[PATCH v2 2/6] target/mips: Introduce decode tree bindings for nanoMIPS ISA

[Philippe Mathieu-Daudé]

From: Philippe Mathieu-Daudé <f4...@amsat.org>

Introduce the nanoMIPS decodetree configs for the 16-bit
and 32-bit instructions.

Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org>
Reviewed-by: Aleksandar Rikalo <arik...@gmail.com>
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
---
 target/mips/tcg/translate.h              |  2 ++
 target/mips/tcg/nanomips16.decode        |  8 ++++++++
 target/mips/tcg/nanomips32.decode        |  8 ++++++++
 target/mips/tcg/nanomips_translate.c     | 14 ++++++++++++++
 target/mips/tcg/nanomips_translate.c.inc |  7 +++++++
 target/mips/tcg/meson.build              |  3 +++
 6 files changed, 42 insertions(+)
 create mode 100644 target/mips/tcg/nanomips16.decode
 create mode 100644 target/mips/tcg/nanomips32.decode
 create mode 100644 target/mips/tcg/nanomips_translate.c

diff --git a/target/mips/tcg/translate.h b/target/mips/tcg/translate.h
index 816453f2be..a91c003f96 100644
--- a/target/mips/tcg/translate.h
+++ b/target/mips/tcg/translate.h
@@ -224,6 +224,8 @@ bool decode_64bit_enabled(DisasContext *ctx);
 /* decodetree generated */
 bool decode_isa_micromips16(DisasContext *ctx, uint16_t insn);
 bool decode_isa_micromips32(DisasContext *ctx, uint32_t insn);
+bool decode_isa_nanomips16(DisasContext *ctx, uint16_t insn);
+bool decode_isa_nanomips32(DisasContext *ctx, uint32_t insn);
 bool decode_isa_rel6(DisasContext *ctx, uint32_t insn);
 bool decode_ase_msa(DisasContext *ctx, uint32_t insn);
 bool decode_ext_txx9(DisasContext *ctx, uint32_t insn);
diff --git a/target/mips/tcg/nanomips16.decode 
b/target/mips/tcg/nanomips16.decode
new file mode 100644
index 0000000000..81fdc68e98
--- /dev/null
+++ b/target/mips/tcg/nanomips16.decode
@@ -0,0 +1,8 @@
+# nanoMIPS32 16-bit instruction set extensions
+#
+# Copyright (C) 2021  Philippe Mathieu-Daudé
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# Reference: nanoMIPS32 Instruction Set Technical Reference Manual
+#            (Document Number: MD01247)
diff --git a/target/mips/tcg/nanomips32.decode 
b/target/mips/tcg/nanomips32.decode
new file mode 100644
index 0000000000..9cecf1e13d
--- /dev/null
+++ b/target/mips/tcg/nanomips32.decode
@@ -0,0 +1,8 @@
+# nanoMIPS32 32-bit instruction set extensions
+#
+# Copyright (C) 2021  Philippe Mathieu-Daudé
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# Reference: nanoMIPS32 Instruction Set Technical Reference Manual
+#            (Document Number: MD01247)
diff --git a/target/mips/tcg/nanomips_translate.c 
b/target/mips/tcg/nanomips_translate.c
new file mode 100644
index 0000000000..c148c13ed9
--- /dev/null
+++ b/target/mips/tcg/nanomips_translate.c
@@ -0,0 +1,14 @@
+/*
+ * MIPS emulation for QEMU - nanoMIPS translation routines
+ *
+ * Copyright (c) 2021 Philippe Mathieu-Daudé <f4...@amsat.org>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "translate.h"
+
+/* Include the auto-generated decoders.  */
+#include "decode-nanomips16.c.inc"
+#include "decode-nanomips32.c.inc"
diff --git a/target/mips/tcg/nanomips_translate.c.inc 
b/target/mips/tcg/nanomips_translate.c.inc
index 1e274143bb..e401b92bfd 100644
--- a/target/mips/tcg/nanomips_translate.c.inc
+++ b/target/mips/tcg/nanomips_translate.c.inc
@@ -4482,6 +4482,13 @@ static int decode_isa_nanomips(CPUMIPSState *env, 
DisasContext *ctx)
         return 2;
     }
 
+    if (decode_isa_nanomips16(ctx, ctx->opcode)) {
+        return 2;
+    }
+    if (decode_isa_nanomips32(ctx, ctx->opcode)) {
+        return 4;
+    }
+
     op = extract32(ctx->opcode, 10, 6);
     switch (op) {
     case NM_P16_MV:
diff --git a/target/mips/tcg/meson.build b/target/mips/tcg/meson.build
index 5db5681eb1..f815174ed1 100644
--- a/target/mips/tcg/meson.build
+++ b/target/mips/tcg/meson.build
@@ -2,6 +2,8 @@ gen = [
   decodetree.process('micromips16.decode', extra_args: 
['--decode=decode_isa_micromips16', '--insnwidth=16']),
   decodetree.process('micromips32.decode', extra_args: 
['--decode=decode_isa_micromips32']),
   decodetree.process('rel6.decode', extra_args: ['--decode=decode_isa_rel6']),
+  decodetree.process('nanomips16.decode', extra_args: 
['--decode=decode_isa_nanomips16', '--insnwidth=16']),
+  decodetree.process('nanomips32.decode', extra_args: 
['--decode=decode_isa_nanomips32']),
   decodetree.process('msa.decode', extra_args: '--decode=decode_ase_msa'),
   decodetree.process('tx79.decode', extra_args: '--static-decode=decode_tx79'),
   decodetree.process('vr54xx.decode', extra_args: 
'--decode=decode_ext_vr54xx'),
@@ -21,6 +23,7 @@ mips_ss.add(files(
   'micromips_translate.c',
   'msa_helper.c',
   'msa_translate.c',
+  'nanomips_translate.c',
   'op_helper.c',
   'rel6_translate.c',
   'translate.c',
-- 
2.45.2