[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051 Richard Guenther rguenth at gcc dot gnu.org changed: What|Removed |Added Target Milestone|--- |4.6.0
[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051 Richard Guenther rguenth at gcc dot gnu.org changed: What|Removed |Added Status|REOPENED|RESOLVED Resolution||FIXED --- Comment #10 from Richard Guenther rguenth at gcc dot gnu.org 2011-01-03 20:01:41 UTC --- Original problem was fixed. Please open a new bug for any other issues.
[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051 --- Comment #9 from Hans-Peter Nilsson hp at gcc dot gnu.org 2010-12-23 14:29:13 UTC --- (In reply to comment #8) Nevertheless, I'm testing r162418 with your patch. FWIW, no regressions for cris-elf, with your patch (manually) applied on top of Bernds's patch applied to r162418.
[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051
Ian Bolton ibolton at gcc dot gnu.org changed:
What|Removed |Added
Status|RESOLVED|REOPENED
CC||ibolton at gcc dot gnu.org
Resolution|FIXED |
--- Comment #7 from Ian Bolton ibolton at gcc dot gnu.org 2010-12-22 16:23:21
UTC ---
(In reply to comment #5)
Assuming fixed and closing. Please reopen if you still have a problem.
This patch has caused SpecCPU2000 Ammp to fail for ARM -O3 thumb.
I assume the patch was meant to prevent deletions that shouldn't occur. This
might be what happens for the original symptomatic test, but I am now seeing
extra deletions that shouldn't happen for Ammp.
For example, without this patch, you get these insns somewhere in the ira dump
for mm_fv_update_nonbon() from rectmm.c:
(insn 3163 3161 3164 107 rectmm.c:1041 (set (reg:SI 1 r1)
(plus:SI (reg:SI 1 r1)
(const_int 280 [0x118]))) 4 {*arm_addsi3} (nil))
(insn 3164 3163 1730 107 rectmm.c:1041 (set (reg:SI 3 r3)
(reg:SI 1 r1)) 586 {*thumb2_movsi_vfp} (nil))
With the patch, you lose the add and just get this:
(insn 3164 3161 1730 107 rectmm.c:1041 (set (reg:SI 3 r3)
(reg:SI 1 r1)) 586 {*thumb2_movsi_vfp} (nil))
The incrementing of r1 is perfectly legitimate and useful and removing it is a
bug. Other increments of r9, ip, r0 and r3 are also lost.
I think the issue might be that reg_mentioned_p() considers output registers to
have been mentioned, whereas the refers_to_regno_p() does not consider an
output register to have been referred to. I can see the problem with only
using reg_mentioned_p() because it doesn't handle subregs, but there is also a
problem with only using refers_to_regno_p(), as we can see with this segfault
in Ammp.
I therefore wonder if the fix might be this:
Index: gcc/reload1.c
===
--- gcc/reload1.c (revision 168082)
+++ gcc/reload1.c (working copy)
@@ -8395,7 +8395,8 @@ delete_output_reload (rtx insn, int j, i
if (NOTE_INSN_BASIC_BLOCK_P (i1))
return;
if ((NONJUMP_INSN_P (i1) || CALL_P (i1))
- refers_to_regno_p (regno, regno + nregs, PATTERN (i1), NULL))
+ (refers_to_regno_p (regno, regno + nregs, PATTERN (i1), NULL)
+ || reg_mentioned_p (reg, PATTERN (i1
{
/* If this is USE in front of INSN, we only have to check that
there are no more references than accounted for by inheritance.
*/
I am heading off for Christmas vacation shortly, so cannot look into this any
further, but I wanted to record my findings so far publicly. Apologies if
there is missing information. I return to work Jan 4th.
[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051
--- Comment #8 from Hans-Peter Nilsson hp at gcc dot gnu.org 2010-12-23
01:56:08 UTC ---
(In reply to comment #7)
(insn 3163 3161 3164 107 rectmm.c:1041 (set (reg:SI 1 r1)
(plus:SI (reg:SI 1 r1)
(const_int 280 [0x118]))) 4 {*arm_addsi3} (nil))
I think the issue might be that reg_mentioned_p() considers output registers
to
have been mentioned, whereas the refers_to_regno_p() does not consider an
output register to have been referred to.
But r1 is an input as well as an output , i.e. referred to, so insn 3163
should have matched without your patch. I'm missing analysis on why that
didn't happen. Nevertheless, I'm testing r162418 with your patch.
