Branch (computer Science) - Typical Branch/jump Instructions Exemplified By Some Well-known Architectures

Typical Branch/jump Instructions Exemplified By Some Well-known Architectures

condition or result x86 PDP-11, VAX ARM (partly 6502) equation
zero (implies equal for sub/cmp) JZ; JNZ BEQ; BNE BEQ; BNE zero; not zero
negative (N), sign (S), or minus (M) JS; JNS BMI; BPL BMI; BPL negative; not negative
arithmetic overflow (flag called O or V) JO; JNO BVS; BVC BVS; BVC overflow; not overflow
carry (from add,cmp,shift, etc.) JC; JNC BCS; BCC BCS; BCC carry; not carry
unsigned below (lower) JB BLO BLO * borrow
unsigned below or equal (lower or same) JBE BLOS BLS * borrow or zero
unsigned above or equal (higher or same) JAE BHIS BHS * not borrow
unsigned above (higher) JA BHI BHI * not borrow and not zero
signed less than JL BLT BLT sign≠overflow
signed less or equal JLE BLE BLE sign≠overflow or zero
signed greater or equal JGE BGE BGE sign=overflow
signed greater than JG BGT BGT sign=overflow and not zero

* x86, the PDP-11, VAX, and some others, set the carry-flag to signal borrow and clear the carry-flag to signal no borrow. ARM, 6502, the PIC, and some others, do the opposite for subtractive operations. This inverted function of the carry flag for certain instructions is marked by (*), that is, borrow=not carry in some parts of the table, but if not otherwise noted, borrow≡carry. However, carry on additive operations are handled the same way by most architectures.

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