LLVM fails to properly optimize the shifts used to convert the source
value to the right endianess. The resulting assembly copies the value
to the stack one byte at a time even when there's no conversion required
(e.g. u64_to_le_bytes on a little endian machine).
Instead of doing the conversion ourselves using shifts, we can use the
existing intrinsics to perform the endianess conversion and then
transmute the value to get a fixed vector of its bytes.
Before:
test be_i8 ... bench: 21442 ns/iter (+/- 70)
test be_i16 ... bench: 21447 ns/iter (+/- 45)
test be_i32 ... bench: 23832 ns/iter (+/- 63)
test be_i64 ... bench: 26887 ns/iter (+/- 267)
test le_i8 ... bench: 21442 ns/iter (+/- 56)
test le_i16 ... bench: 21448 ns/iter (+/- 36)
test le_i32 ... bench: 23825 ns/iter (+/- 153)
test le_i64 ... bench: 26271 ns/iter (+/- 138)
After:
test be_i8 ... bench: 21438 ns/iter (+/- 10)
test be_i16 ... bench: 21441 ns/iter (+/- 15)
test be_i32 ... bench: 19057 ns/iter (+/- 6)
test be_i64 ... bench: 21439 ns/iter (+/- 34)
test le_i8 ... bench: 21438 ns/iter (+/- 19)
test le_i16 ... bench: 21439 ns/iter (+/- 8)
test le_i32 ... bench: 21439 ns/iter (+/- 19)
test le_i64 ... bench: 21438 ns/iter (+/- 22)
Right now the bots are all injecting a libstd version, so all the rustpkg tests
are passing. All rustpkg compilations will fail unless the version number is
explicitly given because rustpkg attempts to exactly guess the target file name.
Switch back to using a pattern match in order to unbreak tests.
Closes#11852
This is has been obsolete for quite a while now (including a release),
so removing the special handling seems fine. (The error message is quite
good still anyway.)
Fixes#9580.
Introduce marker types for indicating variance and for opting out
of builtin bounds.
Fixes#10834.
Fixes#11385.
cc #5922.
r? @pnkfelix (since you reviewed the variance inference in the first place)
EINVAL means that the requested stack size is either not a multiple
of the system page size or that it's smaller than PTHREAD_STACK_MIN.
Figure out what the case is, fix it up and retry. If it still fails,
give up, like before.
Suggestions for future improvements:
* don't fail!() but instead signal a condition, or
* silently ignore the error and use a default sized stack.
Fixes#11694.
The first two commits put the framework in place, the third one contains the meat.
