[Bug c/36336] New: ICE push_reload - psuedo reg_equiv_constant

[Bug c/36336] New: ICE push_reload - psuedo reg_equiv_constant

[hutchinsonandy at aim dot com]

The follow ICE occurs with various testsuite tests. It appears to be real bug.

Executing on host: /home/hutchia/Desktop/awhconf/gcc/xgcc
-B/home/hutchia/Desktop/awhconf/gcc/   -O2  -w -DSTACK_SIZE=2048
-DNO_TRAMPOLINES -fno-show-column -c  -DSIGNAL_SUPPRESS -mmcu=atmega128   -o
980408-1.o
/home/hutchia/Desktop/gcc/gcc/testsuite/gcc.c-torture/compile/980408-1.c   
(timeout = 300)
/home/hutchia/Desktop/gcc/gcc/testsuite/gcc.c-torture/compile/980408-1.c: In
function 'MinifyImage':
/home/hutchia/Desktop/gcc/gcc/testsuite/gcc.c-torture/compile/980408-1.c:129:
internal compiler error: in push_reload, at reload.c:940


The assertion failure is due to push_reload receiving pseudo (e.g. p68) that
has not replaced with its reg_equiv_constant.

The assert was added by this bug fix:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34641


Analysis

push_reload is called by target LEGITIMIZE_RELOAD_ADDRESS. This received 
operand p68 + 2 and is attempting to reload p68.

LEGITIMIZE_RELOAD_ADDRESS was invoked by find_reloads_address after
strict_memory_address_p rejects  p68+2.

The assert was added 
2008-01-10  Andreas Krebbel  <krebbel1@de.ibm.com>

This also added extra code to convert pseudo register equivalent constants were
converted by before push_reload is called. However, it does not consider the
case where the operand is a sum of reg_equiv_reg and constant.

This does not get replaced before LEGITIMIZE_RELOAD_ADDRESS is called in 
find_reloads_address.


The internals manual clearly indicates that GO_IF_LEGITIMATE_ADDRESS should
reject p68+2 unless there is const wrapper.

http://gcc.gnu.org/onlinedocs/gccint/Addressing-Modes.html

But the call from reload does not seem to provide that wrapper. Perhaps this is
the bug?

I have attached the smallest testcase. It is nonsense but will cause failure
when compiled using:

avr-gcc -c -mmcu=atmega128  -w  -O1 -mmcu=atmega128  -std=gnu99 memcpy-chk.c -o
memcpy-chk.o


The attached testcase uses __builtin_setjmp as a reduction from a failing test.
However, the ICE is not unique to this function.
gcc/gcc/testsuite/gcc.c-torture/compile/980408-1.c also fails and this does not
use _builtin_setjmp. But I was unable to create small testcase from this.


-- 
           Summary: ICE push_reload - psuedo reg_equiv_constant
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hutchinsonandy at aim dot com
 GCC build triplet: i686-pc-cygwin
  GCC host triplet: i686-pc-cygwin
GCC target triplet: avr-unknown-none


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36336

[Bug c/36336] ICE push_reload - psuedo reg_equiv_constant

[hutchinsonandy at aim dot com]

------- Comment #1 from hutchinsonandy at aim dot com  2008-05-26 19:24 -------
Created an attachment (id=15688)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15688&action=view)
Testcase

Testcase derived from gcc testsuite failure memcpy-chk.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36336

[Bug target/36336] ICE push_reload - psuedo reg_equiv_constant

[eric dot weddington at atmel dot com]

------- Comment #2 from eric dot weddington at atmel dot com  2008-06-06 19:24 -------
Andy, I'm having a difficulty in trying to reproduce this bug. I use this
command line:
avr-gcc -O1 -mmcu=atmega128 -w -std=gnu99 -c memcpy-chk.c -o memcpy-chk.o
But I'm using WinAVR 20080512, which is patched, and it does not give an ICE.

Are you also getting this ICE with HEAD?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36336

[Bug target/36336] ICE push_reload - psuedo reg_equiv_constant

[hutchinsonandy at aim dot com]

------- Comment #3 from hutchinsonandy at aim dot com  2008-06-06 19:42 -------
Subject: Re:  ICE push_reload - psuedo reg_equiv_constant

O2



----------------------------------------------
Sent from my Dingleberry wired device.


