On 2018-02-06 17:34:23 +0000, Joseph Myers wrote: > Use -ffp-contract=off to disable all contraction, or -ffp-contract=on to > disable it between statements (which currently actually disables all > contraction, as the FMA generation doesn't know what was originally a > single source expression). The default in the absence of such -std > options is -ffp-contract=fast (allowing contraction including between > different statements).
An environment variable to specify default GCC options would be very useful. It is too easy to forget such an option. Note: In the long term, -std=c99 or -std=c11 is better, as if one day, GCC supports the STDC FP_CONTRACT pragma, contraction could be partly enabled. -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
