[PATCH] fix improper destination register in mpn/arm/invert_limb.asm

Torbjorn Granlund tg at gmplib.org
Wed Jul 6 07:57:46 CEST 2011


Kelly Anderson <kelly at silka.with-linux.com> writes:

  A minor patch to fix a warning (gcc 4.6.1) about using r3 destination
  register when r3 is a source register.  Not sure how gcc handles it,
  but the arm spec states that it is not allowed.  This applies to
  libgmp 5.0.2.  It passes all tests after patch is applied.
  
I don't think any ARM implementations`actually have problems with reuse
of a source register as destination.  At any rate, if we worry about it,
we should not put in an additional mov instruction, but instead somehow
remap subsequent register usage.

(It is surely the assembler, from the binutils package, that emits those
warnings.  Gcc does not inspect assembly code.)

-- 
Torbjörn


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