[PULL 16/23] target/arm: Convert Neon VTBL, VTBX to decodetree

[Peter Maydell <peter.maydell@linaro.org>]

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>
---
 target/arm/neon-dp.decode       |  3 ++
 target/arm/translate-neon.inc.c | 56 +++++++++++++++++++++++++++++++++
 target/arm/translate.c          | 41 +++---------------------
 3 files changed, 63 insertions(+), 37 deletions(-)

diff --git a/target/arm/neon-dp.decode b/target/arm/neon-dp.decode
index 26d60220168..91bc770dfbc 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 84bc2b239ca..da0e5dbc6fd 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 a0822dba5e2..0c6425928f6 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;
-- 
2.20.1