Try to compile the attached program with "gcc -O2 -g test.c" on i386. It fails with this error:
test.c: In function ‘main’:
test.c:7:3: error: can't find a register in class ‘GENERAL_REGS’ while reloading ‘asm’
test.c:7:3: error: ‘asm’ operand has impossible constraints
As I understand it, the correct behaviour would be to use memory for some parameters and registers for other parameters as I specifically allow both.
ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: gcc 4:4.5.2-1ubuntu3
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
NonfreeKernelModules: nvidia
Architecture: i386
Date: Fri May 27 11:23:16 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110322.1)
ProcEnviron:
LANGUAGE=sv_SE:en
LANG=sv_SE.UTF-8
SHELL=/bin/bash
SourcePackage: gcc-defaults
UpgradeStatus: No upgrade log present (probably fresh install)
Seems to be present in 4.6 (from oneiric) also:
(oneiric-i386)$ gcc-4.6 -O2 -g -o test2 test2.c
test2.c: In function 'main':
test2.c:7:3: error: can't find a register in class 'GENERAL_REGS' while reloading 'asm'
test2.c:7:3: error: 'asm' operand has impossible constraints
and in 4.4 (from lucid):
(oneiric-i386)$ gcc-4.6 -O2 -g -o test2 test2.c
test2.c: In function 'main':
test2.c:7:3: error: can't find a register in class 'GENERAL_REGS' while reloading 'asm'
test2.c:7:3: error: 'asm' operand has impossible constraints