-----Original Message-----
From: eric dot weddington at atmel dot com <gcc-bugzilla@gcc.gnu.org>
To: hutchinsonandy@aim.com
Sent: Fri, 6 Jun 2008 3:24 pm
Subject: [Bug target/36336] ICE push_reload - psuedo reg_equiv_constant




------- Comment #2 from eric dot weddington at atmel dot com  
2008-06-06 19:24
-------
Andy, I'm having a difficulty in trying to reproduce this bug. I use 
this
command line:
avr-gcc -O1 -mmcu=atmega128 -w -std=gnu99 -c memcpy-chk.c -o 
memcpy-chk.o
But I'm using WinAVR 20080512, which is patched, and it does not give 
an ICE.

Are you also getting this ICE with HEAD?


--


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36336

[Bug target/36336] ICE push_reload - psuedo reg_equiv_constant

[eric dot weddington at atmel dot com]

------- Comment #4 from eric dot weddington at atmel dot com  2008-06-06 19:48 -------
Test case passes with -O[0123s], with WinAVR 20080512 (patched 4.3.0).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36336

[Bug target/36336] ICE push_reload - psuedo reg_equiv_constant

[hutchinsonandy at aim dot com]

------- Comment #5 from hutchinsonandy at aim dot com  2008-06-06 20:18 -------
Subject: Re:  ICE push_reload - psuedo reg_equiv_constant


The patch for

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31786

removes one problematic part of LEGITIMIZE_RELOAD_ADDRESS. This is  
applied to WinAVR 20080512 (patched 4.3.0). But is still waiting for 
approval on avr-gcc 4.3/4.4 HEAD.

Even with that patch, the other parts of L_R_A are bad and need fixing 
with added check of reg_equivalent_constant.
So if register is equivalent constant LEGITIMIZE_RELOAD_ADDRESS should 
do nothing.

The assert that triggers is an explicit check for this.

I have not posted patch due to overlap with pending patch.

BTW gcc list has short discussion on this bug, including explanation 
for the AVR code.

Andy




----------------------------------------------
Sent from my Dingleberry wired device.


-----Original Message-----
From: eric dot weddington at atmel dot com <gcc-bugzilla@gcc.gnu.org>
To: hutchinsonandy@aim.com
Sent: Fri, 6 Jun 2008 3:48 pm
Subject: [Bug target/36336] ICE push_reload - psuedo reg_equiv_constant




------- Comment #4 from eric dot weddington at atmel dot com  
2008-06-06 19:48
-------
Test case passes with -O[0123s], with WinAVR 20080512 (patched 4.3.0).


--


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36336

------- You are receiving this mail because: -------
You reported the bug, or are watching the reporter.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36336

[Bug target/36336] ICE push_reload - psuedo reg_equiv_constant

[hutchinsonandy at gcc dot gnu dot org]

------- Comment #6 from hutchinsonandy at gcc dot gnu dot org  2008-06-15 18:25 -------
Subject: Bug 36336

Author: hutchinsonandy
Date: Sun Jun 15 18:24:27 2008
New Revision: 136818

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=136818
Log:
PR target/36336
* config/avr/avr.h (LEGITIMIZE_RELOAD_ADDRESS): Add check for
reg_equiv_constant.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/avr/avr.h


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36336

[Bug target/36336] ICE push_reload - psuedo reg_equiv_constant

[hutchinsonandy at gcc dot gnu dot org]

------- Comment #7 from hutchinsonandy at gcc dot gnu dot org  2008-06-15 18:35 -------
Subject: Bug 36336

Author: hutchinsonandy
Date: Sun Jun 15 18:34:45 2008
New Revision: 136819

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=136819
Log:
PR target/36336
* config/avr/avr.h (LEGITIMIZE_RELOAD_ADDRESS): Add check for
reg_equiv_constant.

Modified:
    branches/gcc-4_3-branch/gcc/ChangeLog
    branches/gcc-4_3-branch/gcc/config/avr/avr.h


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36336

[Bug target/36336] ICE push_reload - psuedo reg_equiv_constant

[hutchinsonandy at gcc dot gnu dot org]

------- Comment #8 from hutchinsonandy at gcc dot gnu dot org  2008-06-15 18:36 -------
Fixed 4.4 and 4.3


-- 

hutchinsonandy at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36336