3b00222f15
When using clang with x86_64 CPUs that support AVX, some floating point transformations may raise exceptions that would not have been raised by the original code. To avoid this, use the -fp-exception-behavior=maytrap flag, introduced in clang 10.0.0. In particular, this fixes a number of test failures with ctanhf(3) and ctanf(3), when libm is compiled with -mavx. An unexpected FE_INVALID exception is then raised, because clang emits vdivps instructions to perform certain divides. (The vdivps instruction operates on multiple single-precision float operands simultaneously, but the exceptions may be influenced by unused parts of the XMM registers. In this particular case, it was calculating 0 / 0, which results in FE_INVALID.) If -fp-exception-behavior=maytrap is specified however, clang uses vdivss instructions instead, which work on one operand, and should not raise unexpected exceptions. Reported by: olivier Reviewed by: arichardson PR: 254911 MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D29686
FreeBSD Source:
This is the top level of the FreeBSD source directory.
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Source Roadmap:
| Directory | Description |
|---|---|
| bin | System/user commands. |
| cddl | Various commands and libraries under the Common Development and Distribution License. |
| contrib | Packages contributed by 3rd parties. |
| crypto | Cryptography stuff (see crypto/README). |
| etc | Template files for /etc. |
| gnu | Various commands and libraries under the GNU Public License. Please see gnu/COPYING and gnu/COPYING.LIB for more information. |
| include | System include files. |
| kerberos5 | Kerberos5 (Heimdal) package. |
| lib | System libraries. |
| libexec | System daemons. |
| release | Release building Makefile & associated tools. |
| rescue | Build system for statically linked /rescue utilities. |
| sbin | System commands. |
| secure | Cryptographic libraries and commands. |
| share | Shared resources. |
| stand | Boot loader sources. |
| sys | Kernel sources. |
sys/arch/conf |
Kernel configuration files. GENERIC is the configuration used in release builds. NOTES contains documentation of all possible entries. |
| tests | Regression tests which can be run by Kyua. See tests/README for additional information. |
| tools | Utilities for regression testing and miscellaneous tasks. |
| usr.bin | User commands. |
| usr.sbin | System administration commands. |
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