------- Comment #1 from jakub at gcc dot gnu dot org 2009-02-09 16:39 ------- Regression since http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=134321 tree-ssa-sink.c moves e = {} store across a1 = 11 initialization, where a1 is a register asm ("%rdi") variable, so into a spot where %rdi is live and thus can't be used for rep; stos*. Not sure what we should do. i386 expander avoids using stos* etc. when %rdi is a global reg variable or fixed register, but doesn't have df info to find out that %rdi is just locally live across this spot. Probably it would be better not to sink that store across register var initialization.
-- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39139
