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Contained within the PSW are the two bit condition code, representing zero, positive, negative, overflow, and similar flags of other architectures' status registers. Conditional branch instructions test this encoded as a four bit value, with each bit representing a test of one of the four condition code values, 2 3 + 2 2 + 2 1 + 2 0. (Since IBM ...
The four condition codes in the processor status word (PSW) are N indicating a negative value; Z indicating a zero (equal) condition; V indicating an overflow condition, and; C indicating a carry condition. Instructions in this group were what Digital called "micro-programmed": A single bit in the instruction word referenced a single condition ...
A status register, flag register, or condition code register (CCR) is a collection of status flag bits for a processor.Examples of such registers include FLAGS register in the x86 architecture, flags in the program status word (PSW) register in the IBM System/360 architecture through z/Architecture, and the application program status register (APSR) in the ARM Cortex-A architecture.
The Program Status Word (PSW) [2]: 71–72 contains a variety of controls for the currently operating program. The 64-bit PSW describes (among other things) the address of the current instruction being executed, condition code and interrupt masks.
The FLAGS register is the status register that contains the current state of an x86 CPU.The size and meanings of the flag bits are architecture dependent. It usually reflects the result of arithmetic operations as well as information about restrictions placed on the CPU operation at the current time.
Short PSW abbreviations; Bits Field Meaning 1 R PER Mask 5 T DAT mode 6 IO I/O mask 7 EX External Mask 8-11 Key PSW key 12 E=1 Must be one for LPSW 13 M Machine-check mask 14 W Wait state 15 P Problem state 16-17 AS Address-Space Control 00=primary-space mode 01=Access-register mode 10=Secondary-space mode 11=Home-space mode 18-19 CC Condition Code
Conditional move instructions write the contents of one register over another only if the predicate's value is true, whereas conditional select instructions choose which of two registers has its contents written to a third based on the predicate's value. A more generalized and capable form is full predication. Full predication has a set of ...
If-then-else flow diagram A nested if–then–else flow diagram. In computer science, conditionals (that is, conditional statements, conditional expressions and conditional constructs) are programming language constructs that perform different computations or actions or return different values depending on the value of a Boolean expression, called a condition.