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authorSzabolcs Nagy <nsz@port70.net>2012-12-11 23:56:59 +0100
committerSzabolcs Nagy <nsz@port70.net>2012-12-11 23:56:59 +0100
commitb12a73d5bf595b7fbb73db30c6bb144078e86ef5 (patch)
tree547edc4ee13453230bb1c154015150b9fc88c766 /src
parent482ccd2f7497a79ca83e998f54e823e7cedaaa6e (diff)
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math: clean up inverse trigonometric functions
modifications: * avoid unsigned->signed conversions * removed various volatile hacks * use FORCE_EVAL when evaluating only for side-effects * factor out R() rational approximation instead of manual inline * __invtrigl.h now only provides __invtrigl_R, __pio2_hi and __pio2_lo * use 2*pio2_hi, 2*pio2_lo instead of pi_hi, pi_lo otherwise the logic is not changed, long double versions will need a revisit when a genaral long double cleanup happens
Diffstat (limited to 'src')
-rw-r--r--src/math/__invtrigl.c41
-rw-r--r--src/math/__invtrigl.h66
-rw-r--r--src/math/acos.c74
-rw-r--r--src/math/acosf.c77
-rw-r--r--src/math/acosl.c61
-rw-r--r--src/math/asin.c71
-rw-r--r--src/math/asinf.c51
-rw-r--r--src/math/asinl.c61
-rw-r--r--src/math/atan.c32
-rw-r--r--src/math/atan2l.c40
-rw-r--r--src/math/atanf.c28
-rw-r--r--src/math/atanl.c33
12 files changed, 258 insertions, 377 deletions
diff --git a/src/math/__invtrigl.c b/src/math/__invtrigl.c
index a51330e2..f2d33d3e 100644
--- a/src/math/__invtrigl.c
+++ b/src/math/__invtrigl.c
@@ -1,36 +1,8 @@
-/* origin: FreeBSD /usr/src/lib/msun/src/ld80/invtrig.c */
-/*-
- * Copyright (c) 2008 David Schultz <das@FreeBSD.ORG>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
#include "__invtrigl.h"
#if LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
-/* coefficients used in asinl() and acosl() */
-const long double
+static const long double
pS0 = 1.66666666666666666631e-01L,
pS1 = -4.16313987993683104320e-01L,
pS2 = 3.69068046323246813704e-01L,
@@ -44,9 +16,16 @@ qS3 = -1.68285799854822427013e+00L,
qS4 = 3.90699412641738801874e-01L,
qS5 = -3.14365703596053263322e-02L;
-const long double pi_hi = 3.1415926535897932384626433832795L;
-const long double pi_lo = -5.01655761266833202345e-20L;
const long double pio2_hi = 1.57079632679489661926L;
const long double pio2_lo = -2.50827880633416601173e-20L;
+/* used in asinl() and acosl() */
+/* R(x^2) is a rational approximation of (asin(x)-x)/x^3 with Remez algorithm */
+long double __invtrigl_R(long double z)
+{
+ long double p, q;
+ p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*(pS5+z*pS6))))));
+ q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*(qS4+z*qS5))));
+ return p/q;
+}
#endif
diff --git a/src/math/__invtrigl.h b/src/math/__invtrigl.h
index 22748b68..cac465c2 100644
--- a/src/math/__invtrigl.h
+++ b/src/math/__invtrigl.h
@@ -1,68 +1,10 @@
-/* origin: FreeBSD /usr/src/lib/msun/src/ld80/invtrig.h */
-/*-
- * Copyright (c) 2008 David Schultz <das@FreeBSD.ORG>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include "libm.h"
+#include <float.h>
#if LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
-
-#define BIAS (LDBL_MAX_EXP - 1)
-#define MANH_SIZE LDBL_MANH_SIZE
-
-/* Constants shared by the long double inverse trig functions. */
-#define pS0 __pS0
-#define pS1 __pS1
-#define pS2 __pS2
-#define pS3 __pS3
-#define pS4 __pS4
-#define pS5 __pS5
-#define pS6 __pS6
-#define qS1 __qS1
-#define qS2 __qS2
-#define qS3 __qS3
-#define qS4 __qS4
-#define qS5 __qS5
-#define pi_hi __pi_hi
-#define pi_lo __pi_lo
+/* shared by acosl, asinl and atan2l */
#define pio2_hi __pio2_hi
