[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #11 from kkojima at gcc dot gnu dot org 2008-12-02 08:36 --- Fixed. -- kkojima at gcc dot gnu dot org changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED Resolution||FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #9 from hjl at gcc dot gnu dot org 2008-12-01 17:04 --- Subject: Bug 37514 Author: hjl Date: Mon Dec 1 17:03:13 2008 New Revision: 142324 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=142324 Log: 2008-12-01 Vladimir Makarov [EMAIL PROTECTED] PR rtl-optimization/37514 * reload1.c (reload_as_needed): Invalidate reg_last_reload from previous insns. Modified: branches/ira-merge/gcc/ChangeLog.ira branches/ira-merge/gcc/reload1.c -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #10 from vmakarov at gcc dot gnu dot org 2008-12-01 19:33 --- Subject: Bug 37514 Author: vmakarov Date: Mon Dec 1 19:31:41 2008 New Revision: 142328 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=142328 Log: 2008-12-01 Vladimir Makarov [EMAIL PROTECTED] PR rtl-optimization/37514 * reload1.c (reload_as_needed): Invalidate reg_last_reload from previous insns. Modified: trunk/gcc/ChangeLog trunk/gcc/reload1.c -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #8 from kkojima at gcc dot gnu dot org 2008-11-26 00:03 --- Vlad, thanks for taking the time to look into this! Your comments in #7 and http://gcc.gnu.org/ml/gcc-patches/2008-11/msg01323.html give a very clear picture of the problem. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #7 from vmakarov at redhat dot com 2008-11-24 22:26 ---
This is a latent bug in reload inheritance which IRA triggered. Here
is the important info. r434 was assigned to hard register 2 and r551
was assigned to memory. After insn #1164, r434 and r551 are
synchronized and as a consequence the value of r551 is in hard register 2
(see reload1.c::reg_last_reload_reg). After insn 179, the
pseudo-registers should be not synchronized (because of increment of r551) but
reload does not invalidate reg_last_reload_reg[551]. For this case it is done
in inc_for_reload by the following code
/* No hard register is equivalent to this register after
inc/dec operation. If REG_LAST_RELOAD_REG were nonzero,
we could inc/dec that register as well (maybe even using it for
the source), but I'm not sure it's worth worrying about. */
if (REG_P (incloc))
reg_last_reload_reg[REGNO (incloc)] = 0;
It is not done because incloc is memory assigned to pseudo-register
r551. So after insn #179 reg_last_reload_reg[551] is still hard
register 2. This results in that hard register #2 is used for reload #1
in in insn 831 which is wrong
I'll sent a patch solving the problem soon.
--
(insn:HI 1161 25 27 5 a.i:30 (set (reg/f:SI 434)
(symbol_ref:SI (gf) var_decl 0x7f9a1cc6f500 gf)) 175 {movsi_ie}
(nil))
...
(insn:HI 1164 177 179 6 a.i:15 (set (reg/f:SI 551)
(reg/f:SI 434)) 175 {movsi_ie} (nil))
(insn:HI 179 1164 183 6 a.i:15 (parallel [
(set (reg/v:SF 289 [ f00 ])
(mem/s/v:SF (post_inc:SI (reg/f:SI 551)) [2 gf+0 S4 A32]))
(use (reg/v:PSI 151 ))
(clobber (scratch:SI))
]) 205 {movsf_ie} (expr_list:REG_INC (reg/f:SI 551)
(expr_list:REG_EQUAL (mem/s/v:SF (symbol_ref:SI (gf) var_decl
0x7f9a1cc6f500 gf) [2 gf+0 S4 A32])
(nil
...
(insn:HI 827 825 831 6 a.i:19 (parallel [
(set (mem/s/v:SF (reg/f:SI 434) [2 gf+0 S4 A32])
(reg/v:SF 289 [ f00 ]))
(use (reg/v:PSI 151 ))
(clobber (scratch:SI))
]) 205 {movsf_ie} (expr_list:REG_DEAD (reg/f:SI 434)
(expr_list:REG_DEAD (reg/v:SF 289 [ f00 ])
(nil
(insn:HI 831 827 835 6 a.i:19 (parallel [
(set (mem/s/v:SF (reg/f:SI 551) [2 gf+4 S4 A32])
(reg/v:SF 288 [ f10 ]))
(use (reg/v:PSI 151 ))
(clobber (scratch:SI))
]) 205 {movsf_ie} (expr_list:REG_DEAD (reg/f:SI 551)
(expr_list:REG_DEAD (reg/v:SF 288 [ f10 ])
(nil
Spilling for insn 827.
Using reg 7 for reload 0
Using reg 78 for reload 2
Spilling for insn 831.
Using reg 2 for reload 0
Using reg 2 for reload 1
Using reg 2 for reload 2
Using reg 78 for reload 4
Reloads for insn # 827
...
Reload 1: reload_out (SF) = (mem/s/v:SF (reg/f:SI 2 r2 [434]) [2 gf+0 S4 A32])
NO_REGS, RELOAD_FOR_OUTPUT (opnum = 0), optional
reload_out_reg: (mem/s/v:SF (reg/f:SI 2 r2 [434]) [2 gf+0 S4 A32])
...
Reloads for insn # 831
...
Reload 1: reload_in (SI) = (mem/c:SI (plus:SI (plus:SI (reg/f:SI 15 r15)
(const_int 764
[0x2fc]))
(const_int 52 [0x34]))
[5 %sfp+-196 S4 A32])
GENERAL_REGS, RELOAD_FOR_OPERAND_ADDRESS (opnum = 0), can't combine
reload_in_reg: (reg/f:SI 551)
reload_reg_rtx: (reg/f:SI 2 r2 [434])
...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #6 from vmakarov at redhat dot com 2008-11-11 15:22 --- Sorry, Kaz. I missed this PR. I've just found it after Bernd's email. I don't think it is a right solution or stable workaround. In fact all pseudos (551, 289, 288) involved in 2 wrong insns got different stack slots. It might be IRA triggered some latent bug in reload inheritence. Reload decided that r2 contains value of 551 (gf+4) but it contains gf+0 (pseudo 434 which died in prev insn 828). I'll look at this problem but taking reload complexity into account it will take a few days. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #4 from kkojima at gcc dot gnu dot org 2008-11-10 23:11 --- Subject: Bug 37514 Author: kkojima Date: Mon Nov 10 23:10:10 2008 New Revision: 141752 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=141752 Log: PR rtl-optimization/37514 * config/sh/sh.h (OPTIMIZATION_OPTIONS): Set flag_ira_share_spill_slots to 2 if it's already non-zero. (OVERRIDE_OPTIONS): Clear flag_ira_share_spill_slots if flag_ira_share_spill_slots is 2. * gcc.target/sh/pr37514.c: New test. Added: trunk/gcc/testsuite/gcc.target/sh/pr37514.c Modified: trunk/gcc/ChangeLog trunk/gcc/config/sh/sh.h trunk/gcc/testsuite/ChangeLog -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #5 from kkojima at gcc dot gnu dot org 2008-11-10 23:25 --- Currently worked around with the patch in #4. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
-- jakub at gcc dot gnu dot org changed: What|Removed |Added Priority|P3 |P4 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #1 from kkojima at gcc dot gnu dot org 2008-09-14 00:38 --- Created an attachment (id=16315) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16315action=view) a test case I've attached a slightly reduced testcase. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #2 from kkojima at gcc dot gnu dot org 2008-09-14 00:38 ---
Here is the problematic part of the generated code:
mov.w .L240,r7
add #4,r1
mov.w .L241,r6
add #4,r3
add r15,r7
fmov.s @r7,fr14
add r15,r6
add #4,r14
mov.l .L242,r7
fmov.s fr14,@r2
add #4,r13
fmov.s @r6,fr14
add #4,r12
add #4,r11
mov.l .L243,r6
fmov.s fr14,@r2
...
.L240:
.short 368
.L241:
.short 364
where r2 is set to gf[0]. Thus the float value in [r15+368]
is written to gf[0] and then the float value in [r15+364] is
stored to gf[0] again. The corresponding rtl dump in .sched1
is:
(insn:HI 828 826 832 6 xxx.c:42 (parallel [
(set (mem/s/v:SF (reg/f:SI 434) [3 gf+0 S4 A32])
(reg/v:SF 289 [ f00 ]))
(use (reg/v:PSI 151 ))
(clobber (scratch:SI))
]) 205 {movsf_ie} (expr_list:REG_DEAD (reg/f:SI 434)
(expr_list:REG_DEAD (reg/v:SF 289 [ f00 ])
(nil
(insn:HI 832 828 836 6 xxx.c:42 (parallel [
(set (mem/s/v:SF (reg/f:SI 551) [3 gf+4 S4 A32])
(reg/v:SF 288 [ f10 ]))
(use (reg/v:PSI 151 ))
(clobber (scratch:SI))
]) 205 {movsf_ie} (expr_list:REG_DEAD (reg/f:SI 551)
(expr_list:REG_DEAD (reg/v:SF 288 [ f10 ])
(nil
which looks to be right. OTOH that in .ira is:
(insn 2024 826 2025 5 xxx.c:42 (set (reg:SI 7 r7)
(const_int 368 [0x170])) 175 {movsi_ie} (nil))
(insn 2025 2024 2026 5 xxx.c:42 (set (reg:SI 7 r7)
(plus:SI (reg:SI 7 r7)
(reg/f:SI 15 r15))) 35 {*addsi3_compact} (expr_list:REG_EQUIV
(plus:SI (reg/f:SI 15 r15)
(const_int 368 [0x170]))
(nil)))
(insn 2026 2025 828 5 xxx.c:42 (parallel [
(set (reg:SF 78 fr14)
(mem/c:SF (reg:SI 7 r7) [7 f00+0 S4 A32]))
(use (reg/v:PSI 151 ))
(clobber (scratch:SI))
]) 205 {movsf_ie} (nil))
(insn:HI 828 2026 2028 5 xxx.c:42 (parallel [
(set (mem/s/v:SF (reg/f:SI 2 r2 [434]) [3 gf+0 S4 A32])
(reg:SF 78 fr14))
(use (reg/v:PSI 151 ))
(clobber (scratch:SI))
]) 205 {movsf_ie} (nil))
(insn 2028 828 2029 5 xxx.c:42 (set (reg:SI 6 r6)
(const_int 364 [0x16c])) 175 {movsi_ie} (nil))
(insn 2029 2028 2030 5 xxx.c:42 (set (reg:SI 6 r6)
(plus:SI (reg:SI 6 r6)
(reg/f:SI 15 r15))) 35 {*addsi3_compact} (expr_list:REG_EQUIV
(plus:SI (reg/f:SI 15 r15)
(const_int 364 [0x16c]))
(nil)))
(insn 2030 2029 832 5 xxx.c:42 (parallel [
(set (reg:SF 78 fr14)
(mem/c:SF (reg:SI 6 r6) [8 f10+0 S4 A32]))
(use (reg/v:PSI 151 ))
(clobber (scratch:SI))
]) 205 {movsf_ie} (nil))
(insn:HI 832 2030 2033 5 xxx.c:42 (parallel [
(set (mem/s/v:SF (reg/f:SI 2 r2 [434]) [3 gf+4 S4 A32])
(reg:SF 78 fr14))
(use (reg/v:PSI 151 ))
(clobber (scratch:SI))
]) 205 {movsf_ie} (nil))
which shows that IRA uses r434 both for gf+0 and gf+4.
I've confirmed that the error goes away with -fno-ira-share-spill-slots.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
--- Comment #3 from kkojima at gcc dot gnu dot org 2008-09-14 00:51 --- I'd like to add Vlad to the CC list. -- kkojima at gcc dot gnu dot org changed: What|Removed |Added CC||vmakarov at redhat dot com Summary|[4.4 Regression] Wrong code|[4.4 Regression] Wrong code |generated for 20021120-1.c |generated for 20021120-1.c |with -O3 -fomit-frame- |with -O3 -fomit-frame- |pointer on sh4 |pointer on sh4 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
[Bug rtl-optimization/37514] [4.4 Regression] Wrong code generated for 20021120-1.c with -O3 -fomit-frame-pointer on sh4
-- pinskia at gcc dot gnu dot org changed: What|Removed |Added Keywords||ra Target Milestone|--- |4.4.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37514
