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* [Bug rtl-optimization/57518] New: Redundent insn generated in LRA
@ 2013-06-03 21:04 wmi at google dot com
2013-06-12 21:47 ` [Bug rtl-optimization/57518] [4.8/4.9 Regression] Redundant " wmi at google dot com
` (12 more replies)
0 siblings, 13 replies; 14+ messages in thread
From: wmi at google dot com @ 2013-06-03 21:04 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Bug ID: 57518
Summary: Redundent insn generated in LRA
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: wmi at google dot com
Testcase:
char ip[10];
int total, total1;
void foo() {
int t;
t = ip[2];
total = t & 0x3;
}
Target: x86_64-linux-gnu
gcc version 4.9.0 20130529 (experimental) (GCC)
~/workarea/gcc-r199418/build/install/bin/gcc -O2 -S 1.c
.cfi_startproc
movzbl ip+2(%rip), %eax
movb %al, -16(%rsp) ==> redundent
movl -16(%rsp), %eax ==> redundent
andl $3, %eax
movl %eax, total(%rip)
ret
.cfi_endproc
Target: x86_64-linux-gnu
gcc version 4.8.0 20120613 (experimental) (GCC)
gcc -O2 -S 1.c
.cfi_startproc
movzbl ip+2(%rip), %eax
andl $3, %eax
movl %eax, total(%rip)
ret
.cfi_endproc
IR before LRA:
(insn 12 7 8 2 (set (reg:QI 64 [ ip+2 ])
(mem/j/c:QI (const:DI (plus:DI (symbol_ref:DI ("ip") <var_decl
0x7ffff61da260 ip>)
(const_int 2 [0x2]))) [0 ip+2 S1 A8])) 1.c:9 87
{*movqi_internal}
(expr_list:REG_EQUIV (mem/j/c:QI (const:DI (plus:DI (symbol_ref:DI ("ip")
<var_decl 0x7ffff61da260 ip>)
(const_int 2 [0x2]))) [0 ip+2 S1 A8])
(nil)))
(insn 8 12 9 2 (parallel [
(set (reg:SI 65 [ D.1731 ])
(and:SI (subreg:SI (reg:QI 64 [ ip+2 ]) 0)
(const_int 3 [0x3])))
(clobber (reg:CC 17 flags))
]) 1.c:9 387 {*andsi_1}
(expr_list:REG_DEAD (reg:QI 64 [ ip+2 ])
(expr_list:REG_UNUSED (reg:CC 17 flags)
(expr_list:REG_EQUIV (mem/c:SI (symbol_ref:DI ("total") <var_decl
0x7ffff61da2f8 total>) [2 total+0 S4 A32])
(nil)))))
IR after LRA:
(insn 12 7 14 2 (set (reg:QI 0 ax [orig:64 ip+2 ] [64])
(mem/j/c:QI (const:DI (plus:DI (symbol_ref:DI ("ip") <var_decl
0x7ffff61da260 ip>)
(const_int 2 [0x2]))) [0 ip+2 S1 A8])) 1.c:9 87
{*movqi_internal}
(expr_list:REG_EQUIV (mem/j/c:QI (const:DI (plus:DI (symbol_ref:DI ("ip")
<var_decl 0x7ffff61da260 ip>)
(const_int 2 [0x2]))) [0 ip+2 S1 A8])
(nil)))
(insn 14 12 15 2 (set (mem/c:QI (plus:DI (reg/f:DI 7 sp)
(const_int -16 [0xfffffffffffffff0])) [3 %sfp+-16 S1 A64])
(reg:QI 0 ax [orig:64 ip+2 ] [64])) 1.c:9 87 {*movqi_internal}
(expr_list:REG_DEAD (reg:QI 0 ax [orig:64 ip+2 ] [64])
(nil)))
(insn 15 14 8 2 (set (reg:SI 0 ax [orig:65 D.1731 ] [65])
(mem/c:SI (plus:DI (reg/f:DI 7 sp)
(const_int -16 [0xfffffffffffffff0])) [3 %sfp+-16 S4 A64]))
1.c:9 85 {*movsi_internal}
(nil))
(insn 8 15 16 2 (parallel [
(set (reg:SI 0 ax [orig:65 D.1731 ] [65])
(and:SI (reg:SI 0 ax [orig:65 D.1731 ] [65])
(const_int 3 [0x3])))
(clobber (reg:CC 17 flags))
]) 1.c:9 387 {*andsi_1}
(expr_list:REG_EQUIV (mem/c:SI (symbol_ref:DI ("total") <var_decl
0x7ffff61da2f8 total>) [2 total+0 S4 A32])
(nil)))
IRA Trace:
Pass 0 for finding pseudo/allocno costs
a0 (r65,l0) best GENERAL_REGS, allocno GENERAL_REGS
a1 (r64,l0) best NO_REGS, allocno NO_REGS
a1's rclass are all NO_REGS because it has REG_EQUIV note (equivalent to mem
ip+2)
Because reg 64 is marked as equivalent to mem ip+2, insn 12 is expected to be
deleted and reg 64 in insn 8 replaced by mem ip+2. In LRA constraints, insn 12
is not deleted because the subreg op in insn 8 (see lra-constraints.c:3662
r199418). In addition, reg 64's rclass is NO_REGS, so redundent spills are
inserted.
