target/s390x: Improve SUB LOGICAL WITH BORROW

Now that SUB LOGICAL outputs borrow, we can use that as input directly.
It also means we can re-use CC_OP_SUBU and produce an output borrow
directly from SUB LOGICAL WITH BORROW.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20201214221356.68039-5-richard.henderson@linaro.org>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

1 files changed, 0 insertions, 32 deletions

diff --git a/target/s390x/cc_helper.c b/target/s390x/cc_helper.c
index c7728d1225..e7039d0d18 100644
--- a/target/s390x/cc_helper.c
+++ b/target/s390x/cc_helper.c
@@ -164,19 +164,6 @@ static uint32_t cc_calc_sub_64(int64_t a1, int64_t a2, int64_t ar)
     }
 }
 
-static uint32_t cc_calc_subb_64(uint64_t a1, uint64_t a2, uint64_t ar)
-{
-    int borrow_out;
-
-    if (ar != a1 - a2) {	/* difference means borrow-in */
-        borrow_out = (a2 >= a1);
-    } else {
-        borrow_out = (a2 > a1);
-    }
-
-    return (ar != 0) + 2 * !borrow_out;
-}
-
 static uint32_t cc_calc_abs_64(int64_t dst)
 {
     if ((uint64_t)dst == 0x8000000000000000ULL) {
@@ -237,19 +224,6 @@ static uint32_t cc_calc_sub_32(int32_t a1, int32_t a2, int32_t ar)
     }
 }
 
-static uint32_t cc_calc_subb_32(uint32_t a1, uint32_t a2, uint32_t ar)
-{
-    int borrow_out;
-
-    if (ar != a1 - a2) {	/* difference means borrow-in */
-        borrow_out = (a2 >= a1);
-    } else {
-        borrow_out = (a2 > a1);
-    }
-
-    return (ar != 0) + 2 * !borrow_out;
-}
-
 static uint32_t cc_calc_abs_32(int32_t dst)
 {
     if ((uint32_t)dst == 0x80000000UL) {
@@ -450,9 +424,6 @@ static uint32_t do_calc_cc(CPUS390XState *env, uint32_t cc_op,
     case CC_OP_SUB_64:
         r =  cc_calc_sub_64(src, dst, vr);
         break;
-    case CC_OP_SUBB_64:
-        r =  cc_calc_subb_64(src, dst, vr);
-        break;
     case CC_OP_ABS_64:
         r =  cc_calc_abs_64(dst);
         break;
@@ -472,9 +443,6 @@ static uint32_t do_calc_cc(CPUS390XState *env, uint32_t cc_op,
     case CC_OP_SUB_32:
         r =  cc_calc_sub_32(src, dst, vr);
         break;
-    case CC_OP_SUBB_32:
-        r =  cc_calc_subb_32(src, dst, vr);
-        break;
     case CC_OP_ABS_32:
         r =  cc_calc_abs_32(dst);
         break;