https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3507
Uroš Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
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CC| |law at gcc dot gnu.org
--- Comment #66 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Ivan Sorokin from comment #60)
> Another similar case. On this function:
>
> unsigned wrap(unsigned index, unsigned limit)
> {
> if (index >= limit)
> index -= limit;
> return index;
> }
This is actually PR97603.
We expand the above testcase to:
(insn 7 4 8 2 (set (reg:CC 17 flags)
(compare:CC (reg/v:SI 99 [ index ])
(reg/v:SI 100 [ limit ]))) "pr3507-1.c":3:8 15 {*cmpsi_1}
(nil))
(jump_insn 8 7 9 2 (set (pc)
(if_then_else (ltu (reg:CC 17 flags)
(const_int 0 [0]))
(label_ref 11)
(pc))) "pr3507-1.c":3:8 1490 {*jcc}
(int_list:REG_BR_PROB 536870913 (nil))
-> 11)
(note 9 8 10 4 [bb 4] NOTE_INSN_BASIC_BLOCK)
(insn 10 9 11 4 (parallel [
(set (reg/v:SI 99 [ index ])
(minus:SI (reg/v:SI 99 [ index ])
(reg/v:SI 100 [ limit ])))
(clobber (reg:CC 17 flags))
]) "pr3507-1.c":4:15 393 {*subsi_1}
(nil))
which is the same as for testcase from PR97603:
(insn 7 4 8 2 (set (reg:CCGC 17 flags)
(compare:CCGC (reg/v:SI 99 [ a ])
(reg/v:SI 100 [ b ]))) "pr97603.c":5:8 15 {*cmpsi_1}
(nil))
(jump_insn 8 7 9 2 (set (pc)
(if_then_else (ge (reg:CCGC 17 flags)
(const_int 0 [0]))
(label_ref 13)
(pc))) "pr97603.c":5:8 1490 {*jcc}
(int_list:REG_BR_PROB 524845001 (nil))
-> 13)
(note 9 8 10 4 [bb 4] NOTE_INSN_BASIC_BLOCK)
(insn 10 9 11 4 (parallel [
(set (reg:SI 98 [ <retval> ])
(minus:SI (reg/v:SI 99 [ a ])
(reg/v:SI 100 [ b ])))
(clobber (reg:CC 17 flags))
]) "pr97603.c":6:18 393 {*subsi_1}
(nil))
Please note that (insn 7) and (insn 10) could be merged to:
(define_insn "*sub<mode>_3"
[(set (reg FLAGS_REG)
(compare (match_operand:SWI 1 "nonimmediate_operand" "0,0,r,r,m")
(match_operand:SWI 2 "<general_operand>"
"<r><i>,<m>,r<i>,<m>,r<i>")))
(set (match_operand:SWI 0 "nonimmediate_operand" "=<r>m,<r>,r,r,r")
(minus:SWI (match_dup 1) (match_dup 2)))]
"ix86_match_ccmode (insn, CCmode)
&& ix86_binary_operator_ok (MINUS, <MODE>mode, operands, TARGET_APX_NDD)"
