Hi Richard,
On 5/12/24 17:08, Richard Henderson wrote:
On 5/12/24 11:38, Chinmay Rath wrote:
@@ -2934,6 +2870,184 @@ static bool do_vx_vaddsubcuw(DisasContext
*ctx, arg_VX *a, int add)
return true;
}
+static inline void do_vadd_vsub_sat
+(
+ unsigned vece, TCGv_vec t, TCGv_vec sat, TCGv_vec a, TCGv_vec b,
+ void (*norm_op)(unsigned, TCGv_vec, TCGv_vec, TCGv_vec),
+ void (*sat_op)(unsigned, TCGv_vec, TCGv_vec, TCGv_vec))
+{
+ TCGv_vec x = tcg_temp_new_vec_matching(t);
+ norm_op(vece, x, a, b);
+ sat_op(vece, t, a, b);
+ tcg_gen_cmp_vec(TCG_COND_NE, vece, x, x, t);
+ tcg_gen_or_vec(vece, sat, sat, x);
+}
As a separate change, before or after, the cmp_vec may be simplified
to xor_vec. Which means that INDEX_op_cmp_vec need not be probed in
the vecop_lists. See
https://lore.kernel.org/qemu-devel/20240506010403.6204-31-richard.hender...@linaro.org/
which is performing the same operation on AArch64.
Noted ! Will do.
+static bool do_vx_vadd_vsub_sat(DisasContext *ctx, arg_VX *a,
+ int sign, int vece, int add)
+{
+ static const TCGOpcode vecop_list_sub_u[] = {
+ INDEX_op_sub_vec, INDEX_op_ussub_vec, INDEX_op_cmp_vec, 0
+ };
+ static const TCGOpcode vecop_list_sub_s[] = {
+ INDEX_op_sub_vec, INDEX_op_sssub_vec, INDEX_op_cmp_vec, 0
+ };
+ static const TCGOpcode vecop_list_add_u[] = {
+ INDEX_op_add_vec, INDEX_op_usadd_vec, INDEX_op_cmp_vec, 0
+ };
+ static const TCGOpcode vecop_list_add_s[] = {
+ INDEX_op_add_vec, INDEX_op_ssadd_vec, INDEX_op_cmp_vec, 0
+ };
+
+ static const GVecGen4 op[2][3][2] = {
+ {
+ {
+ {
+ .fniv = gen_vsub_sat_u,
+ .fno = gen_helper_VSUBUBS,
+ .opt_opc = vecop_list_sub_u,
+ .write_aofs = true,
+ .vece = MO_8
+ },
.
.
.
+ {
+ .fniv = gen_vadd_sat_s,
+ .fno = gen_helper_VADDSWS,
+ .opt_opc = vecop_list_add_s,
+ .write_aofs = true,
+ .vece = MO_32
+ },
+ },
+ },
+ };
While this table is not wrong, I think it is clearer to have separate
tables, one per operation, which are then passed in to a common expander.
+
+ REQUIRE_INSNS_FLAGS(ctx, ALTIVEC);
+ REQUIRE_VECTOR(ctx);
+
+ tcg_gen_gvec_4(avr_full_offset(a->vrt), offsetof(CPUPPCState,
vscr_sat),
+ avr_full_offset(a->vra), avr_full_offset(a->vrb),
16, 16,
+ &op[sign][vece][add]);
+
+ return true;
+}
+
+TRANS(VSUBUBS, do_vx_vadd_vsub_sat, 0, MO_8, 0)
I think it is clearer to use TRANS_FLAGS than to sink the ISA check
into the helper. In general I seem to find the helper later gets
reused for something else with a different ISA check.
Thus
static const TCGOpcode vecop_list_vsub_sat_u[] = {
INDEX_op_sub_vec, INDEX_op_ussub_vec, 0
};
static const GVecGen4 op_vsububs = {
.fno = gen_helper_VSUBUBS,
.fniv = gen_vsub_sat_u,
.opt_opc = vecop_list_vsub_sat_u,
.write_aofs = true,
.vece = MO_8
};
TRANS_FLAGS(VSUBUBS, do_vx_vadd_vsub_sat, &op_vsububs)
static const GVecGen4 op_vsubuhs = {
.fno = gen_helper_VSUBUHS,
.fniv = gen_vsub_sat_u,
.opt_opc = vecop_list_vsub_sat_u,
.write_aofs = true,
.vece = MO_16
};
TRANS_FLAGS(VSUBUHS, do_vx_vadd_vsub_sat, &op_vsubuhs)
etc.
Will add those changes in v2.
-GEN_VXFORM_DUAL(vaddubs, vmul10uq, 0, 8, PPC_ALTIVEC, PPC_NONE),
You are correct in your cover letter that this is not right.
We should have been testing ISA300 for vmul10uq here.
Thank you very much for the clarification !
+GEN_VXFORM(vmul10euq, 0, 9),
And thus need GEN_VXFORM_300 here.
+GEN_VXFORM(vmul10euq, 0, 9),
+GEN_VXFORM(bcdcpsgn, 0, 13),
+GEN_VXFORM(bcdadd, 0, 24),
+GEN_VXFORM(bcdsub, 0, 25),
...
+GEN_VXFORM(xpnd04_2, 0, 30),
None of these are in the base ISA, so all need a flag check.
r~
Thanks & Regards,
Chinmay
