https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104198
--- Comment #10 from rdapp at linux dot ibm.com --- Created attachment 52297 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52297&action=edit Tentative patch I now have something that successfully bootstraps on s390x, PowerPC and SPARC but I'm not really happy with it. The idea is basically to check if the newly introduced sequence (getting passed a cc comparison) emits an instruction other than the movcc that reads a register used in the comparison. I'm not sure what backends are supposed to emit for such a sequence but most likely everything is admissible. reg_overlap_mentioned_p does not handle every rtx_code so special handling is necessary which needs to be exhaustive in order for reg_overlap_mentioned_p not to ICE. I feel like this is not the best way to achieve what we want and would appreciate some insight. I attached the current full diff to master (including the fix for the problem triggered by the or1k backend. It's pretty raw/unpolished/ugly but the idea should come across. A full testsuite run on gcc202 just finished, 83 FAILs, but I haven't yet done a comparison run from before the ifcvt changes.
