https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71020
--- Comment #4 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> --- Author: rsandifo Date: Wed May 18 14:01:31 2016 New Revision: 236393 URL: https://gcc.gnu.org/viewcvs?rev=236393&root=gcc&view=rev Log: To: gcc-patc...@gcc.gnu.org Subject: PR 71020: Handle abnormal PHIs in tree-call-cdce.c From: Richard Sandiford <richard.sandif...@arm.com> Gcc: private.sent --text follows this line-- The PR is about a case where tree-call-cdce.c causes two abnormal PHIs for the same variable to be live at the same time, leading to a coalescing failure. It seemed like getting rid of these kinds of input would be generally useful, so I added a utility to tree-dfa.c. Tested on x86_64-linux-gnu. gcc/ PR middle-end/71020 * tree-dfa.h (replace_abnormal_ssa_names): Declare. * tree-dfa.c (replace_abnormal_ssa_names): New function. * tree-call-cdce.c: Include tree-dfa.h. (can_guard_call_p): New function, extracted from... (can_use_internal_fn): ...here. (shrink_wrap_one_built_in_call_with_conds): Remove failure path and return void. (shrink_wrap_one_built_in_call): Likewise. (use_internal_fn): Likewise. (shrink_wrap_conditional_dead_built_in_calls): Update accordingly and return void. Call replace_abnormal_ssa_names. (pass_call_cdce::execute): Check can_guard_call_p during the initial walk. Assume shrink_wrap_conditional_dead_built_in_calls will always change something. gcc/testsuite/ * gcc.dg/torture/pr71020.c: New test. Added: trunk/gcc/testsuite/gcc.dg/torture/pr71020.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-call-cdce.c trunk/gcc/tree-dfa.c trunk/gcc/tree-dfa.h
