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assemble.c: for the signed byte operand, check overflow then rawbyte

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When we are generating a signed byte operand, we anyway have to do the
overflow check "manually".  After doing so, output the result using
out_rawbyte() instead of out_imm(), so we don't end up doing a
redundant, and incorrect, second overflow check.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
H. Peter Anvin 2017-03-01 13:45:02 -08:00
parent 02788e1675
commit 64e87d0dfc
1 changed files with 28 additions and 22 deletions
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50
asm/assemble.c
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@ -1751,31 +1751,37 @@ static void gencode(struct out_data *data, insn *ins)
uint64_t uv, um;
int s;
if (ins->rex & REX_W)
s = 64;
else if (ins->prefixes[PPS_OSIZE] == P_O16)
s = 16;
else if (ins->prefixes[PPS_OSIZE] == P_O32)
s = 32;
else
s = bits;
if (absolute_op(opx)) {
if (ins->rex & REX_W)
s = 64;
else if (ins->prefixes[PPS_OSIZE] == P_O16)
s = 16;
else if (ins->prefixes[PPS_OSIZE] == P_O32)
s = 32;
else
s = bits;
um = (uint64_t)2 << (s-1);
uv = opx->offset;
um = (uint64_t)2 << (s-1);
uv = opx->offset;
if (uv > 127 && uv < (uint64_t)-128 &&
(uv < um-128 || uv > um-1)) {
/* If this wasn't explicitly byte-sized, warn as though we
* had fallen through to the imm16/32/64 case.
*/
nasm_error(ERR_WARNING | ERR_PASS2 | ERR_WARN_NOV,
"%s value exceeds bounds",
(opx->type & BITS8) ? "signed byte" :
s == 16 ? "word" :
s == 32 ? "dword" :
"signed dword");
if (uv > 127 && uv < (uint64_t)-128 &&
(uv < um-128 || uv > um-1)) {
/* If this wasn't explicitly byte-sized, warn as though we
* had fallen through to the imm16/32/64 case.
*/
nasm_error(ERR_WARNING | ERR_PASS2 | ERR_WARN_NOV,
"%s value exceeds bounds",
(opx->type & BITS8) ? "signed byte" :
s == 16 ? "word" :
s == 32 ? "dword" :
"signed dword");
}
/* Output as a raw byte to avoid byte overflow check */
out_rawbyte(data, (uint8_t)uv);
} else {
out_imm(data, opx, 1, OUT_WRAP); /* XXX: OUT_SIGNED? */
}
out_imm(data, opx, 1, OUT_WRAP); /* XXX: OUT_SIGNED? */
break;
}