orc.b

Bitware OR-combine, byte granule

This instruction is defined by:

Encoding

Synopsis

Combines the bits within each byte using bitwise logical OR. This sets the bits of each byte in the result xd to all zeros if no bit within the respective byte of xs1 is set, or to all ones if any bit within the respective byte of xs1 is set.

Access

M	HS	U	VS	VU
Always	Always	Always	Always	Always

Always

Decode Variables

Bits<5> xs1 = $encoding[19:15];
Bits<5> xd = $encoding[11:7];

Execution

Pruned, XLEN == 64
Original

XReg input = X[xs1];
XReg output = 0;
for (U32 i = 0; i < 8'64; i = i + 8) {
  output[(i + 7):i] = (input[(i + 7):i] == 0) ? 8'd0 : 8'255;
}
X[xd] = output;

if (implemented?(ExtensionName::B) && (CSR[misa].B == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
XReg input = X[xs1];
XReg output = 0;
for (U32 i = 0; i < xlen(); i = i + 8) {
  output[(i + 7):i] = (input[(i + 7):i] == 0) ? 8'd0 : ~8'd0;
}
X[xd] = output;