922 Commits

Author SHA1 Message Date
Eli Friedman 673dbe1b5e [clang codegen] Use IR "align" attribute for static array arguments.
Without the "align" attribute, marking the argument dereferenceable is
basically useless.  See also D80166.

Fixes https://bugs.llvm.org/show_bug.cgi?id=46876 .

Differential Revision: https://reviews.llvm.org/D84992
2020-08-18 12:51:16 -07:00
Matt Arsenault 30eeb742f1 clang: Use byref for aggregate kernel arguments
Add address space to indirect abi info and use it for kernels.

Previously, indirect arguments assumed assumed a stack passed object
in the alloca address space using byval. A stack pointer is unsuitable
for kernel arguments, which are passed in a separate, constant buffer
with a different address space.

Start using the new byref for aggregate kernel arguments. Previously
these were emitted as raw struct arguments, and turned into loads in
the backend. These will lower identically, although with byref you now
have the option of applying an explicit alignment. In the future, a
reasonable implementation would use byref for all kernel arguments
(this would be a practical problem at the moment due to losing things
like noalias on pointer arguments).

This is mostly to avoid fighting the optimizer's treatment of
aggregate load/store. SROA and instcombine both turn aggregate loads
and stores into a long sequence of element loads and stores, rather
than the optimizable memcpy I would expect in this situation. Now an
explicit memcpy will be introduced up-front which is better understood
and helps eliminate the alloca in more situations.

This skips using byref in the case where HIP kernel pointer arguments
in structs are promoted to global pointers. At minimum an additional
patch is needed to allow coercion with indirect arguments. This also
skips using it for OpenCL due to the current workaround used to
support kernels calling kernels. Distinct function bodies would need
to be generated up front instead of emitting an illegal call.
2020-08-06 15:52:26 -04:00
Akira Hatanaka ed6b578040 [CodeGen] Emit a call instruction instead of an invoke if the called
llvm function is marked nounwind

This fixes cases where an invoke is emitted, despite the called llvm
function being marked nounwind, because ConstructAttributeList failed to
add the attribute to the attribute list. llvm optimization passes turn
invokes into calls and optimize away the exception handling code, but
it's better to avoid emitting the code in the front-end if the called
function is known not to raise an exception.

Differential Revision: https://reviews.llvm.org/D83906
2020-07-15 14:47:45 -07:00
Aaron Ballman 006c49d890 Change behavior with zero-sized static array extents
Currently, Clang previously diagnosed this code by default:
  void f(int a[static 0]);
saying that "static has no effect on zero-length arrays", which was
accurate.

However, static array extents require that the caller of the function
pass a nonnull pointer to an array of *at least* that number of
elements, but it can pass more (see C17 6.7.6.3p6). Given that we allow
zero-sized arrays as a GNU extension and that it's valid to pass more
elements than specified by the static array extent, we now support
zero-sized static array extents with the usual semantics because it can
be useful in cases like:

  void my_bzero(char p[static 0], int n);
  my_bzero(&c+1, 0); //ok
  my_bzero(t+k,n-k); //ok, pattern from actual code
2020-07-10 15:58:11 -04:00
Erich Keane 2831a317b6 Implement AVX ABI Warning/error
The x86-64 "avx" feature changes how >128 bit vector types are passed,
instead of being passed in separate 128 bit registers, they can be
passed in 256 bit registers.

"avx512f" does the same thing, except it switches from 256 bit registers
to 512 bit registers.

The result of both of these is an ABI incompatibility between functions
compiled with and without these features.

This patch implements a warning/error pair upon an attempt to call a
function that would run afoul of this. First, if a function is called
that would have its ABI changed, we issue a warning.

Second, if said call is made in a situation where the caller and callee
are known to have different calling conventions (such as the case of
'target'), we instead issue an error.

