x87 Input Assistsx87 Input AssistsBy default for this event, the mask bits are set to count the number of occurrence of x87 input operands needing assistance to handle an exception condition. This metric is often used in a per-instruction ratio.
The VTuneTM Performance Analyzer counts the retirement of x87 instructions that required special handling.
The raw data collected by the VTune analyzer can be used to compute various indicators. For example, ratios of the Non-sleep Clockticks, Instructions Retired, and x87 assists can give you a good indication that the floating-point computation code in the application may be stalled and is suited for re-coding.
MOB Load Replays Retired (Blocked Store-to-Load Forwards Retired)
Streaming SIMD Extensions (SSE) Input Assists