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Re: Fix for df problems, and and an ifcvt improvement

On 04/22/2010 12:30 PM, Bernd Schmidt wrote: 
This isn't always true.  While working on regrename a while ago I was
reminded that there are sequences like
  (set (zero_extract of upper 16 bits) (something))
  (set (zero_extract of lower 16 bits) (something else))

The same happens (more frequently actually) with cond_exec:
  (cond_exec (condition A) (set (reg X) (Y)))
  (cond_exec (reverse-condition A) (set (reg X) (Z)))

Yes, these are what I had in mind. However I was thinking of DF_LR and you were thinking of DF_LIVE, likely. These are DF_LR because GCC doesn't know that reg X cannot be left uninitialized.

Paolo

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