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| author | Szabolcs Nagy <nsz@port70.net> | 2013-11-24 01:06:38 +0000 |
|---|---|---|
| committer | Szabolcs Nagy <nsz@port70.net> | 2013-11-24 01:06:38 +0000 |
| commit | 3fdf94ec5101fab63d0e8196d3e557641a0e19e2 (patch) | |
| tree | a8684dad2f216505e97263187b768013648146d0 /src/math/__rem_pio2_large.c | |
| parent | 10c8b7148b918938d8e681c5801b913dd56cb7e4 (diff) | |
| download | musl-3fdf94ec5101fab63d0e8196d3e557641a0e19e2.tar.gz | |
math: clean up __rem_pio2
- 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
Diffstat (limited to 'src/math/__rem_pio2_large.c')
| -rw-r--r-- | src/math/__rem_pio2_large.c | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/src/math/__rem_pio2_large.c b/src/math/__rem_pio2_large.c index bb2dc43f..958f28c2 100644 --- a/src/math/__rem_pio2_large.c +++ b/src/math/__rem_pio2_large.c @@ -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] */ |