[PATCH] D64969: [llvm-objdump][NFC] Make the PrettyPrinter::printInst() output buffered

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added a comment.

Nice finding!

> [1]: https://github.com/llvm/llvm-project/blob/2946cd701067404b99c39fb29dc9c74bd7193eb3/llvm/include/llvm/Support/FormattedStream.h#L83

I think the 4x (line buffered vs unbuffered) slowdown can be explained by your first link. The formatted_raw_ostream ctor resets the underlying stream (`outs()`) to unbuffered. There are several solutions to the problem. Given `formatted_raw_ostream FOS(OS);` is only used once in PrettyPrinter and can be easily replaced, I suggest deleting it and tracking the column manually.


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