RISC-V: Add T-Head Fmv vendor extension

This patch adds the XTheadFmv extension, which allows to access the
upper 32 bits of a double-precision floating-point register in RV32.

The XTheadFmv extension is documented in the RISC-V toolchain
contentions:
  https://github.com/riscv-non-isa/riscv-toolchain-conventions

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

8 files changed, 40 insertions, 3 deletions

diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index 300ccf4..a1e4206 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -1239,6 +1239,7 @@ static struct riscv_supported_ext riscv_supported_vendor_x_ext[] =
   {"xtheadcmo",		ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
   {"xtheadcondmov",	ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
   {"xtheadfmemidx",	ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
+  {"xtheadfmv",		ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
   {"xtheadmac",		ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
   {"xtheadmemidx",	ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
   {"xtheadmempair",	ISA_SPEC_CLASS_DRAFT,	1, 0, 0 },
@@ -2419,6 +2420,8 @@ riscv_multi_subset_supports (riscv_parse_subset_t *rps,
       return riscv_subset_supports (rps, "xtheadcondmov");
     case INSN_CLASS_XTHEADFMEMIDX:
       return riscv_subset_supports (rps, "xtheadfmemidx");
+    case INSN_CLASS_XTHEADFMV:
+      return riscv_subset_supports (rps, "xtheadfmv");
     case INSN_CLASS_XTHEADMAC:
       return riscv_subset_supports (rps, "xtheadmac");
     case INSN_CLASS_XTHEADMEMIDX:
@@ -2573,6 +2576,8 @@ riscv_multi_subset_supports_ext (riscv_parse_subset_t *rps,
       return "xtheadcondmov";
     case INSN_CLASS_XTHEADFMEMIDX:
       return "xtheadfmemidx";
+    case INSN_CLASS_XTHEADFMV:
+      return "xtheadfmv";
     case INSN_CLASS_XTHEADMAC:
       return "xtheadmac";
     case INSN_CLASS_XTHEADMEMIDX:
diff --git a/gas/NEWS b/gas/NEWS
index 2d80ddc..ff0a25d 100644
--- a/gas/NEWS
+++ b/gas/NEWS
@@ -26,9 +26,9 @@
   for --enable-compressed-debug-sections.
 
 * Add support for various T-Head extensions (XTheadBa, XTheadBb, XTheadBs,
-  XTheadCmo, XTheadCondMov, XTheadFMemIdx, XTheadMemIdx, XTheadMemPair,
-  XTheadMac, and XTheadSync) from version 2.0 of the T-Head ISA manual, which
-  are implemented in the Allwinner D1.
+  XTheadCmo, XTheadCondMov, XTheadFMemIdx, XTheadFmv, XTheadMemIdx,
+  XTheadMemPair, XTheadMac, and XTheadSync) from version 2.0 of the T-Head
+  ISA manual, which are implemented in the Allwinner D1.
 
 * Add support for the RISC-V Zawrs extension, version 1.0-rc4.
 
diff --git a/gas/doc/c-riscv.texi b/gas/doc/c-riscv.texi
index cc63760..f2a69d8 100644
--- a/gas/doc/c-riscv.texi
+++ b/gas/doc/c-riscv.texi
@@ -734,6 +734,11 @@ The XTheadFMemIdx extension provides floating-point memory operations.
 
 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 XTheadFmv
+The XTheadFmv extension provides access to the upper 32 bits of a doulbe-precision floating point register.
+
+It is documented in @url{https://github.com/T-head-Semi/thead-extension-spec/releases/download/2.1.0/xthead-2022-11-07-2.1.0.pdf}.
+
 @item XTheadMac
 The XTheadMac extension provides multiply-accumulate instructions.
 
