| /** |
| * This file has no copyright assigned and is placed in the Public Domain. |
| * This file is part of the w64 mingw-runtime package. |
| * No warranty is given; refer to the file DISCLAIMER within this package. |
| */ |
| #include <math.h> |
| #include "cephes_mconf.h" /* for max and min log thresholds */ |
| |
| static long double c0 = 1.44268798828125L; |
| static long double c1 = 7.05260771340735992468e-6L; |
| |
| static long double |
| __expl (long double x) |
| { |
| long double res = 0.0L; |
| asm ("fldl2e\n\t" /* 1 log2(e) */ |
| "fmul %%st(1),%%st\n\t" /* 1 x log2(e) */ |
| "frndint\n\t" /* 1 i */ |
| "fld %%st(1)\n\t" /* 2 x */ |
| "frndint\n\t" /* 2 xi */ |
| "fld %%st(1)\n\t" /* 3 i */ |
| "fldt %2\n\t" /* 4 c0 */ |
| "fld %%st(2)\n\t" /* 5 xi */ |
| "fmul %%st(1),%%st\n\t" /* 5 c0 xi */ |
| "fsubp %%st,%%st(2)\n\t" /* 4 f = c0 xi - i */ |
| "fld %%st(4)\n\t" /* 5 x */ |
| "fsub %%st(3),%%st\n\t" /* 5 xf = x - xi */ |
| "fmulp %%st,%%st(1)\n\t" /* 4 c0 xf */ |
| "faddp %%st,%%st(1)\n\t" /* 3 f = f + c0 xf */ |
| "fldt %3\n\t" /* 4 */ |
| "fmul %%st(4),%%st\n\t" /* 4 c1 * x */ |
| "faddp %%st,%%st(1)\n\t" /* 3 f = f + c1 * x */ |
| "f2xm1\n\t" /* 3 2^(fract(x * log2(e))) - 1 */ |
| "fld1\n\t" /* 4 1.0 */ |
| "faddp\n\t" /* 3 2^(fract(x * log2(e))) */ |
| "fstp %%st(1)\n\t" /* 2 */ |
| "fscale\n\t" /* 2 scale factor is st(1); e^x */ |
| "fstp %%st(1)\n\t" /* 1 */ |
| "fstp %%st(1)\n\t" /* 0 */ |
| : "=t" (res) : "0" (x), "m" (c0), "m" (c1) : "ax", "dx"); |
| return res; |
| } |
| |
| long double expl (long double x) |
| { |
| if (x > MAXLOGL) |
| return INFINITY; |
| else if (x < MINLOGL) |
| return 0.0L; |
| else |
| return __expl (x); |
| } |
