[PULL 51/85] target/arm: Convert FCVTXN to decodetree

[Peter Maydell]

From: Richard Henderson <richard.henderson@linaro.org>

Remove handle_2misc_narrow as this was the last insn decoded
by that function.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211163036.2297116-52-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/tcg/a64.decode      |   4 ++
 target/arm/tcg/translate-a64.c | 101 +++++++--------------------------
 2 files changed, 24 insertions(+), 81 deletions(-)

diff --git a/target/arm/tcg/a64.decode b/target/arm/tcg/a64.decode
index 456912cd7ca..d8902dfb226 100644
--- a/target/arm/tcg/a64.decode
+++ b/target/arm/tcg/a64.decode
@@ -74,6 +74,7 @@
 
 @qrr_b          . q:1 ...... .. ...... ...... rn:5 rd:5  &qrr_e esz=0
 @qrr_h          . q:1 ...... .. ...... ...... rn:5 rd:5  &qrr_e esz=1
+@qrr_s          . q:1 ...... .. ...... ...... rn:5 rd:5  &qrr_e esz=2
 @qrr_bh         . q:1 ...... . esz:1 ...... ...... rn:5 rd:5  &qrr_e
 @qrr_hs         . q:1 ...... .. ...... ...... rn:5 rd:5  &qrr_e esz=%esz_hs
 @qrr_e          . q:1 ...... esz:2 ...... ...... rn:5 rd:5  &qrr_e
@@ -1648,6 +1649,8 @@ SQXTUN_s        0111 1110 ..1 00001 00101 0 ..... .....   
  @rr_e
 SQXTN_s         0101 1110 ..1 00001 01001 0 ..... .....     @rr_e
 UQXTN_s         0111 1110 ..1 00001 01001 0 ..... .....     @rr_e
 
+FCVTXN_s        0111 1110 011 00001 01101 0 ..... .....     @rr_s
+
 # Advanced SIMD two-register miscellaneous
 
 SQABS_v         0.00 1110 ..1 00000 01111 0 ..... .....     @qrr_e
@@ -1680,4 +1683,5 @@ SQXTN_v         0.00 1110 ..1 00001 01001 0 ..... .....   
  @qrr_e
 UQXTN_v         0.10 1110 ..1 00001 01001 0 ..... .....     @qrr_e
 
 FCVTN_v         0.00 1110 0.1 00001 01101 0 ..... .....     @qrr_hs
+FCVTXN_v        0.10 1110 011 00001 01101 0 ..... .....     @qrr_s
 BFCVTN_v        0.00 1110 101 00001 01101 0 ..... .....     @qrr_h
diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index d4d19c9caaf..1c454a37f41 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -8975,6 +8975,24 @@ static ArithOneOp * const f_scalar_uqxtn[] = {
 };
 TRANS(UQXTN_s, do_2misc_narrow_scalar, a, f_scalar_uqxtn)
 
+static void gen_fcvtxn_sd(TCGv_i64 d, TCGv_i64 n)
+{
+    /*
+     * 64 bit to 32 bit float conversion
+     * with von Neumann rounding (round to odd)
+     */
+    TCGv_i32 tmp = tcg_temp_new_i32();
+    gen_helper_fcvtx_f64_to_f32(tmp, n, tcg_env);
+    tcg_gen_extu_i32_i64(d, tmp);
+}
+
+static ArithOneOp * const f_scalar_fcvtxn[] = {
+    NULL,
+    NULL,
+    gen_fcvtxn_sd,
+};
+TRANS(FCVTXN_s, do_2misc_narrow_scalar, a, f_scalar_fcvtxn)
+
 #undef WRAP_ENV
 
 static bool do_gvec_fn2(DisasContext *s, arg_qrr_e *a, GVecGen2Fn *fn)
@@ -9078,6 +9096,7 @@ static ArithOneOp * const f_vector_fcvtn[] = {
     gen_fcvtn_sd,
 };
 TRANS(FCVTN_v, do_2misc_narrow_vector, a, f_vector_fcvtn)
+TRANS(FCVTXN_v, do_2misc_narrow_vector, a, f_scalar_fcvtxn)
 
 static void gen_bfcvtn_hs(TCGv_i64 d, TCGv_i64 n)
 {
@@ -9647,68 +9666,6 @@ static void handle_2misc_reciprocal(DisasContext *s, int 
opcode,
     }
 }
 
