RISC-V: Add T-Head MAC vendor extension

T-Head has a range of vendor-specific instructions.
Therefore it makes sense to group them into smaller chunks
in form of vendor extensions.

This patch adds the XTheadMac extension, a collection of
T-Head-specific multiply-accumulate instructions.
The 'th' prefix and the "XTheadMac" extension are documented
in a PR for the RISC-V toolchain conventions ([1]).

[1] https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/19

Co-developed-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>

7 files changed, 61 insertions, 0 deletions

diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index e96b987..41f7849 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -1229,6 +1229,7 @@ static struct riscv_supported_ext riscv_supported_vendor_x_ext[] =
   {"xtheadbs",		ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
   {"xtheadcmo",		ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
   {"xtheadcondmov",	ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
+  {"xtheadmac",		ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
   {"xtheadsync",	ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
   {NULL, 0, 0, 0, 0}
 };
@@ -2402,6 +2403,8 @@ riscv_multi_subset_supports (riscv_parse_subset_t *rps,
       return riscv_subset_supports (rps, "xtheadcmo");
     case INSN_CLASS_XTHEADCONDMOV:
       return riscv_subset_supports (rps, "xtheadcondmov");
+    case INSN_CLASS_XTHEADMAC:
+      return riscv_subset_supports (rps, "xtheadmac");
     case INSN_CLASS_XTHEADSYNC:
       return riscv_subset_supports (rps, "xtheadsync");
     default:
@@ -2541,6 +2544,8 @@ riscv_multi_subset_supports_ext (riscv_parse_subset_t *rps,
       return "xtheadcmo";
     case INSN_CLASS_XTHEADCONDMOV:
       return "xtheadcondmov";
+    case INSN_CLASS_XTHEADMAC:
+      return "xtheadmac";
     case INSN_CLASS_XTHEADSYNC:
       return "xtheadsync";
     default:
diff --git a/gas/doc/c-riscv.texi b/gas/doc/c-riscv.texi
index b1462ce..401f7e4 100644
--- a/gas/doc/c-riscv.texi
+++ b/gas/doc/c-riscv.texi
@@ -729,6 +729,11 @@ The XTheadCondMov extension provides instructions for conditional moves.
 
 It is documented in @url{https://github.com/T-head-Semi/thead-extension-spec/releases/download/2.0.0/xthead-2022-09-05-2.0.0.pdf}.
 
+@item XTheadMac
+The XTheadMac extension provides multiply-accumulate instructions.
+
+It is documented in @url{https://github.com/T-head-Semi/thead-extension-spec/releases/download/2.0.0/xthead-2022-09-05-2.0.0.pdf}.
+
 @item XTheadSync
 The XTheadSync extension provides instructions for multi-processor synchronization.
 
