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From: marcus@mc.pp.se
To: gcc-gnats@gcc.gnu.org
Subject: optimization/5768: sh codegen leaves stuff on stack
Date: Sat, 23 Feb 2002 21:47:00 -0000 [thread overview]
Message-ID: <20020224033018.E78E5C8@continuity.mc.pp.se> (raw)
>Number: 5768
>Category: optimization
>Synopsis: sh codegen leaves stuff on stack
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: unassigned
>State: open
>Class: wrong-code
>Submitter-Id: net
>Arrival-Date: Sat Feb 23 19:36:00 PST 2002
>Closed-Date:
>Last-Modified:
>Originator: Marcus Comstedt
>Release: 3.0.4
>Organization:
>Environment:
System: SunOS continuity 5.8 Generic_108528-10 sun4m sparc SUNW,SPARCstation-10
Architecture: sun4
host: sparc-sun-solaris2.8
build: sparc-sun-solaris2.8
target: sh-unknown-elf
configured with: ../configure --target=sh-elf --with-newlib
>Description:
When using enough optimization options, the SuperH backend
can produce code that chains to another function without
removing its own stackframe.
Needless to say, this causes the program to go haywire.
Well, source code should go into the next section, so not
much more to say here, except that the problem exists in both
3.0.3 and 3.0.4.
>How-To-Repeat:
Example program:
---8<--- foo.c ---8<---
int x[2];
void foo()
{
int i;
for(i = 0; i<2; i++ )
if(x[i]) {
bar();
return;
}
}
---8<---
Compile with
sh-elf-gcc -S -O2 -fomit-frame-pointer -funroll-loops foo.c -o foo.s
and this is the result:
---8<--- foo.s ---8<---
.file "foo.c"
.text
.align 2
.global _foo
.type _foo,@function
_foo:
mov.l .L17,r1
mov.l @r1+,r2
sts.l pr,@-r15
tst r2,r2
mov.l .L18,r3
bf .L15
mov.l @r1,r2
tst r2,r2
bf .L16
lds.l @r15+,pr
rts
nop
.align 2
.L15:
jmp @r3
nop
.align 2
.L16:
jmp @r3
nop
.L19:
.align 2
.L17:
.long _x
.L18:
.long _bar
.Lfe1:
.size _foo,.Lfe1-_foo
.comm _x,8,4
.ident "GCC: (GNU) 3.0.4"
---8<---
The code at .L15 and .L16 is obviously faulty, as it never
removes the saved value of pr from the stack.
>Fix:
Compile with less optimization. :-6
>Release-Note:
>Audit-Trail:
>Unformatted:
next reply other threads:[~2002-02-24 3:36 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-02-23 21:47 marcus [this message]
2002-03-06 15:06 Marcus Comstedt
2002-03-06 21:36 Arati Dikey
2002-03-07 8:06 Marcus Comstedt
2002-03-25 10:10 rth
2002-03-25 14:06 rth
2002-03-27 14:16 Marcus Comstedt
2002-03-27 14:20 rth
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