slli.uw

Shift left unsigned word (Immediate)

This instruction is defined by:

Encoding

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Synopsis

Takes the least-significant word of rs1, zero-extends it, and shifts it left by the immediate.

This instruction is the same as slli with zext.w performed on rs1 before shifting.

Access

M

HS

U

VS

VU

Always

Always

Always

Always

Always

Decode Variables

Bits<6> shamt = $encoding[25:20];
Bits<5> rs1 = $encoding[19:15];
Bits<5> rd = $encoding[11:7];

Execution

  • Pruned, XLEN == 64

  • Original

if ((misa.B == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
X[rd] = X[rs1][31:0] << shamt;
if (implemented?(ExtensionName::B) && (misa.B == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
X[rd] = X[rs1][31:0] << shamt;

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction