This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug lto/45729] New: -flto conflicts with -mthumb
- From: "rafael dot carre at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 19 Sep 2010 19:09:12 -0000
- Subject: [Bug lto/45729] New: -flto conflicts with -mthumb
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
% cat thumb.i
int _start(void)
{
extern int f(void);
return f();
}
% cat arm.i
int f(void)
{
int ret;
asm ("\tmov %0, #0x200\n" : "=r"(ret));
return ret;
}
% /usr/local/arm-elf-eabi-cvs/bin/arm-elf-eabi-gcc -O -flto -mthumb-interwork
thumb.i -c -mthumb
% /usr/local/arm-elf-eabi-cvs/bin/arm-elf-eabi-gcc -O -flto -mthumb-interwork
arm.i -c
% /usr/local/arm-elf-eabi-cvs/bin/arm-elf-eabi-gcc -O -flto -mthumb-interwork
arm.o thumb.o -lgcc -nostdlib
/tmp/cc6zNKqK.s: Assembler messages:
/tmp/cc6zNKqK.s:20: Error: invalid immediate: 512 is out of range
lto-wrapper: /usr/local/arm-elf-eabi-cvs/bin/arm-elf-eabi-gcc returned 1 exit
status
collect2: lto-wrapper returned 1 exit status
% /usr/local/arm-elf-eabi-cvs/bin/arm-elf-eabi-gcc -O -flto -mthumb-interwork
arm.o thumb.o -lgcc -nostdlib -mthumb
/tmp/ccIIQlpY.s: Assembler messages:
/tmp/ccIIQlpY.s:20: Error: invalid immediate: 512 is out of range
lto-wrapper: /usr/local/arm-elf-eabi-cvs/bin/arm-elf-eabi-gcc returned 1 exit
status
collect2: lto-wrapper returned 1 exit status
% /usr/local/arm-elf-eabi-cvs/bin/arm-elf-eabi-gcc -O -flto -mthumb-interwork
arm.o thumb.o -lgcc -nostdlib -mno-thumb
% /usr/local/arm-elf-eabi-cvs/bin/arm-elf-eabi-gcc -v
Using built-in specs.
COLLECT_GCC=/usr/local/arm-elf-eabi-cvs/bin/arm-elf-eabi-gcc
COLLECT_LTO_WRAPPER=/usr/local/arm-elf-eabi-cvs/libexec/gcc/arm-elf-eabi/4.6.0/lto-wrapper
Target: arm-elf-eabi
Configured with: ../gcc-4.6-20100918/configure
--prefix=/usr/local/arm-elf-eabi-cvs --target=arm-elf-eabi --enable-lto
--enable-languages=c --disable-docs --disable-libssp
Thread model: single
gcc version 4.6.0 20100918 (experimental) (GCC)
I am not sure what is wrong here:
If -mthumb is not specified during linking, I would expect -flto to generate
ARM code which is interworked properly with existing thumb code
If -mthumb is explicited, I would expect -flto to generate Thumb code which is
interworked properly with existing ARM code
Linking with -mno-thumb on a larger binary (rockbox) shows that the binary is
using both Thumb and ARM,
does it mean that -flto doesn't regenerate assembler for every file from the
GIMPLE representation?
--
Summary: -flto conflicts with -mthumb
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: lto
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: rafael dot carre at gmail dot com
GCC target triplet: arm-elf-eabi
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45729