Differential Revision: https://reviews.llvm.org/D82562
2020-07-01 07:14:31 -07:00
Lucas Prates ada4c9dc4a [ARM][Clang] Removing lowering of half-precision FP arguments and returns from Clang's CodeGen
Summary:
On the process of moving the argument lowering handling for
half-precision floating point arguments and returns to the backend, this
patch removes the code that was responsible for handling the coercion of
those arguments in Clang's Codegen.

Reviewers: rjmccall, chill, ostannard, dnsampaio

Reviewed By: ostannard

Subscribers: stuij, kristof.beyls, dmgreen, danielkiss, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D81451
2020-06-18 13:17:07 +01:00
Tyker 51e4aa87e0 attempt to fix failing buildbots after 3bab88b7ba
Prevent IR-gen from emitting consteval declarations

Summary: with this patch instead of emitting calls to consteval function. the IR-gen will emit a store of the already computed result.
2020-06-15 12:58:37 +02:00
Kirill Bobyrev 550c4562d1 Revert "Prevent IR-gen from emitting consteval declarations"
This reverts commit 3bab88b7ba.

This patch causes test failures:
http://lab.llvm.org:8011/builders/clang-cmake-armv7-quick/builds/17260
2020-06-15 12:14:15 +02:00
Tyker 3bab88b7ba Prevent IR-gen from emitting consteval declarations
Summary: with this patch instead of emitting calls to consteval function. the IR-gen will emit a store of the already computed result.

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76420
2020-06-15 10:47:14 +02:00
Nikita Popov 7cac7e0cfc [IR] Prefer hasFnAttribute() where possible (NFC)
When checking for an enum function attribute, use hasFnAttribute()
rather than hasAttribute() at FunctionIndex, because it is
significantly faster (and more concise to boot).
2020-06-15 09:30:35 +02:00
Arthur Eubanks ce7d3e1c55 Reland (again) D80966 [codeview] Put !heapallocsite on calls to operator new
Check that getDebugInfo() is not null, as in the first revision, before
calling getDebugInfo()->addHeapAllocSiteMetadata().
Else would cause a crash with a new expression in a default arg.

---

Clang marks calls to operator new as heap allocation sites, but the
operator declared at global scope returns a void pointer. There is no
explicit cast in the code, so the compiler has to write down the
allocated type itself.

Also generalize a cast to use CallBase, so that we mark heap alloc sites
when exceptions are enabled.

Differential Revision: https://reviews.llvm.org/D80966
2020-06-09 09:27:32 -07:00
Arthur Eubanks a92ce3b706 Revert "Reland D80966 [codeview] Put !heapallocsite on calls to operator new"
This reverts commit b6e143aa54.

Causes https://bugs.chromium.org/p/chromium/issues/detail?id=1092370#c5.
Will investigate and reland (again).
2020-06-08 12:49:41 -07:00
Fangrui Song b6e143aa54 Reland D80966 [codeview] Put !heapallocsite on calls to operator new
With a change to use `CGM.getCodeGenOpts().getDebugInfo() != codegenoptions::NoDebugInfo`
instead of `getDebugInfo()`,
to fix `Profile-<arch> :: instrprof-gcov-multithread_fork.test`

See CodeGenModule::CodeGenModule, `EmitGcovArcs || EmitGcovNotes` can
set `clang::CodeGen::CodeGenModule::DebugInfo`.

---

Clang marks calls to operator new as heap allocation sites, but the
operator declared at global scope returns a void pointer. There is no
explicit cast in the code, so the compiler has to write down the
allocated type itself.

Also generalize a cast to use CallBase, so that we mark heap alloc sites
when exceptions are enabled.

Differential Revision: https://reviews.llvm.org/D80966
2020-06-07 13:35:20 -07:00
Douglas Yung 059ba74bb6 Revert "[codeview] Put !heapallocsite on calls to operator new"
This reverts commit 672ed53860.