#define pio2_lo __pio2_lo
+extern const long double pio2_hi, pio2_lo;
-extern const long double pS0, pS1, pS2, pS3, pS4, pS5, pS6;
-extern const long double qS1, qS2, qS3, qS4, qS5;
-extern const long double pi_hi, pi_lo, pio2_hi, pio2_lo;
-
-static long double P(long double x)
-{
- return x * (pS0 + x * (pS1 + x * (pS2 + x * (pS3 +
- x * (pS4 + x * (pS5 + x * pS6))))));
-}
-
-static long double Q(long double x)
-{
- return 1.0 + x * (qS1 + x * (qS2 + x * (qS3 + x * (qS4 + x * qS5))));
-}
-
+long double __invtrigl_R(long double z);
#endif
diff --git a/src/math/acos.c b/src/math/acos.c
index 0eb15bed..be95d25e 100644
--- a/src/math/acos.c
+++ b/src/math/acos.c
@@ -36,12 +36,8 @@
#include "libm.h"
static const double
-pi = 3.14159265358979311600e+00, /* 0x400921FB, 0x54442D18 */
-pio2_hi = 1.57079632679489655800e+00; /* 0x3FF921FB, 0x54442D18 */
-// FIXME
-static const volatile double
-pio2_lo = 6.12323399573676603587e-17; /* 0x3C91A626, 0x33145C07 */
-static const double
+pio2_hi = 1.57079632679489655800e+00, /* 0x3FF921FB, 0x54442D18 */
+pio2_lo = 6.12323399573676603587e-17, /* 0x3C91A626, 0x33145C07 */
pS0 = 1.66666666666666657415e-01, /* 0x3FC55555, 0x55555555 */
pS1 = -3.25565818622400915405e-01, /* 0xBFD4D612, 0x03EB6F7D */
pS2 = 2.01212532134862925881e-01, /* 0x3FC9C155, 0x0E884455 */
@@ -53,49 +49,53 @@ qS2 = 2.02094576023350569471e+00, /* 0x40002AE5, 0x9C598AC8 */
qS3 = -6.88283971605453293030e-01, /* 0xBFE6066C, 0x1B8D0159 */
qS4 = 7.70381505559019352791e-02; /* 0x3FB3B8C5, 0xB12E9282 */
+static double R(double z)
+{
+ double p, q;
+ p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
+ q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
+ return p/q;
+}
+
double acos(double x)
{
- double z,p,q,r,w,s,c,df;
- int32_t hx,ix;
+ double z,w,s,c,df;
+ uint32_t hx,ix;
GET_HIGH_WORD(hx, x);
ix = hx & 0x7fffffff;
- if (ix >= 0x3ff00000) { /* |x| >= 1 */
+ /* |x| >= 1 or nan */
+ if (ix >= 0x3ff00000) {
uint32_t lx;
GET_LOW_WORD(lx,x);
- if ((ix-0x3ff00000 | lx) == 0) { /* |x|==1 */
- if (hx > 0) return 0.0; /* acos(1) = 0 */
- return pi + 2.0*pio2_lo; /* acos(-1)= pi */
+ if ((ix-0x3ff00000 | lx) == 0) {
+ /* acos(1)=0, acos(-1)=pi */
+ if (hx >> 31)
+ return 2*pio2_hi + 0x1p-1000;
+ return 0;
}
- return (x-x)/(x-x); /* acos(|x|>1) is NaN */
+ return 0/(x-x);
}
- if (ix < 0x3fe00000) { /* |x| < 0.5 */
+ /* |x| < 0.5 */
+ if (ix < 0x3fe00000) {
if (ix <= 0x3c600000) /* |x| < 2**-57 */
- return pio2_hi + pio2_lo;
- z = x*x;
- p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
- q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
- r = p/q;
- return pio2_hi - (x - (pio2_lo-x*r));
- } else if (hx < 0) { /* x < -0.5 */
+ return pio2_hi + 0x1p-1000;
+ return pio2_hi - (x - (pio2_lo-x*R(x*x)));
+ }
+ /* x < -0.5 */
+ if (hx >> 31) {
z = (1.0+x)*0.5;
- p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
- q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
- s = sqrt(z);
- r = p/q;
- w = r*s-pio2_lo;
- return pi - 2.0*(s+w);
- } else { /* x > 0.5 */
- z = (1.0-x)*0.5;
s = sqrt(z);
- df = s;
- SET_LOW_WORD(df,0);
- c = (z-df*df)/(s+df);
- p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
- q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
- r = p/q;
- w = r*s+c;
- return 2.0*(df+w);
+ w = R(z)*s-pio2_lo;
+ return 2*(pio2_hi - (s+w));
}
+ /* x > 0.5 */
+ z = (1.0-x)*0.5;
+ s = sqrt(z);
+ df = s;
+ SET_LOW_WORD(df,0);
+ c = (z-df*df)/(s+df);
+ w = R(z)*s+c;
+ return 2*(df+w);
}
diff --git a/src/math/acosf.c b/src/math/acosf.c
index d875f3ef..5d7c0270 100644
--- a/src/math/acosf.c
