target/arm: Convert Neon VTBL, VTBX to decodetree

Convert the Neon VTBL, VTBX instructions to decodetree.  The actual
implementation of the insn is copied across to the new trans function
unchanged except for renaming 'tmp5' to 'tmp4'.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

3 files changed, 63 insertions, 37 deletions

diff --git a/target/arm/neon-dp.decode b/target/arm/neon-dp.decode
index 26d6022..91bc770 100644
--- a/target/arm/neon-dp.decode
+++ b/target/arm/neon-dp.decode
@@ -419,6 +419,9 @@ Vimm_1r          1111 001 . 1 . 000 ... .... cmode:4 0 . op:1 1 .... @1reg_imm
     ##################################################################
     VEXT         1111 001 0 1 . 11 .... .... imm:4 . q:1 . 0 .... \
                  vm=%vm_dp vn=%vn_dp vd=%vd_dp
+
+    VTBL         1111 001 1 1 . 11 .... .... 10 len:2 . op:1 . 0 .... \
+                 vm=%vm_dp vn=%vn_dp vd=%vd_dp
   ]
 
   # Subgroup for size != 0b11
diff --git a/target/arm/translate-neon.inc.c b/target/arm/translate-neon.inc.c
index 84bc2b2..da0e5db 100644
--- a/target/arm/translate-neon.inc.c
+++ b/target/arm/translate-neon.inc.c
@@ -2888,3 +2888,59 @@ static bool trans_VEXT(DisasContext *s, arg_VEXT *a)
     }
     return true;
 }
+
+static bool trans_VTBL(DisasContext *s, arg_VTBL *a)
+{
+    int n;
+    TCGv_i32 tmp, tmp2, tmp3, tmp4;
+    TCGv_ptr ptr1;
+
+    if (!arm_dc_feature(s, ARM_FEATURE_NEON)) {
+        return false;
+    }
+
+    /* UNDEF accesses to D16-D31 if they don't exist. */
+    if (!dc_isar_feature(aa32_simd_r32, s) &&
+        ((a->vd | a->vn | a->vm) & 0x10)) {
+        return false;
+    }
+
+    if (!vfp_access_check(s)) {
+        return true;
+    }
+
+    n = a->len + 1;
+    if ((a->vn + n) > 32) {
+        /*
+         * This is UNPREDICTABLE; we choose to UNDEF to avoid the
+         * helper function running off the end of the register file.
+         */
+        return false;
+    }
+    n <<= 3;
+    if (a->op) {
+        tmp = neon_load_reg(a->vd, 0);
+    } else {
+        tmp = tcg_temp_new_i32();
+        tcg_gen_movi_i32(tmp, 0);
+    }
+    tmp2 = neon_load_reg(a->vm, 0);
+    ptr1 = vfp_reg_ptr(true, a->vn);
+    tmp4 = tcg_const_i32(n);
+    gen_helper_neon_tbl(tmp2, tmp2, tmp, ptr1, tmp4);
+    tcg_temp_free_i32(tmp);
+    if (a->op) {
+        tmp = neon_load_reg(a->vd, 1);
+    } else {
+        tmp = tcg_temp_new_i32();
+        tcg_gen_movi_i32(tmp, 0);
+    }
+    tmp3 = neon_load_reg(a->vm, 1);
+    gen_helper_neon_tbl(tmp3, tmp3, tmp, ptr1, tmp4);
+    tcg_temp_free_i32(tmp4);
+    tcg_temp_free_ptr(ptr1);
+    neon_store_reg(a->vd, 0, tmp2);
+    neon_store_reg(a->vd, 1, tmp3);
+    tcg_temp_free_i32(tmp);
+    return true;
+}
diff --git a/target/arm/translate.c b/target/arm/translate.c
index a0822db..0c64259 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -5025,13 +5025,12 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
 {
     int op;
     int q;
-    int rd, rn, rm, rd_ofs, rm_ofs;
+    int rd, rm, rd_ofs, rm_ofs;
     int size;
     int pass;
     int u;
     int vec_size;
-    TCGv_i32 tmp, tmp2, tmp3, tmp5;
-    TCGv_ptr ptr1;
+    TCGv_i32 tmp, tmp2, tmp3;
 
     if (!arm_dc_feature(s, ARM_FEATURE_NEON)) {
         return 1;
@@ -5052,7 +5051,6 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
     q = (insn & (1 << 6)) != 0;
     u = (insn >> 24) & 1;
     VFP_DREG_D(rd, insn);
-    VFP_DREG_N(rn, insn);
     VFP_DREG_M(rm, insn);
     size = (insn >> 20) & 3;
     vec_size = q ? 16 : 8;
@@ -5577,39 +5575,8 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
                     break;
                 }
             } else if ((insn & (1 << 10)) == 0) {
-                /* VTBL, VTBX.  */
-                int n = ((insn >> 8) & 3) + 1;
-                if ((rn + n) > 32) {
-                    /* This is UNPREDICTABLE; we choose to UNDEF to avoid the
-                     * helper function running off the end of the register file.
-                     */
-                    return 1;
-                }
-                n <<= 3;
-                if (insn & (1 << 6)) {
-                    tmp = neon_load_reg(rd, 0);
-                } else {
-                    tmp = tcg_temp_new_i32();
-                    tcg_gen_movi_i32(tmp, 0);
-                }
-                tmp2 = neon_load_reg(rm, 0);
-                ptr1 = vfp_reg_ptr(true, rn);
-                tmp5 = tcg_const_i32(n);
-                gen_helper_neon_tbl(tmp2, tmp2, tmp, ptr1, tmp5);
-                tcg_temp_free_i32(tmp);
-                if (insn & (1 << 6)) {
-                    tmp = neon_load_reg(rd, 1);
-                } else {
-                    tmp = tcg_temp_new_i32();
-                    tcg_gen_movi_i32(tmp, 0);
-                }
-                tmp3 = neon_load_reg(rm, 1);
-                gen_helper_neon_tbl(tmp3, tmp3, tmp, ptr1, tmp5);
-                tcg_temp_free_i32(tmp5);
-                tcg_temp_free_ptr(ptr1);
-                neon_store_reg(rd, 0, tmp2);
-                neon_store_reg(rd, 1, tmp3);
-                tcg_temp_free_i32(tmp);
+                /* VTBL, VTBX: handled by decodetree */
+                return 1;
             } else if ((insn & 0x380) == 0) {
                 /* VDUP */
                 int element;