sh1add

Shift left by 1 and add

This instruction is defined by:

Encoding

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Synopsis

This instruction shifts rs1 to the left by 1 bit and adds it to rs2.

Access

M

HS

U

VS

VU

Always

Always

Always

Always

Always

Decode Variables

Bits<5> rs2 = $encoding[24:20];
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[rs2] + (X[rs1] << 1);
if (implemented?(ExtensionName::B) && (misa.B == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
X[rd] = X[rs2] + (X[rs1] << 1);

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction