teq

Test Equivalence (A32)

TEQ<c> <Rn>, <Operand2>

Bitwise Exclusive OR and update flags (discard result).

Details

Performs a bitwise exclusive OR of Rn and Operand2, updates the condition flags based on the result, and discards the result. The N flag is set if bit 31 of the result is 1; Z is set if the result is 0; C is affected by the shifter (if applicable); V is unchanged. This instruction is useful for testing equality of two values.

Pseudocode Operation

result ← Rn XOR Operand2
N ← result[31]
Z ← (result == 0)
C ← shifter_carry_out
V ← V  // Unchanged

Example

TEQ r1, r2

Encoding

Binary Layout
cond
00110
01
1
Rn
0
0
0
0
imm12
 
Format Data Proc
Opcode 0x03300000
Extension A32 (Base)

Operands

  • Rn
    First source / base general-purpose register
  • Operand2
    Flexible second operand (register or shifted register)

Reference (Arm AArch32 ISA)

Instruction Forms

Encoding Instruction ISA Bit pattern
0x03300000 TEQ{<c>}{<q>} <Rn>, #<const> A32 cond | 00110 | 01 | 1 | Rn | 0 | 0 | 0 | 0 | imm12
0xF0900F00 TEQ{<c>}{<q>} <Rn>, #<const> T32 11110 | i | 0 | 0100 | 1 | Rn | 0 | imm3 | 1111 | imm8
0x01300060 TEQ{<c>}{<q>} <Rn>, <Rm>, RRX A32 cond | 00010 | 01 | 1 | Rn | 0 | 0 | 0 | 0 | 00000 | 11 | 0 | Rm
0x01300000 TEQ{<c>}{<q>} <Rn>, <Rm> {, <shift> #<amount>} A32 cond | 00010 | 01 | 1 | Rn | 0 | 0 | 0 | 0 | imm5 | stype | 0 | Rm
0xEA900F30 TEQ{<c>}{<q>} <Rn>, <Rm>, RRX T32 1110101 | 0100 | 1 | Rn | 0 | 000 | 1111 | 00 | 11 | Rm
0xEA900F00 TEQ{<c>}{<q>} <Rn>, <Rm> {, <shift> #<amount>} T32 1110101 | 0100 | 1 | Rn | 0 | imm3 | 1111 | imm2 | stype | Rm
0x01300010 TEQ{<c>}{<q>} <Rn>, <Rm>, <type> <Rs> A32 cond | 00010 | 01 | 1 | Rn | 0 | 0 | 0 | 0 | Rs | 0 | stype | 1 | Rm

Description

Test Equivalence (immediate) performs a bitwise exclusive OR operation on a register value and an immediate value. It updates the condition flags based on the result, and discards the result.

Operation

if ConditionPassed() then
    EncodingSpecificOperations();
    result = R[n] EOR imm32;
    PSTATE.N = result<31>;
    PSTATE.Z = IsZeroBit(result);
    PSTATE.C = carry;
    // PSTATE.V unchanged