target/arm: Convert FCSEL to decodetree

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240528203044.612851-34-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/tcg/a64.decode

@@ -1000,6 +1000,10 @@ SQDMULH_vi      0.00 1111 10 . ..... 1100 . 0 ..... .....   @qrrx_s
 SQRDMULH_vi     0.00 1111 01 .. .... 1101 . 0 ..... .....   @qrrx_h
 SQRDMULH_vi     0.00 1111 10 . ..... 1101 . 0 ..... .....   @qrrx_s
 
+# Floating-point conditional select
+
+FCSEL           0001 1110 .. 1 rm:5 cond:4 11 rn:5 rd:5     esz=%esz_hsd
+
 # Floating-point data-processing (3 source)
 
 @rrrr_hsd       .... .... .. . rm:5  . ra:5  rn:5  rd:5     &rrrr_e esz=%esz_hsd

target/arm/tcg/translate-a64.c

@@ -5866,6 +5866,50 @@ static bool trans_ADDP_s(DisasContext *s, arg_rr_e *a)
     return true;
 }
 
+/*
+ * Floating-point conditional select
+ */
+
+static bool trans_FCSEL(DisasContext *s, arg_FCSEL *a)
+{
+    TCGv_i64 t_true, t_false;
+    DisasCompare64 c;
+
+    switch (a->esz) {
+    case MO_32:
+    case MO_64:
+        break;
+    case MO_16:
+        if (!dc_isar_feature(aa64_fp16, s)) {
+            return false;
+        }
+        break;
+    default:
+        return false;
+    }
+
+    if (!fp_access_check(s)) {
+        return true;
+    }
+
+    /* Zero extend sreg & hreg inputs to 64 bits now.  */
+    t_true = tcg_temp_new_i64();
+    t_false = tcg_temp_new_i64();
+    read_vec_element(s, t_true, a->rn, 0, a->esz);
+    read_vec_element(s, t_false, a->rm, 0, a->esz);
+
+    a64_test_cc(&c, a->cond);
+    tcg_gen_movcond_i64(c.cond, t_true, c.value, tcg_constant_i64(0),
+                        t_true, t_false);
+
+    /*
+     * Note that sregs & hregs write back zeros to the high bits,
+     * and we've already done the zero-extension.
+     */
+    write_fp_dreg(s, a->rd, t_true);
+    return true;
+}
+
 /*
  * Floating-point data-processing (3 source)
  */
@@ -7332,68 +7376,6 @@ static void disas_fp_ccomp(DisasContext *s, uint32_t insn)
     }
 }
 
-/* Floating point conditional select
- *   31  30  29 28       24 23  22  21 20  16 15  12 11 10 9    5 4    0
- * +---+---+---+-----------+------+---+------+------+-----+------+------+
- * | M | 0 | S | 1 1 1 1 0 | type | 1 |  Rm  | cond | 1 1 |  Rn  |  Rd  |
- * +---+---+---+-----------+------+---+------+------+-----+------+------+
- */
-static void disas_fp_csel(DisasContext *s, uint32_t insn)
-{
-    unsigned int mos, type, rm, cond, rn, rd;
-    TCGv_i64 t_true, t_false;
-    DisasCompare64 c;
-    MemOp sz;
-
-    mos = extract32(insn, 29, 3);
-    type = extract32(insn, 22, 2);
-    rm = extract32(insn, 16, 5);
-    cond = extract32(insn, 12, 4);
-    rn = extract32(insn, 5, 5);
-    rd = extract32(insn, 0, 5);
-
-    if (mos) {
-        unallocated_encoding(s);
-        return;
-    }
-
-    switch (type) {
-    case 0:
-        sz = MO_32;
-        break;
-    case 1:
-        sz = MO_64;
-        break;
-    case 3:
-        sz = MO_16;
-        if (dc_isar_feature(aa64_fp16, s)) {
-            break;
-        }
-        /* fallthru */
-    default:
-        unallocated_encoding(s);
-        return;
-    }
-
-    if (!fp_access_check(s)) {
-        return;
-    }
-
-    /* Zero extend sreg & hreg inputs to 64 bits now.  */
-    t_true = tcg_temp_new_i64();
-    t_false = tcg_temp_new_i64();
-    read_vec_element(s, t_true, rn, 0, sz);
-    read_vec_element(s, t_false, rm, 0, sz);
-
-    a64_test_cc(&c, cond);
-    tcg_gen_movcond_i64(c.cond, t_true, c.value, tcg_constant_i64(0),
-                        t_true, t_false);
-
-    /* Note that sregs & hregs write back zeros to the high bits,
-       and we've already done the zero-extension.  */
-    write_fp_dreg(s, rd, t_true);
-}
-
 /* Floating-point data-processing (1 source) - half precision */
 static void handle_fp_1src_half(DisasContext *s, int opcode, int rd, int rn)
 {
@@ -8207,7 +8189,7 @@ static void disas_data_proc_fp(DisasContext *s, uint32_t insn)
             break;
         case 3:
             /* Floating point conditional select */
-            disas_fp_csel(s, insn);
+            unallocated_encoding(s); /* in decodetree */
             break;
         case 0:
             switch (ctz32(extract32(insn, 12, 4))) {