diff options
author | Joseph Myers <joseph@codesourcery.com> | 2017-08-21 17:46:34 +0000 |
---|---|---|
committer | Joseph Myers <joseph@codesourcery.com> | 2017-08-21 17:46:34 +0000 |
commit | 831bbd55271eacc0190a13954bd347f0a521b096 (patch) | |
tree | a46d925f2fca35cd930d73c6d0890ee005ba17fb /INSTALL | |
parent | 813378e9fe17e029caf627cab76fe23eb46815fa (diff) | |
download | glibc-831bbd55271eacc0190a13954bd347f0a521b096.tar.gz glibc-831bbd55271eacc0190a13954bd347f0a521b096.tar.xz glibc-831bbd55271eacc0190a13954bd347f0a521b096.zip |
Remove SPARC sqrt wrappers (bug 21973).
This patch removes the SPARC-specific wrappers for sqrt and sqrtf. These wrappers, by adding architecture-specific uses of _LIB_VERSION and __kernel_standard, unnecessarily complicate cleanups of libm error handling. They also do not serve a useful optimization purpose. GCC knows about sqrt as a built-in function, and can generate direct calls to a hardware square root instruction, either on its own, in the -fno-math-errno case, or together with an inline check for the argument being negative and a call to the out-of-line sqrt function for error handling only in that case (and has been able to do so for a long time). Thus in practice the wrapper will only be called only in the case of negative arguments, which is not a case it is useful to optimize for. The removal of the wrappers also uncovers, and fixes, an old bug. 32-bit SPARC libm used (checked with glibc 2.8 binaries) to have a sqrtl compat symbol, version GLIBC_2.0, for old binaries when sqrtl was an alias of sqrt (I don't have pre-glibc-2.4 binaries for SPARC to hand to check for the sqrtl symbol in those). This disappeared, probably with: commit 8847f0377003fbfe9cbe951ce9f8717d74f26247 Author: David S. Miller <davem@davemloft.net> Date: Tue Feb 28 22:37:58 2012 -0800 Add sparc optimized sqrt{,f}. Removing the wrappers brings back the generic ldbl-opt logic for creating such compat symbols, and so restores the compat symbol that should be there. This could of course also be fixed in the wrappers - but as noted above, the wrappers are optimizing a case it's not useful to optimize, so the bug of the missing compat symbol serves to illustrate the risks involved with the extra complexity of architecture-specific function versions where not needed. Tested with build-many-glibcs.py. [BZ #21973] * sysdeps/sparc/sparc32/fpu/w_sqrt_compat.S: Remove file. * sysdeps/sparc/sparc32/fpu/w_sqrtf_compat.S: Likewise. * sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/w_sqrt_compat-vis3.S: Likewise. * sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/w_sqrt_compat.S: Likewise. * sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/w_sqrtf_compat-vis3.S: Likewise. * sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/w_sqrtf_compat.S: Likewise. * sysdeps/sparc/sparc32/sparcv9/fpu/w_sqrt_compat.S : Likewise. * sysdeps/sparc/sparc32/sparcv9/fpu/w_sqrtf_compat.S: Likewise. * sysdeps/sparc/sparc64/fpu/w_sqrt_compat.S: Likewise. * sysdeps/sparc/sparc64/fpu/w_sqrtf_compat.S: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Add GLIBC_2.0 sqrtl symbol.
Diffstat (limited to 'INSTALL')
0 files changed, 0 insertions, 0 deletions