The mode size check (lra-constraints.c:3662 r199418) needs to be considered in
update_equiv_regs in IRA, in order not to mark the reg 64 equivalent with mem
ip + 2 in this case.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8/4.9 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
@ 2013-06-12 21:47 ` wmi at google dot com
2013-06-20 8:56 ` [Bug rtl-optimization/57518] [4.9 " rguenth at gcc dot gnu.org
` (11 subsequent siblings)
12 siblings, 0 replies; 14+ messages in thread
From: wmi at google dot com @ 2013-06-12 21:47 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
--- Comment #1 from wmi at google dot com ---
post a candidate patch here:
http://gcc.gnu.org/ml/gcc-patches/2013-06/msg00748.html
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.9 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
2013-06-12 21:47 ` [Bug rtl-optimization/57518] [4.8/4.9 Regression] Redundant " wmi at google dot com
@ 2013-06-20 8:56 ` rguenth at gcc dot gnu.org
2013-06-20 15:55 ` wmi at google dot com
` (10 subsequent siblings)
12 siblings, 0 replies; 14+ messages in thread
From: rguenth at gcc dot gnu.org @ 2013-06-20 8:56 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |4.9.0
Summary|[4.8/4.9 Regression] |[4.9 Regression] Redundant
|Redundant insn generated in |insn generated in LRA
|LRA |
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
>From the description I gather that 4.8.0 works.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.9 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
2013-06-12 21:47 ` [Bug rtl-optimization/57518] [4.8/4.9 Regression] Redundant " wmi at google dot com
2013-06-20 8:56 ` [Bug rtl-optimization/57518] [4.9 " rguenth at gcc dot gnu.org
@ 2013-06-20 15:55 ` wmi at google dot com
2013-06-24 10:20 ` [Bug rtl-optimization/57518] [4.8/4.9 " rguenth at gcc dot gnu.org
` (9 subsequent siblings)
12 siblings, 0 replies; 14+ messages in thread
From: wmi at google dot com @ 2013-06-20 15:55 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
wmi at google dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu.org
--- Comment #3 from wmi at google dot com ---
oh, sorry to make it misleading, but the 4.8.0 below is an experimental version
(see its date is 20120613, at that time LRA has not been merged):
Target: x86_64-linux-gnu
gcc version 4.8.0 20120613 (experimental) (GCC)
gcc -O2 -S 1.c
.cfi_startproc
movzbl ip+2(%rip), %eax
andl $3, %eax
movl %eax, total(%rip)
ret
.cfi_endproc
I just verified using 4.8.0 and 4.8.1 releases, the problem was there for both.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8/4.9 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
` (2 preceding siblings ...)
2013-06-20 15:55 ` wmi at google dot com
@ 2013-06-24 10:20 ` rguenth at gcc dot gnu.org
2013-10-12 0:25 ` brooks at gcc dot gnu.org
` (8 subsequent siblings)
12 siblings, 0 replies; 14+ messages in thread
From: rguenth at gcc dot gnu.org @ 2013-06-24 10:20 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.9.0 |4.8.2
Summary|[4.9 Regression] Redundant |[4.8/4.9 Regression]
|insn generated in LRA |Redundant insn generated in
| |LRA
Known to fail| |4.8.0
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Not sure if we want to backport such change though.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8/4.9 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
` (3 preceding siblings ...)
2013-06-24 10:20 ` [Bug rtl-optimization/57518] [4.8/4.9 " rguenth at gcc dot gnu.org
@ 2013-10-12 0:25 ` brooks at gcc dot gnu.org
2013-10-14 8:08 ` [Bug rtl-optimization/57518] [4.8 " rguenth at gcc dot gnu.org
` (7 subsequent siblings)
12 siblings, 0 replies; 14+ messages in thread
From: brooks at gcc dot gnu.org @ 2013-10-12 0:25 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Brooks Moses <brooks at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |brooks at gcc dot gnu.org
--- Comment #5 from Brooks Moses <brooks at gcc dot gnu.org> ---
For the record, this is failing in the Google 4.8 branch (which has the
backported patch applied, along with the testcase) in our 32-bit Power builds.
It may be worth seeing if that replicates on trunk.
Otherwise, since the relevant patch has been applied to trunk, shouldn't this
be closed?
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
` (4 preceding siblings ...)
