1 1 17.19 Instruction Attributes 1 ============================ 1 1 In addition to describing the instruction supported by the target 1 machine, the 'md' file also defines a group of "attributes" and a set of 1 values for each. Every generated insn is assigned a value for each 1 attribute. One possible attribute would be the effect that the insn has 1 on the machine's condition code. This attribute can then be used by 1 'NOTICE_UPDATE_CC' to track the condition codes. 1
1 · Defining Attributes Specifying attributes and their values. · Expressions Valid expressions for attribute values. · Tagging Insns Assigning attribute values to insns. · Attr Example An example of assigning attributes. · Insn Lengths Computing the length of insns. · Constant Attributes Defining attributes that are constant. · Mnemonic Attribute Obtain the instruction mnemonic as attribute value. · Delay Slots Defining delay slots required for a machine. · Processor pipeline description Specifying information for insn scheduling. 1