DESCRIPTION:
----------------------------------------
Simple test case is below.
There is redundant stack manipulation in the assembly output.
Use gcc -Wall -Os -S test.c
-----------------------------------------
VERSION INFO:
----------------------------------
gcc -v
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v
--enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr
--enable-shared --with-system-zlib --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix --enable-nls
--program-suffix=-4.1 --enable-__cxa_atexit --enable-clocale=gnu
--enable-libstdcxx-debug --enable-mpfr --enable-checking=release i486-linux-gnu
Thread model: posix
gcc version 4.1.2 20060928 (prerelease) (Ubuntu 4.1.1-13ubuntu5)
-----------------------------------
SOURCE CODE:
----------------------------------
extern int ii(int i);
void
mm()
{
int i=99;
more:
i = ii(i);
goto inc;
inc:
if(i==0)
goto more;
i++;
goto more;
}
---------------------------------------
--
Summary: -Os produces redundant instructions
Product: gcc
Version: 4.1.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: reza at parvan dot net
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37990
