Looks like my idea of what a "borrow" is was wrong. We are dealing with
unsigned numbers. A subtraction is simply an addition with the bitwise
complement. If we get a carry during the addition, that's the borrow.
"The operands are treated as unsigned binary integers."
This is nice, as we can reuse the VECTOR ADD COMPUTE CARRY functions
and avoid helpers, all we have to do is compute the bitwise complement.
Fixes: 1ee2d7ba72f6 ("s390x/tcg: Implement VECTOR SUBTRACT COMPUTE BORROW
INDICATION")
Signed-off-by: David Hildenbrand <da...@redhat.com>
---
target/s390x/helper.h | 2 --
target/s390x/translate_vx.inc.c | 45 ++++++++++++++++++++++++---------
target/s390x/vec_int_helper.c | 16 ------------
3 files changed, 33 insertions(+), 30 deletions(-)
diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index 56e8149866..ca1e08100a 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -207,8 +207,6 @@ DEF_HELPER_FLAGS_4(gvec_verim16, TCG_CALL_NO_RWG, void,
ptr, cptr, cptr, i32)
DEF_HELPER_FLAGS_4(gvec_vsl, TCG_CALL_NO_RWG, void, ptr, cptr, i64, i32)
DEF_HELPER_FLAGS_4(gvec_vsra, TCG_CALL_NO_RWG, void, ptr, cptr, i64, i32)
DEF_HELPER_FLAGS_4(gvec_vsrl, TCG_CALL_NO_RWG, void, ptr, cptr, i64, i32)
-DEF_HELPER_FLAGS_4(gvec_vscbi8, TCG_CALL_NO_RWG, void, ptr, cptr, cptr, i32)
-DEF_HELPER_FLAGS_4(gvec_vscbi16, TCG_CALL_NO_RWG, void, ptr, cptr, cptr, i32)
DEF_HELPER_4(gvec_vtm, void, ptr, cptr, env, i32)
/* === Vector String Instructions === */
diff --git a/target/s390x/translate_vx.inc.c b/target/s390x/translate_vx.inc.c
index 5ce7bfb0af..40bcc1604e 100644
--- a/target/s390x/translate_vx.inc.c
+++ b/target/s390x/translate_vx.inc.c
@@ -2130,14 +2130,40 @@ static DisasJumpType op_vs(DisasContext *s, DisasOps *o)
return DISAS_NEXT;
}
+static void gen_scbi8_i64(TCGv_i64 d, TCGv_i64 a, TCGv_i64 b)
+{
+ TCGv_i64 t = tcg_temp_new_i64();
+
+ tcg_gen_not_i64(t, b);
+ gen_acc(d, a, t, ES_8);
+ tcg_temp_free_i64(t);
+}
