rvb: add xperm.[nbhw] (#629)

Signed-off-by: Chih-Min Chao <chihmin.chao@sifive.com>

disasm/disasm.cc

@@ -606,6 +606,10 @@ disassembler_t::disassembler_t(int xlen)
   DEFINE_RTYPE(gorc);
   add_insn(new disasm_insn_t("orc.b", match_gorci | (0x7 << imm_shift), mask_grevi | mask_imm, {&xrd, &xrs1}));
   DEFINE_ITYPE_SHIFT(gorci);
+  DEFINE_RTYPE(xperm_n);
+  DEFINE_RTYPE(xperm_b);
+  DEFINE_RTYPE(xperm_h);
+  DEFINE_RTYPE(xperm_w);
 
   DEFINE_NOARG(ecall);
   DEFINE_NOARG(ebreak);

riscv/arith.h

@@ -6,6 +6,7 @@
 #include <cassert>
 #include <cstdint>
 #include <climits>
+#include <cstddef>
 
 inline uint64_t mulhu(uint64_t a, uint64_t b)
 {
@@ -174,4 +175,21 @@ static inline int log2(uint64_t val)
   return 63 - clz(val);
 }
 
+static inline uint64_t xperm(uint64_t rs1, uint64_t rs2, size_t sz_log2, size_t len)
+{
+  uint64_t r = 0;
+  uint64_t sz = 1LL << sz_log2;
+  uint64_t mask = (1LL << sz) - 1;
+
+  assert(sz_log2 <= 6 && len <= 64);
+
+  for (size_t i = 0; i < len; i += sz) {
+    uint64_t pos = ((rs2 >> i) & mask) << sz_log2;
+    if (pos < len)
+      r |= ((rs1 >> pos) & mask) << i;
+  }
+
+  return r;
+}
+
 #endif

riscv/encoding.h

@@ -1,6 +1,6 @@
 /*
  * This file is auto-generated by running 'make ../riscv-isa-sim/riscv/encoding.h' in
- * https://github.com/riscv/riscv-opcodes (2aa7492)
+ * https://github.com/riscv/riscv-opcodes (c4d2cc0)
  */
 
 /* See LICENSE for license details. */
@@ -838,6 +838,12 @@
 #define MASK_SHFLI  0xfe00707f
 #define MATCH_UNSHFLI 0x8005013
 #define MASK_UNSHFLI  0xfe00707f
+#define MATCH_XPERM_N 0x28002033
+#define MASK_XPERM_N  0xfe00707f
+#define MATCH_XPERM_B 0x28004033
+#define MASK_XPERM_B  0xfe00707f
+#define MATCH_XPERM_H 0x28006033
+#define MASK_XPERM_H  0xfe00707f
 #define MATCH_BMATFLIP 0x60301013
 #define MASK_BMATFLIP  0xfff0707f
 #define MATCH_CRC32_D 0x61301013
@@ -920,6 +926,8 @@
 #define MASK_PACKUW  0xfe00707f
 #define MATCH_BFPW 0x4800703b
 #define MASK_BFPW  0xfe00707f
+#define MATCH_XPERM_W 0x28000033
+#define MASK_XPERM_W  0xfe00707f
 #define MATCH_ECALL 0x73
 #define MASK_ECALL  0xffffffff
 #define MATCH_EBREAK 0x100073
@@ -2630,6 +2638,9 @@ DECLARE_INSN(packh, MATCH_PACKH, MASK_PACKH)
 DECLARE_INSN(bfp, MATCH_BFP, MASK_BFP)
 DECLARE_INSN(shfli, MATCH_SHFLI, MASK_SHFLI)
 DECLARE_INSN(unshfli, MATCH_UNSHFLI, MASK_UNSHFLI)
+DECLARE_INSN(xperm_n, MATCH_XPERM_N, MASK_XPERM_N)
+DECLARE_INSN(xperm_b, MATCH_XPERM_B, MASK_XPERM_B)
+DECLARE_INSN(xperm_h, MATCH_XPERM_H, MASK_XPERM_H)
 DECLARE_INSN(bmatflip, MATCH_BMATFLIP, MASK_BMATFLIP)
 DECLARE_INSN(crc32_d, MATCH_CRC32_D, MASK_CRC32_D)
 DECLARE_INSN(crc32c_d, MATCH_CRC32C_D, MASK_CRC32C_D)
@@ -2671,6 +2682,7 @@ DECLARE_INSN(bdecompressw, MATCH_BDECOMPRESSW, MASK_BDECOMPRESSW)
 DECLARE_INSN(packw, MATCH_PACKW, MASK_PACKW)
 DECLARE_INSN(packuw, MATCH_PACKUW, MASK_PACKUW)
 DECLARE_INSN(bfpw, MATCH_BFPW, MASK_BFPW)
+DECLARE_INSN(xperm_w, MATCH_XPERM_W, MASK_XPERM_W)
 DECLARE_INSN(ecall, MATCH_ECALL, MASK_ECALL)
 DECLARE_INSN(ebreak, MATCH_EBREAK, MASK_EBREAK)
 DECLARE_INSN(uret, MATCH_URET, MASK_URET)

riscv/insns/xperm_b.h

@@ -0,0 +1,2 @@
+require_extension('B');
+WRITE_RD(xperm(RS1, RS2, 3, xlen));

riscv/insns/xperm_h.h

@@ -0,0 +1,2 @@
+require_extension('B');
+WRITE_RD(xperm(RS1, RS2, 4, xlen));

riscv/insns/xperm_n.h

@@ -0,0 +1,2 @@
+require_extension('B');
+WRITE_RD(xperm(RS1, RS2, 2, xlen));

riscv/insns/xperm_w.h

@@ -0,0 +1,3 @@
+require_rv64;
+require_extension('B');
+WRITE_RD(xperm(RS1, RS2, 5, xlen));

riscv/riscv.mk.in

@@ -426,6 +426,10 @@ riscv_insn_ext_b = \
 	unshfli \
 	unshflw \
 	xnor \
+	xperm_n \
+	xperm_b \
+	xperm_h \
+	xperm_w \
 
 riscv_insn_ext_v_alu_int = \
 	vaadd_vv \