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authorSzabolcs Nagy <nsz@port70.net>2013-05-18 14:40:22 +0000
committerSzabolcs Nagy <nsz@port70.net>2013-05-18 14:40:22 +0000
commitbfda37935867f9bf271d6074db0accf05c63ad10 (patch)
tree92d7fffcc6fb7fd9caad6f3bde14dcd768d32b66 /src
parent1d5ba3bb5a3f55e10db05219638cfcd967d65417 (diff)
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math: sin cos cleanup
* use unsigned arithmetics * use unsigned to store arg reduction quotient (so n&3 is understood) * remove z=0.0 variables, use literal 0 * raise underflow and inexact exceptions properly when x is small * fix spurious underflow in tanl
Diffstat (limited to 'src')
-rw-r--r--src/math/cos.c20
-rw-r--r--src/math/cosf.c33
-rw-r--r--src/math/cosl.c22
-rw-r--r--src/math/sin.c15
-rw-r--r--src/math/sincos.c12
-rw-r--r--src/math/sincosf.c45
-rw-r--r--src/math/sincosl.c20
-rw-r--r--src/math/sinf.c33
-rw-r--r--src/math/sinl.c29
-rw-r--r--src/math/tanl.c11
10 files changed, 128 insertions, 112 deletions
diff --git a/src/math/cos.c b/src/math/cos.c
index 76990e7f..ee97f68b 100644
--- a/src/math/cos.c
+++ b/src/math/cos.c
@@ -44,26 +44,28 @@
double cos(double x)
{
- double y[2],z=0.0;
- int32_t n, ix;
+ double y[2];
+ uint32_t ix;
+ unsigned n;
GET_HIGH_WORD(ix, x);
+ ix &= 0x7fffffff;
/* |x| ~< pi/4 */
- ix &= 0x7fffffff;
if (ix <= 0x3fe921fb) {
- if (ix < 0x3e46a09e) /* if x < 2**-27 * sqrt(2) */
- /* raise inexact if x != 0 */
- if ((int)x == 0)
- return 1.0;
- return __cos(x, z);
+ if (ix < 0x3e46a09e) { /* |x| < 2**-27 * sqrt(2) */
+ /* raise inexact if x!=0 */
+ FORCE_EVAL(x + 0x1p120f);
+ return 1.0;
+ }
+ return __cos(x, 0);
}
/* cos(Inf or NaN) is NaN */
if (ix >= 0x7ff00000)
return x-x;
- /* argument reduction needed */
+ /* argument reduction */
n = __rem_pio2(x, y);
switch (n&3) {
case 0: return __cos(y[0], y[1]);
diff --git a/src/math/cosf.c b/src/math/cosf.c
index 4d94130f..23f3e5bf 100644
--- a/src/math/cosf.c
+++ b/src/math/cosf.c
@@ -26,34 +26,39 @@ c4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
float cosf(float x)
{
double y;
- int32_t n, hx, ix;
+ uint32_t ix;
+ unsigned n, sign;
+
+ GET_FLOAT_WORD(ix, x);
+ sign = ix >> 31;
+ ix &= 0x7fffffff;
- GET_FLOAT_WORD(hx, x);
- ix = hx & 0x7fffffff;
if (ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
- if (ix < 0x39800000) /* |x| < 2**-12 */
- if ((int)x == 0) /* raise inexact if x != 0 */
- return 1.0;
+ if (ix < 0x39800000) { /* |x| < 2**-12 */
+ /* raise inexact if x != 0 */
+ FORCE_EVAL(x + 0x1p120f);
+ return 1.0f;
+ }
return __cosdf(x);
}
if (ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */
if (ix > 0x4016cbe3) /* |x| ~> 3*pi/4 */
- return -__cosdf(hx > 0 ? x-c2pio2 : x+c2pio2);
+ return -__cosdf(sign ? x+c2pio2 : x-c2pio2);
else {
- if (hx > 0)
- return __sindf(c1pio2 - x);
- else
+ if (sign)
return __sindf(x + c1pio2);
+ else
+ return __sindf(c1pio2 - x);
}
}
if (ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */
if (ix > 0x40afeddf) /* |x| ~> 7*pi/4 */