This commit is hitting an assertion failure across multiple bots in the test:
Profile-<arch> :: instrprof-gcov-multithread_fork.test

Failing bots include:
http://lab.llvm.org:8011/builders/llvm-avr-linux/builds/2205
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-lld/builds/8967
http://lab.llvm.org:8011/builders/clang-cmake-armv7-full/builds/10789
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/27750
http://lab.llvm.org:8011/builders/sanitizer-ppc64be-linux/builds/16751
2020-06-06 23:30:46 +00:00
Reid Kleckner 672ed53860 [codeview] Put !heapallocsite on calls to operator new
Clang marks calls to operator new as heap allocation sites, but the
operator declared at global scope returns a void pointer. There is no
explicit cast in the code, so the compiler has to write down the
allocated type itself.

Also generalize a cast to use CallBase, so that we mark heap alloc sites
when exceptions are enabled.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D80966
2020-06-05 12:52:38 -07:00
John McCall 8a8d703be0 Fix how cc1 command line options are mapped into FP options.
Canonicalize on storing FP options in LangOptions instead of
redundantly in CodeGenOptions.  Incorporate -ffast-math directly
into the values of those LangOptions rather than considering it
separately when building FPOptions.  Build IR attributes from
those options rather than a mix of sources.

We should really simplify the driver/cc1 interaction here and have
the driver pass down options that cc1 directly honors.  That can
happen in a follow-up, though.

Patch by Michele Scandale!
https://reviews.llvm.org/D80315
2020-06-01 22:00:30 -04:00
Zequan Wu e36076ee3a [clang] Add nomerge function attribute to clang
Differential Revision: https://reviews.llvm.org/D79121
2020-05-21 17:07:39 -07:00
Zequan Wu b0a0f01bc1 Revert "Add nomerge function attribute to clang"
This reverts commit 307e853954.
2020-05-21 16:13:18 -07:00
Zequan Wu 307e853954 Add nomerge function attribute to clang 2020-05-21 15:28:27 -07:00
Eli Friedman 62f3ef2b53 [CGCall] Annotate references with "align" attribute.
If we're going to assume references are dereferenceable, we should also
assume they're aligned: otherwise, we can't actually dereference them.

See also D80072.

Differential Revision: https://reviews.llvm.org/D80166
2020-05-19 20:21:30 -07:00
Martin Böhme 4c09289f63 [clang] Add an API to retrieve implicit constructor arguments.
Summary:
This is needed in Swift for C++ interop -- see here for the corresponding Swift change:

https://github.com/apple/swift/pull/30630

As part of this change, I've had to make some changes to the interface of CGCXXABI to return the additional parameters separately rather than adding them directly to a `CallArgList`.

Reviewers: rjmccall

Reviewed By: rjmccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D79942
2020-05-19 09:21:26 +02:00
John McCall 32870a84d9 Expose IRGen API to add the default IR attributes to a function definition.
I've also made a stab at imposing some more order on where and how we add
attributes; this part should be NFC.  I wasn't sure whether the CUDA use
case for libdevice should propagate CPU/features attributes, so there's a
bit of unnecessary duplication.
2020-05-16 14:44:54 -04:00
Nikita Popov f89f7da999 [IR] Convert null-pointer-is-valid into an enum attribute
The "null-pointer-is-valid" attribute needs to be checked by many
pointer-related combines. To make the check more efficient, convert
it from a string into an enum attribute.

In the future, this attribute may be replaced with data layout
properties.

Differential Revision: https://reviews.llvm.org/D78862
2020-05-15 19:41:07 +02:00
Matt Arsenault 03cb328d6f clang: Cleanup usage of CreateMemCpy
It handles the the pointee type casts in preparation for opaque
pointers.
2020-05-08 20:57:56 -04:00
Michael Liao 9142c0b46b [clang][codegen] Hoist parameter attribute setting in function prolog.
Summary:
- If the coerced type is still a pointer, it should be set with proper
  parameter attributes, such as `noalias`, `nonnull`, and etc. Hoist
  that (pointer) parameter attribute setting so that the coerced pointer
  parameter could be marked properly.

Depends on D79394

Reviewers: rjmccall, kerbowa, yaxunl

Subscribers: jvesely, nhaehnle, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D79395
2020-05-05 15:31:51 -04:00