Inside Macintosh: PowerPC System Software /

Chapter 4 - Exception Manager / Exception Manager Reference

Data Structures

Floating-Point Information Records

The Exception Manager uses a floating-point information record to encode the state of the floating-point unit at the time an exception occurs. A floating-point information record is defined by the FPUInformation data type.

struct FPUInformation {
   UnsignedWide         Registers[32]; /*FPU registers*/
   unsigned long        FPSCR;         /*status/control reg*/
};
typedef struct FPUInformation FPUInformation;

Field Description

Registers

The contents of the 32 floating-point registers. This array is zero-based; for example, the contents of FPR0 are accessed
as Registers[0].

FPSCR

The contents of the Floating-Point Status and Control
Register (FPSCR).

IMPORTANT

The fields of a floating-point information record are aligned in memory in accordance with 680x0 alignment conventions.