Fix#6805: add --enable-ccache configure option to prefix compiler invocations with `ccache` to attempt to reuse common results, e.g. for LLVM (re)builds.
The information at developer [Note-ccache](../../wiki/Note-ccache) and at [ccache and clang concerns](http://petereisentraut.blogspot.fr/2011/09/ccache-and-clang-part-2.html) were what drove my introduction of the `-Qunused-arguments` and `CCACHE_CPP2` options. (Though I did confirm first-hand that at least the first really is necessary.)
Yes, one certainly can re-route how `gcc` and `clang` are resolved in one's PATH and use that as a way to invoke `ccache`. But I personally do not want to introduce that change to my own PATH, and this seems like a small enough change that it does not hurt to add it, at least for now. (I don't know what form it would take when we move over to `rustpkg`.)
Calls to the libc versions of fmin and fmax were relatively slow (perhaps because they could not be inlined?). This pull request provides f32 and f64 with fmin and fmax written in Rust, and shows a significant speed increase on my system; I used https://github.com/thiez/rustray as my benchmark, with --opt-level 3 it brings the ray-tracing time down from 10.8 seconds to about 9.2, which seemed significant to me.
r?
Most of the relevant information can be found in the commit messages.
r? @brson - I just wanted to make sure the make changes aren't completely bogus
This would close#2400, #6517, and #6489 (although a run through incoming-full on linux would have to confirm the latter two)
Previously, FromBase64 was only implemented on ~[u8] and ~str when
any pointer would do. The implementations of FromBase64 are now
consistent with the implementations of ToBase64.
Move the computation of what data is moved out of `liveness` and into `borrowck`. The resulting code is cleaner, since before we had a split distribution of responsibilities, and also this avoids having multiple implementations of the dataflow code. Liveness is still used to report warnings about useless writes. This will go away when we get the control-flow graph code landed (working on that).
Also adds borrow checker documentation.
Fixes#4384.
Required to support once fns and to properly fix closures (#2202).
First step to generalize our treatment of moves somewhat as well.
Refactor the optimization passes to explicitly use the passes. This commit just re-implements the same passes as were already being run.
It also adds an option (behind `-Z`) to run the LLVM lint pass on the unoptimized IR.
This should close#2812. It is also the first step towards #2396
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This is pretty much just an initial "get it out there" PR. With finer control over the optimization passes coming later. I also just blindly copied the passes we were already doing, so there could almost certainly be some more work in paring it down.
The other thing is the addition of the `mergefunctions` pass, which is currently enabled at `--opt-level=3` and does have a small impact on the code size. However the fact that it is at the end of the optimization pipeline is probably not ideal, so some more experimentation is in order.
