target/arm: Split out do_neon_ddda_fpst

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

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210525010358.152808-85-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/translate-neon.c

@@ -151,45 +151,56 @@ static void neon_store_element64(int reg, int ele, MemOp size, TCGv_i64 var)
     }
 }
 
-static bool trans_VCMLA(DisasContext *s, arg_VCMLA *a)
+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)
 {
-    int opr_sz;
-    TCGv_ptr fpst;
-    gen_helper_gvec_4_ptr *fn_gvec_ptr;
-
-    if (!dc_isar_feature(aa32_vcma, s)
-        || (a->size == MO_16 && !dc_isar_feature(aa32_fp16_arith, 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)) {
+    if (((vd | vn | vm) & 0x10) && !dc_isar_feature(aa32_simd_r32, s)) {
         return false;
     }
 
-    if ((a->vn | a->vm | a->vd) & a->q) {
+    /*
+     * 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;
     }
 
-    opr_sz = (1 + a->q) * 8;
-    fpst = fpstatus_ptr(a->size == MO_16 ? FPST_STD_F16 : FPST_STD);
-    fn_gvec_ptr = (a->size == MO_16) ?
-        gen_helper_gvec_fcmlah : gen_helper_gvec_fcmlas;
-    tcg_gen_gvec_4_ptr(vfp_reg_offset(1, a->vd),
-                       vfp_reg_offset(1, a->vn),
-                       vfp_reg_offset(1, a->vm),
-                       vfp_reg_offset(1, a->vd),
-                       fpst, opr_sz, opr_sz, a->rot,
-                       fn_gvec_ptr);
+    int opr_sz = q ? 16 : 8;
+    TCGv_ptr fpst = fpstatus_ptr(fp_flavour);
+
+    tcg_gen_gvec_4_ptr(vfp_reg_offset(1, vd),
+                       vfp_reg_offset(1, vn),
+                       vfp_reg_offset(1, vm),
+                       vfp_reg_offset(1, vd),
+                       fpst, opr_sz, opr_sz, data, fn_gvec_ptr);
     tcg_temp_free_ptr(fpst);
     return true;
 }
 
+static bool trans_VCMLA(DisasContext *s, arg_VCMLA *a)
+{
+    if (!dc_isar_feature(aa32_vcma, s)) {
+        return false;
+    }
+    if (a->size == MO_16) {
+        if (!dc_isar_feature(aa32_fp16_arith, s)) {
+            return false;
+        }
+        return do_neon_ddda_fpst(s, a->q * 7, a->vd, a->vn, a->vm, a->rot,
+                                 FPST_STD_F16, gen_helper_gvec_fcmlah);
+    }
+    return do_neon_ddda_fpst(s, a->q * 7, a->vd, a->vn, a->vm, a->rot,
+                             FPST_STD, gen_helper_gvec_fcmlas);
+}
+
 static bool trans_VCADD(DisasContext *s, arg_VCADD *a)
 {
     int opr_sz;
@@ -294,43 +305,20 @@ static bool trans_VFML(DisasContext *s, arg_VFML *a)
 
 static bool trans_VCMLA_scalar(DisasContext *s, arg_VCMLA_scalar *a)
 {
-    gen_helper_gvec_4_ptr *fn_gvec_ptr;
-    int opr_sz;
-    TCGv_ptr fpst;
+    int data = (a->index << 2) | a->rot;
 
     if (!dc_isar_feature(aa32_vcma, s)) {
         return false;
     }
-    if (a->size == MO_16 && !dc_isar_feature(aa32_fp16_arith, 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->vd | a->vn) & a->q) {
-        return false;
-    }
-
-    if (!vfp_access_check(s)) {
-        return true;
+    if (a->size == MO_16) {
+        if (!dc_isar_feature(aa32_fp16_arith, s)) {
+            return false;
+        }
+        return do_neon_ddda_fpst(s, a->q * 6, a->vd, a->vn, a->vm, data,
+                                 FPST_STD_F16, gen_helper_gvec_fcmlah_idx);
     }
-
-    fn_gvec_ptr = (a->size == MO_16) ?
-        gen_helper_gvec_fcmlah_idx : gen_helper_gvec_fcmlas_idx;
-    opr_sz = (1 + a->q) * 8;
-    fpst = fpstatus_ptr(a->size == MO_16 ? FPST_STD_F16 : FPST_STD);
-    tcg_gen_gvec_4_ptr(vfp_reg_offset(1, a->vd),
-                       vfp_reg_offset(1, a->vn),
-                       vfp_reg_offset(1, a->vm),
-                       vfp_reg_offset(1, a->vd),
-                       fpst, opr_sz, opr_sz,
-                       (a->index << 2) | a->rot, fn_gvec_ptr);
-    tcg_temp_free_ptr(fpst);
-    return true;
+    return do_neon_ddda_fpst(s, a->q * 6, a->vd, a->vn, a->vm, data,
+                             FPST_STD, gen_helper_gvec_fcmlas_idx);
 }
 
 static bool trans_VDOT_scalar(DisasContext *s, arg_VDOT_scalar *a)