target/arm: Convert VSUB to decodetree

Convert the VSUB instruction to decodetree.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>

target/arm/translate-vfp.inc.c

@@ -1461,3 +1461,13 @@ static bool trans_VADD_dp(DisasContext *s, arg_VADD_sp *a)
 {
     return do_vfp_3op_dp(s, gen_helper_vfp_addd, a->vd, a->vn, a->vm, false);
 }
+
+static bool trans_VSUB_sp(DisasContext *s, arg_VSUB_sp *a)
+{
+    return do_vfp_3op_sp(s, gen_helper_vfp_subs, a->vd, a->vn, a->vm, false);
+}
+
+static bool trans_VSUB_dp(DisasContext *s, arg_VSUB_sp *a)
+{
+    return do_vfp_3op_dp(s, gen_helper_vfp_subd, a->vd, a->vn, a->vm, false);
+}

target/arm/translate.c

@@ -1386,7 +1386,6 @@ static inline void gen_vfp_##name(int dp)                             \
     tcg_temp_free_ptr(fpst);                                          \
 }
 
-VFP_OP2(sub)
 VFP_OP2(div)
 
 #undef VFP_OP2
@@ -3110,7 +3109,7 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn)
             rn = VFP_SREG_N(insn);
 
             switch (op) {
-            case 0 ... 6:
+            case 0 ... 7:
                 /* Already handled by decodetree */
                 return 1;
             default:
@@ -3296,9 +3295,6 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn)
             for (;;) {
                 /* Perform the calculation.  */
                 switch (op) {
-                case 7: /* sub: fn - fm */
-                    gen_vfp_sub(dp);
-                    break;
                 case 8: /* div: fn / fm */
                     gen_vfp_div(dp);
                     break;

target/arm/vfp.decode

@@ -132,3 +132,8 @@ VADD_sp      ---- 1110 0.11 .... .... 1010 .0.0 .... \
              vm=%vm_sp vn=%vn_sp vd=%vd_sp
 VADD_dp      ---- 1110 0.11 .... .... 1011 .0.0 .... \
              vm=%vm_dp vn=%vn_dp vd=%vd_dp
+
+VSUB_sp      ---- 1110 0.11 .... .... 1010 .1.0 .... \
+             vm=%vm_sp vn=%vn_sp vd=%vd_sp
+VSUB_dp      ---- 1110 0.11 .... .... 1011 .1.0 .... \
+             vm=%vm_dp vn=%vn_dp vd=%vd_dp