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* Avoid excess range in results from i386 scalb functions (bug 18981).Joseph Myers2015-09-181-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | i386 scalb / scalbn / scalbln (and thus ldexp) functions for float and double can return results with excess range (and consequently excess precision for subnormal results). As the results of these functions are fully determined by reference to IEEE 754 operations, this is unambiguously a bug, apart from the testsuite failures it causes. This patch makes those functions store their results on the stack and load them back to eliminate the excess range. Double rounding is not a problem, as the only cases where it could occur are when the result overflows or underflows for extended precision, and then the double-rounded results are the same as the single-rounded results. The new macros will be used for more functions, more such macros added, and existing code refactored to use such macros, in subsequent patches. Tested for x86. Committed. [BZ #18981] * sysdeps/i386/fpu/i386-math-asm.h: New file. * sysdeps/i386/fpu/e_scalb.S: Include <i386-math-asm.h>. (__ieee754_scalb): Use DBL_NARROW_EVAL. * sysdeps/i386/fpu/e_scalbf.S: Include <i386-math-asm.h>. (__ieee754_scalbf): Use FLT_NARROW_EVAL. * sysdeps/i386/fpu/s_scalbn.S: Include <i386-math-asm.h>. (__scalbn): Use DBL_NARROW_EVAL. * sysdeps/i386/fpu/s_scalbnf.S: Include <i386-math-asm.h>. (__scalbnf): Use FLT_NARROW_EVAL.
* Make scalbn set errno (bug 6803).Joseph Myers2015-09-161-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As noted in bug 6803, scalbn fails to set errno on overflow and underflow. This patch fixes this by making scalbn an alias of ldexp, which has exactly the same semantics (for floating-point types with radix 2) and already has wrappers that deal with setting errno, instead of an alias of the internal __scalbn (which ldexp calls). Notes: * Where compat symbols were defined for scalbn functions, I didn't change what they point to (to keep the patch minimal), so such compat symbols continue to go directly to the non-errno-setting functions. * Mike, I didn't do anything with the IA64 versions of these functions, where I think both the ldexp and scalbn functions already deal with setting errno. As a cleanup (not needed to fix this bug) however you might want to make those functions into aliases for IA64; there is no need for them to be separate function implementations at all. * This concludes the fix for bug 6803 since the scalb and scalbln cases of that bug were fixed some time ago. Tested for x86_64, x86, mips64 and powerpc. [BZ #6803] * math/s_ldexp.c (scalbn): Define as weak alias of __ldexp. [NO_LONG_DOUBLE] (scalbnl): Define as weak alias of __ldexp. * math/s_ldexpf.c (scalbnf): Define as weak alias of __ldexpf. * math/s_ldexpl.c (scalbnl): Define as weak alias of __ldexpl. * sysdeps/i386/fpu/s_scalbn.S (scalbn): Remove alias. * sysdeps/i386/fpu/s_scalbnf.S (scalbnf): Likewise. * sysdeps/i386/fpu/s_scalbnl.S (scalbnl): Likewise. * sysdeps/ieee754/dbl-64/s_scalbn.c (scalbn): Likewise. [NO_LONG_DOUBLE] (scalbnl): Likewise. * sysdeps/ieee754/dbl-64/wordsize-64/s_scalbn.c (scalbn): Likewise. [NO_LONG_DOUBLE] (scalbnl): Likewise. * sysdeps/ieee754/flt-32/s_scalbnf.c (scalbnf): Likewise. * sysdeps/ieee754/ldbl-128/s_scalbnl.c (scalbnl): Likewise. * sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c (scalbnl): Remove long_double_symbol calls. * sysdeps/ieee754/ldbl-64-128/s_scalbnl.c (scalbnl): Likewise. * sysdeps/ieee754/ldbl-opt/s_ldexpl.c (__ldexpl_2): Define as strong alias of __ldexpl. (scalbnl): Define using long_double_symbol. * sysdeps/m68k/m680x0/fpu/s_scalbn.c (__CONCATX(scalbn,suffix)): Remove alias. * sysdeps/sparc/sparc64/soft-fp/s_scalbnl.c (scalbnl): Likewise. * sysdeps/x86_64/fpu/s_scalbnl.S (scalbnl): Likewise. * math/libm-test.inc (scalbn_test_data): Add errno expectations. (scalbln_test_data): Add more errno expectations.
* Add compat symbols for scalb* in i386Siddhesh Poyarekar2014-06-251-0/+5
| | | | | Bring back symbols into libc.so for scalb* functions. They are no longer used but unfortunately they're now part of the ABI.
* [BZ #6803] Set errno for scalbln, scalbnStefan Liebler2014-06-201-1/+0
| | | | | | | | | | | Errno is not set and the testcases will fail. Now the scalbln-aliases are removed in i386/m68 and the wrappers are used when calling the scalbln-functions. On ia64 only scalblnf has its own implementation. For scalbln and scalblnl the ieee754/dbl-64 and ieee754/ldbl-96 are used, thus the wrappers are needed, too.
* Update.Ulrich Drepper1999-07-141-0/+19