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Postings from May 2015
While fiddling around with some empty blocks that had been used as placeholders,
happened to accidentally notice that "do {;}" and "{;}" have different realtime
costs. For example, with perl 5.20.1, on x86_64:
for (my $i = 0; $i < 1e8; ++$i) { } # ET ~= 5s
for (my $i = 0; $i < 1e8; ++$i) { do { ; } } # ET ~= 5s
for (my $i = 0; $i < 1e8; ++$i) { { ; } } # ET ~= 10s
I'd have guessed that both constructs would get optimized away during
compilation, but evidently "{;}" incurs some execution overhead that
"do {;}" does not.
This is not causing any difficulty whatsoever, nor am I suggesting that
anything is wrong or even peculiar about this; simply curious about why it is.
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