Commit ff8263a9 authored by bellard's avatar bellard
Browse files

ARM saturating arithmetic fixes (Paul Brook)


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1431 c046a42c-6fe2-441c-8c8c-71466251a162
parent 04d81be8
......@@ -805,6 +805,23 @@ void OPPROTO op_subl_T0_T1_saturate(void)
FORCE_RET();
}
void OPPROTO op_double_T1_saturate(void)
{
int32_t val;
val = T1;
if (val >= 0x40000000) {
T1 = 0x7fffffff;
env->QF = 1;
} else if (val <= (int32_t)0xc0000000) {
T1 = 0x80000000;
env->QF = 1;
} else {
T1 = val << 1;
}
FORCE_RET();
}
/* thumb shift by immediate */
void OPPROTO op_shll_T0_im_thumb(void)
{
......
......@@ -1019,20 +1019,15 @@ static void disas_arm_insn(CPUState * env, DisasContext *s)
case 0x5: /* saturating add/subtract */
rd = (insn >> 12) & 0xf;
rn = (insn >> 16) & 0xf;
gen_movl_T0_reg(s, rn);
if (op1 & 2) {
gen_movl_T1_reg(s, rn);
if (op1 & 1)
gen_op_subl_T0_T1_saturate();
else
gen_op_addl_T0_T1_saturate();
}
gen_movl_T1_reg(s, rm);
gen_movl_T0_reg(s, rm);
gen_movl_T1_reg(s, rn);
if (op1 & 2)
gen_op_double_T1_saturate();
if (op1 & 1)
gen_op_subl_T0_T1_saturate();
else
gen_op_addl_T0_T1_saturate();
gen_movl_reg_T0(s, rn);
gen_movl_reg_T0(s, rd);
break;
case 0x8: /* signed multiply */
case 0xa:
......
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