b

Branch (A32)

B<c> <label>

Branch relative (PC +/- 32MB).

Details

Performs a relative branch to a label up to ±32 MB from the current instruction. The branch is taken only if the condition code (specified by <c>) is satisfied; if no condition is specified, it is always taken (AL). The PC is updated to point to the target address. Executes in A32 only.

Pseudocode Operation

if condition_satisfied then
  PC ← PC + (sign_extend(imm24) << 2) + 8

Example

B label

Encoding

Binary Layout

cond

101

imm24

Format Branch

Opcode 0x0A000000

Extension A32 (Base)

Operands

label
Label

Reference (Arm AArch32 ISA)

Instruction Forms

Encoding	Instruction	ISA	Bit pattern
0x0A000000	B{<c>}{<q>} <label>	A32	cond \| 101 \| 0 \| imm24
0xD000	B<c>{<q>} <label>	T32	1101 \| cond \| imm8
0xE000	B{<c>}{<q>} <label>	T32	11100 \| imm11
0xF0008000	B<c>.W <label>	T32	11110 \| S \| cond \| imm6 \| 10 \| J1 \| 0 \| J2 \| imm11
0xF0009000	B{<c>}.W <label>	T32	11110 \| S \| imm10 \| 10 \| J1 \| 1 \| J2 \| imm11

Description

Branch causes a branch to a target address.

Operation

if ConditionPassed() then
    EncodingSpecificOperations();
    BranchWritePC(PC + imm32, BranchType_DIR);