diff options
Diffstat (limited to 'target-s390x/cc_helper.c')
| -rw-r--r-- | target-s390x/cc_helper.c | 18 |
1 files changed, 4 insertions, 14 deletions
diff --git a/target-s390x/cc_helper.c b/target-s390x/cc_helper.c index 373eb176a1..00bc883a8a 100644 --- a/target-s390x/cc_helper.c +++ b/target-s390x/cc_helper.c @@ -179,16 +179,11 @@ static uint32_t cc_calc_subu_64(uint64_t a1, uint64_t a2, uint64_t ar) static uint32_t cc_calc_subb_64(uint64_t a1, uint64_t a2, uint64_t ar) { - /* We had borrow-in if normal subtraction isn't equal. */ - int borrow_in = ar - (a1 - a2); int borrow_out; - /* If a2 was ULONG_MAX, and borrow_in, then a2 is logically 65 bits, - and we must have had borrow out. */ - if (borrow_in && a2 == (uint64_t)-1) { - borrow_out = 1; + if (ar != a1 - a2) { /* difference means borrow-in */ + borrow_out = (a2 >= a1); } else { - a2 += borrow_in; borrow_out = (a2 > a1); } @@ -285,16 +280,11 @@ static uint32_t cc_calc_subu_32(uint32_t a1, uint32_t a2, uint32_t ar) static uint32_t cc_calc_subb_32(uint32_t a1, uint32_t a2, uint32_t ar) { - /* We had borrow-in if normal subtraction isn't equal. */ - int borrow_in = ar - (a1 - a2); int borrow_out; - /* If a2 was UINT_MAX, and borrow_in, then a2 is logically 65 bits, - and we must have had borrow out. */ - if (borrow_in && a2 == (uint32_t)-1) { - borrow_out = 1; + if (ar != a1 - a2) { /* difference means borrow-in */ + borrow_out = (a2 >= a1); } else { - a2 += borrow_in; borrow_out = (a2 > a1); } |