy.bits.sign;
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} else if (x < y ^ ux.bits.sign) {
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ux.bits.mlo++;
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if (ux.bits.mlo == 0) {
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ux.bits.mhi++;
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if (ux.bits.mhi == 0)
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ux.bits.exp++;
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}
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} else {
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if (ux.bits.mlo == 0) {
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if (ux.bits.mhi == 0)
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ux.bits.exp--;
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ux.bits.mhi--;
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}
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ux.bits.mlo--;
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}
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/* raise overflow if ux.value is infinite and x is finite */
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if (ux.bits.exp == 0x7fff)
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return x + x;
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/* raise underflow if ux.value is subnormal or zero */
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if (ux.bits.exp == 0)
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FORCE_EVAL(x*x + ux.value*ux.value);
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return ux.value;
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}
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#endif
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