+++ b/src/math/acosf.c
@@ -16,59 +16,56 @@
#include "libm.h"
static const float
-pi = 3.1415925026e+00, /* 0x40490fda */
-pio2_hi = 1.5707962513e+00; /* 0x3fc90fda */
-static const volatile float
-pio2_lo = 7.5497894159e-08; /* 0x33a22168 */
-static const float
+pio2_hi = 1.5707962513e+00, /* 0x3fc90fda */
+pio2_lo = 7.5497894159e-08, /* 0x33a22168 */
pS0 = 1.6666586697e-01,
pS1 = -4.2743422091e-02,
pS2 = -8.6563630030e-03,
qS1 = -7.0662963390e-01;
+static float R(float z)
+{
+ float p, q;
+ p = z*(pS0+z*(pS1+z*pS2));
+ q = 1.0f+z*qS1;
+ return p/q;
+}
+
float acosf(float x)
{
- float z,p,q,r,w,s,c,df;
- int32_t hx,ix;
+ float z,w,s,c,df;
+ uint32_t hx,ix;
GET_FLOAT_WORD(hx, x);
ix = hx & 0x7fffffff;
- if (ix >= 0x3f800000) { /* |x| >= 1 */
- if (ix == 0x3f800000) { /* |x| == 1 */
- if (hx > 0) return 0.0f; /* acos(1) = 0 */
- return pi + 2.0f*pio2_lo; /* acos(-1)= pi */
+ /* |x| >= 1 or nan */
+ if (ix >= 0x3f800000) {
+ if (ix == 0x3f800000) {
+ if (hx >> 31)
+ return 2*pio2_hi + 0x1p-120f;
+ return 0;
}
- return (x-x)/(x-x); /* acos(|x|>1) is NaN */
+ return 0/(x-x);
}
- if (ix < 0x3f000000) { /* |x| < 0.5 */
+ /* |x| < 0.5 */
+ if (ix < 0x3f000000) {
if (ix <= 0x32800000) /* |x| < 2**-26 */
- return pio2_hi + pio2_lo;
- z = x*x;
- p = z*(pS0+z*(pS1+z*pS2));
- q = 1.0f+z*qS1;
- r = p/q;
- return pio2_hi - (x - (pio2_lo-x*r));
- } else if (hx < 0) { /* x < -0.5 */
- z = (1.0f+x)*0.5f;
- p = z*(pS0+z*(pS1+z*pS2));
- q = 1.0f+z*qS1;
- s = sqrtf(z);
- r = p/q;
- w = r*s-pio2_lo;
- return pi - 2.0f*(s+w);
- } else { /* x > 0.5 */
- int32_t idf;
-
- z = (1.0f-x)*0.5f;
+ return pio2_hi + 0x1p-120f;
+ return pio2_hi - (x - (pio2_lo-x*R(x*x)));
+ }
+ /* x < -0.5 */
+ if (hx >> 31) {
+ z = (1+x)*0.5f;
s = sqrtf(z);
- df = s;
- GET_FLOAT_WORD(idf,df);
- SET_FLOAT_WORD(df,idf&0xfffff000);
- c = (z-df*df)/(s+df);
- p = z*(pS0+z*(pS1+z*pS2));
- q = 1.0f+z*qS1;
- r = p/q;
- w = r*s+c;
- return 2.0f*(df+w);
+ w = R(z)*s-pio2_lo;
+ return 2*(pio2_hi - (s+w));
}
+ /* x > 0.5 */
+ z = (1-x)*0.5f;
+ s = sqrtf(z);
+ GET_FLOAT_WORD(hx,s);
+ SET_FLOAT_WORD(df,hx&0xfffff000);
+ c = (z-df*df)/(s+df);
+ w = R(z)*s+c;
+ return 2*(df+w);
}
diff --git a/src/math/acosl.c b/src/math/acosl.c
index 83857d49..9e9b01e4 100644
--- a/src/math/acosl.c
+++ b/src/math/acosl.c
@@ -23,55 +23,46 @@ long double acosl(long double x)
}
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
#include "__invtrigl.h"
-#define ACOS_CONST (BIAS - 65) /* 2**-65 */
long double acosl(long double x)
{
union IEEEl2bits u;
- long double z, p, q, r, w, s, c, df;
+ long double z, w, s, c, df;
int16_t expsign, expt;
u.e = x;
expsign = u.xbits.expsign;
expt = expsign & 0x7fff;
- if (expt >= BIAS) { /* |x| >= 1 */
- if (expt == BIAS &&
+ /* |x| >= 1 or nan */
+ if (expt >= 0x3fff) {
+ if (expt == 0x3fff &&
((u.bits.manh & ~LDBL_NBIT) | u.bits.manl) == 0) {
if (expsign > 0)
- return 0.0; /* acos(1) = 0 */
- else
- // FIXME
- return pi_hi + 2.0 * pio2_lo; /* acos(-1)= pi */
+ return 0; /* acos(1) = 0 */
+ return 2*pio2_hi + 0x1p-1000; /* acos(-1)= pi */
}
- return (x - x) / (x - x); /* acos(|x|>1) is NaN */
+ return 0/(x-x); /* acos(|x|>1) is NaN */
}
- if (expt < BIAS - 1) { /* |x| < 0.5 */
- if (expt < ACOS_CONST)
- return pio2_hi + pio2_lo; /* x tiny: acosl=pi/2 */
- z = x * x;
- p = P(z);
- q = Q(z);
- r = p / q;
- return pio2_hi - (x - (pio2_lo - x * r));
- } else if (expsign < 0) { /* x < -0.5 */
+ /* |x| < 0.5 */
+ if (expt < 0x3fff - 1) {
+ if (expt < 0x3fff - 65)
+ return pio2_hi + 0x1p-1000; /* x < 0x1p-65: acosl(x)=pi/2 */
