[Bug tree-optimization/37916] [4.0 Regression] SSA names causing register pressure; unnecessarily many simultaneously "live" names.

[hp at gcc dot gnu dot org]

------- Comment #6 from hp at gcc dot gnu dot org  2008-10-25 21:20 -------
Created an attachment (id=16546)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16546&action=view)
As 4.3.3 above but with -fno-tree-reassoc

As attachment id=16544, but adding -fno-tree-reassoc.
Note that it now "only" uses 6 of the 9 available call-saved registers,
still quite a regression since 3.2.1 (three registers).

FWIW, I don't think only using call-clobbered registers (5 plus 2 special
registers suitable only for moves) should be unpossible for this code.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37916