Purpose
Sets the number of cache lines unit_cnt and the prefetch depth prefetch_depth for the limited
length protected load or store stream with identifier stream_id.
The term "transient" indicates that the time interval during which
the program accesses the stream's memory is likely to be short, so
the processor can remove it from the cache earlier.
Prototype
void __transient_protected_stream_count_depth
(unsigned int unit_cnt, unsigned int prefetch_depth,
unsigned int stream_id);
Parameters
- unit_cnt
- The number of cache lines. Must be an integer with a value of
0 to 1023.
- prefetch_depth
- A relative, qualitative value which sets the steady-state fetch-ahead distance
of the prefetches for a stream. The fetch-ahead distance is the number
of lines being prefetched in advance of the line from which data is
currently being loaded, or to which data is currently being stored.
Valid values are as follows:
- 0
- The default defined in the Data Stream Control Register.
- 1
- None.
- 2
- Shallowest.
- 3
- Shallow.
- 4
- Medium.
- 5
- Deep.
- 6
- Deeper.
- 7
- Deepest.
- stream_id
- An integer with a value 0 to 11 on POWER7 processors.
Usage
Valid only when -qarch is set
to target POWER7 processors.