+ return pio2_hi - (x - (pio2_lo - x * __invtrigl_R(x*x)));
+ }
+ /* x < -0.5 */
+ if (expsign < 0) {
z = (1.0 + x) * 0.5;
- p = P(z);
- q = Q(z);
- s = sqrtl(z);
- r = p / q;
- w = r * s - pio2_lo;
- return pi_hi - 2.0 * (s + w);
- } else { /* x > 0.5 */
- z = (1.0 - x) * 0.5;
s = sqrtl(z);
- u.e = s;
- u.bits.manl = 0;
- df = u.e;
- c = (z - df * df) / (s + df);
- p = P(z);
- q = Q(z);
- r = p / q;
- w = r * s + c;
- return 2.0 * (df + w);
+ w = __invtrigl_R(z) * s - pio2_lo;
+ return 2*(pio2_hi - (s + w));
}
+ /* x > 0.5 */
+ z = (1.0 - x) * 0.5;
+ s = sqrtl(z);
+ u.e = s;
+ u.bits.manl = 0;
+ df = u.e;
+ c = (z - df * df) / (s + df);
+ w = __invtrigl_R(z) * s + c;
+ return 2*(df + w);
}
#endif
diff --git a/src/math/asin.c b/src/math/asin.c
index e3d8b250..a1906b08 100644
--- a/src/math/asin.c
+++ b/src/math/asin.c
@@ -42,10 +42,8 @@
#include "libm.h"
static const double
-huge = 1.000e+300,
pio2_hi = 1.57079632679489655800e+00, /* 0x3FF921FB, 0x54442D18 */
pio2_lo = 6.12323399573676603587e-17, /* 0x3C91A626, 0x33145C07 */
-pio4_hi = 7.85398163397448278999e-01, /* 0x3FE921FB, 0x54442D18 */
/* coefficients for R(x^2) */
pS0 = 1.66666666666666657415e-01, /* 0x3FC55555, 0x55555555 */
pS1 = -3.25565818622400915405e-01, /* 0xBFD4D612, 0x03EB6F7D */
@@ -58,51 +56,54 @@ qS2 = 2.02094576023350569471e+00, /* 0x40002AE5, 0x9C598AC8 */
qS3 = -6.88283971605453293030e-01, /* 0xBFE6066C, 0x1B8D0159 */
qS4 = 7.70381505559019352791e-02; /* 0x3FB3B8C5, 0xB12E9282 */
+static double R(double z)
+{
+ double p, q;
+ p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
+ q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
+ return p/q;
+}
+
double asin(double x)
{
- double t=0.0,w,p,q,c,r,s;
- int32_t hx,ix;
+ double z,r,s;
+ uint32_t hx,ix;
GET_HIGH_WORD(hx, x);
ix = hx & 0x7fffffff;
- if (ix >= 0x3ff00000) { /* |x|>= 1 */
+ /* |x| >= 1 or nan */
+ if (ix >= 0x3ff00000) {
uint32_t lx;
-
GET_LOW_WORD(lx, x);
if ((ix-0x3ff00000 | lx) == 0)
/* asin(1) = +-pi/2 with inexact */
- return x*pio2_hi + x*pio2_lo;
- return (x-x)/(x-x); /* asin(|x|>1) is NaN */
- } else if (ix < 0x3fe00000) { /* |x|<0.5 */
- if (ix < 0x3e500000) { /* if |x| < 2**-26 */
- if (huge+x > 1.0)
- return x; /* return x with inexact if x!=0*/
+ return x*pio2_hi + 0x1p-1000;
+ return 0/(x-x);
+ }
+ /* |x| < 0.5 */
+ if (ix < 0x3fe00000) {
+ if (ix < 0x3e500000) {
+ /* |x|<0x1p-26, return x with inexact if x!=0*/
+ FORCE_EVAL(x + 0x1p1000);
+ return x;
}
- t = x*x;
- p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5)))));
- q = 1.0+t*(qS1+t*(qS2+t*(qS3+t*qS4)));
- w = p/q;
- return x + x*w;
+ return x + x*R(x*x);
}
/* 1 > |x| >= 0.5 */
- w = 1.0 - fabs(x);
- t = w*0.5;
- p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5)))));
- q = 1.0+t*(qS1+t*(qS2+t*(qS3+t*qS4)));
- s = sqrt(t);
- if (ix >= 0x3FEF3333) { /* if |x| > 0.975 */
- w = p/q;
- t = pio2_hi-(2.0*(s+s*w)-pio2_lo);
+ z = (1 - fabs(x))*0.5;
+ s = sqrt(z);
+ r = R(z);
+ if (ix >= 0x3fef3333) { /* if |x| > 0.975 */
+ x = pio2_hi-(2*(s+s*r)-pio2_lo);
} else {
- w = s;
- SET_LOW_WORD(w,0);
- c = (t-w*w)/(s+w);
- r = p/q;
- p = 2.0*s*r-(pio2_lo-2.0*c);
- q = pio4_hi - 2.0*w;
- t = pio4_hi - (p-q);
+ double f,c;
+ /* f+c = sqrt(z) */
+ f = s;
+ SET_LOW_WORD(f,0);
+ c = (z-f*f)/(s+f);
+ x = 0.5*pio2_hi - (2*s*r - (pio2_lo-2*c) - (0.5*pio2_hi-2*f));
}
- if (hx > 0)
- return t;
- return -t;
+ if (hx >> 31)
+ return -x;
+ return x;
}
diff --git a/src/math/asinf.c b/src/math/asinf.c
index c1c42c7b..462bf043 100644
--- a/src/math/asinf.c
+++ b/src/math/asinf.c
@@ -12,52 +12,51 @@
* is preserved.
