rolw
Rotate left word (Register)
This instruction is defined by:
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anyOf:
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B, version >= B@1.0.0
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Zbb, version >= Zbb@1.0.0
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Zbkb, version >= Zbkb@1.0.0
-
Zk, version >= Zk@1.0.0
-
Zkn, version >= Zkn@1.0.0
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Zks, version >= Zks@1.0.0
-
This instruction is included in the following profiles:
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RVA22U64 (Mandatory)
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RVA23U64 (Mandatory)
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RVB23U64 (Mandatory)
Synopsis
| This instruction must have data-independent timing when extension Zkt is enabled. |
This instruction performs a rotate left of the least-significant word of rs1 by the amount in least-significant 5 bits of rs2. The resulting word value is sign-extended by copying bit 31 to all of the more-significant bits.
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);
}
XReg rs1_word = X[rs1][31:0];
XReg shamt = X[rs2][4:0];
XReg unextended_result = (rs1_word << shamt) | (rs1_word >> (32 - shamt));
X[rd] = {{32{unextended_result[31]}}, unextended_result};{
let rs1_val = (X(rs1))[31..0];
let shamt = (X(rs2))[4..0];
let result : bits(32) = match op {
RISCV_ROLW => rs1_val <<< shamt,
RISCV_RORW => rs1_val >>> shamt
};
X(rd) = sign_extend(result);
RETIRE_SUCCESS
}