Re: [PATCH 2/2] tcg: possibly convert deposit_z to shl+shr

[Jim MacArthur]

On 1/15/26 13:54, Paolo Bonzini wrote:
  
@@ -2628,8 +2638,18 @@ void tcg_gen_deposit_z_i64(TCGv_i64 ret, TCGv_i64 arg,
              tcg_gen_extract_i64(ret, ret, 0, ofs + len);
              return;
          }
-        tcg_gen_andi_i64(ret, arg, (1ull << len) - 1);
-        tcg_gen_shli_i64(ret, ret, ofs);
+        /*
+         * Use TCG_TARGET_extract_valid to check for 8-, 16- and 32-bit 
extension
+         * opcodes, which tcg_gen_andi_i64 can produce.
+         */
+        if (TCG_TARGET_extract_valid(TCG_TYPE_I64, 0, len) ||
+           tcg_op_imm_match(INDEX_op_and, TCG_TYPE_I64, (1ull << len) - 1)) {
+            tcg_gen_andi_i64(ret, arg, (1ull << len) - 1);
+            tcg_gen_shli_i64(ret, ret, ofs);
+        } else {
+            tcg_gen_shli_i64(ret, arg, 64 - len);
+            tcg_gen_shri_i64(ret, ret, 64 - len - ofs);
+        }
      }
  }
  

Also just a couple of coding standards issues - "Use 
TCG_TARGET_extract_valid" comment is over 80 characters and you have a 
tab at the start of the call to tcp_op_imm_match. Otherwise, looks good.

Jim