bclr
Single-Bit clear (Register)
This instruction is defined by:
Synopsis
Returns xs1 with a single bit cleared at the index specified in xs2. The index is read from the lower log2(XLEN) bits of xs2.
Decode Variables
Bits<5> xs2 = $encoding[24:20];
Bits<5> xs1 = $encoding[19:15];
Bits<5> xd = $encoding[11:7];Execution
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Pruned, XLEN == 64
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Original
if (implemented?(ExtensionName::B) && (misa.B == 1'b0)) {
raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
XReg index = X[xs2] & (63);
X[xd] = X[xs1] & ~(1 << index);if (implemented?(ExtensionName::B) && (misa.B == 1'b0)) {
raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
XReg index = X[xs2] & (xlen() - 1);
X[xd] = X[xs1] & ~(1 << index);