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fa752c6981
The flt-32 version of powf can be inaccurate because of bugs in the extra-precision calculation of (x-1)/(x+1) or (x-1.5)/(x+1.5) as part of calculating log(x) with extra precision: a constant used (as part of adding 1 or 1.5 through integer arithmetic) is incorrect, and then the code fails to mask a computed high part before using it in arithmetic that relies on s_h*t_h being exactly representable. This patch fixes these bugs. Tested for x86_64 and x86. x86_64 ulps for powf removed and regenerated to reflect reduced ulps from the increased accuracy for existing tests. [BZ #18956] * sysdeps/ieee754/flt-32/e_powf.c (__ieee754_powf): Add 0x00400000 not 0x0040000 for high bit of mantissa. Mask with 0xfffff000 when extracting high part. * math/auto-libm-test-in: Add another test of pow. * math/auto-libm-test-out: Regenerated. * sysdeps/x86_64/fpu/libm-test-ulps: Update. |
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| .. | ||
| bits | ||
| dbl-64 | ||
| flt-32 | ||
| ldbl-64-128 | ||
| ldbl-96 | ||
| ldbl-128 | ||
| ldbl-128ibm | ||
| ldbl-opt | ||
| ieee754.h | ||
| k_standard.c | ||
| k_standardf.c | ||
| k_standardl.c | ||
| Makefile | ||
| s_lib_version.c | ||
| s_matherr.c | ||
| s_signgam.c | ||