https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88861
--- Comment #7 from David Malcolm <dmalcolm at gcc dot gnu.org> --- Author: dmalcolm Date: Wed Jan 16 20:13:23 2019 New Revision: 267984 URL: https://gcc.gnu.org/viewcvs?rev=267984&root=gcc&view=rev Log: Fix ICE due to "combine" creating unreachable EH blocks (PR target/88861) PR target/88861 reports an ICE in "ce2" due to an unreachable basic block. The block becomes unreachable in "combine" when delete_noop_moves deletes an insn with a REG_EH_REGION, deleting the EH edge, the only edge leading to the basic block. Normally, rest_of_handle_combine would call cleanup_cfg, deleting unreachable blocks, if combine_instructions returns true, and combine_instructions does return true for some cases of edge-removal, but it doesn't for this case, leading to the ICE. This patch updates delete_noop_moves so that it returns true if it deletes any edges, and passes that through to combine_instructions, so that it too will return true if any edges were deleted, ensuring that cleanup_cfg will be called by rest_of_handle_combine for this case, deleting the now-unreachable block, and fixing the ICE. gcc/ChangeLog: PR target/88861 * combine.c (delete_noop_moves): Convert to "bool" return, returning true if any edges are eliminated. (combine_instructions): Also return true if delete_noop_moves returns true. gcc/testsuite/ChangeLog: PR target/88861 * g++.dg/torture/pr88861.C: New test. Added: trunk/gcc/testsuite/g++.dg/torture/pr88861.C Modified: trunk/gcc/ChangeLog trunk/gcc/combine.c trunk/gcc/testsuite/ChangeLog
