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| author | Joseph Myers <joseph@codesourcery.com> | 2012-04-30 18:56:39 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2012-04-30 18:56:39 +0000 |
| commit | adfbc8ac9e192b6e3007f7a47852df937afa2145 (patch) | |
| tree | 09a345d547258a55e1d410065f9ca09a1bed480c /sysdeps/i386/fpu/e_acos.S | |
| parent | 5ba3cc691c856e5c67a7d4cd4713f20a79f7ba81 (diff) | |
| download | glibc-adfbc8ac9e192b6e3007f7a47852df937afa2145.tar.gz glibc-adfbc8ac9e192b6e3007f7a47852df937afa2145.tar.xz glibc-adfbc8ac9e192b6e3007f7a47852df937afa2145.zip | |
Fix x86 acos near 1 (bug 13942).
Diffstat (limited to 'sysdeps/i386/fpu/e_acos.S')
| -rw-r--r-- | sysdeps/i386/fpu/e_acos.S | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/sysdeps/i386/fpu/e_acos.S b/sysdeps/i386/fpu/e_acos.S index d10a054b9c..586c7fc406 100644 --- a/sysdeps/i386/fpu/e_acos.S +++ b/sysdeps/i386/fpu/e_acos.S @@ -7,13 +7,15 @@ RCSID("$NetBSD: e_acos.S,v 1.4 1995/05/08 23:44:37 jtc Exp $") -/* acos = atan (sqrt(1 - x^2) / x) */ +/* acos = atan (sqrt((1-x) (1+x)) / x) */ ENTRY(__ieee754_acos) fldl 4(%esp) /* x */ fld %st /* x : x */ - fmul %st(0) /* x^2 : x */ - fld1 /* 1 : x^2 : x */ - fsubp /* 1 - x^2 : x */ + fld1 /* 1 : x : x */ + fsubp /* 1 - x : x */ + fld1 /* 1 : 1 - x : x */ + fadd %st(2) /* 1 + x : 1 - x : x */ + fmulp /* 1 - x^2 : x */ fsqrt /* sqrt (1 - x^2) : x */ fabs fxch %st(1) /* x : sqrt (1 - x^2) */ |