sh3add.uw
Shift unsigend word left by 3 and add
This instruction is defined by:
-
anyOf:
-
B, version >= 0
-
Zba, version >= 0
-
This instruction is included in the following profiles:
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RVA22U64 (Mandatory)
Synopsis
This instruction performs an XLEN-wide addition of two addends. The first addend is rs2. The second addend is the unsigned value formed by extracting the least-significant word of rs1 and shifting it left by 3 places.
Decode Variables
Bits<5> rs2 = $encoding[24:20];
Bits<5> rs1 = $encoding[19:15];
Bits<5> rd = $encoding[11:7];
Execution
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IDL
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Sail
if (implemented?(ExtensionName::B) && (CSR[misa].B == 1'b0)) {
raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
X[rd] = X[rs2] + (X[rs1][31:0] << 3);
{
let rs1_val = X(rs1);
let rs2_val = X(rs2);
let shamt : bits(2) = match op {
RISCV_ADDUW => 0b00,
RISCV_SH1ADDUW => 0b01,
RISCV_SH2ADDUW => 0b10,
RISCV_SH3ADDUW => 0b11
};
let result : xlenbits = (zero_extend(rs1_val[31..0]) << shamt) + rs2_val;
X(rd) = result;
RETIRE_SUCCESS
}