* ====================================================
*/
-
#include "libm.h"
+static const double
+pio2 = 1.570796326794896558e+00;
+
static const float
-huge = 1.000e+30,
/* coefficients for R(x^2) */
pS0 = 1.6666586697e-01,
pS1 = -4.2743422091e-02,
pS2 = -8.6563630030e-03,
qS1 = -7.0662963390e-01;
-static const double
-pio2 = 1.570796326794896558e+00;
+static float R(float z)
+{
+ float p, q;
+ p = z*(pS0+z*(pS1+z*pS2));
+ q = 1.0f+z*qS1;
+ return p/q;
+}
float asinf(float x)
{
double s;
- float t,w,p,q;
- int32_t hx,ix;
+ float z;
+ uint32_t hx,ix;
GET_FLOAT_WORD(hx, x);
ix = hx & 0x7fffffff;
if (ix >= 0x3f800000) { /* |x| >= 1 */
if (ix == 0x3f800000) /* |x| == 1 */
- return x*pio2; /* asin(+-1) = +-pi/2 with inexact */
- return (x-x)/(x-x); /* asin(|x|>1) is NaN */
- } else if (ix < 0x3f000000) { /* |x|<0.5 */
+ return x*pio2 + 0x1p-120f; /* asin(+-1) = +-pi/2 with inexact */
+ return 0/(x-x); /* asin(|x|>1) is NaN */
+ }
+ if (ix < 0x3f000000) { /* |x| < 0.5 */
if (ix < 0x39800000) { /* |x| < 2**-12 */
- if (huge+x > 1.0f)
- return x; /* return x with inexact if x!=0 */
+ FORCE_EVAL(x + 0x1p120f);
+ return x; /* return x with inexact if x!=0 */
}
- t = x*x;
- p = t*(pS0+t*(pS1+t*pS2));
- q = 1.0f+t*qS1;
- w = p/q;
- return x + x*w;
+ return x + x*R(x*x);
}
/* 1 > |x| >= 0.5 */
- w = 1.0f - fabsf(x);
- t = w*0.5f;
- p = t*(pS0+t*(pS1+t*pS2));
- q = 1.0f+t*qS1;
- s = sqrt(t);
- w = p/q;
- t = pio2-2.0*(s+s*w);
- if (hx > 0)
- return t;
- return -t;
+ z = (1 - fabsf(x))*0.5f;
+ s = sqrt(z);
+ x = pio2 - 2*(s+s*R(z));
+ if (hx >> 31)
+ return -x;
+ return x;
}
diff --git a/src/math/asinl.c b/src/math/asinl.c
index 7572767c..0ef9853b 100644
--- a/src/math/asinl.c
+++ b/src/math/asinl.c
@@ -23,60 +23,49 @@ long double asinl(long double x)
}
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
#include "__invtrigl.h"
-static const long double huge = 1.000e+300;
-static const long double pio4_hi = 7.85398163397448309628e-01L;
-#define ASIN_LINEAR (BIAS - 32) /* 2**-32 */
/* 0.95 */
-#define THRESH ((0xe666666666666666ULL>>(64-(MANH_SIZE-1)))|LDBL_NBIT)
+#define THRESH ((0xe666666666666666ULL>>(64-(LDBL_MANH_SIZE-1)))|LDBL_NBIT)
long double asinl(long double x)
{
union IEEEl2bits u;
- long double t=0.0,w,p,q,c,r,s;
- int16_t expsign, expt;
+ long double z,r,s;
+ uint16_t expsign, expt;
u.e = x;
expsign = u.xbits.expsign;
expt = expsign & 0x7fff;
- if (expt >= BIAS) { /* |x|>= 1 */
- if (expt == BIAS &&
+ if (expt >= 0x3fff) { /* |x| >= 1 or nan */
+ if (expt == 0x3fff &&
((u.bits.manh&~LDBL_NBIT)|u.bits.manl) == 0)
- /* asin(1)=+-pi/2 with inexact */
- return x*pio2_hi + x*pio2_lo;
- return (x-x)/(x-x); /* asin(|x|>1) is NaN */
- } else if (expt < BIAS-1) { /* |x|<0.5 */
- if (expt < ASIN_LINEAR) { /* if |x| is small, asinl(x)=x */
+ /* asin(+-1)=+-pi/2 with inexact */
+ return x*pio2_hi + 0x1p-1000;
+ return 0/(x-x);
+ }
+ if (expt < 0x3fff - 1) { /* |x| < 0.5 */
+ if (expt < 0x3fff - 32) { /* |x|<0x1p-32, asinl(x)=x */
