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Optimization for eliminating redundant memory operations #281

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Optimization for eliminating redundant memory operations #281

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4 changes: 3 additions & 1 deletion csv-core/src/reader.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -666,7 +666,9 @@ impl Reader {
let mut state = self.dfa_state;
while nin < input.len() && nout < output.len() && nend < ends.len() {
let (s, has_out) = self.dfa.get_output(state, input[nin]);
self.line += (input[nin] == b'\n') as u64;
if input[nin] == b'\n'{
self.line += 1;
}
Comment on lines +669 to +671
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Do you have benchmarks backing this up? I'm a little skeptical that the cost of looking up self.line in order to increment it by zero is higher than the cost of adding a branch in the code path, at least on most modern CPUs where branches do unpleasant things to instruction pipelining.

state = s;
if has_out {
output[nout] = input[nin];
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