target/arm: Add stubs for aa32 decodetree

Add the infrastructure that will become the new decoder.
No instructions adjusted so far.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/Makefile.objs

@@ -28,9 +28,27 @@ target/arm/decode-vfp-uncond.inc.c: $(SRC_PATH)/target/arm/vfp-uncond.decode $(D
 	  $(PYTHON) $(DECODETREE) --static-decode disas_vfp_uncond -o $@ $<,\
 	  "GEN", $(TARGET_DIR)$@)
 
+target/arm/decode-a32.inc.c: $(SRC_PATH)/target/arm/a32.decode $(DECODETREE)
+	$(call quiet-command,\
+	  $(PYTHON) $(DECODETREE) --static-decode disas_a32 -o $@ $<,\
+	  "GEN", $(TARGET_DIR)$@)
+
+target/arm/decode-a32-uncond.inc.c: $(SRC_PATH)/target/arm/a32-uncond.decode $(DECODETREE)
+	$(call quiet-command,\
+	  $(PYTHON) $(DECODETREE) --static-decode disas_a32_uncond -o $@ $<,\
+	  "GEN", $(TARGET_DIR)$@)
+
+target/arm/decode-t32.inc.c: $(SRC_PATH)/target/arm/t32.decode $(DECODETREE)
+	$(call quiet-command,\
+	  $(PYTHON) $(DECODETREE) --static-decode disas_t32 -o $@ $<,\
+	  "GEN", $(TARGET_DIR)$@)
+
 target/arm/translate-sve.o: target/arm/decode-sve.inc.c
 target/arm/translate.o: target/arm/decode-vfp.inc.c
 target/arm/translate.o: target/arm/decode-vfp-uncond.inc.c
+target/arm/translate.o: target/arm/decode-a32.inc.c
+target/arm/translate.o: target/arm/decode-a32-uncond.inc.c
+target/arm/translate.o: target/arm/decode-t32.inc.c
 
 obj-y += tlb_helper.o debug_helper.o
 obj-y += translate.o op_helper.o

target/arm/a32-uncond.decode

@@ -0,0 +1,23 @@
+# A32 unconditional instructions
+#
+#  Copyright (c) 2019 Linaro, Ltd
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, see <http://www.gnu.org/licenses/>.
+
+#
+# This file is processed by scripts/decodetree.py
+#
+# All insns that have 0xf in insn[31:28] are decoded here.
+# All of those that have a COND field in insn[31:28] are in a32.decode
+#

target/arm/a32.decode

@@ -0,0 +1,23 @@
+# A32 conditional instructions
+#
+#  Copyright (c) 2019 Linaro, Ltd
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, see <http://www.gnu.org/licenses/>.
+
+#
+# This file is processed by scripts/decodetree.py
+#
+# All of the insn that have a COND field in insn[31:28] are here.
+# All insns that have 0xf in insn[31:28] are in a32-uncond.decode.
+#

target/arm/t32.decode

@@ -0,0 +1,20 @@
+# Thumb2 instructions
+#
+#  Copyright (c) 2019 Linaro, Ltd
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, see <http://www.gnu.org/licenses/>.
+
+#
+# This file is processed by scripts/decodetree.py
+#

target/arm/translate.c

@@ -7683,6 +7683,18 @@ static void arm_skip_unless(DisasContext *s, uint32_t cond)
     arm_gen_test_cc(cond ^ 1, s->condlabel);
 }
 
+/*
+ * Include the generated decoders.
+ */
+
+#include "decode-a32.inc.c"
+#include "decode-a32-uncond.inc.c"
+#include "decode-t32.inc.c"
+
+/*
+ * Legacy decoder.
+ */
+
 static void disas_arm_insn(DisasContext *s, unsigned int insn)
 {
     unsigned int cond, val, op1, i, shift, rm, rs, rn, rd, sh;
@@ -7701,14 +7713,20 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn)
         return;
     }
     cond = insn >> 28;
-    if (cond == 0xf){
+
+    if (cond == 0xf) {
         /* In ARMv3 and v4 the NV condition is UNPREDICTABLE; we
          * choose to UNDEF. In ARMv5 and above the space is used
          * for miscellaneous unconditional instructions.
          */
         ARCH(5);
 
         /* Unconditional instructions.  */
+        if (disas_a32_uncond(s, insn)) {
+            return;
+        }
+        /* fall back to legacy decoder */
+
         if (((insn >> 25) & 7) == 1) {
             /* NEON Data processing.  */
             if (!arm_dc_feature(s, ARM_FEATURE_NEON)) {
@@ -7923,6 +7941,12 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn)
            next instruction */
         arm_skip_unless(s, cond);
     }
+
+    if (disas_a32(s, insn)) {
+        return;
+    }
+    /* fall back to legacy decoder */
+
     if ((insn & 0x0f900000) == 0x03000000) {
         if ((insn & (1 << 21)) == 0) {
             ARCH(6T2);
@@ -9414,6 +9438,11 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
         ARCH(6T2);
     }
 
+    if (disas_t32(s, insn)) {
+        return;
+    }
+    /* fall back to legacy decoder */
+
     rn = (insn >> 16) & 0xf;
     rs = (insn >> 12) & 0xf;
     rd = (insn >> 8) & 0xf;