Re: [rs6000, patch] Enable have_cbranchcc4 on rs6000

[HAO CHEN GUI <guihaoc@linux.ibm.com>]

Hi David,
  I found definition of the operands in 'cbranch'. The argumnets matters.
I will create a new expand pattern for cbranchcc4. Thanks a lot for your
comments.

'cbranchmode4’
Conditional branch instruction combined with a compare instruction.
Operand 0 is a comparison operator. Operand 1 and operand 2 are the
first and second operands of the comparison, respectively. Operand 3
is the code_label to jump to.

Gui Haochen
Thanks

在 2022/11/16 11:04, David Edelsohn 写道:
> It's great to add cbranchcc4 to the Power port where it definitely was an omission, but adapting *cbranch for that purpose is the wrong approach.  The changes to the pattern are incorrect because they are covering up a difference in ordering of the operands.  One can argue that the named pattern only enables the functionality in ifcvt and the pattern otherwise is used in its previous role.  But this is a Frankenstein monster approach.  You're trying to twist the existing pattern so that it triggers as cbranchcc4, but creating a pattern that messes up its arguments and only works because the new, named pattern never is called.  This is too ugly.  Please fix.