On Windows, it is often applied to the second parameter, and the x86
backend is prepared to deal with sret appearing on any parameter.
Other backends assume it only appears on parameter zero, but those are
target-specific requirements, and not an IR-level rule.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280951 91177308-0d34-0410-b5e6-96231b3b80d8
No need to have a long inline code snippet in this doc.
Also move "flags that control numerical code" underneath the "invoking
clang" section, and reformat things a bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280857 91177308-0d34-0410-b5e6-96231b3b80d8
CUDA is an extension to C++ -- there is no such thing as "CUDA C". But
also, the language is much more commonly called "CUDA" than "CUDA C++".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280849 91177308-0d34-0410-b5e6-96231b3b80d8
auto-brief format for doxygen comments. Most notable is switching to
that in the example doxygen comment. I've also tweaked the wording but
am happy to tweak it further if others have suggestions here.
Mostly doing this to capture something I and others have been writing
consistently and repeatedly in code reviews.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280419 91177308-0d34-0410-b5e6-96231b3b80d8
This is a partial revert of r280013. Brad King pointed out these variable names are matching CMake conventions, so we should preserve them.
I've also added a direct mapping of the LLVM_*_DIR variables which we need to make projects support building in and out of tree.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280380 91177308-0d34-0410-b5e6-96231b3b80d8
I've found this out the hard way; LLVM will not normally catch this
error (unless -verify-machineinstrs is passed), and under certain
very specific circumstances (such as register scavenger running
under pressure) this would result in an opaque crash in codegen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280071 91177308-0d34-0410-b5e6-96231b3b80d8
With the runtimes build we're trying to use LLVMConfig.cmake as a way of providing LLVM_* variables that are needed to behave as if the project is building in tree. To make this work we need to rename two variables by dropping the "S" from the end. This makes the variables match the in-tree names.
This renames:
LLVM_INCLUDE_DIRS -> LLVM_INCLUDE_DIR
LLVM_LIBRARY_DIRS -> LLVM_LIBRARY_DIR
The versions ending in S are not used in-tree anywhere. This also cleans up LLVM_LIBRARY_DIR being set to the same value with and without the "S".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280013 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
[Coroutines] Part 9: Add cleanup subfunction.
This patch completes coroutine heap allocation elision. Now, the heap elision example from docs\Coroutines.rst compiles and produces expected result (see test/Transform/Coroutines/ex3.ll)
Intrinsic Changes:
* coro.free gets a token parameter tying it to coro.id to allow reliably discovering all coro.frees associated with a particular coroutine.
* coro.id gets an extra parameter that points back to a coroutine function. This allows to check whether a coro.id describes the enclosing function or it belongs to a different function that was later inlined.
CoroSplit now creates three subfunctions:
# f$resume - resume logic
# f$destroy - cleanup logic, followed by a deallocation code
# f$cleanup - just the cleanup code
CoroElide pass during devirtualization replaces coro.destroy with either f$destroy or f$cleanup depending whether heap elision is performed or not.
Other fixes, improvements:
* Fixed buglet in Shape::buildFrame that was not creating coro.save properly if coroutine has more than one suspend point.
* Switched to using variable width suspend index field (no longer limited to 32 bit index field can be as little as i1 or as large as i<whatever-size_t-is>)
Reviewers: majnemer
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23844
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279971 91177308-0d34-0410-b5e6-96231b3b80d8
Primarily, this clarifies wording in a few places, and adds "\ "s to
make the formatting of things like "``Foo`` s" better.
Thanks to Michael Kuperstein for the comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279007 91177308-0d34-0410-b5e6-96231b3b80d8
Making explicit our current policy to accept new targets as experimental and
later official. Every new target should follow these rules to be added,
and kept relevant in the upstream tree.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278971 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
1. Make coroutine representation more robust against optimization that may duplicate instruction by introducing coro.id intrinsics that returns a token that will get fed into coro.alloc and coro.begin. Due to coro.id returning a token, it won't get duplicated and can be used as reliable indicator of coroutine identify when a particular coroutine call gets inlined.