Also, you should open a separate PR for the regression you see, not just reuse
this one. Use the depends-on features for the dependency.
[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
--- Comment #6 from hp at gcc dot gnu dot org 2010-09-21 21:26 --- Subject: Bug 45051 Author: hp Date: Tue Sep 21 21:25:57 2010 New Revision: 164498 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=164498 Log: PR rtl-optimization/41085 Backport from mainline 2010-07-27 Bernd Schmidt ber...@codesourcery.com PR rtl-optimization/45051 * reload1.c (delete_output_reload): Use refers_to_regno_p rather than reg_mentioned_p. Modified: branches/gcc-4_5-branch/gcc/ChangeLog branches/gcc-4_5-branch/gcc/reload1.c -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051
[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
--- Comment #4 from bernds at gcc dot gnu dot org 2010-07-27 09:35 --- Subject: Bug 45051 Author: bernds Date: Tue Jul 27 09:34:51 2010 New Revision: 162558 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=162558 Log: PR rtl-optimization/45051 * reload1.c (delete_output_reload): Use refers_to_regno_p rather than reg_mentioned_p. Modified: trunk/gcc/ChangeLog trunk/gcc/reload1.c -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051
[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
--- Comment #5 from bernds at gcc dot gnu dot org 2010-07-27 21:49 --- Assuming fixed and closing. Please reopen if you still have a problem. -- bernds at gcc dot gnu dot org changed: What|Removed |Added Status|NEW |RESOLVED Resolution||FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051
[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
--- Comment #1 from hp at gcc dot gnu dot org 2010-07-24 02:46 --- Created an attachment (id=21295) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=21295action=view) Shortened gcc.c-torture/execute/builtins/abs-2.c Compile with e.g. -O2 -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051
[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
--- Comment #2 from hp at gcc dot gnu dot org 2010-07-24 02:51 --- (In reply to comment #0) Oops; replace: containing 0x for the low-part of 9223372036854775807LL ((163)-1), with: containing 0x7fff for the high-part of 9223372036854775807LL ((163)-1), -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051
[Bug rtl-optimization/45051] [4.6 Regression]: gcc.c-torture/execute/builtins/abs-2.c and abs-3.c due to track subwords of DImode allocnos
--- Comment #3 from hp at gcc dot gnu dot org 2010-07-24 03:02 --- --- good:r162417/abs-2.sSat Jul 24 03:13:36 2010 +++ bad:r162418/abs-2.s Sat Jul 24 03:15:53 2010 @@ -9,27 +9,27 @@ _main_test: move $srp,[$sp] subu.b 84,$sp movem $r8,[$sp] - clear.d $r4 - clear.d $r5 - move.b 1,$r4 - move.d $r4,[$sp+76] - move.d $r5,[$sp+80] + clear.d $r0 ; (set (reg:SI r0) (const_int 0)) + clear.d $r1 + move.b 1,$r0 ; (set (strict_low_part:QI (reg:SI r0)) (const_int 1)) + move.d $r0,[$sp+76] + move.d $r1,[$sp+80] moveq -1,$r12 move.d $r12,[$sp+68] move.d $r12,[$sp+72] - clear.d $r10 - move.d $r4,$r11 - move.d $r11,$r8 - move.d -2147483648,$r0 - move.d $r11,[$sp+60] - move.d $r10,[$sp+64] - move.d 2147483647,$r11 + move.d $r0,$r10 + move.d -2147483648,$r11 + move.d $r10,[$sp+60] + move.d $r11,[$sp+64] + clear.b $r0 ; (set (strict_low_part:QI (reg:SI r9)) (const_int 0)) + move.d $r0,$r9 ; (set (reg:SI r9) (reg:SI r0)) + move.d 2147483647,$r0 move.d $r12,[$sp+52] - move.d $r11,[$sp+56] - move.d $r8,[$sp+44] - move.d $r0,[$sp+48] + move.d $r9,[$sp+56] ; stored here + move.d $r10,[$sp+44] + move.d $r11,[$sp+48] move.d $r12,[$sp+36] - move.d $r11,[$sp+40] + move.d $r0,[$sp+40] move.d [$sp+52],$r12 move.d [$sp+56],$r13; loaded here test.d $r12 ; fatally tested below; containing 0, expected 0x7fff -- hp at gcc dot gnu dot org changed: What|Removed |Added Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Last reconfirmed|-00-00 00:00:00 |2010-07-24 03:02:58 date|| http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45051
