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* [Bug rtl-optimization/36409] New: Additional instructions in prologue and epilogue.
@ 2008-06-01 10:47 ramana at icerasemi dot com
2009-02-04 23:39 ` [Bug target/36409] " ramana dot r at gmail dot com
2009-04-21 14:42 ` ramana at gcc dot gnu dot org
0 siblings, 2 replies; 3+ messages in thread
From: ramana at icerasemi dot com @ 2008-06-01 10:47 UTC (permalink / raw)
To: gcc-bugs
Stack space creation instructions in prologue and epilogue don't get deleted.
foo:
sub sp, sp, #8 --> Unnecessary
mov r3, #0
add sp, sp, #8 --> Unnecessary
str r3, [r0]
struct Foo {
int *p;
int *q;
};
void __attribute__((noinline))
foo(struct Foo f)
{
*f.p = 0;
}
This appears to be due to get_frame_size returning the size of the incoming
parameters being 8 bytes in the backend .
--
Summary: Additional instructions in prologue and epilogue.
Product: gcc
Version: 4.3.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: ramana at icerasemi dot com
GCC host triplet: i686-linux
GCC target triplet: arm-none-eabi
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36409
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug target/36409] Additional instructions in prologue and epilogue.
2008-06-01 10:47 [Bug rtl-optimization/36409] New: Additional instructions in prologue and epilogue ramana at icerasemi dot com
@ 2009-02-04 23:39 ` ramana dot r at gmail dot com
2009-04-21 14:42 ` ramana at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: ramana dot r at gmail dot com @ 2009-02-04 23:39 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from ramana dot r at gmail dot com 2009-02-04 23:38 -------
4.4.0 with revision id 143499 generates the following code with -O3 , -O2 and
-Os . The same code is generated for 4.3.3 as well
sub sp, sp, #8
mov r3, sp
mov r2, #0
stmia r3, {r0, r1}
str r2, [r0, #0]
add sp, sp, #8
bx lr
Clearly things have gotten worse with an extra stmia being generated in this
case where the argument registers are being saved on the stack with the stmia
instruction.
--
ramana dot r at gmail dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rearnsha at arm dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36409
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug target/36409] Additional instructions in prologue and epilogue.
2008-06-01 10:47 [Bug rtl-optimization/36409] New: Additional instructions in prologue and epilogue ramana at icerasemi dot com
2009-02-04 23:39 ` [Bug target/36409] " ramana dot r at gmail dot com
@ 2009-04-21 14:42 ` ramana at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: ramana at gcc dot gnu dot org @ 2009-04-21 14:42 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from ramana at gcc dot gnu dot org 2009-04-21 14:42 -------
confirmed.
--
ramana at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2009-04-21 14:42:20
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36409
^ permalink raw reply [flat|nested] 3+ messages in thread
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2008-06-01 10:47 [Bug rtl-optimization/36409] New: Additional instructions in prologue and epilogue ramana at icerasemi dot com
2009-02-04 23:39 ` [Bug target/36409] " ramana dot r at gmail dot com
2009-04-21 14:42 ` ramana at gcc dot gnu dot org
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