https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77689
--- Comment #18 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jan Hubicka <hubi...@gcc.gnu.org>: https://gcc.gnu.org/g:f5fb9ff2396fd41fdd2e6d35a412e936d2d42f75 commit r14-2852-gf5fb9ff2396fd41fdd2e6d35a412e936d2d42f75 Author: Jan Hubicka <j...@suse.cz> Date: Fri Jul 28 16:18:32 2023 +0200 loop-split improvements, part 3 extend tree-ssa-loop-split to understand test of the form if (i==0) and if (i!=0) which triggers only during the first iteration. Naturally we should also be able to trigger last iteration or split into 3 cases if the test indeed can fire in the middle of the loop. Last iteration is bit trickier pattern matching so I want to do it incrementally, but I implemented easy case using value range that handled loops with constant iterations. The testcase gets misupdated profile, I will also fix that incrementally. gcc/ChangeLog: PR middle-end/77689 * tree-ssa-loop-split.cc: Include value-query.h. (split_at_bb_p): Analyze cases where EQ/NE can be turned into LT/LE/GT/GE; return updated guard code. (split_loop): Use guard code. gcc/testsuite/ChangeLog: PR middle-end/77689 * g++.dg/tree-ssa/loop-split-1.C: New test.
