Re: [Patch, microblaze]: Adjustments to pcmp instruction generation

[Michael Eager]

On 02/10/2013 10:40 PM, David Holsgrove wrote:

Adjustments to pcmp instruction generation

avoid pcmpe insns when not valuable

For pure in and equality comparisions, xor is better,
Xor is a one cycle insn as pcmp.

Pattern insns will still be used when you need to
conditionally set something to one or zero, e.g

if (a)
   return 1;
else
   return 0;

Define contraint for first operand in insn matching
fcmp as general register

Add a constraint to the cstoresf pattern forcing the use of
general regs for the operands. This avoids an ICE where the
compiler would crash on late usage of pseudo registers.

Changelog

2013-02-11  Edgar E. Iglesias <edgar.igles...@gmail.com>

   * config/microblaze/microblaze.c (microblaze_emit_compare):
      Use xor for EQ/NE comparisions
   * config/microblaze/microblaze.md (cstoresf4): Add constraints
      (cbranchsf4): Adjust operator to comparison_operator

Committed revision 196315.


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Michael Eager    ea...@eagercon.com
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