[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #11 from steven at gcc dot gnu dot org 2005-11-11 19:34 --- Subject: Bug 24265 Author: steven Date: Fri Nov 11 19:34:39 2005 New Revision: 106795 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=106795 Log: PR 24265 * loop-invariant.c (may_assign_reg_p): Make sure a hard register can be assigned to. (find_invariant_insn): Do the cheapest check, may_assign_reg_p, before check_maybe_invariant. (move_invariant_reg): Use gen_move_insn instead of replacing SET_DEST with the temporary for the invariant. (move_loop_invariants): If checking is enabled, do internal consistency checks after completing the pass. Modified: trunk/gcc/ChangeLog trunk/gcc/loop-invariant.c -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #12 from steven at gcc dot gnu dot org 2005-11-11 19:39 --- Fixed on mainline. The bug is also on the GCC 4.0 branch, but I am not going to backport the patch. -- steven at gcc dot gnu dot org changed: What|Removed |Added Status|NEW |RESOLVED Resolution||FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #7 from uros at kss-loka dot si 2005-11-08 12:40 --- Created an attachment (id=10173) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10173action=view) Patch to fix the ice This patch fixes the failure for me, but... -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #8 from uros at kss-loka dot si 2005-11-08 12:53 ---
This patch fixes the failure for me, but...
... we actually gain nothing here.
From .loop2_done, we have following sequence, where mem-reg load is pushed out
of the loop:
(insn 21 16 39 0 (set (reg:DF 64)
(mem/u/c/i:DF (symbol_ref/u:SI (*.LC0) [flags 0x2]) [0 S8 A64])) -1
(nil)
(nil))
;; End of basic block 0, registers live:
(nil)
(note 39 21 17 NOTE_INSN_LOOP_BEG)
;; Start of basic block 1, registers live: (nil)
(code_label 17 39 18 1 2 [1 uses])
(note 18 17 47 1 [bb 1] NOTE_INSN_BASIC_BLOCK)
(insn 47 18 22 1 (set (mem:DF (plus:SI (reg/f:SI 7 sp)
(const_int 8 [0x8])) [0 S8 A32])
(reg:DF 64)) -1 (nil)
(nil))
However, in .postreload, the insn 21 (now insn 53) is moved back _into_ the
loop (why?):
(note 21 16 39 0 NOTE_INSN_DELETED)
;; End of basic block 0, registers live:
6 [bp] 7 [sp] 16 [argp] 20 [frame] 60 64
(note 39 21 17 NOTE_INSN_LOOP_BEG)
;; Start of basic block 1, registers live: 6 [bp] 7 [sp] 59 60 64
(code_label 17 39 18 1 2 [1 uses])
(note 18 17 53 1 [bb 1] NOTE_INSN_BASIC_BLOCK)
(insn 53 18 47 1 (set (reg:DF 8 st)
(mem/u/c/i:DF (symbol_ref/u:SI (*.LC0) [flags 0x2]) [0 S8 A64])) 63
{*movdf_noin
teger} (nil)
(nil))
(insn 47 53 54 1 (set (mem:DF (plus:SI (reg/f:SI 7 sp)
(const_int 8 [0x8])) [0 S8 A32])
(reg:DF 8 st)) 63 {*movdf_nointeger} (nil)
(nil))
Proposed patch thus only fixes the damage. Otherwise, all this register
moving/copying doesn't gain anything, as reload fixes something on its own.
Also, REG_EQUAL notes are lost (before and after the patch). This results in
following asm:
...
