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| author | Aurelien Jarno <aurelien@aurel32.net> | 2016-08-02 09:18:59 +0200 |
|---|---|---|
| committer | Mike Frysinger <vapier@gentoo.org> | 2016-12-08 00:57:52 -0500 |
| commit | b73ec923c79ab493a9265930a45800391329571a (patch) | |
| tree | f8501dc68a0627188aeaf8c1aa7f55e6d7b68c3e | |
| parent | 04c5f782796052de9d06975061eb3376ccbcbdb1 (diff) | |
| download | glibc-b73ec923c79ab493a9265930a45800391329571a.tar.gz glibc-b73ec923c79ab493a9265930a45800391329571a.tar.xz glibc-b73ec923c79ab493a9265930a45800391329571a.zip | |
alpha: fix trunc for big input values
The alpha specific version of trunc and truncf always add and subtract 0x1.0p23 or 0x1.0p52 even for big values. This causes this kind of errors in the testsuite: Failure: Test: trunc_towardzero (0x1p107) Result: is: 1.6225927682921334e+32 0x1.fffffffffffffp+106 should be: 1.6225927682921336e+32 0x1.0000000000000p+107 difference: 1.8014398509481984e+16 0x1.0000000000000p+54 ulp : 0.5000 max.ulp : 0.0000 Change this by returning the input value when its absolute value is greater than 0x1.0p23 or 0x1.0p52. NaN have to go through the add and subtract operations to get possibly silenced. Finally remove the code to handle inexact exception, trunc should never generate such an exception. Changelog: * sysdeps/alpha/fpu/s_trunc.c (__trunc): Return the input value when its absolute value is greater than 0x1.0p52. [_IEEE_FP_INEXACT] Remove. * sysdeps/alpha/fpu/s_truncf.c (__truncf): Return the input value when its absolute value is greater than 0x1.0p23. [_IEEE_FP_INEXACT] Remove. (cherry picked from commit b74d259fe793499134eb743222cd8dd7c74a31ce) (cherry picked from commit e6eab16cc302e6c42f79e1af02ce98ebb9a783bc)
| -rw-r--r-- | sysdeps/alpha/fpu/s_trunc.c | 7 | ||||
| -rw-r--r-- | sysdeps/alpha/fpu/s_truncf.c | 7 |
2 files changed, 6 insertions, 8 deletions
diff --git a/sysdeps/alpha/fpu/s_trunc.c b/sysdeps/alpha/fpu/s_trunc.c index 16cb114a72..4b986a6926 100644 --- a/sysdeps/alpha/fpu/s_trunc.c +++ b/sysdeps/alpha/fpu/s_trunc.c @@ -28,12 +28,11 @@ __trunc (double x) double two52 = copysign (0x1.0p52, x); double r, tmp; + if (isgreaterequal (fabs (x), 0x1.0p52)) + return x; + __asm ( -#ifdef _IEEE_FP_INEXACT - "addt/suic %2, %3, %1\n\tsubt/suic %1, %3, %0" -#else "addt/suc %2, %3, %1\n\tsubt/suc %1, %3, %0" -#endif : "=&f"(r), "=&f"(tmp) : "f"(x), "f"(two52)); diff --git a/sysdeps/alpha/fpu/s_truncf.c b/sysdeps/alpha/fpu/s_truncf.c index 2290f28295..3e93356166 100644 --- a/sysdeps/alpha/fpu/s_truncf.c +++ b/sysdeps/alpha/fpu/s_truncf.c @@ -27,12 +27,11 @@ __truncf (float x) float two23 = copysignf (0x1.0p23, x); float r, tmp; + if (isgreaterequal (fabsf (x), 0x1.0p23)) + return x; + __asm ( -#ifdef _IEEE_FP_INEXACT - "adds/suic %2, %3, %1\n\tsubs/suic %1, %3, %0" -#else "adds/suc %2, %3, %1\n\tsubs/suc %1, %3, %0" -#endif : "=&f"(r), "=&f"(tmp) : "f"(x), "f"(two23)); |