diff options
Diffstat (limited to 'sysdeps/libm-ieee754')
-rw-r--r-- | sysdeps/libm-ieee754/e_exp.c | 48 | ||||
-rw-r--r-- | sysdeps/libm-ieee754/e_expf.c | 48 | ||||
-rw-r--r-- | sysdeps/libm-ieee754/s_exp2.c | 14 | ||||
-rw-r--r-- | sysdeps/libm-ieee754/s_exp2f.c | 14 |
4 files changed, 36 insertions, 88 deletions
diff --git a/sysdeps/libm-ieee754/e_exp.c b/sysdeps/libm-ieee754/e_exp.c index 660c5bc88d..5eae12a19c 100644 --- a/sysdeps/libm-ieee754/e_exp.c +++ b/sysdeps/libm-ieee754/e_exp.c @@ -76,8 +76,8 @@ __ieee754_exp (double x) /* Check for usual case. */ if (isless (x, himark) && isgreater (x, lomark)) { - static const double TWO43 = 8796093022208.0; - static const double TWO52 = 4503599627370496.0; + static const double THREEp42 = 13194139533312.0; + static const double THREEp51 = 6755399441055744.0; /* 1/ln(2). */ static const double M_1_LN2 = 1.442695040888963387; /* ln(2), part 1 */ @@ -94,40 +94,22 @@ __ieee754_exp (double x) fesetround (FE_TONEAREST); /* Calculate n. */ - if (x >= 0) - { - n = x * M_1_LN2 + TWO52; - n -= TWO52; - } - else - { - n = x * M_1_LN2 - TWO52; - n += TWO52; - } + n = x * M_1_LN2 + THREEp51; + n -= THREEp51; x = x - n*M_LN2_0; - if (x >= 0) - { - /* Calculate t/512. */ - t = x + TWO43; - t -= TWO43; - x -= t; - - /* Compute tval = t. */ - tval = (int) (t * 512.0); - - x -= __exp_deltatable[tval]; - } - else - { - /* As above, but x is negative. */ - t = x - TWO43; - t += TWO43; - x -= t; - tval = (int) (t * 512.0); + /* Calculate t/512. */ + t = x + THREEp42; + t -= THREEp42; + x -= t; - x += __exp_deltatable[-tval]; - } + /* Compute tval = t. */ + tval = (int) (t * 512.0); + + if (t >= 0) + x -= __exp_deltatable[tval]; + else + x += __exp_deltatable[-tval]; /* Now, the variable x contains x + n*ln(2)_1. */ dely = n*M_LN2_1; diff --git a/sysdeps/libm-ieee754/e_expf.c b/sysdeps/libm-ieee754/e_expf.c index c4a7b644fd..ff6357bd1d 100644 --- a/sysdeps/libm-ieee754/e_expf.c +++ b/sysdeps/libm-ieee754/e_expf.c @@ -71,8 +71,8 @@ __ieee754_expf (float x) /* Check for usual case. */ if (isless (x, himark) && isgreater (x, lomark)) { - static const float TWO43 = 8796093022208.0; - static const float TWO23 = 8388608.0; + static const float THREEp42 = 13194139533312.0; + static const float THREEp22 = 12582912.0; /* 1/ln(2). */ #undef M_1_LN2 static const float M_1_LN2 = 1.44269502163f; @@ -90,40 +90,22 @@ __ieee754_expf (float x) fesetround (FE_TONEAREST); /* Calculate n. */ - if (x >= 0) - { - n = x * M_1_LN2 + TWO23; - n -= TWO23; - } - else - { - n = x * M_1_LN2 - TWO23; - n += TWO23; - } + n = x * M_1_LN2 + THREEp22; + n -= THREEp22; dx = x - n*M_LN2; - if (dx >= 0) - { - /* Calculate t/512. */ - t = dx + TWO43; - t -= TWO43; - dx -= t; - - /* Compute tval = t. */ - tval = (int) (t * 512.0); - - delta = - __exp_deltatable[tval]; - } - else - { - /* As above, but x is negative. */ - t = dx - TWO43; - t += TWO43; - dx -= t; - tval = (int) (t * 512.0); + /* Calculate t/512. */ + t = dx + THREEp42; + t -= THREEp42; + dx -= t; - delta = __exp_deltatable[-tval]; - } + /* Compute tval = t. */ + tval = (int) (t * 512.0); + + if (t >= 0) + delta = - __exp_deltatable[tval]; + else + delta = __exp_deltatable[-tval]; /* Compute ex2 = 2^n e^(t/512+delta[t]). */ ex2_u.d = __exp_atable[tval+177]; diff --git a/sysdeps/libm-ieee754/s_exp2.c b/sysdeps/libm-ieee754/s_exp2.c index ead1ce89eb..875d4d6f2c 100644 --- a/sysdeps/libm-ieee754/s_exp2.c +++ b/sysdeps/libm-ieee754/s_exp2.c @@ -48,7 +48,7 @@ __ieee754_exp2 (double x) /* Check for usual case. */ if (isless (x, himark) && isgreater (x, lomark)) { - static const double TWO43 = 8796093022208.0; + static const double THREEp42 = 13194139533312.0; int tval, unsafe; double rx, x22, result; union ieee754_double ex2_u, scale_u; @@ -66,16 +66,8 @@ __ieee754_exp2 (double x) x = ex + t/512 + x1. First, calculate rx = ex + t/512. */ - if (x >= 0) - { - rx = x + TWO43; - rx -= TWO43; - } - else - { - rx = x - TWO43; - rx += TWO43; - } + rx = x + THREEp42; + rx -= THREEp42; x -= rx; /* Compute x=x1. */ /* Compute tval = (ex*512 + t)+256. Now, t = (tval mod 512)-256 and ex=tval/512 [that's mod, NOT %; and diff --git a/sysdeps/libm-ieee754/s_exp2f.c b/sysdeps/libm-ieee754/s_exp2f.c index 641b7548f1..8229885453 100644 --- a/sysdeps/libm-ieee754/s_exp2f.c +++ b/sysdeps/libm-ieee754/s_exp2f.c @@ -49,7 +49,7 @@ __ieee754_exp2f (float x) /* Check for usual case. */ if (isless (x, himark) && isgreater (x, lomark)) { - static const float TWO15 = 32768.0; + static const float THREEp14 = 49152.0; int tval, unsafe; float rx, x22, result; union ieee754_float ex2_u, scale_u; @@ -67,16 +67,8 @@ __ieee754_exp2f (float x) x = ex + t/512 + x1. First, calculate rx = ex + t/256. */ - if (x >= 0) - { - rx = x + TWO15; - rx -= TWO15; - } - else - { - rx = x - TWO15; - rx += TWO15; - } + rx = x + THREEp14; + rx -= THREEp14; x -= rx; /* Compute x=x1. */ /* Compute tval = (ex*256 + t)+128. Now, t = (tval mod 256)-128 and ex=tval/256 [that's mod, NOT %; and |