condition codes, haifa-sched and virtual-stack-vars

[Alexandre Oliva]

On Jan 30, 2002, Greg McGary <greg@mcgary.org> wrote:

> Haifa-sched schedules the move from virtual-stack-vars between the
> bitfield test sequence and the branch.  Later, global-reg alloc
> instantiates virtual-stack-vars as an offset from FP, so the move
> mutates into an add of fp+offset, clobbering the condition codes
> computed earlier in the bitfield test.

How about having a pre-reload move pattern that clobbers CC, split
after reload into one that does not, so that sched2 could put the move
between compare and branch should it indeed not affect CC?

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
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CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
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