| Message ID | 20191021085715.3797-7-david@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | s390x/tcg: Vector instruction fixes | expand |
On 10/21/19 1:57 AM, David Hildenbrand wrote: > The numbers are unsigned, the computation is wrong. "Each operand is > treated as an unsigned binary integer". > Let's implement as given in the PoP: > > "A subtraction is performed by adding the contents of the second operand > with the bitwise complement of the third operand along with a borrow > indication from the rightmost bit of the fourth operand." > > Reuse gen_accc2_i64(). > > Fixes: bc725e65152c ("s390x/tcg: Implement VECTOR SUBTRACT WITH BORROW COMPUTE BORROW INDICATION") > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > target/s390x/translate_vx.inc.c | 13 +++---------- > 1 file changed, 3 insertions(+), 10 deletions(-) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/target/s390x/translate_vx.inc.c b/target/s390x/translate_vx.inc.c index fd746ba35f..71059f9ca0 100644 --- a/target/s390x/translate_vx.inc.c +++ b/target/s390x/translate_vx.inc.c @@ -2214,20 +2214,13 @@ static void gen_sbcbi2_i64(TCGv_i64 dl, TCGv_i64 dh, TCGv_i64 al, TCGv_i64 ah, { TCGv_i64 th = tcg_temp_new_i64(); TCGv_i64 tl = tcg_temp_new_i64(); - TCGv_i64 zero = tcg_const_i64(0); - tcg_gen_andi_i64(tl, cl, 1); - tcg_gen_sub2_i64(tl, th, al, zero, tl, zero); - tcg_gen_sub2_i64(tl, th, tl, th, bl, zero); - tcg_gen_andi_i64(th, th, 1); - tcg_gen_sub2_i64(tl, th, ah, zero, th, zero); - tcg_gen_sub2_i64(tl, th, tl, th, bh, zero); - tcg_gen_andi_i64(dl, th, 1); - tcg_gen_mov_i64(dh, zero); + tcg_gen_not_i64(tl, bl); + tcg_gen_not_i64(th, bh); + gen_accc2_i64(dl, dh, al, ah, tl, th, cl, ch); tcg_temp_free_i64(tl); tcg_temp_free_i64(th); - tcg_temp_free_i64(zero); } static DisasJumpType op_vsbcbi(DisasContext *s, DisasOps *o)
The numbers are unsigned, the computation is wrong. "Each operand is treated as an unsigned binary integer". Let's implement as given in the PoP: "A subtraction is performed by adding the contents of the second operand with the bitwise complement of the third operand along with a borrow indication from the rightmost bit of the fourth operand." Reuse gen_accc2_i64(). Fixes: bc725e65152c ("s390x/tcg: Implement VECTOR SUBTRACT WITH BORROW COMPUTE BORROW INDICATION") Signed-off-by: David Hildenbrand <david@redhat.com> --- target/s390x/translate_vx.inc.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-)