- Synopsis
-
Test for NUL bytes.
- Mnemonic
-
th.tstnbz rd, rs1
- Encoding
{reg:[
{ bits: 7, name: 0xb, attr: ['custom-0, 32 bit'] },
{ bits: 5, name: 'rd' },
{ bits: 3, name: 0x1 },
{ bits: 5, name: 'rs1' },
{ bits: 5, name: 0x0 },
{ bits: 2, name: 0x0 },
{ bits: 5, name: 0x10 },
]}
- Description
-
Tests each byte in register rs1 for equality with 0. If a byte is 0, then the corresponding byte in register rd will be set to 0xff. Otherwise, the corresponding byte in register rd will be set to 0.
- Operation
for i=0..(xlen/8-1):
if reg[rs1][i] == 0:
reg[rd][i] := 0xff
else
reg[rd][i] := 0- Permission
-
This instruction can be executed in all privilege levels.
- Exceptions
-
This instruction does not trigger any exceptions.
- Included in
| Extension |
|---|
XTheadBb ([xtheadbb]) |