[Bug target/39139] [4.4 Regression] ICE with stringop and register var

[jakub at gcc dot gnu dot org]

------- 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.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39139