The conditional dead call elimination pass shrink wraps certain dead calls to math functions. It doesn't handle case like this:
D.142420_139 = powD.549 (D.142421_138, D.142419_132); fooD.120935.barD.113815 = D.142420_139; # foo.bar is dead here. This code gets cleaned up by DCE and leaves only pow, which can then be shrink-wrapped by cdce. So it seems reasonable to do this reordering. Bootstraps on x86_64 on linux with no test regression. OK for trunk? - Easwaran ---------------------- 2012-06-14 Easwaran Raman <era...@google.com> * gcc/passes.c (init_optimization_passes): Remove pass_call_cdce from its current position and insert after pass_dce. Index: gcc/passes.c =================================================================== --- gcc/passes.c (revision 188535) +++ gcc/passes.c (working copy) @@ -1374,7 +1374,6 @@ init_optimization_passes (void) NEXT_PASS (pass_complete_unrolli); NEXT_PASS (pass_ccp); NEXT_PASS (pass_forwprop); - NEXT_PASS (pass_call_cdce); /* pass_build_alias is a dummy pass that ensures that we execute TODO_rebuild_alias at this point. Re-building alias information also rewrites no longer addressed @@ -1387,6 +1386,7 @@ init_optimization_passes (void) NEXT_PASS (pass_merge_phi); NEXT_PASS (pass_vrp); NEXT_PASS (pass_dce); + NEXT_PASS (pass_call_cdce); NEXT_PASS (pass_cselim); NEXT_PASS (pass_tree_ifcombine); NEXT_PASS (pass_phiopt);