2013-10-12 0:25 ` brooks at gcc dot gnu.org
@ 2013-10-14 8:08 ` rguenth at gcc dot gnu.org
2013-10-16 9:49 ` jakub at gcc dot gnu.org
` (6 subsequent siblings)
12 siblings, 0 replies; 14+ messages in thread
From: rguenth at gcc dot gnu.org @ 2013-10-14 8:08 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2013-10-14
Known to work| |4.9.0
Summary|[4.8/4.9 Regression] |[4.8 Regression] Redundant
|Redundant insn generated in |insn generated in LRA
|LRA |
Ever confirmed|0 |1
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk sofar.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
` (5 preceding siblings ...)
2013-10-14 8:08 ` [Bug rtl-optimization/57518] [4.8 " rguenth at gcc dot gnu.org
@ 2013-10-16 9:49 ` jakub at gcc dot gnu.org
2013-11-04 14:07 ` hp at gcc dot gnu.org
` (5 subsequent siblings)
12 siblings, 0 replies; 14+ messages in thread
From: jakub at gcc dot gnu.org @ 2013-10-16 9:49 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.8.2 |4.8.3
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.2 has been released.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
` (6 preceding siblings ...)
2013-10-16 9:49 ` jakub at gcc dot gnu.org
@ 2013-11-04 14:07 ` hp at gcc dot gnu.org
2013-11-04 14:32 ` hp at gcc dot gnu.org
` (4 subsequent siblings)
12 siblings, 0 replies; 14+ messages in thread
From: hp at gcc dot gnu.org @ 2013-11-04 14:07 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Hans-Peter Nilsson <hp at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |hp at gcc dot gnu.org
--- Comment #8 from Hans-Peter Nilsson <hp at gcc dot gnu.org> ---
Why is the test-case gcc.dg/pr57518.c valid?
It just checks that a REG_EQUIV is not attached, but from the analysis it seems
the need is to check the related register against some condition; the note
seems valid. Or maybe the test-case should be made machine-specific.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
` (7 preceding siblings ...)
2013-11-04 14:07 ` hp at gcc dot gnu.org
@ 2013-11-04 14:32 ` hp at gcc dot gnu.org
2014-05-22 9:06 ` rguenth at gcc dot gnu.org
` (3 subsequent siblings)
12 siblings, 0 replies; 14+ messages in thread
From: hp at gcc dot gnu.org @ 2013-11-04 14:32 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
--- Comment #9 from Hans-Peter Nilsson <hp at gcc dot gnu.org> ---
See also PR58985.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
` (8 preceding siblings ...)
2013-11-04 14:32 ` hp at gcc dot gnu.org
@ 2014-05-22 9:06 ` rguenth at gcc dot gnu.org
2014-12-10 12:41 ` rguenth at gcc dot gnu.org
` (2 subsequent siblings)
12 siblings, 0 replies; 14+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-05-22 9:06 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.8.3 |4.8.4
--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 4.8.3 is being released, adjusting target milestone.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
` (9 preceding siblings ...)
2014-05-22 9:06 ` rguenth at gcc dot gnu.org
@ 2014-12-10 12:41 ` rguenth at gcc dot gnu.org
2014-12-19 13:28 ` jakub at gcc dot gnu.org
2015-06-23 8:42 ` rguenth at gcc dot gnu.org
12 siblings, 0 replies; 14+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-12-10 12:41 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Priority|P3 |P2
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
` (10 preceding siblings ...)
2014-12-10 12:41 ` rguenth at gcc dot gnu.org
@ 2014-12-19 13:28 ` jakub at gcc dot gnu.org
2015-06-23 8:42 ` rguenth at gcc dot gnu.org
12 siblings, 0 replies; 14+ messages in thread
From: jakub at gcc dot gnu.org @ 2014-12-19 13:28 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.8.4 |4.8.5
--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.4 has been released.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Bug rtl-optimization/57518] [4.8 Regression] Redundant insn generated in LRA
2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
` (11 preceding siblings ...)
2014-12-19 13:28 ` jakub at gcc dot gnu.org
@ 2015-06-23 8:42 ` rguenth at gcc dot gnu.org
12 siblings, 0 replies; 14+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-06-23 8:42 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |FIXED
Target Milestone|4.8.5 |4.9.0
Known to fail| |4.8.5
--- Comment #13 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed for 4.9.0.
^ permalink raw reply [flat|nested] 14+ messages in thread
end of thread, other threads:[~2015-06-23 8:41 UTC | newest]
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2013-06-03 21:04 [Bug rtl-optimization/57518] New: Redundent insn generated in LRA wmi at google dot com
2013-06-12 21:47 ` [Bug rtl-optimization/57518] [4.8/4.9 Regression] Redundant " wmi at google dot com
2013-06-20 8:56 ` [Bug rtl-optimization/57518] [4.9 " rguenth at gcc dot gnu.org
2013-06-20 15:55 ` wmi at google dot com
2013-06-24 10:20 ` [Bug rtl-optimization/57518] [4.8/4.9 " rguenth at gcc dot gnu.org
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