movl $-1717986918, 8(%esp)
movl $1070176665, 12(%esp)
fldl -16(%ebp)
fstpl (%esp)
call dset
movl $1, %ebx
.L2:
fldl .LC0 reload moves this insn back into the loop
fstpl 8(%esp)
fldl -16(%ebp)
fstpl (%esp)
call dset
incl %ebx
cmpl $4, %ebx
jne .L2
addl $36, %esp
...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #9 from uros at kss-loka dot si 2005-11-08 13:23 ---
Bah... set_unique_reg_note is needed:
/* If new move insn is invalid (i.e. move of const_double to
387 stack register), force constant into memory. */
if (recog_memoized (inv-insn) == -1)
{
rtx src = SET_SRC (set);
if (GET_CODE (src) == CONST_DOUBLE)
{
SET_SRC (set) = validize_mem (force_const_mem (mode, src));
set_unique_reg_note (inv-insn, REG_EQUAL, src);
}
}
to produce:
movl $1, %ebx
.L2:
movl $-1717986918, 8(%esp)
movl $1070176665, 12(%esp)
fldl -16(%ebp)
fstpl (%esp)
call dset
addl $1, %ebx
cmpl $4, %ebx
jne .L2
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #10 from steven at gcc dot gnu dot org 2005-11-08 13:45 --- The patch from comment #7 is wrong. The proper fix is already on the killloop-branch. You could try my patch for PR 24408, which should depend on this one. -- steven at gcc dot gnu dot org changed: What|Removed |Added OtherBugsDependingO||24408 nThis|| http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #6 from steven at gcc dot gnu dot org 2005-11-06 01:20 --- Oh well, I'll try and fix this... -- steven at gcc dot gnu dot org changed: What|Removed |Added CC||steven at gcc dot gnu dot ||org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #5 from hubicka at gcc dot gnu dot org 2005-11-03 19:38 --- This is ineed move-loop-invariants bug. It assumes that destination of memory store can be changed to register without validating that is not the case on i386 - you can write arbitrary floating point value to memory, but you can load only 0 and 1 to register by single direct move. -- hubicka at gcc dot gnu dot org changed: What|Removed |Added CC||rakdver at gcc dot gnu dot ||org, hubicka at gcc dot gnu ||dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #4 from mmitchel at gcc dot gnu dot org 2005-10-31 06:07 --- Does the analysis in Comment #3 imply that -fmove-loop-invariants is really not ready for use by the general public? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #3 from steven at gcc dot gnu dot org 2005-10-17 18:54 --- The patch identified in comment #2 has nothing to do with this problem. Pinski is right in comment #1, loop-invariant.c does not verify that the insns it moves/inserts are valid. Using emit_move_insn is just one thing it should do. Another thing is verifying that a reg-reg move exists for expressions moved out of a loop into a register before the loop. There are a few other issues I found some time ago, but I don't recall the details. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #1 from pinskia at gcc dot gnu dot org 2005-10-07 19:58 --- Confirmed, a regression from 4.0.0. I think this is a target bug as you had: (set (mem:DF (plus:SI (reg/f:SI 7 sp) (const_int 8 [0x8])) [0 S8 A32]) (const_double:DF -858993460 [0x] 2.00011102230246251565404236316680908e-1 [0x0.dp-2])) before loop-invariant but after, you have: (insn 21 16 17 0 (set (reg:DF 64) +(const_double:DF -858993460 [0x] 2.00011102230246251565404236316680908e-1 [0x0.dp-2])) -1 (nil) +(nil)) Unless -fmove-loop-invariants is not calling emit_move_insn which might be the issue. -- pinskia at gcc dot gnu dot org changed: What|Removed |Added Status|UNCONFIRMED |NEW Component|rtl-optimization|target Ever Confirmed|0 |1 Keywords||ice-on-valid-code Known to fail||4.1.0 Known to work||4.0.0 Last reconfirmed|-00-00 00:00:00 |2005-10-07 19:58:56 date|| Summary|ICE: in extract_insn, at|[4.1 Regression] ICE: in |recog.c:2084 with -O -fgcse |extract_insn, at |-fmove-loop-invariants -|recog.c:2084 with -O -fgcse |mtune=pentiumpro|-fmove-loop-invariants - ||mtune=pentiumpro Target Milestone|--- |4.1.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
[Bug target/24265] [4.1 Regression] ICE: in extract_insn, at recog.c:2084 with -O -fgcse -fmove-loop-invariants -mtune=pentiumpro
--- Comment #2 from janis at gcc dot gnu dot org 2005-10-08 00:03 --- A regression hunt using an i686-linux cross compiler identified this patch from [EMAIL PROTECTED]: http://gcc.gnu.org/ml/gcc-cvs/2005-06/msg00015.html -- janis at gcc dot gnu dot org changed: What|Removed |Added CC||hagog at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24265