diff --git a/gas/testsuite/gas/riscv/x-thead-mac.d b/gas/testsuite/gas/riscv/x-thead-mac.d
new file mode 100644
index 0000000..3f8e654
--- /dev/null
+++ b/gas/testsuite/gas/riscv/x-thead-mac.d
@@ -0,0 +1,15 @@
+#as: -march=rv64i_xtheadmac
+#source: x-thead-mac.s
+#objdump: -dr
+
+.*:[ 	]+file format .*
+
+Disassembly of section .text:
+
+0+000 <target>:
+[ 	]+[0-9a-f]+:[ 	]+20c5950b[ 	]+th.mula[ 	]+a0,a1,a2
+[ 	]+[0-9a-f]+:[ 	]+28c5950b[ 	]+th.mulah[ 	]+a0,a1,a2
+[ 	]+[0-9a-f]+:[ 	]+24c5950b[ 	]+th.mulaw[ 	]+a0,a1,a2
+[ 	]+[0-9a-f]+:[ 	]+22c5950b[ 	]+th.muls[ 	]+a0,a1,a2
+[ 	]+[0-9a-f]+:[ 	]+2ac5950b[ 	]+th.mulsh[ 	]+a0,a1,a2
+[ 	]+[0-9a-f]+:[ 	]+26c5950b[ 	]+th.mulsw[ 	]+a0,a1,a2
diff --git a/gas/testsuite/gas/riscv/x-thead-mac.s b/gas/testsuite/gas/riscv/x-thead-mac.s
new file mode 100644
index 0000000..986b96f
--- /dev/null
+++ b/gas/testsuite/gas/riscv/x-thead-mac.s
@@ -0,0 +1,7 @@
+target:
+	th.mula		a0, a1, a2
+	th.mulah	a0, a1, a2
+	th.mulaw	a0, a1, a2
+	th.muls		a0, a1, a2
+	th.mulsh	a0, a1, a2
+	th.mulsw	a0, a1, a2
diff --git a/include/opcode/riscv-opc.h b/include/opcode/riscv-opc.h
index 5c0f610..b504ce0 100644
--- a/include/opcode/riscv-opc.h
+++ b/include/opcode/riscv-opc.h
@@ -2186,6 +2186,19 @@
 #define MASK_TH_MVEQZ 0xfe00707f
 #define MATCH_TH_MVNEZ 0x4200100b
 #define MASK_TH_MVNEZ 0xfe00707f
+/* Vendor-specific (T-Head) XTheadMac instructions.  */
+#define MATCH_TH_MULA 0x2000100b
+#define MASK_TH_MULA 0xfe00707f
+#define MATCH_TH_MULAH 0x2800100b
+#define MASK_TH_MULAH 0xfe00707f
+#define MATCH_TH_MULAW 0x2400100b
+#define MASK_TH_MULAW 0xfe00707f
+#define MATCH_TH_MULS 0x2200100b
+#define MASK_TH_MULS 0xfe00707f
+#define MATCH_TH_MULSH 0x2a00100b
+#define MASK_TH_MULSH 0xfe00707f
+#define MATCH_TH_MULSW 0x2600100b
+#define MASK_TH_MULSW 0xfe00707f
 /* Vendor-specific (T-Head) XTheadSync instructions.  */
 #define MATCH_TH_SFENCE_VMAS 0x0400000b
 #define MASK_TH_SFENCE_VMAS 0xfe007fff
@@ -2975,6 +2988,13 @@ DECLARE_INSN(th_l2cache_iall, MATCH_TH_L2CACHE_IALL, MASK_TH_L2CACHE_IALL)
 /* Vendor-specific (T-Head) XTheadCondMov instructions.  */
 DECLARE_INSN(th_mveqz, MATCH_TH_MVEQZ, MASK_TH_MVEQZ)
 DECLARE_INSN(th_mvnez, MATCH_TH_MVNEZ, MASK_TH_MVNEZ)
+/* Vendor-specific (T-Head) XTheadMac instructions.  */
+DECLARE_INSN(th_mula, MATCH_TH_MULA, MASK_TH_MULA)
+DECLARE_INSN(th_mulah, MATCH_TH_MULAH, MASK_TH_MULAH)
+DECLARE_INSN(th_mulaw, MATCH_TH_MULAW, MASK_TH_MULAW)
+DECLARE_INSN(th_muls, MATCH_TH_MULS, MASK_TH_MULS)
+DECLARE_INSN(th_mulsh, MATCH_TH_MULSH, MASK_TH_MULSH)
+DECLARE_INSN(th_mulsw, MATCH_TH_MULSW, MASK_TH_MULSW)
 /* Vendor-specific (T-Head) XTheadSync instructions.  */
 DECLARE_INSN(th_sfence_vmas, MATCH_TH_SFENCE_VMAS, MASK_TH_SFENCE_VMAS)
 DECLARE_INSN(th_sync, MATCH_TH_SYNC, MASK_TH_SYNC)
diff --git a/include/opcode/riscv.h b/include/opcode/riscv.h
index d0ff929..854269a 100644
--- a/include/opcode/riscv.h
+++ b/include/opcode/riscv.h
@@ -420,6 +420,7 @@ enum riscv_insn_class
   INSN_CLASS_XTHEADBS,
   INSN_CLASS_XTHEADCMO,
   INSN_CLASS_XTHEADCONDMOV,
+  INSN_CLASS_XTHEADMAC,
   INSN_CLASS_XTHEADSYNC,
 };
 
diff --git a/opcodes/riscv-opc.c b/opcodes/riscv-opc.c
index 1113086..5d52989 100644
--- a/opcodes/riscv-opc.c
+++ b/opcodes/riscv-opc.c
@@ -1871,6 +1871,14 @@ const struct riscv_opcode riscv_opcodes[] =
 {"th.mveqz",         0, INSN_CLASS_XTHEADCONDMOV, "d,s,t", MATCH_TH_MVEQZ, MASK_TH_MVEQZ, match_opcode, 0},
 {"th.mvnez",         0, INSN_CLASS_XTHEADCONDMOV, "d,s,t", MATCH_TH_MVNEZ, MASK_TH_MVNEZ, match_opcode, 0},
 
+/* Vendor-specific (T-Head) XTheadMac instructions.  */
+{"th.mula",          0, INSN_CLASS_XTHEADMAC, "d,s,t", MATCH_TH_MULA,  MASK_TH_MULA,  match_opcode, 0},
+{"th.mulah",         0, INSN_CLASS_XTHEADMAC, "d,s,t", MATCH_TH_MULAH, MASK_TH_MULAH, match_opcode, 0},
+{"th.mulaw",        64, INSN_CLASS_XTHEADMAC, "d,s,t", MATCH_TH_MULAW, MASK_TH_MULAW, match_opcode, 0},
+{"th.muls",          0, INSN_CLASS_XTHEADMAC, "d,s,t", MATCH_TH_MULS,  MASK_TH_MULS,  match_opcode, 0},
+{"th.mulsh",         0, INSN_CLASS_XTHEADMAC, "d,s,t", MATCH_TH_MULSH, MASK_TH_MULSH, match_opcode, 0},
+{"th.mulsw",        64, INSN_CLASS_XTHEADMAC, "d,s,t", MATCH_TH_MULSW, MASK_TH_MULSW, match_opcode, 0},
+
 /* Vendor-specific (T-Head) XTheadSync instructions.  */
 {"th.sfence.vmas",   0, INSN_CLASS_XTHEADSYNC,  "s,t",MATCH_TH_SFENCE_VMAS,   MASK_TH_SFENCE_VMAS,   match_opcode, 0},
 {"th.sync",          0, INSN_CLASS_XTHEADSYNC,  "",   MATCH_TH_SYNC,          MASK_TH_SYNC,          match_opcode, 0},