2. Move last three arguments of coro.begin into coro.id as they will be shared if coro.begin will get duplicated.
3. doc + test + code updated to support the new intrinsic.
Reviewers: mehdi_amini, majnemer
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D23412
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278481 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
A particular coroutine usage pattern, where a coroutine is created, manipulated and
destroyed by the same calling function, is common for coroutines implementing
RAII idiom and is suitable for allocation elision optimization which avoid
dynamic allocation by storing the coroutine frame as a static `alloca` in its
caller.
coro.free and coro.alloc intrinsics are used to indicate which code needs to be suppressed
when dynamic allocation elision happens:
```
entry:
%elide = call i8* @llvm.coro.alloc()
%need.dyn.alloc = icmp ne i8* %elide, null
br i1 %need.dyn.alloc, label %coro.begin, label %dyn.alloc
dyn.alloc:
%alloc = call i8* @CustomAlloc(i32 4)
br label %coro.begin
coro.begin:
%phi = phi i8* [ %elide, %entry ], [ %alloc, %dyn.alloc ]
%hdl = call i8* @llvm.coro.begin(i8* %phi, i32 0, i8* null,
i8* bitcast ([2 x void (%f.frame*)*]* @f.resumers to i8*))
```
and
```
%mem = call i8* @llvm.coro.free(i8* %hdl)
%need.dyn.free = icmp ne i8* %mem, null
br i1 %need.dyn.free, label %dyn.free, label %if.end
dyn.free:
call void @CustomFree(i8* %mem)
br label %if.end
if.end:
...
```
If heap allocation elision is performed, we replace coro.alloc with a static alloca on the caller frame and coro.free with null constant.
Also, we need to make sure that if there are any tail calls referencing the coroutine frame, we need to remote tail call attribute, since now coroutine frame lives on the stack.
Documentation and overview is here: http://llvm.org/docs/Coroutines.html.
Upstreaming sequence (rough plan)
1.Add documentation. (https://reviews.llvm.org/D22603)
2.Add coroutine intrinsics. (https://reviews.llvm.org/D22659)
3.Add empty coroutine passes. (https://reviews.llvm.org/D22847)
4.Add coroutine devirtualization + tests.
ab) Lower coro.resume and coro.destroy (https://reviews.llvm.org/D22998)
c) Do devirtualization (https://reviews.llvm.org/D23229)
5.Add CGSCC restart trigger + tests. (https://reviews.llvm.org/D23234)
6.Add coroutine heap elision + tests. <= we are here
7.Add the rest of the logic (split into more patches)
Reviewers: mehdi_amini, majnemer
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D23245
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278242 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r278048. Something changed between the last time I
built this--it takes awhile on my ridiculously slow and ancient
computer--and now that broke this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278053 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Based on two patches by Michael Mueller.
This is a target attribute that causes a function marked with it to be
emitted as "hotpatchable". This particular mechanism was originally
devised by Microsoft for patching their binaries (which they are
constantly updating to stay ahead of crackers, script kiddies, and other
ne'er-do-wells on the Internet), but is now commonly abused by Windows
programs to hook API functions.
This mechanism is target-specific. For x86, a two-byte no-op instruction
is emitted at the function's entry point; the entry point must be
immediately preceded by 64 (32-bit) or 128 (64-bit) bytes of padding.
This padding is where the patch code is written. The two byte no-op is
then overwritten with a short jump into this code. The no-op is usually
a `movl %edi, %edi` instruction; this is used as a magic value
indicating that this is a hotpatchable function.
Reviewers: majnemer, sanjoy, rnk
Subscribers: dberris, llvm-commits
Differential Revision: https://reviews.llvm.org/D19908
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278048 91177308-0d34-0410-b5e6-96231b3b80d8