remove shamt parsing in shift right arithmetic in favor of top level …

…shamt
o1-labs · Dec 11, 2024 · becb4ee · becb4ee
1 parent 2e42495
commit becb4ee
Showing 1 changed file with 0 additions and 7 deletions.
diff --git a/o1vm/src/interpreters/riscv32im/interpreter.rs b/o1vm/src/interpreters/riscv32im/interpreter.rs
@@ -1793,13 +1793,6 @@ pub fn interpret_itype<Env: InterpreterEnv>(env: &mut Env, instr: IInstruction)
         IInstruction::ShiftRightArithmeticImmediate => {
             // srai: x[rd] = x[rs1] >> shamt
             let local_rs1 = env.read_register(&rs1);
-            let shamt = {
-                let pos = env.alloc_scratch();
-                unsafe { env.bitmask(&imm, 5, 0, pos) }
-            };
-            // parse shamt from imm as 20-24 of instruction and 0-4 wrt to imm
-            // sign extend shamt for arithmetic shift
-            let shamt = env.sign_extend(&shamt, 4);
 
             let local_rd = {
                 let pos = env.alloc_scratch();