New RV64C proposal

1 files changed, 35 insertions, 24 deletions

diff --git a/riscv/decode.h b/riscv/decode.h
index 4d4c447..4f57656 100644
--- a/riscv/decode.h
+++ b/riscv/decode.h
@@ -22,6 +22,9 @@ typedef uint64_t freg_t;
 const int NXPR = 32;
 const int NFPR = 32;
 
+#define X_RA 1
+#define X_SP 2
+
 #define FP_RD_NE  0
 #define FP_RD_0   1
 #define FP_RD_DN  2
@@ -72,18 +75,22 @@ public:
   uint64_t csr() { return x(20, 12); }
 
   int64_t rvc_imm() { return x(2, 5) + (xs(12, 1) << 5); }
+  int64_t rvc_addi4spn_imm() { return (x(6, 1) << 2) + (x(5, 1) << 3) + (x(11, 2) << 4) + (x(7, 4) << 6); }
+  int64_t rvc_addi16sp_imm() { return (x(6, 1) << 4) + (x(5, 1) << 5) + (x(2, 3) << 6) + (xs(12, 1) << 9); }
   int64_t rvc_lwsp_imm() { return (x(4, 3) << 2) + (x(12, 1) << 5) + (x(2, 2) << 6); }
   int64_t rvc_ldsp_imm() { return (x(5, 2) << 3) + (x(12, 1) << 5) + (x(2, 3) << 6); }
-  int64_t rvc_lw_imm() { return (x(5, 2) << 3) + (x(10, 1) << 6) + (x(11, 1) << 2) + (x(12, 1) << 5); }
-  int64_t rvc_ld_imm() { return (x(5, 2) << 3) + (x(10, 1) << 6) + (x(11, 1) << 7) + (x(12, 1) << 5); }
-  int64_t rvc_j_imm() { return (xs(2, 3) << 9) + (x(5, 2) << 3) + (x(7, 1) << 1) + (x(8, 2) << 7) + (x(10, 1) << 6) + (x(11, 1) << 2) + (x(12, 1) << 5); }
-  int64_t rvc_b_imm() { return (x(5, 2) << 3) + (x(7, 1) << 1) + (xs(8, 2) << 7) + (x(10, 1) << 6) + (x(11, 1) << 2) + (x(12, 1) << 5); }
+  int64_t rvc_swsp_imm() { return (x(9, 4) << 2) + (x(7, 2) << 6); }
+  int64_t rvc_sdsp_imm() { return (x(10, 3) << 3) + (x(7, 3) << 6); }
+  int64_t rvc_lw_imm() { return (x(6, 1) << 2) + (x(10, 3) << 3) + (x(5, 1) << 6); }
+  int64_t rvc_ld_imm() { return (x(10, 3) << 3) + (x(5, 2) << 6); }
+  int64_t rvc_j_imm() { return (x(3, 4) << 1) + (x(2, 1) << 5) + (xs(7, 6) << 6); }
+  int64_t rvc_b_imm() { return (x(3, 4) << 1) + (x(2, 1) << 5) + (xs(10, 3) << 6); }
   uint64_t rvc_rd() { return rd(); }
-  uint64_t rvc_rs1() { return x(2, 5); }
-  uint64_t rvc_rs2() { return rd(); }
-  uint64_t rvc_rds() { return 8 + x(7, 3); }
-  uint64_t rvc_rs1s() { return 8 + x(2, 3); }
-  uint64_t rvc_rs2s() { return rvc_rds(); }
+  uint64_t rvc_rs1() { return rd(); }
+  uint64_t rvc_rs2() { return x(2, 5); }
+  uint64_t rvc_rds() { return 8 + x(10, 3); }
+  uint64_t rvc_rs1s() { return 8 + x(7, 3); }
+  uint64_t rvc_rs2s() { return 8 + x(2, 3); }
 private:
   insn_bits_t b;
   uint64_t x(int lo, int len) { return (b >> lo) & ((insn_bits_t(1) << len)-1); }
@@ -111,27 +118,30 @@ private:
 // helpful macros, etc
 #define MMU (*p->get_mmu())
 #define STATE (*p->get_state())
-#define RS1 STATE.XPR[insn.rs1()]
-#define RS2 STATE.XPR[insn.rs2()]
+#define READ_REG(reg) STATE.XPR[reg]
+#define RS1 READ_REG(insn.rs1())
+#define RS2 READ_REG(insn.rs2())
 #define WRITE_REG(reg, value) STATE.XPR.write(reg, value)
 #define WRITE_RD(value) WRITE_REG(insn.rd(), value)
 