diff --git a/gas/testsuite/gas/riscv/x-thead-fmv.d b/gas/testsuite/gas/riscv/x-thead-fmv.d
new file mode 100644
index 0000000..f2bbe01
--- /dev/null
+++ b/gas/testsuite/gas/riscv/x-thead-fmv.d
@@ -0,0 +1,11 @@
+#as: -march=rv32i_xtheadfmv
+#source: x-thead-fmv.s
+#objdump: -dr
+
+.*:[ 	]+file format .*
+
+Disassembly of section .text:
+
+0+000 <target>:
+[ 	]+[0-9a-f]+:[ 	]+6005950b[ 	]+th.fmv.hw.x[ 	]+a0,fa1
+[ 	]+[0-9a-f]+:[ 	]+5005158b[ 	]+th.fmv.x.hw[ 	]+a1,fa0
diff --git a/gas/testsuite/gas/riscv/x-thead-fmv.s b/gas/testsuite/gas/riscv/x-thead-fmv.s
new file mode 100644
index 0000000..250ba83
--- /dev/null
+++ b/gas/testsuite/gas/riscv/x-thead-fmv.s
@@ -0,0 +1,3 @@
+target:
+	th.fmv.hw.x	a0, fa1
+	th.fmv.x.hw	a1, fa0
diff --git a/include/opcode/riscv-opc.h b/include/opcode/riscv-opc.h
index e405921..d7d9dbc 100644
--- a/include/opcode/riscv-opc.h
+++ b/include/opcode/riscv-opc.h
@@ -2208,6 +2208,11 @@
 #define MASK_TH_FSURD 0xf800707f
 #define MATCH_TH_FSURW 0x5000700b
 #define MASK_TH_FSURW 0xf800707f
+/* Vendor-specific (T-Head) XTheadFmv instructions. */
+#define MATCH_TH_FMV_HW_X 0x6000100b
+#define MASK_TH_FMV_HW_X 0xfff0707f
+#define MATCH_TH_FMV_X_HW 0x5000100b
+#define MASK_TH_FMV_X_HW 0xfff0707f
 /* Vendor-specific (T-Head) XTheadMac instructions.  */
 #define MATCH_TH_MULA 0x2000100b
 #define MASK_TH_MULA 0xfe00707f
@@ -3122,6 +3127,9 @@ DECLARE_INSN(th_fsrd, MATCH_TH_FSRD, MASK_TH_FSRD)
 DECLARE_INSN(th_fsrw, MATCH_TH_FSRW, MASK_TH_FSRW)
 DECLARE_INSN(th_fsurd, MATCH_TH_FSURD, MASK_TH_FSURD)
 DECLARE_INSN(th_fsurw, MATCH_TH_FSURW, MASK_TH_FSURW)
+/* Vendor-specific (T-Head) XTheadFmv instructions. */
+DECLARE_INSN(th_fmv_hw_x, MATCH_TH_FMV_HW_X, MASK_TH_FMV_HW_X)
+DECLARE_INSN(th_fmv_x_hw, MATCH_TH_FMV_X_HW, MASK_TH_FMV_X_HW)
 /* 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)
diff --git a/include/opcode/riscv.h b/include/opcode/riscv.h
index dddabfd..f90cf97 100644
--- a/include/opcode/riscv.h
+++ b/include/opcode/riscv.h
@@ -416,6 +416,7 @@ enum riscv_insn_class
   INSN_CLASS_XTHEADCMO,
   INSN_CLASS_XTHEADCONDMOV,
   INSN_CLASS_XTHEADFMEMIDX,
+  INSN_CLASS_XTHEADFMV,
   INSN_CLASS_XTHEADMAC,
   INSN_CLASS_XTHEADMEMIDX,
   INSN_CLASS_XTHEADMEMPAIR,
diff --git a/opcodes/riscv-opc.c b/opcodes/riscv-opc.c
index 599486f..dfd508b 100644
--- a/opcodes/riscv-opc.c
+++ b/opcodes/riscv-opc.c
@@ -1931,6 +1931,10 @@ const struct riscv_opcode riscv_opcodes[] =
 {"th.fsurd",   0, INSN_CLASS_XTHEADFMEMIDX, "D,s,t,Xu2@25", MATCH_TH_FSURD, MASK_TH_FSURD, match_opcode, 0},
 {"th.fsurw",   0, INSN_CLASS_XTHEADFMEMIDX, "D,s,t,Xu2@25", MATCH_TH_FSURW, MASK_TH_FSURW, match_opcode, 0},
 
+/* Vendor-specific (T-Head) XTheadFmv instructions.  */
+{"th.fmv.hw.x", 32, INSN_CLASS_XTHEADFMV, "d,S", MATCH_TH_FMV_HW_X,  MASK_TH_FMV_HW_X,  match_opcode, 0},
+{"th.fmv.x.hw", 32, INSN_CLASS_XTHEADFMV, "d,S", MATCH_TH_FMV_X_HW,  MASK_TH_FMV_X_HW,  match_opcode, 0},
+
 /* Vendor-specific (T-Head) XTheadMemIdx instructions.  */
 {"th.ldia",  64, INSN_CLASS_XTHEADMEMIDX, "d,(s),Xs5@20,Xu2@25", MATCH_TH_LDIA,  MASK_TH_LDIA,  match_th_load_inc, 0},
 {"th.ldib",  64, INSN_CLASS_XTHEADMEMIDX, "d,(s),Xs5@20,Xu2@25", MATCH_TH_LDIB,  MASK_TH_LDIB,  match_th_load_inc, 0},