target/arm: Split out do_neon_ddda

Split out a helper that can handle the 4-register
format for helpers shared with SVE.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210525010358.152808-88-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 38 insertions, 52 deletions

diff --git a/target/arm/translate-neon.c b/target/arm/translate-neon.c
index 9f7a88a..dfa3391 100644
--- a/target/arm/translate-neon.c
+++ b/target/arm/translate-neon.c
@@ -151,6 +151,36 @@ static void neon_store_element64(int reg, int ele, MemOp size, TCGv_i64 var)
     }
 }
 
+static bool do_neon_ddda(DisasContext *s, int q, int vd, int vn, int vm,
+                         int data, gen_helper_gvec_4 *fn_gvec)
+{
+    /* UNDEF accesses to D16-D31 if they don't exist. */
+    if (((vd | vn | vm) & 0x10) && !dc_isar_feature(aa32_simd_r32, s)) {
+        return false;
+    }
+
+    /*
+     * UNDEF accesses to odd registers for each bit of Q.
+     * Q will be 0b111 for all Q-reg instructions, otherwise
+     * when we have mixed Q- and D-reg inputs.
+     */
+    if (((vd & 1) * 4 | (vn & 1) * 2 | (vm & 1)) & q) {
+        return false;
+    }
+
+    if (!vfp_access_check(s)) {
+        return true;
+    }
+
+    int opr_sz = q ? 16 : 8;
+    tcg_gen_gvec_4_ool(vfp_reg_offset(1, vd),
+                       vfp_reg_offset(1, vn),
+                       vfp_reg_offset(1, vm),
+                       vfp_reg_offset(1, vd),
+                       opr_sz, opr_sz, data, fn_gvec);
+    return true;
+}
+
 static bool do_neon_ddda_fpst(DisasContext *s, int q, int vd, int vn, int vm,
                               int data, ARMFPStatusFlavour fp_flavour,
                               gen_helper_gvec_4_ptr *fn_gvec_ptr)
@@ -241,35 +271,13 @@ static bool trans_VCADD(DisasContext *s, arg_VCADD *a)
 
 static bool trans_VDOT(DisasContext *s, arg_VDOT *a)
 {
-    int opr_sz;
-    gen_helper_gvec_4 *fn_gvec;
-
     if (!dc_isar_feature(aa32_dp, s)) {
         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 ((a->vn | a->vm | a->vd) & a->q) {
-        return false;
-    }
-
-    if (!vfp_access_check(s)) {
-        return true;
-    }
-
-    opr_sz = (1 + a->q) * 8;
-    fn_gvec = a->u ? gen_helper_gvec_udot_b : gen_helper_gvec_sdot_b;
-    tcg_gen_gvec_4_ool(vfp_reg_offset(1, a->vd),
-                       vfp_reg_offset(1, a->vn),
-                       vfp_reg_offset(1, a->vm),
-                       vfp_reg_offset(1, a->vd),
-                       opr_sz, opr_sz, 0, fn_gvec);
-    return true;
+    return do_neon_ddda(s, a->q * 7, a->vd, a->vn, a->vm, 0,
+                        a->u
+                        ? gen_helper_gvec_udot_b
+                        : gen_helper_gvec_sdot_b);
 }
 
 static bool trans_VFML(DisasContext *s, arg_VFML *a)
@@ -323,35 +331,13 @@ static bool trans_VCMLA_scalar(DisasContext *s, arg_VCMLA_scalar *a)
 
 static bool trans_VDOT_scalar(DisasContext *s, arg_VDOT_scalar *a)
 {
-    gen_helper_gvec_4 *fn_gvec;
-    int opr_sz;
-
     if (!dc_isar_feature(aa32_dp, s)) {
         return false;
     }
-
-    /* UNDEF accesses to D16-D31 if they don't exist. */
-    if (!dc_isar_feature(aa32_simd_r32, s) &&
-        ((a->vd | a->vn) & 0x10)) {
-        return false;
-    }
-
-    if ((a->vd | a->vn) & a->q) {
-        return false;
-    }
-
-    if (!vfp_access_check(s)) {
-        return true;
-    }
-
-    fn_gvec = a->u ? gen_helper_gvec_udot_idx_b : gen_helper_gvec_sdot_idx_b;
-    opr_sz = (1 + a->q) * 8;
-    tcg_gen_gvec_4_ool(vfp_reg_offset(1, a->vd),
-                       vfp_reg_offset(1, a->vn),
-                       vfp_reg_offset(1, a->vm),
-                       vfp_reg_offset(1, a->vd),
-                       opr_sz, opr_sz, a->index, fn_gvec);
-    return true;
+    return do_neon_ddda(s, a->q * 6, a->vd, a->vn, a->vm, a->index,
+                        a->u
+                        ? gen_helper_gvec_udot_idx_b
+                        : gen_helper_gvec_sdot_idx_b);
 }
 
 static bool trans_VFML_scalar(DisasContext *s, arg_VFML_scalar *a)