/* return x with inexact if x!=0 */
- if (huge+x > 1.0)
- return x;
+ FORCE_EVAL(x + 0x1p1000);
+ return x;
}
- t = x*x;
- p = P(t);
- q = Q(t);
- w = p/q;
- return x + x*w;
+ return x + x*__invtrigl_R(x*x);
}
/* 1 > |x| >= 0.5 */
- w = 1.0 - fabsl(x);
- t = w*0.5;
- p = P(t);
- q = Q(t);
- s = sqrtl(t);
+ z = (1.0 - fabsl(x))*0.5;
+ s = sqrtl(z);
+ r = __invtrigl_R(z);
if (u.bits.manh >= THRESH) { /* if |x| is close to 1 */
- w = p/q;
- t = pio2_hi-(2.0*(s+s*w)-pio2_lo);
+ x = pio2_hi - (2*(s+s*r)-pio2_lo);
} else {
+ long double f, c;
u.e = s;
u.bits.manl = 0;
- w = u.e;
- c = (t-w*w)/(s+w);
- r = p/q;
- p = 2.0*s*r-(pio2_lo-2.0*c);
- q = pio4_hi-2.0*w;
- t = pio4_hi-(p-q);
+ f = u.e;
+ c = (z-f*f)/(s+f);
+ x = 0.5*pio2_hi-(2*s*r - (pio2_lo-2*c) - (0.5*pio2_hi-2*f));
}
- if (expsign > 0)
- return t;
- return -t;
+ if (expsign>>15)
+ return -x;
+ return x;
}
#endif
diff --git a/src/math/atan.c b/src/math/atan.c
index f34551c7..7fd8a3b8 100644
--- a/src/math/atan.c
+++ b/src/math/atan.c
@@ -60,32 +60,26 @@ static const double aT[] = {
1.62858201153657823623e-02, /* 0x3F90AD3A, 0xE322DA11 */
};
-static const double huge = 1.0e300;
-
double atan(double x)
{
double w,s1,s2,z;
- int32_t ix,hx,id;
+ uint32_t ix,sign;
+ int id;
- GET_HIGH_WORD(hx, x);
- ix = hx & 0x7fffffff;
+ GET_HIGH_WORD(ix, x);
+ sign = ix >> 31;
+ ix &= 0x7fffffff;
if (ix >= 0x44100000) { /* if |x| >= 2^66 */
- uint32_t low;
-
- GET_LOW_WORD(low, x);
- if (ix > 0x7ff00000 ||
- (ix == 0x7ff00000 && low != 0)) /* NaN */
- return x+x;
- if (hx > 0)
- return atanhi[3] + *(volatile double *)&atanlo[3];
- else
- return -atanhi[3] - *(volatile double *)&atanlo[3];
+ if (isnan(x))
+ return x;
+ z = atanhi[3] + 0x1p-1000;
+ return sign ? -z : z;
}
if (ix < 0x3fdc0000) { /* |x| < 0.4375 */
if (ix < 0x3e400000) { /* |x| < 2^-27 */
- /* raise inexact */
- if (huge+x > 1.0)
- return x;
+ /* raise inexact if x!=0 */
+ FORCE_EVAL(x + 0x1p1000);
+ return x;
}
id = -1;
} else {
@@ -117,5 +111,5 @@ double atan(double x)
if (id < 0)
return x - x*(s1+s2);
z = atanhi[id] - (x*(s1+s2) - atanlo[id] - x);
- return hx < 0 ? -z : z;
+ return sign ? -z : z;
}
diff --git a/src/math/atan2l.c b/src/math/atan2l.c
index 45cbfcc1..e86dbffb 100644
--- a/src/math/atan2l.c
+++ b/src/math/atan2l.c
@@ -24,8 +24,6 @@ long double atan2l(long double y, long double x)
}
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
#include "__invtrigl.h"
-// FIXME:
-static const volatile long double tiny = 1.0e-300;
long double atan2l(long double y, long double x)
{
@@ -40,12 +38,12 @@ long double atan2l(long double y, long double x)
ux.e = x;
expsignx = ux.xbits.expsign;
exptx = expsignx & 0x7fff;
- if ((exptx==BIAS+LDBL_MAX_EXP &&
+ if ((exptx==0x7fff &&
((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)!=0) || /* x is NaN */
- (expty==BIAS+LDBL_MAX_EXP &&
+ (expty==0x7fff &&
((uy.bits.manh&~LDBL_NBIT)|uy.bits.manl)!=0)) /* y is NaN */
return x+y;
- if (expsignx==BIAS && ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)==0) /* x=1.0 */
