target/mips: Introduce decode tree bindings for MSA ASE

Introduce the 'msa32' decodetree config for the 32-bit MSA ASE.

We start by decoding:
- the branch instructions,
- all instructions based on the MSA opcode.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20201215225757.764263-20-f4bug@amsat.org>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Tested-by: Jiaxun Yang <jiaxun.yang@flygoat.com>

target/mips/meson.build

@@ -1,4 +1,9 @@
+gen = [
+  decodetree.process('msa32.decode', extra_args: '--static-decode=decode_msa32'),
+]
+
 mips_ss = ss.source_set()
+mips_ss.add(gen)
 mips_ss.add(files(
   'cpu.c',
   'gdbstub.c',

target/mips/msa32.decode

@@ -0,0 +1,24 @@
+# MIPS SIMD Architecture Module instruction set
+#
+# Copyright (C) 2020  Philippe Mathieu-Daudé
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# Reference:
+#       MIPS Architecture for Programmers Volume IV-j
+#       The MIPS32 SIMD Architecture Module, Revision 1.12
+#       (Document Number: MD00866-2B-MSA32-AFP-01.12)
+#
+
+&msa_bz             df wt s16
+
+@bz                 ...... ... ..   wt:5 s16:16             &msa_bz df=3
+@bz_df              ...... ... df:2 wt:5 s16:16             &msa_bz
+
+BZ_V                010001 01011  ..... ................    @bz
+BNZ_V               010001 01111  ..... ................    @bz
+
+BZ_x                010001 110 .. ..... ................    @bz_df
+BNZ_x               010001 111 .. ..... ................    @bz_df
+
+MSA                 011110 --------------------------

target/mips/msa_translate.c

@@ -6,6 +6,7 @@
  *  Copyright (c) 2006 Thiemo Seufer (MIPS32R2 support)
  *  Copyright (c) 2009 CodeSourcery (MIPS16 and microMIPS support)
  *  Copyright (c) 2012 Jia Liu & Dongxue Zhang (MIPS ASE DSP support)
+ *  Copyright (c) 2020 Philippe Mathieu-Daudé
  *
  * SPDX-License-Identifier: LGPL-2.1-or-later
  */
@@ -16,6 +17,9 @@
 #include "fpu_helper.h"
 #include "internal.h"
 
+/* Include the auto-generated decoder.  */
+#include "decode-msa32.c.inc"
+
 #define OPC_MSA (0x1E << 26)
 
 #define MASK_MSA_MINOR(op)          (MASK_OP_MAJOR(op) | (op & 0x3F))
@@ -370,6 +374,16 @@ static bool gen_msa_BxZ_V(DisasContext *ctx, int wt, int s16, TCGCond cond)
     return true;
 }
 
+static bool trans_BZ_V(DisasContext *ctx, arg_msa_bz *a)
+{
+    return gen_msa_BxZ_V(ctx, a->wt, a->s16, TCG_COND_EQ);
+}
+
+static bool trans_BNZ_V(DisasContext *ctx, arg_msa_bz *a)
+{
+    return gen_msa_BxZ_V(ctx, a->wt, a->s16, TCG_COND_NE);
+}
+
 static bool gen_msa_BxZ(DisasContext *ctx, int df, int wt, int s16, bool if_not)
 {
     check_msa_access(ctx);
@@ -388,6 +402,16 @@ static bool gen_msa_BxZ(DisasContext *ctx, int df, int wt, int s16, bool if_not)
     return true;
 }
 
+static bool trans_BZ_x(DisasContext *ctx, arg_msa_bz *a)
+{
+    return gen_msa_BxZ(ctx, a->df, a->wt, a->s16, false);
+}
+
+static bool trans_BNZ_x(DisasContext *ctx, arg_msa_bz *a)
+{
+    return gen_msa_BxZ(ctx, a->df, a->wt, a->s16, true);
+}
+
 void gen_msa_branch(DisasContext *ctx, uint32_t op1)
 {
     uint8_t df = (ctx->opcode >> 21) & 0x3;
@@ -2261,3 +2285,15 @@ void gen_msa(DisasContext *ctx)
         break;
     }
 }
+
+static bool trans_MSA(DisasContext *ctx, arg_MSA *a)
+{
+    gen_msa(ctx);
+
+    return true;
+}
+
+bool decode_ase_msa(DisasContext *ctx, uint32_t insn)
+{
+    return decode_msa32(ctx, insn);
+}

target/mips/translate.h

@@ -177,4 +177,7 @@ void msa_translate_init(void);
 void gen_msa(DisasContext *ctx);
 void gen_msa_branch(DisasContext *ctx, uint32_t op1);
 
+/* decodetree generated */
+bool decode_ase_msa(DisasContext *ctx, uint32_t insn);
+
 #endif