https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103218
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Andrew Pinski <pins...@gcc.gnu.org>: https://gcc.gnu.org/g:11c4a06a6c1a9db0bfdb3ee8509392dd7163709c commit r12-5305-g11c4a06a6c1a9db0bfdb3ee8509392dd7163709c Author: Andrew Pinski <apin...@marvell.com> Date: Sat Nov 13 04:16:55 2021 +0000 tree-optimization: [PR103218] Fold ((type)(a<0)) << SIGNBITOFA into ((type)a) & signbit This folds Fold ((type)(a<0)) << SIGNBITOFA into ((type)a) & signbit inside match.pd. This was already handled in fold-cost by: /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */ I have not removed as we only simplify "a ? POW2 : 0" at the gimple level to "a << CST1" and fold actually does the reverse of folding "(a<0)<<CST" into "(a<0) ? 1<<CST : 0". OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. PR tree-optimization/103218 gcc/ChangeLog: * match.pd: New pattern for "((type)(a<0)) << SIGNBITOFA". gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/pr103218-1.c: New test.
