The parser for windows x86_64 does sign extensions
on values from 0x80000000 to 0xffffffff
even for constant 64-bit values.
Even if 32-bit is the norm for constant expressions,
at least MOVABS instruction is supposed to accept 64-bit immediate values,
but the sign extension mechanism is still applied in that case.
This happens in config/tc-i386.c
in i386_finalize_immediate.
Linux assembler is not affected as
`use_rela_relocations' variable is set to 1
for 64 bit ELF target objects.
This creates incompatible output from a single assembler source.
>>>> Example <<<<<<<
>>>> source file: test-sign.s <<<<<<<
.data
test:
.quad 0
.text
.global _settest1
_settest1:
movq $0x80000001,%rax
movq %rax,test
retq
.global _settest2
_settest2:
movq $0x180000001,%rax
movq %rax,test
retq
.global _gettest
_gettest:
movq test,%rax
retq
.global _test_push_imm
_test_push_imm:
pushq %rbp
movq %rsp,%rbp
pushq $0x80000001
movq -8(%rbp),%rax
movq %rax,test
leaveq
retq
.global _settestmovabs
_settestmovabs:
movabsq $0x80000001,%rax
retq
>>>> End of source <<<<<<<
>>>> Source file test.c <<<<<<<
#include <stdio.h>
extern void settest1 ();
extern void settest2 ();
extern void settestmovabs ();
extern long long int gettest ();
int
main ()
{
long long int res;
res = gettest ();
if (res != 0)
printf ("Error for value 0\n");
settest2 ();
res = gettest ();
if (res != (long long int) (0x180000001))
printf ("Error for value 0x180000001\n");
settest1 ();
res = gettest ();
if (res != (long long int) (0x80000001))
printf ("Error for value 0x80000001\n");
settestmovabs ();
res = gettest ();
if (res != (long long int) (0x80000001))
printf ("Error for value 0x80000001\n");
return 0;
}
>>>> End of source <<<<<<<
Assemble sign-test.s using GNU as for x86_64 windows
as -o test-sign.o test-sign.s
Compile test.c:
gcc -o test.exe test-sign.o test.c
Run ./test.exe:
$ ./test
Error for value 0x80000001 with settest1
Error for value 0x80000001 with settestmovabs
--
Summary: windows x86_64 sign extension
Product: binutils
Version: 2.21 (HEAD)
Status: NEW
Severity: normal
Priority: P2
Component: gas
AssignedTo: unassigned at sources dot redhat dot com
ReportedBy: muller at ics dot u-strasbg dot fr
CC: bug-binutils at gnu dot org
GCC host triplet: x86_64-w64-mingw32
http://sourceware.org/bugzilla/show_bug.cgi?id=11974
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