srai
Shift right arithmetic immediate
Arithmetic shift (the original sign bit is copied into the vacated upper bits) the value in xs1 right by shamt, and store the result in xd.
| This instruction must have data-independent timing when extension Zkt is enabled. |
Decode Variables
-
RV32
-
RV64
Bits<5> shamt = $encoding[24:20];
Bits<5> xs1 = $encoding[19:15];
Bits<5> xd = $encoding[11:7];Bits<6> shamt = $encoding[25:20];
Bits<5> xs1 = $encoding[19:15];
Bits<5> xd = $encoding[11:7];Execution
-
IDL
-
Sail
X[xd] = X[xs1] >>> shamt;{
let xs1_val = X(xs1);
/* the decoder guaxd should ensure that shamt[5] = 0 for RV32 */
let result : xlenbits = match op {
RISCV_SLLI => if sizeof(xlen) == 32
then xs1_val << shamt[4..0]
else xs1_val << shamt,
RISCV_SRLI => if sizeof(xlen) == 32
then xs1_val >> shamt[4..0]
else xs1_val >> shamt,
RISCV_SRAI => if sizeof(xlen) == 32
then shift_right_arith32(xs1_val, shamt[4..0])
else shift_right_arith64(xs1_val, shamt)
};
X(xd) = result;
RETIRE_SUCCESS
}