fluencelabs/musl
1
0
Fork 0
mirror of https://github.com/fluencelabs/musl synced 2025-06-30 07:02:41 +00:00
Code Issues Projects Releases Wiki Activity

math: clean up __rem_pio2

Browse Source 
- remove the HAVE_EFFICIENT_IRINT case: fn is an exact integer, so
  it can be converted to int32_t a bit more efficiently than with a
  cast (the rounding mode change can be avoided), but musl does not
  support this case on any arch.
- __rem_pio2: use double_t where possible
- __rem_pio2f: use less assignments to avoid stores on i386
- use unsigned int bit manipulation (and union instead of macros)
- use hexfloat literals instead of named constants
This commit is contained in:
Szabolcs Nagy
2013-11-24 01:06:38 +00:00
parent 10c8b7148b
commit 3fdf94ec51
3 changed files with 53 additions and 71 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
src/math/__rem_pio2_large.c
View File

@ -270,10 +270,6 @@ static const double PIo2[] = {
2.16741683877804819444e-51, /* 0x3569F31D, 0x00000000 */
};
static const double
two24 = 1.67772160000000000000e+07, /* 0x41700000, 0x00000000 */
twon24 = 5.96046447753906250000e-08; /* 0x3E700000, 0x00000000 */
int __rem_pio2_large(double *x, double *y, int e0, int nx, int prec)
{
int32_t jz,jx,jv,jp,jk,carry,n,iq[20],i,j,k,m,q0,ih;
@ -304,8 +300,8 @@ int __rem_pio2_large(double *x, double *y, int e0, int nx, int prec)
recompute:
/* distill q[] into iq[] reversingly */
for (i=0,j=jz,z=q[jz]; j>0; i++,j--) {
fw = (double)((int32_t)(twon24* z));
iq[i] = (int32_t)(z-two24*fw);
fw = (double)(int32_t)(0x1p-24*z);
iq[i] = (int32_t)(z - 0x1p24*fw);
z = q[j-1]+fw;
}
@ -330,7 +326,7 @@ recompute:
if (carry == 0) {
if (j != 0) {
carry = 1;
iq[i] = 0x1000000- j;
iq[i] = 0x1000000 - j;
}
} else
iq[i] = 0xffffff - j;
@ -378,9 +374,9 @@ recompute:
}
} else { /* break z into 24-bit if necessary */
z = scalbn(z,-q0);
if (z >= two24) {
fw = (double)((int32_t)(twon24*z));
iq[jz] = (int32_t)(z-two24*fw);
if (z >= 0x1p24) {
fw = (double)(int32_t)(0x1p-24*z);
iq[jz] = (int32_t)(z - 0x1p24*fw);
jz += 1;
q0 += 24;
iq[jz] = (int32_t)fw;
@ -392,7 +388,7 @@ recompute:
fw = scalbn(1.0,q0);
for (i=jz; i>=0; i--) {
q[i] = fw*(double)iq[i];
fw *= twon24;
fw *= 0x1p-24;
}
/* compute PIo2[0,...,jp]*q[jz,...,0] */