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From: "kkojima at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/65153] [SH][4.9 Regression] "insn does not satisfy its constraints" when compiling libmcrypt
Date: Sun, 22 Feb 2015 05:18:00 -0000 [thread overview]
Message-ID: <bug-65153-4-FnKdEJYomt@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-65153-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65153
--- Comment #5 from Kazumoto Kojima <kkojima at gcc dot gnu.org> ---
Created attachment 34828
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34828&action=edit
reduced testcase
Looks an interesting "why didn't we see it?" target bug.
The problem happens at peephole2 phase. The insn sequence
(insn 353 103 105 4 (set (reg:SI 1 r1) (reg:SI 6 r6)))
(insn 105 353 106 4 (set (reg:SI 7 r7) (ashift:SI (reg:SI 7 r7) (reg:SI 0
r0))))
(insn 106 105 107 4 (set (reg/v:SI 6 r6)
(ior:SI (reg:SI 6 r6) (reg:SI 7 r7))))
is tested by the complex peephole
(define_peephole2
[(set (match_operand 0 "any_register_operand" "")
(match_operand 1 "any_register_operand" ""))
(set (match_operand 2 "any_register_operand" "") (match_operand 3 "" ""))
(set (match_operand 4 "" "") (match_operand 5 "" ""))]
"(HARD_REGNO_NREGS (REGNO (operands[0]), GET_MODE (operands[2]))
<= HARD_REGNO_NREGS (REGNO (operands[0]), GET_MODE (operands[0])))
&& peep2_reg_dead_p (3, operands[0]) && peep2_reg_dead_p (3, operands[2])
&& ! FIND_REG_INC_NOTE (peep2_next_insn (2), operands[0])
&& ! FIND_REG_INC_NOTE (peep2_next_insn (2), operands[2])
&& ! reg_overlap_mentioned_p (operands[0], operands[3])
&& ! reg_overlap_mentioned_p (operands[2], operands[0])
&& ! reg_overlap_mentioned_p (operands[0], operands[1])
&& (REGNO_REG_CLASS (REGNO (operands[0]))
== REGNO_REG_CLASS (REGNO (operands[2])))
&& (REGNO_REG_CLASS (REGNO (operands[1]))
== REGNO_REG_CLASS (REGNO (operands[0])))"
[(set (match_dup 0) (match_dup 3))
(set (match_dup 4) (match_dup 5))]
{
...
This peephole2 in sh.md tries to replace operands[0] with operands[1]
and operands[2] with operands[0] in operands[4]/operands[5]. In our
case, operands[5] is (ior:SI (reg:SI 6 r6) (reg:SI 7 r7)) and the peephole
tries to do term rewriting r1 -> r6, r7 -> r1. This peephole fails
after all and then tries to restore operands[5] with term rewriting
r6 -> r1, r1 -> r7. Unfortunately this can't reverse the first term
rewriting and yields (ior:SI (reg:SI 1 r1) (reg:SI 7 r7)). Thus we
got a wrong insn
(set (reg/v:SI 6 r6) (ior:SI (reg:SI 1 r1) (reg:SI 7 r7))).
next prev parent reply other threads:[~2015-02-22 4:41 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-21 9:52 [Bug target/65153] New: sh: " glaubitz at physik dot fu-berlin.de
2015-02-21 13:46 ` [Bug target/65153] " olegendo at gcc dot gnu.org
2015-02-21 14:41 ` glaubitz at physik dot fu-berlin.de
2015-02-21 15:07 ` [Bug target/65153] [SH][4.9 Regression] " olegendo at gcc dot gnu.org
2015-02-21 15:30 ` olegendo at gcc dot gnu.org
2015-02-21 17:07 ` olegendo at gcc dot gnu.org
2015-02-22 5:18 ` kkojima at gcc dot gnu.org [this message]
2015-02-22 5:20 ` kkojima at gcc dot gnu.org
2015-02-22 14:48 ` olegendo at gcc dot gnu.org
2015-02-22 23:49 ` olegendo at gcc dot gnu.org
2015-02-23 0:13 ` kkojima at gcc dot gnu.org
2015-02-23 1:19 ` olegendo at gcc dot gnu.org
2015-02-23 8:19 ` kkojima at gcc dot gnu.org
2015-02-23 10:58 ` rguenth at gcc dot gnu.org
2015-02-25 5:45 ` kkojima at gcc dot gnu.org
2015-02-25 6:30 ` kkojima at gcc dot gnu.org
2015-03-07 19:35 ` olegendo at gcc dot gnu.org
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