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target-alpha: Fix integer overflow checking insns

Browse source 
We need to write the result to the destination register before
raising any exception.  Thus inline the code for each insn, and
check for any exception after we're done.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2014-07-03 13:18:26 -07:00
parent 7b4dde839e
commit 4d1628e832
3 changed files with 56 additions and 70 deletions
Download patch file Download diff file Expand all files Collapse all files

59
target-alpha/int_helper.c
View file

@ -249,64 +249,9 @@ uint64_t helper_unpkbw(uint64_t op1)
| ((op1 & 0xff000000) << 24));
}
uint64_t helper_addqv(CPUAlphaState *env, uint64_t op1, uint64_t op2)
void helper_check_overflow(CPUAlphaState *env, uint64_t op1, uint64_t op2)
{
uint64_t tmp = op1;
op1 += op2;
if (unlikely((tmp ^ op2 ^ (-1ULL)) & (tmp ^ op1) & (1ULL << 63))) {
if (unlikely(op1 != op2)) {
arith_excp(env, GETPC(), EXC_M_IOV, 0);
}
return op1;
}
uint64_t helper_addlv(CPUAlphaState *env, uint64_t op1, uint64_t op2)
{
uint64_t tmp = op1;
op1 = (uint32_t)(op1 + op2);
if (unlikely((tmp ^ op2 ^ (-1UL)) & (tmp ^ op1) & (1UL << 31))) {
arith_excp(env, GETPC(), EXC_M_IOV, 0);
}
return op1;
}
uint64_t helper_subqv(CPUAlphaState *env, uint64_t op1, uint64_t op2)
{
uint64_t res;
res = op1 - op2;
if (unlikely((op1 ^ op2) & (res ^ op1) & (1ULL << 63))) {
arith_excp(env, GETPC(), EXC_M_IOV, 0);
}
return res;
}
uint64_t helper_sublv(CPUAlphaState *env, uint64_t op1, uint64_t op2)
{
uint32_t res;
res = op1 - op2;
if (unlikely((op1 ^ op2) & (res ^ op1) & (1UL << 31))) {
arith_excp(env, GETPC(), EXC_M_IOV, 0);
}
return res;
}
uint64_t helper_mullv(CPUAlphaState *env, uint64_t op1, uint64_t op2)
{
int64_t res = (int64_t)op1 * (int64_t)op2;
if (unlikely((int32_t)res != res)) {
arith_excp(env, GETPC(), EXC_M_IOV, 0);
}
return (int64_t)((int32_t)res);
}
uint64_t helper_mulqv(CPUAlphaState *env, uint64_t op1, uint64_t op2)
{
uint64_t tl, th;
muls64(&tl, &th, op1, op2);
/* If th != 0 && th != -1, then we had an overflow */
if (unlikely((th + 1) > 1)) {
arith_excp(env, GETPC(), EXC_M_IOV, 0);
}
return tl;
}