Avoids the overhead of read_char for every character.
Benchmark reading example.json 10 times from
https://code.google.com/p/rapidjson/wiki/Performance
Before: 2.55s
After: 0.16s
Regression testing is already done by isrustfastyet.
for cases where it's hard to decide what id to use for the lookup); modify
irrefutable bindings code to move or copy depending on the type, rather than
threading through a flag. Also updates how local variables and arguments are
registered. These changes were hard to isolate.
In particular, it is not valid to go around passing uninitialized or zero'd
memory as arguments. Rust should generally be free to assume that the arguments
it gets are valid input values, but the output of intrinsics::uninit() and
intrinsics::init() are not (e.g., an @T is just null, leading to an error
if we should try to increment the ref count).
The free-standing functions in f32, f64, i8, i16, i32, i64, u8, u16,
u32, u64, float, int, and uint are replaced with generic functions in
num instead.
If you were previously using any of those functions, just replace them
with the corresponding function with the same name in num.
Note: If you were using a function that corresponds to an operator, use
the operator instead.
There are lots of unneeded allocas and Store/Load cycles for calls with
immediate return values. This is a first step towards removing that, allowing
immediate return values to be directly returned from trans_call_inner and
trans_lang_call (for now), instead of always stuffing them into an alloca.
For now, only a few things take advantage of the new behaviour, but this
already saves 16k allocas and 43k lines in total in the unoptimized IR
for librustc. Running "make check" under time shows that CPU time for
the unoptimized test suite is reduced by about 7%.
We currently still handle immediate return values a lot like
non-immediate ones. We provide a slot for them and store them into
memory, often just to immediately load them again. To improve this
situation, trans_call_inner has to return a Result which contains the
immediate return value.
Also, it also needs to accept "No destination" in addition to just
SaveIn and Ignore. Since "No destination" isn't something that fits
well into the Dest type, I've chosen to simply use Option<Dest>
instead, paired with an assertion that checks that "None" is only
allowed for immediate return values.
A lot of cross-platform issues stem from rusti/rustpkg, so include these two test suites in the 'check-lite' target which is run on the cross-compile bots. It shouldn't be much of a performance hit because these suites are pretty fast to run.
Hopefully this will make snapshot/tarball creation easier in the future.
There's no need to allocate a return slot for anykind of immediate
return value, not just not for nils. Also, when the return value is
ignored, we only have to copy it to a temporary alloca if it's actually
required to call drop_ty on it.
This is work continued from the now landed #7495 and #7521 pulls.
Removing the headers from unique vectors is another project, so I've separated the allocator.