+ if (expsignx==0x3fff && ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)==0) /* x=1.0 */
return atanl(y);
m = ((expsigny>>15)&1) | ((expsignx>>14)&2); /* 2*sign(x)+sign(y) */
@@ -54,39 +52,39 @@ long double atan2l(long double y, long double x)
switch(m) {
case 0:
case 1: return y; /* atan(+-0,+anything)=+-0 */
- case 2: return pi_hi+tiny; /* atan(+0,-anything) = pi */
- case 3: return -pi_hi-tiny; /* atan(-0,-anything) =-pi */
+ case 2: return 2*pio2_hi+0x1p-1000; /* atan(+0,-anything) = pi */
+ case 3: return -2*pio2_hi-0x1p-1000; /* atan(-0,-anything) =-pi */
}
}
/* when x = 0 */
if (exptx==0 && ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)==0)
- return expsigny < 0 ? -pio2_hi-tiny : pio2_hi+tiny;
+ return expsigny < 0 ? -pio2_hi-0x1p-1000 : pio2_hi+0x1p-1000;
/* when x is INF */
- if (exptx == BIAS+LDBL_MAX_EXP) {
- if (expty == BIAS+LDBL_MAX_EXP) {
+ if (exptx == 0x7fff) {
+ if (expty == 0x7fff) {
switch(m) {
- case 0: return pio2_hi*0.5+tiny; /* atan(+INF,+INF) */
- case 1: return -pio2_hi*0.5-tiny; /* atan(-INF,+INF) */
- case 2: return 1.5*pio2_hi+tiny; /* atan(+INF,-INF) */
- case 3: return -1.5*pio2_hi-tiny; /* atan(-INF,-INF) */
+ case 0: return pio2_hi*0.5+0x1p-1000; /* atan(+INF,+INF) */
+ case 1: return -pio2_hi*0.5-0x1p-1000; /* atan(-INF,+INF) */
+ case 2: return 1.5*pio2_hi+0x1p-1000; /* atan(+INF,-INF) */
+ case 3: return -1.5*pio2_hi-0x1p-1000; /* atan(-INF,-INF) */
}
} else {
switch(m) {
case 0: return 0.0; /* atan(+...,+INF) */
case 1: return -0.0; /* atan(-...,+INF) */
- case 2: return pi_hi+tiny; /* atan(+...,-INF) */
- case 3: return -pi_hi-tiny; /* atan(-...,-INF) */
+ case 2: return 2*pio2_hi+0x1p-1000; /* atan(+...,-INF) */
+ case 3: return -2*pio2_hi-0x1p-1000; /* atan(-...,-INF) */
}
}
}
/* when y is INF */
- if (expty == BIAS+LDBL_MAX_EXP)
- return expsigny < 0 ? -pio2_hi-tiny : pio2_hi+tiny;
+ if (expty == 0x7fff)
+ return expsigny < 0 ? -pio2_hi-0x1p-1000 : pio2_hi+0x1p-1000;
/* compute y/x */
k = expty-exptx;
if(k > LDBL_MANT_DIG+2) { /* |y/x| huge */
- z = pio2_hi+pio2_lo;
+ z = pio2_hi+0x1p-1000;
m &= 1;
} else if (expsignx < 0 && k < -LDBL_MANT_DIG-2) /* |y/x| tiny, x<0 */
z = 0.0;
@@ -95,9 +93,9 @@ long double atan2l(long double y, long double x)
switch (m) {
case 0: return z; /* atan(+,+) */
case 1: return -z; /* atan(-,+) */
- case 2: return pi_hi-(z-pi_lo); /* atan(+,-) */
+ case 2: return 2*pio2_hi-(z-2*pio2_lo); /* atan(+,-) */
default: /* case 3 */
- return (z-pi_lo)-pi_hi; /* atan(-,-) */
+ return (z-2*pio2_lo)-2*pio2_hi; /* atan(-,-) */
}
}
#endif
diff --git a/src/math/atanf.c b/src/math/atanf.c
index 4e31b902..4b59509a 100644
--- a/src/math/atanf.c
+++ b/src/math/atanf.c
@@ -38,28 +38,26 @@ static const float aT[] = {
6.1687607318e-02,
};
-static const float huge = 1.0e30;
-
float atanf(float x)
{
float w,s1,s2,z;
- int32_t ix,hx,id;
+ uint32_t ix,sign;
+ int id;
- GET_FLOAT_WORD(hx, x);
- ix = hx & 0x7fffffff;
+ GET_FLOAT_WORD(ix, x);
+ sign = ix>>31;
+ ix &= 0x7fffffff;
