The deprecated `LLVM{Get,Set}ValueName` only work with NUL-terminated
strings, but the `2` variants use explicit lengths, which fits better
with Rust strings and slices. We now use these in new helper functions
`llvm::{get,set}_value_name` that convert to/from `&[u8]`.
LLVM 7 is over a year old, which should be plenty for compatibility. The
last LLVM 6 holdout was llvm-emscripten, which went away in #65501.
I've also included a fix for LLVM 8 lacking `MemorySanitizerOptions`,
which was broken by #66522.
Just to make it useable for profiling and such inside
rustc itself. It was vaguely useful in
https://wiki.alopex.li/WhereRustcSpendsItsTime and I figured
I might as well upstream it; I may or may not ever get around
to doing more with it (hopefully I will), but it may be useful
for others.
This commit doesn't actually migrate to LLVM 9, but it brings our own
C++ bindings in line with LLVM 9 and able to compile against tip of
tree. The changes made were:
* The `MainSubprogram` flag for debuginfo moved between flag types.
* Iteration of archive members was tweaked slightly and we have to
construct the two iterators before constructing the returned
`RustArchiveIterator` value.
* The `getOrInsertFunction` binding now returns a wrapper which we use
`getCallee()` on to get the value we're interested in.
Implement optimize(size) and optimize(speed) attributes
This PR implements both `optimize(size)` and `optimize(speed)` attributes.
While the functionality itself works fine now, this PR is not yet complete: the code might be messy in places and, most importantly, the compiletest must be improved with functionality to run tests with custom optimization levels. Otherwise the new attribute cannot be tested properly. Oh, and not all of the RFC is implemented – attribute propagation is not implemented for example.
# TODO
* [x] Improve compiletest so that tests can be written;
* [x] Assign a proper error number (E9999 currently, no idea how to allocate a number properly);
* [ ] Perhaps reduce the duplication in LLVM attribute assignment code…
The new git submodule src/llvm-project is a monorepo replacing src/llvm
and src/tools/{clang,lld,lldb}. This also serves as a rebase for these
projects to the new 8.x branch from trunk.
The src/llvm-emscripten fork is unchanged for now.
If the Rust LLVM fork is used, enable the -mergefunc-use-aliases
flag, which will create aliases for merged functions, rather than
inserting a call from one to the other.
A number of codegen tests needed to be adjusted, because functions
that previously fell below the thunk limit are now being merged.
Merging is prevented either using -C no-prepopulate-passes, or by
making the functions non-identical.
I expect that this is going to break something, somewhere, because
it isn't able to deal with aliases properly, but we won't find out
until we try :)
This fixes#52651.
Support memcpy/memmove with differing src/dst alignment
If LLVM 7 is used, generate memcpy/memmove with differing src/dst alignment. I've added new FFI functions to construct these through the builder API, which is more convenient than dealing with differing intrinsic signatures depending on the LLVM version.
Fixes#49740.
If LLVM 7 is used, generate memcpy/memmove with differing
src/dst alignment. I've added new FFI functions to construct
these through the builder API, which is more convenient than
dealing with differing intrinsic signatures depending on the
LLVM version.
The DWARF generated for Rust enums was always somewhat unusual.
Rather than using DWARF constructs directly, it would emit magic field
names like "RUST$ENCODED$ENUM$0$Name" and "RUST$ENUM$DISR". Since
PR #45225, though, even this has not worked -- the ad hoc scheme was
not updated to handle the wider variety of niche-filling layout
optimizations now available.
This patch changes the generated DWARF to use the standard tags meant
for this purpose; namely, DW_TAG_variant and DW_TAG_variant_part.
The patch to implement this went in to LLVM 7. In order to work with
older versions of LLVM, and because LLVM doesn't do anything here for
PDB, the existing code is kept as a fallback mode.
Support for this DWARF is in the Rust lldb and in gdb 8.2.
Closes#32920Closes#32924Closes#52762Closes#53153
Disable the PLT where possible to improve performance
for indirect calls into shared libraries.
This optimization is enabled by default where possible.
- Add the `NonLazyBind` attribute to `rustllvm`:
This attribute informs LLVM to skip PLT calls in codegen.
- Disable PLT unconditionally:
Apply the `NonLazyBind` attribute on every function.
- Only enable no-plt when full relro is enabled:
Ensures we only enable it when we have linker support.
- Add `-Z plt` as a compiler option
LLVM provides a way of checking whether the constraints and the actual
inline assembly make sense. This commit introduces a check before
emitting code for the inline assembly. If LLVM rejects the inline
assembly (or its constraints), then the compiler emits an error E0668
("malformed inline assembly").
Signed-off-by: Levente Kurusa <lkurusa@acm.org>
Previously linker diagnostic were being hidden when two modules were linked
together but failed to link. This commit fixes the situation by ensuring that we
have a diagnostic handler installed and also adds support for handling linker
diagnostics.
implement minmax intrinsics
This adds the `simd_{fmin,fmax}` intrinsics, which do a vertical (lane-wise) `min`/`max` for floating point vectors that's equivalent to Rust's `min`/`max` for `f32`/`f64`.
It might make sense to make `{f32,f64}::{min,max}` use the `minnum` and `minmax` intrinsics as well.
---
~~HELP: I need some help with these. Either I should go to sleep or there must be something that I must be missing. AFAICT I am calling the `maxnum` builder correctly, yet rustc/LLVM seem to insert a call to `llvm.minnum` there instead...~~ EDIT: Rust's LLVM version is too old :/
Add basic PGO support.
This PR adds two mutually exclusive options for profile usage and generation using LLVM's instruction profile generation (the same as clang uses), `-C pgo-use` and `-C pgo-gen`.
See each commit for details.