- return __cosdf(hx > 0 ? x-c4pio2 : x+c4pio2);
+ return __cosdf(sign ? x+c4pio2 : x-c4pio2);
else {
- if (hx > 0)
- return __sindf(x - c3pio2);
+ if (sign)
+ return __sindf(-x - c3pio2);
else
- return __sindf(-c3pio2 - x);
+ return __sindf(x - c3pio2);
}
}
diff --git a/src/math/cosl.c b/src/math/cosl.c
index 25d9005a..0794d284 100644
--- a/src/math/cosl.c
+++ b/src/math/cosl.c
@@ -39,30 +39,30 @@ long double cosl(long double x) {
long double cosl(long double x)
{
union IEEEl2bits z;
- int e0;
+ unsigned n;
long double y[2];
long double hi, lo;
z.e = x;
z.bits.sign = 0;
- /* If x = +-0 or x is a subnormal number, then cos(x) = 1 */
- if (z.bits.exp == 0)
- return 1.0;
-
/* If x = NaN or Inf, then cos(x) = NaN. */
- if (z.bits.exp == 32767)
+ if (z.bits.exp == 0x7fff)
return (x - x) / (x - x);
- /* Optimize the case where x is already within range. */
- if (z.e < M_PI_4)
+ /* |x| < (double)pi/4 */
+ if (z.e < M_PI_4) {
+ /* |x| < 0x1p-64 */
+ if (z.bits.exp < 0x3fff - 64)
+ /* raise inexact if x!=0 */
+ return 1.0 + x;
return __cosl(z.e, 0);
+ }
- e0 = __rem_pio2l(x, y);
+ n = __rem_pio2l(x, y);
hi = y[0];
lo = y[1];
-
- switch (e0 & 3) {
+ switch (n & 3) {
case 0:
hi = __cosl(hi, lo);
break;
diff --git a/src/math/sin.c b/src/math/sin.c
index 8e430f85..055e215b 100644
--- a/src/math/sin.c
+++ b/src/math/sin.c
@@ -44,21 +44,22 @@
double sin(double x)
{
- double y[2], z=0.0;
- int32_t n, ix;
+ double y[2];
+ uint32_t ix;
+ unsigned n;
/* High word of x. */
GET_HIGH_WORD(ix, x);
+ ix &= 0x7fffffff;
/* |x| ~< pi/4 */
- ix &= 0x7fffffff;
if (ix <= 0x3fe921fb) {
if (ix < 0x3e500000) { /* |x| < 2**-26 */
- /* raise inexact if x != 0 */
- if ((int)x == 0)
- return x;
+ /* raise inexact if x != 0 and underflow if subnormal*/
+ FORCE_EVAL(ix < 0x00100000 ? x/0x1p120f : x+0x1p120f);
+ return x;
}
- return __sin(x, z, 0);
+ return __sin(x, 0.0, 0);
}
/* sin(Inf or NaN) is NaN */
diff --git a/src/math/sincos.c b/src/math/sincos.c
index 442e285e..49f8a098 100644
--- a/src/math/sincos.c
+++ b/src/math/sincos.c
@@ -15,7 +15,8 @@
void sincos(double x, double *sin, double *cos)
{
double y[2], s, c;
- uint32_t n, ix;
+ uint32_t ix;
+ unsigned n;
GET_HIGH_WORD(ix, x);
ix &= 0x7fffffff;
@@ -24,11 +25,10 @@ void sincos(double x, double *sin, double *cos)
if (ix <= 0x3fe921fb) {
/* if |x| < 2**-27 * sqrt(2) */
if (ix < 0x3e46a09e) {
- /* raise inexact if x != 0 */
- if ((int)x == 0) {
- *sin = x;
- *cos = 1.0;
- }
+ /* raise inexact if x!=0 and underflow if subnormal */
+ FORCE_EVAL(ix < 0x00100000 ? x/0x1p120f : x+0x1p120f);
+ *sin = x;
+ *cos = 1.0;
return;
}
*sin = __sin(x, 0.0, 0);
diff --git a/src/math/sincosf.c b/src/math/sincosf.c
index 5e3b9a41..1b50f01c 100644
--- a/src/math/sincosf.c
+++ b/src/math/sincosf.c
@@ -25,21 +25,23 @@ s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
void sincosf(float x, float *sin, float *cos)
{
- double y, s, c;
- uint32_t n, hx, ix;
+ double y;
+ float_t s, c;
+ uint32_t ix;
+ unsigned n, sign;
- GET_FLOAT_WORD(hx, x);
