mirror/nasm
2
0
Fork 0
mirror of https://github.com/netwide-assembler/nasm.git synced 2025-04-12 18:40:23 +08:00
Code Issues Packages Projects Releases Wiki Activity

assemble: Only treat a displacement as signed if it is < asize

Browse Source 
Only generate a signed relocation if the displacement size is less
than the address size.  This matters when involving address size
overrides.

It is technically impossible to do this one perfectly, because it is
never really knowable if the displacement offset is used as a base or
an index.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
H. Peter Anvin 2013-11-26 20:19:53 -08:00
parent 186b533425
commit 72bf3fe98c
2 changed files with 22 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
assemble.c
View File

@ -1849,13 +1849,7 @@ static void gencode(int32_t segment, int64_t offset, int bits,
offset += s;
s = 0;
switch (ea_data.bytes) {
case 0:
break;
case 1:
case 2:
case 4:
case 8:
if (ea_data.bytes) {
/* use compressed displacement, if available */
data = ea_data.disp8 ? ea_data.disp8 : opy->offset;
s += ea_data.bytes;
@ -1872,21 +1866,25 @@ static void gencode(int32_t segment, int64_t offset, int bits,
insn_end - offset, opy->segment, opy->wrt);
}
} else {
if (overflow_general(data, ins->addr_size >> 3) ||
int asize = ins->addr_size >> 3;
int atype = ea_data.bytes;
if (overflow_general(data, asize) ||
signed_bits(data, ins->addr_size) !=
signed_bits(data, ea_data.bytes * 8))
signed_bits(data, ea_data.bytes << 3))
warn_overflow(ERR_PASS2, ea_data.bytes);
if (asize > ea_data.bytes) {
/*
* If the address isn't the full width of
* the address size, treat is as signed...
*/
atype = -atype;
}
out(offset, segment, &data, OUT_ADDRESS,
-ea_data.bytes, opy->segment, opy->wrt);
atype, opy->segment, opy->wrt);
}
break;
default:
/* Impossible! */
errfunc(ERR_PANIC,
"Invalid amount of bytes (%d) for offset?!",
ea_data.bytes);
break;
}
offset += s;
}

7
test/relocs.asm
View File

@ -5,6 +5,13 @@
mov rax,[foo]
mov rax,[qword foo]
mov eax,[a32 foo]
mov rax,[a32 foo]
mov rax,[a32 qword foo]
mov eax,foo
mov rax,dword foo
mov rax,qword foo
mov eax,foo
mov rax,dword foo
mov rax,qword foo