 #ifdef RISCV_ENABLE_COMMITLOG
   #undef WRITE_REG
   #define WRITE_REG(reg, value) ({ \
-        reg_t wdata = value; /* value is a func with side-effects */ \
-        STATE.log_reg_write = (commit_log_reg_t){reg << 1, wdata}; \
+        reg_t wdata = (value); /* value is a func with side-effects */ \
+        STATE.log_reg_write = (commit_log_reg_t){(reg) << 1, wdata}; \
         STATE.XPR.write(reg, wdata); \
       })
 #endif
 
 // RVC macros
 #define WRITE_RVC_RDS(value) WRITE_REG(insn.rvc_rds(), value)
-#define RVC_RS1 STATE.XPR[insn.rvc_rs1()]
-#define RVC_RS2 STATE.XPR[insn.rvc_rs2()]
-#define RVC_RS1S STATE.XPR[insn.rvc_rs1s()]
-#define RVC_RS2S STATE.XPR[insn.rvc_rs2s()]
-#define RVC_SP STATE.XPR[2]
+#define WRITE_RVC_RS1S(value) WRITE_REG(insn.rvc_rs1s(), value)
+#define WRITE_RVC_RS2S(value) WRITE_REG(insn.rvc_rs2s(), value)
+#define RVC_RS1 READ_REG(insn.rvc_rs1())
+#define RVC_RS2 READ_REG(insn.rvc_rs2())
+#define RVC_RS1S READ_REG(insn.rvc_rs1s())
+#define RVC_RS2S READ_REG(insn.rvc_rs2s())
+#define RVC_SP READ_REG(X_SP)
 
 // FPU macros
 #define FRS1 STATE.FPR[insn.rs1()]
@@ -162,12 +172,13 @@ private:
 #define get_field(reg, mask) (((reg) & (decltype(reg))(mask)) / ((mask) & ~((mask) << 1)))
 #define set_field(reg, mask, val) (((reg) & ~(decltype(reg))(mask)) | (((decltype(reg))(val) * ((mask) & ~((mask) << 1))) & (decltype(reg))(mask)))
 
-#define require_privilege(p) if (get_field(STATE.mstatus, MSTATUS_PRV) < (p)) throw trap_illegal_instruction()
-#define require_rv64 if(unlikely(xlen != 64)) throw trap_illegal_instruction()
-#define require_rv32 if(unlikely(xlen != 32)) throw trap_illegal_instruction()
-#define require_extension(s) if (!p->supports_extension(s)) throw trap_illegal_instruction()
-#define require_fp if (unlikely((STATE.mstatus & MSTATUS_FS) == 0)) throw trap_illegal_instruction()
-#define require_accelerator if (unlikely((STATE.mstatus & MSTATUS_XS) == 0)) throw trap_illegal_instruction()
+#define require(x) if (unlikely(!(x))) throw trap_illegal_instruction()
+#define require_privilege(p) require(get_field(STATE.mstatus, MSTATUS_PRV) >= (p))
+#define require_rv64 require(xlen == 64)
+#define require_rv32 require(xlen == 32)
+#define require_extension(s) require(p->supports_extension(s))
+#define require_fp require((STATE.mstatus & MSTATUS_FS) != 0)
+#define require_accelerator require((STATE.mstatus & MSTATUS_XS) != 0)
 
 #define set_fp_exceptions ({ STATE.fflags |= softfloat_exceptionFlags; \
                              softfloat_exceptionFlags = 0; })