-static void handle_2misc_narrow(DisasContext *s, bool scalar,
-                                int opcode, bool u, bool is_q,
-                                int size, int rn, int rd)
-{
-    /* Handle 2-reg-misc ops which are narrowing (so each 2*size element
-     * in the source becomes a size element in the destination).
-     */
-    int pass;
-    TCGv_i64 tcg_res[2];
-    int destelt = is_q ? 2 : 0;
-    int passes = scalar ? 1 : 2;
-
-    if (scalar) {
-        tcg_res[1] = tcg_constant_i64(0);
-    }
-
-    for (pass = 0; pass < passes; pass++) {
-        TCGv_i64 tcg_op = tcg_temp_new_i64();
-        NeonGenOne64OpFn *genfn = NULL;
-        NeonGenOne64OpEnvFn *genenvfn = NULL;
-
-        if (scalar) {
-            read_vec_element(s, tcg_op, rn, pass, size + 1);
-        } else {
-            read_vec_element(s, tcg_op, rn, pass, MO_64);
-        }
-        tcg_res[pass] = tcg_temp_new_i64();
-
-        switch (opcode) {
-        case 0x56:  /* FCVTXN, FCVTXN2 */
-            {
-                /*
-                 * 64 bit to 32 bit float conversion
-                 * with von Neumann rounding (round to odd)
-                 */
-                TCGv_i32 tmp = tcg_temp_new_i32();
-                assert(size == 2);
-                gen_helper_fcvtx_f64_to_f32(tmp, tcg_op, tcg_env);
-                tcg_gen_extu_i32_i64(tcg_res[pass], tmp);
-            }
-            break;
-        default:
-        case 0x12: /* XTN, SQXTUN */
-        case 0x14: /* SQXTN, UQXTN */
-        case 0x16: /* FCVTN, FCVTN2 */
-        case 0x36: /* BFCVTN, BFCVTN2 */
-            g_assert_not_reached();
-        }
-
-        if (genfn) {
-            genfn(tcg_res[pass], tcg_op);
-        } else if (genenvfn) {
-            genenvfn(tcg_res[pass], tcg_env, tcg_op);
-        }
-    }
-
-    for (pass = 0; pass < 2; pass++) {
-        write_vec_element(s, tcg_res[pass], rd, destelt + pass, MO_32);
-    }
-    clear_vec_high(s, is_q, rd);
-}
-
 /* AdvSIMD scalar two reg misc
  *  31 30  29 28       24 23  22 21       17 16    12 11 10 9    5 4    0
  * +-----+---+-----------+------+-----------+--------+-----+------+------+
@@ -9780,15 +9737,6 @@ static void disas_simd_scalar_two_reg_misc(DisasContext 
*s, uint32_t insn)
             rmode = FPROUNDING_TIEAWAY;
             break;
         case 0x56: /* FCVTXN, FCVTXN2 */
-            if (size == 2) {
-                unallocated_encoding(s);
-                return;
-            }
-            if (!fp_access_check(s)) {
-                return;
-            }
-            handle_2misc_narrow(s, true, opcode, u, false, size - 1, rn, rd);
-            return;
         default:
             unallocated_encoding(s);
             return;
@@ -10101,16 +10049,6 @@ static void disas_simd_two_reg_misc(DisasContext *s, 
uint32_t insn)
             }
             handle_2misc_reciprocal(s, opcode, false, u, is_q, size, rn, rd);
             return;
-        case 0x56: /* FCVTXN, FCVTXN2 */
-            if (size == 2) {
-                unallocated_encoding(s);
-                return;
-            }
-            if (!fp_access_check(s)) {
-                return;
-            }
-            handle_2misc_narrow(s, false, opcode, 0, is_q, size - 1, rn, rd);
-            return;
         case 0x17: /* FCVTL, FCVTL2 */
             if (!fp_access_check(s)) {
                 return;
@@ -10160,6 +10098,7 @@ static void disas_simd_two_reg_misc(DisasContext *s, 
uint32_t insn)
         default:
         case 0x16: /* FCVTN, FCVTN2 */
         case 0x36: /* BFCVTN, BFCVTN2 */
+        case 0x56: /* FCVTXN, FCVTXN2 */
             unallocated_encoding(s);
             return;
         }
-- 
2.34.1