if (ix >= 0x4c800000) { /* if |x| >= 2**26 */
- if (ix > 0x7f800000) /* NaN */
- return x+x;
- if (hx > 0)
- return atanhi[3] + *(volatile float *)&atanlo[3];
- else
- return -atanhi[3] - *(volatile float *)&atanlo[3];
+ if (isnan(x))
+ return x;
+ z = atanhi[3] + 0x1p-120f;
+ return sign ? -z : z;
}
if (ix < 0x3ee00000) { /* |x| < 0.4375 */
if (ix < 0x39800000) { /* |x| < 2**-12 */
- /* raise inexact */
- if(huge+x>1.0f)
- return x;
+ /* raise inexact if x!=0 */
+ FORCE_EVAL(x + 0x1p120f);
+ return x;
}
id = -1;
} else {
@@ -91,5 +89,5 @@ float atanf(float x)
if (id < 0)
return x - x*(s1+s2);
z = atanhi[id] - ((x*(s1+s2) - atanlo[id]) - x);
- return hx < 0 ? -z : z;
+ return sign ? -z : z;
}
diff --git a/src/math/atanl.c b/src/math/atanl.c
index 33ecff0d..6a480a7a 100644
--- a/src/math/atanl.c
+++ b/src/math/atanl.c
@@ -22,11 +22,6 @@ long double atanl(long double x)
return atan(x);
}
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
-#include "__invtrigl.h"
-
-#define ATAN_CONST (BIAS + 65) /* 2**65 */
-#define ATAN_LINEAR (BIAS - 32) /* 2**-32 */
-static const long double huge = 1.0e300;
static const long double atanhi[] = {
4.63647609000806116202e-01L,
@@ -81,29 +76,27 @@ long double atanl(long double x)
u.e = x;
expsign = u.xbits.expsign;
expt = expsign & 0x7fff;
- if (expt >= ATAN_CONST) { /* if |x| is large, atan(x)~=pi/2 */
- if (expt == BIAS + LDBL_MAX_EXP &&
+ if (expt >= 0x3fff + 65) { /* if |x| is large, atan(x)~=pi/2 */
+ if (expt == 0x7fff &&
((u.bits.manh&~LDBL_NBIT)|u.bits.manl)!=0) /* NaN */
return x+x;
- if (expsign > 0)
- return atanhi[3]+atanlo[3];
- else
- return -atanhi[3]-atanlo[3];
+ z = atanhi[3] + 0x1p-1000;
+ return expsign < 0 ? -z : z;
}
/* Extract the exponent and the first few bits of the mantissa. */
/* XXX There should be a more convenient way to do this. */
- expman = (expt << 8) | ((u.bits.manh >> (MANH_SIZE - 9)) & 0xff);
- if (expman < ((BIAS - 2) << 8) + 0xc0) { /* |x| < 0.4375 */
- if (expt < ATAN_LINEAR) { /* if |x| is small, atanl(x)~=x */
- /* raise inexact */
- if (huge+x > 1.0)
- return x;
+ expman = (expt << 8) | ((u.bits.manh >> (LDBL_MANH_SIZE - 9)) & 0xff);
+ if (expman < ((0x3fff - 2) << 8) + 0xc0) { /* |x| < 0.4375 */
+ if (expt < 0x3fff - 32) { /* if |x| is small, atanl(x)~=x */
+ /* raise inexact if x!=0 */
+ FORCE_EVAL(x + 0x1p1000);
+ return x;
}
id = -1;
} else {
x = fabsl(x);
- if (expman < (BIAS << 8) + 0x30) { /* |x| < 1.1875 */
- if (expman < ((BIAS - 1) << 8) + 0x60) { /* 7/16 <= |x| < 11/16 */
+ if (expman < (0x3fff << 8) + 0x30) { /* |x| < 1.1875 */
+ if (expman < ((0x3fff - 1) << 8) + 0x60) { /* 7/16 <= |x| < 11/16 */
id = 0;
x = (2.0*x-1.0)/(2.0+x);
} else { /* 11/16 <= |x| < 19/16 */
@@ -111,7 +104,7 @@ long double atanl(long double x)
x = (x-1.0)/(x+1.0);
}
} else {
- if (expman < ((BIAS + 1) << 8) + 0x38) { /* |x| < 2.4375 */
+ if (expman < ((0x3fff + 1) << 8) + 0x38) { /* |x| < 2.4375 */
id = 2;
x = (x-1.5)/(1.0+1.5*x);
} else { /* 2.4375 <= |x| < 2^ATAN_CONST */