gsmiller commented on a change in pull request #69: URL: https://github.com/apache/lucene/pull/69#discussion_r609074550
########## File path: lucene/core/src/java/org/apache/lucene/codecs/lucene90/PForUtil.java ########## @@ -121,4 +167,146 @@ void skip(DataInput in) throws IOException { in.skipBytes(forUtil.numBytes(bitsPerValue) + (numExceptions << 1)); } } + + /** + * Fill {@code longs} with the final values for the case of all deltas being 1. Note this assumes + * there are no exceptions to apply. + */ + private static void prefixSumOfOnes(long[] longs, long base) { + System.arraycopy(IDENTITY_PLUS_ONE, 0, longs, 0, ForUtil.BLOCK_SIZE); + // This loop gets auto-vectorized + for (int i = 0; i < ForUtil.BLOCK_SIZE; ++i) { + longs[i] += base; + } + } + + /** + * Fill {@code longs} with the final values for the case of all deltas being {@code val}. Note + * this assumes there are no exceptions to apply. + */ + private static void prefixSumOf(long[] longs, long base, long val) { + for (int i = 0; i < ForUtil.BLOCK_SIZE; i++) { + longs[i] = (i + 1) * val + base; Review comment: Oh, for what it's worth, I pulled in the suggestion anyway to use `IDENTITY_PLUS_ONE[i]` in place of `(i + 1)`. No matter what, I think it makes sense to access this static array vs. computing `i + 1` in each loop... -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org