[Bug target/98060] Failure to optimize cmp+setnb+add to cmp+sbb

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98060

Uroš Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
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           Assignee|unassigned at gcc dot gnu.org      |ubizjak at gmail dot com
             Status|NEW                         |ASSIGNED

--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> ---
Created attachment 49663
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49663&action=edit
Proposed patch

Proposed patch does a couple of things:

a) introduces reversed adc and sbb insn patterns
b) introduces carry_flag_unset_operator
c) SUBSTANTIALLY cleans carry flag checking predicates
d) rearranges integer compares to allow more combines with carry flag
e) enhances ix86_unary_operator_ok to allow input memory operand for adc and
sbb

I don't think this patch is appropriate for stage-3+, let's wait for stage-1 to
reopen.