From 0d25ef9702fbce7073a22b16edbe256c79d336e6 Mon Sep 17 00:00:00 2001
From: Yen-Fu Chen <qwe661234@gmail.com>
Date: Wed, 11 Oct 2023 22:42:16 +0800
Subject: [PATCH] Remove insn_len field in IR structure

---
 src/decode.c  | 2 --
 src/decode.h  | 3 ---
 src/emulate.c | 4 ++--
 3 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/decode.c b/src/decode.c
index 88de60224..6cdd6de1f 100644
--- a/src/decode.c
+++ b/src/decode.c
@@ -1729,7 +1729,6 @@ bool rv_decode(rv_insn_t *ir, uint32_t insn)
     if ((insn & FC_OPCODE) != 3) {
         insn &= 0x0000FFFF;
         const uint16_t c_index = (insn & FC_FUNC3) >> 11 | (insn & FC_OPCODE);
-        ir->insn_len = INSN_16;
 
         /* decode instruction (compressed instructions) */
         const decode_t op = rvc_jump_table[c_index];
@@ -1740,7 +1739,6 @@ bool rv_decode(rv_insn_t *ir, uint32_t insn)
 
     /* standard uncompressed instruction */
     const uint32_t index = (insn & INSN_6_2) >> 2;
-    ir->insn_len = INSN_32;
 
     /* decode instruction */
     const decode_t op = rv_jump_table[index];
diff --git a/src/decode.h b/src/decode.h
index eb5dfb9bf..c4c826d99 100644
--- a/src/decode.h
+++ b/src/decode.h
@@ -275,9 +275,6 @@ typedef struct rv_insn {
 
     uint32_t pc;
 
-    /* instruction length */
-    uint8_t insn_len;
-
     /* Tail-call optimization (TCO) allows a C function to replace a function
      * call to another function or itself, followed by a simple return of the
      * function's result, with a direct jump to the target function. This
diff --git a/src/emulate.c b/src/emulate.c
index e4cba3c5a..30f9d6f80 100644
--- a/src/emulate.c
+++ b/src/emulate.c
@@ -628,14 +628,14 @@ static void block_translate(riscv_t *rv, block_map_t *map, block_t *block)
 
         /* decode the instruction */
         if (!rv_decode(ir, insn)) {
-            rv->compressed = (ir->insn_len == INSN_16);
+            rv->compressed = ((insn & FC_OPCODE) != 3);
             rv_except_illegal_insn(rv, insn);
             break;
         }
         ir->impl = dispatch_table[ir->opcode];
         ir->pc = block->pc_end;
         /* compute the end of pc */
-        block->pc_end += ir->insn_len;
+        block->pc_end += ((insn & FC_OPCODE) != 3) ? 2 : 4;
         block->n_insn++;
         prev_ir = ir;
         /* stop on branch */