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Re: RFA: patch for PR42973
Steven Bosscher wrote:
On Tue, Feb 9, 2010 at 9:00 PM, Vladimir Makarov <email@example.com> wrote:If there are no REG_DEAD notes, there is no sense to try copy
generation. The code in the function after the mentioned code is
expensive. So major purpose of the code fragment is to speed up
constraint and shuffle copy generation.
+ for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+ if (REG_NOTE_KIND (link) == REG_DEAD)
+ if (! link)
What is the purpose of this code? Obviously you're looking for a
REG_DEAD note, but you're not looking at this note anywhere to see
which reg dies.