- ix = hx & 0x7fffffff;
+ GET_FLOAT_WORD(ix, x);
+ sign = ix >> 31;
+ ix &= 0x7fffffff;
/* |x| ~<= pi/4 */
if (ix <= 0x3f490fda) {
/* |x| < 2**-12 */
if (ix < 0x39800000) {
- /* raise inexact if x != 0 */
- if((int)x == 0) {
- *sin = x;
- *cos = 1.0f;
- }
+ /* raise inexact if x!=0 and underflow if subnormal */
+ FORCE_EVAL(ix < 0x00100000 ? x/0x1p120f : x+0x1p120f);
+ *sin = x;
+ *cos = 1.0f;
return;
}
*sin = __sindf(x);
@@ -50,34 +52,35 @@ void sincosf(float x, float *sin, float *cos)
/* |x| ~<= 5*pi/4 */
if (ix <= 0x407b53d1) {
if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */
- if (hx < 0x80000000) {
- *sin = __cosdf(x - s1pio2);
- *cos = __sindf(s1pio2 - x);
- } else {
+ if (sign) {
*sin = -__cosdf(x + s1pio2);
*cos = __sindf(x + s1pio2);
+ } else {
+ *sin = __cosdf(s1pio2 - x);
+ *cos = __sindf(s1pio2 - x);
}
return;
}
- *sin = __sindf(hx < 0x80000000 ? s2pio2 - x : -s2pio2 - x);
- *cos = -__cosdf(hx < 0x80000000 ? x - s2pio2 : x + s2pio2);
+ /* -sin(x+c) is not correct if x+c could be 0: -0 vs +0 */
+ *sin = -__sindf(sign ? x + s2pio2 : x - s2pio2);
+ *cos = -__cosdf(sign ? x + s2pio2 : x - s2pio2);
return;
}
/* |x| ~<= 9*pi/4 */
if (ix <= 0x40e231d5) {
if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */
- if (hx < 0x80000000) {
+ if (sign) {
+ *sin = __cosdf(x + s3pio2);
+ *cos = -__sindf(x + s3pio2);
+ } else {
*sin = -__cosdf(x - s3pio2);
*cos = __sindf(x - s3pio2);
- } else {
- *sin = __cosdf(x + s3pio2);
- *cos = __sindf(-s3pio2 - x);
}
return;
}
- *sin = __sindf(hx < 0x80000000 ? x - s4pio2 : x + s4pio2);
- *cos = __cosdf(hx < 0x80000000 ? x - s4pio2 : x + s4pio2);
+ *sin = __sindf(sign ? x + s4pio2 : x - s4pio2);
+ *cos = __cosdf(sign ? x + s4pio2 : x - s4pio2);
return;
}
diff --git a/src/math/sincosl.c b/src/math/sincosl.c
index d632fe6f..5db69bd6 100644
--- a/src/math/sincosl.c
+++ b/src/math/sincosl.c
@@ -10,27 +10,29 @@ void sincosl(long double x, long double *sin, long double *cos)
void sincosl(long double x, long double *sin, long double *cos)
{
union IEEEl2bits u;
- int n;
+ unsigned n;
long double y[2], s, c;
u.e = x;
u.bits.sign = 0;
- /* x = +-0 or subnormal */
- if (!u.bits.exp) {
- *sin = x;
- *cos = 1.0;
- return;
- }
-
/* x = nan or inf */
if (u.bits.exp == 0x7fff) {
*sin = *cos = x - x;
return;
}
- /* |x| < pi/4 */
+ /* |x| < (double)pi/4 */
if (u.e < M_PI_4) {
+ /* |x| < 0x1p-64 */
+ if (u.bits.exp < 0x3fff - 64) {
+ /* raise underflow if subnormal */
+ if (u.bits.exp == 0) FORCE_EVAL(x*0x1p-120f);
+ *sin = x;
+ /* raise inexact if x!=0 */
+ *cos = 1.0 + x;
+ return;
+ }
*sin = __sinl(x, 0, 0);
*cos = __cosl(x, 0);
return;
diff --git a/src/math/sinf.c b/src/math/sinf.c
index dcca67af..64e39f50 100644
--- a/src/math/sinf.c
+++ b/src/math/sinf.c
@@ -26,35 +26,38 @@ s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
float sinf(float x)
{
double y;
- int32_t n, hx, ix;
+ uint32_t ix;
+ int n, sign;
- GET_FLOAT_WORD(hx, x);
- ix = hx & 0x7fffffff;
+ GET_FLOAT_WORD(ix, x);
+ sign = ix >> 31;
+ ix &= 0x7fffffff;
