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| author | Amar Takhar <amar@rtems.org> | 2016-01-18 00:37:40 -0500 |
|---|---|---|
| committer | Amar Takhar <verm@darkbeer.org> | 2016-05-02 20:51:24 -0400 |
| commit | d389819eea3a84e388935153e3be847342809da3 (patch) | |
| tree | 15cfe55f41281cead805ce87f66c5d7248caa9ce /porting/priority_bitmap.rst | |
| parent | Remove ada_user document. (diff) | |
| download | rtems-docs-d389819eea3a84e388935153e3be847342809da3.tar.bz2 | |
Convert all Unicode to ASCII(128)
Diffstat (limited to 'porting/priority_bitmap.rst')
| -rw-r--r-- | porting/priority_bitmap.rst | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/porting/priority_bitmap.rst b/porting/priority_bitmap.rst index 36c294b..7b24451 100644 --- a/porting/priority_bitmap.rst +++ b/porting/priority_bitmap.rst @@ -85,8 +85,8 @@ major/minor) is the first bit found. This entire "find first bit" and mapping process depends heavily on the manner in which a priority is broken into a major and minor components with the major being the 4 MSB of a priority and minor the 4 LSB. Thus (0 -<< 4) + 0 corresponds to priority 0 – the highest priority. And (15 << -4) + 14 corresponds to priority 254 – the next to the lowest priority. +<< 4) + 0 corresponds to priority 0 - the highest priority. And (15 << +4) + 14 corresponds to priority 254 - the next to the lowest priority. If your CPU does not have a "find first bit" instruction, then there are ways to make do without it. Here are a handful of ways to implement this @@ -94,7 +94,7 @@ in software: - a series of 16 bit test instructions -- a "binary search using if’s" +- a "binary search using if's" - the following algorithm based upon a 16 entry lookup table. In this pseudo-code, bit_set_table[16] has values which indicate the first bit set: |