RISC-V: add Smrnmi 1.0 instruction support

Add instruction `mnret' support

Ref:
https://github.com/riscv/riscv-isa-manual/blob/bb8b9127f81965eeff2d150c211d1c89376591c4/src/rnmi.adoc
https://github.com/riscv/riscv-opcodes/blob/946eb673874b3a0f2474d1424dc28bc7ee53c306/extensions/rv_smrnmi

bfd/ChangeLog:
    * elfxx-riscv.c: Add new Smrnmi instruction class handling

gas/ChangeLog:
    * testsuite/gas/riscv/smrnmi.s: New test for mnret
    * testsuite/gas/riscv/rmrnmi.d: Likewise

include/ChangeLog:
    * opcode/ricsv-opc.h: Add MATCH_MNRET, MASK_MNRET
    * opcode/riscv.h: Add new instruction class

opcodes/ChangeLog:
    * riscv-opc.c: Add `mnret' instruction

Signed-off-by: Jerry Zhang Jian <jerry.zhangjian@sifive.com>

6 files changed, 24 insertions, 0 deletions

diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index 92e024b..ec25491 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -2801,6 +2801,8 @@ riscv_multi_subset_supports (riscv_parse_subset_t *rps,
     case INSN_CLASS_SMCTR_OR_SSCTR:
       return (riscv_subset_supports (rps, "smctr")
 	      || riscv_subset_supports (rps, "ssctr"));
+    case INSN_CLASS_SMRNMI:
+      return riscv_subset_supports (rps, "smrnmi");
     case INSN_CLASS_SVINVAL:
       return riscv_subset_supports (rps, "svinval");
     case INSN_CLASS_H:
@@ -3108,6 +3110,8 @@ riscv_multi_subset_supports_ext (riscv_parse_subset_t *rps,
       return "zcmt";
     case INSN_CLASS_SMCTR_OR_SSCTR:
       return _("smctr' or `ssctr");
+    case INSN_CLASS_SMRNMI:
+      return "smrnmi";
     case INSN_CLASS_SVINVAL:
       return "svinval";
     case INSN_CLASS_H:
diff --git a/gas/testsuite/gas/riscv/smrnmi.d b/gas/testsuite/gas/riscv/smrnmi.d
new file mode 100644
index 0000000..e0659be
--- /dev/null
+++ b/gas/testsuite/gas/riscv/smrnmi.d
@@ -0,0 +1,10 @@
+#as: -march=rv32i_smrnmi
+#source: smrnmi.s
+#objdump: -d
+
+.*:[ 	]+file format .*
+
+Disassembly of section .text:
+
+0+000 <.text>:
+[ 	]+[0-9a-f]+:[ 	]+70200073[ 	]+mnret
diff --git a/gas/testsuite/gas/riscv/smrnmi.s b/gas/testsuite/gas/riscv/smrnmi.s
new file mode 100644
index 0000000..085c10d
--- /dev/null
+++ b/gas/testsuite/gas/riscv/smrnmi.s
@@ -0,0 +1 @@
+    mnret
diff --git a/include/opcode/riscv-opc.h b/include/opcode/riscv-opc.h
index 1f56317..fea4948 100644
--- a/include/opcode/riscv-opc.h
+++ b/include/opcode/riscv-opc.h
@@ -2311,6 +2311,9 @@
 /* Smctr/Ssctr instruction.  */
 #define MATCH_SCTRCLR 0x10400073
 #define MASK_SCTRCLR 0xffffffff
+/* Smrnmi instruction.  */
+#define MATCH_MNRET 0x70200073
+#define MASK_MNRET 0xffffffff
 /* Svinval instruction.  */
 #define MATCH_SINVAL_VMA 0x16000073
 #define MASK_SINVAL_VMA 0xfe007fff
@@ -4808,6 +4811,8 @@ DECLARE_INSN(cm_jt, MATCH_CM_JT, MASK_CM_JT)
 DECLARE_INSN(cm_jalt, MATCH_CM_JALT, MASK_CM_JALT)
 /* Smctr/Ssctr instruction.  */
 DECLARE_INSN(sctrclr, MATCH_SCTRCLR, MASK_SCTRCLR)
+/* Smrnmi instruction */
+DECLARE_INSN(mnret, MATCH_MNRET, MASK_MNRET)
 /* Vendor-specific (T-Head) XTheadBa instructions.  */
 DECLARE_INSN(th_addsl, MATCH_TH_ADDSL, MASK_TH_ADDSL)
 /* Vendor-specific (T-Head) XTheadBb instructions.  */
diff --git a/include/opcode/riscv.h b/include/opcode/riscv.h
index 1f4bede..d76bcdb 100644
--- a/include/opcode/riscv.h
+++ b/include/opcode/riscv.h
@@ -526,6 +526,7 @@ enum riscv_insn_class
   INSN_CLASS_ZCMP,
   INSN_CLASS_ZCMT,
   INSN_CLASS_SMCTR_OR_SSCTR,
+  INSN_CLASS_SMRNMI,
   INSN_CLASS_SVINVAL,
   INSN_CLASS_ZICBOM,
   INSN_CLASS_ZICBOP,
diff --git a/opcodes/riscv-opc.c b/opcodes/riscv-opc.c
index b83dcab..e07f72b 100644
--- a/opcodes/riscv-opc.c
+++ b/opcodes/riscv-opc.c
@@ -2305,6 +2305,9 @@ const struct riscv_opcode riscv_opcodes[] =
 {"hinval.vvma",     0, INSN_CLASS_SVINVAL, "s,t", MATCH_HINVAL_VVMA, MASK_HINVAL_VVMA, match_opcode, 0 },
 {"hinval.gvma",     0, INSN_CLASS_SVINVAL, "s,t", MATCH_HINVAL_GVMA, MASK_HINVAL_GVMA, match_opcode, 0 },
 
+/* Smrnmi instruction */
+{"mnret", 0, INSN_CLASS_SMRNMI, "", MATCH_MNRET, MASK_MNRET, match_opcode, 0 },
+
 /* Hypervisor instructions.  */
 {"hfence.vvma", 0, INSN_CLASS_H, "",       MATCH_HFENCE_VVMA, MASK_HFENCE_VVMA|MASK_RS1|MASK_RS2, match_opcode, INSN_ALIAS },
 {"hfence.vvma", 0, INSN_CLASS_H, "s",      MATCH_HFENCE_VVMA, MASK_HFENCE_VVMA|MASK_RS2, match_opcode, INSN_ALIAS },