if (ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
- if (ix < 0x39800000) /* |x| < 2**-12 */
- /* raise inexact if x != 0 */
- if((int)x == 0)
- return x;
+ if (ix < 0x39800000) { /* |x| < 2**-12 */
+ /* raise inexact if x!=0 and underflow if subnormal */
+ FORCE_EVAL(ix < 0x00800000 ? x/0x1p120f : x+0x1p120f);
+ return x;
+ }
return __sindf(x);
}
if (ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */
if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */
- if (hx > 0)
- return __cosdf(x - s1pio2);
- else
+ if (sign)
return -__cosdf(x + s1pio2);
+ else
+ return __cosdf(x - s1pio2);
}
- return __sindf(hx > 0 ? s2pio2 - x : -s2pio2 - x);
+ return __sindf(sign ? -(x + s2pio2) : -(x - s2pio2));
}
if (ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */
if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */
- if (hx > 0)
- return -__cosdf(x - s3pio2);
- else
+ if (sign)
return __cosdf(x + s3pio2);
+ else
+ return -__cosdf(x - s3pio2);
}
- return __sindf(hx > 0 ? x - s4pio2 : x + s4pio2);
+ return __sindf(sign ? x + s4pio2 : x - s4pio2);
}
/* sin(Inf or NaN) is NaN */
diff --git a/src/math/sinl.c b/src/math/sinl.c
index 7e0b44f4..6ca99986 100644
--- a/src/math/sinl.c
+++ b/src/math/sinl.c
@@ -37,33 +37,32 @@ long double sinl(long double x)
long double sinl(long double x)
{
union IEEEl2bits z;
- int e0, s;
+ unsigned n;
long double y[2];
long double hi, lo;
z.e = x;
- s = z.bits.sign;
z.bits.sign = 0;
- /* If x = +-0 or x is a subnormal number, then sin(x) = x */
- if (z.bits.exp == 0)
- return x;
-
/* If x = NaN or Inf, then sin(x) = NaN. */
- if (z.bits.exp == 32767)
+ if (z.bits.exp == 0x7fff)
return (x - x) / (x - x);
- /* Optimize the case where x is already within range. */
+ /* |x| < (double)pi/4 */
if (z.e < M_PI_4) {
- hi = __sinl(z.e, 0, 0);
- return s ? -hi : hi;
+ /* |x| < 0x1p-64 */
+ if (z.bits.exp < 0x3fff - 64) {
+ /* raise inexact if x!=0 and underflow if subnormal */
+ FORCE_EVAL(z.bits.exp == 0 ? x/0x1p120f : x+0x1p120f);
+ return x;
+ }
+ return __sinl(x, 0.0, 0);
}
- e0 = __rem_pio2l(x, y);
+ n = __rem_pio2l(x, y);
hi = y[0];
lo = y[1];
-
- switch (e0 & 3) {
+ switch (n & 3) {
case 0:
hi = __sinl(hi, lo, 1);
break;
@@ -71,10 +70,10 @@ long double sinl(long double x)
hi = __cosl(hi, lo);
break;
case 2:
- hi = - __sinl(hi, lo, 1);
+ hi = -__sinl(hi, lo, 1);
break;
case 3:
- hi = - __cosl(hi, lo);
+ hi = -__cosl(hi, lo);
break;
}
return hi;
diff --git a/src/math/tanl.c b/src/math/tanl.c
index 3b51e011..546c7a02 100644
--- a/src/math/tanl.c
+++ b/src/math/tanl.c
@@ -53,11 +53,12 @@ long double tanl(long double x)
/* |x| < (double)pi/4 */
if (z.e < M_PI_4) {
- /* x = +-0 or x is subnormal */
- if (z.bits.exp == 0)
- /* inexact and underflow if x!=0 */
- return x + x*0x1p-120f;
- /* can raise spurious underflow */
+ /* |x| < 0x1p-64 */
+ if (z.bits.exp < 0x3fff - 64) {
+ /* raise inexact if x!=0 and underflow if subnormal */
+ FORCE_EVAL(z.bits.exp == 0 ? x/0x1p120f : x+0x1p120f);
+ return x;
+ }
return __tanl(x, 0, 0);
}