Commit Graph

197 Commits

Author SHA1 Message Date
Tyker d7deef1206 Revert "[AssumeBundles] add cannonicalisation to the assume builder"
This reverts commit 90c50cad19.
2020-06-16 14:34:55 +02:00
Tyker 90c50cad19 [AssumeBundles] add cannonicalisation to the assume builder
Summary:
this reduces significantly the number of assumes generated without aftecting too much
the information that is preserved. this improves the compile-time cost
of enable-knowledge-retention significantly.

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: hiraditya, asbirlea, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79650
2020-06-16 13:12:35 +02:00
Eli Friedman f26bdb539e Make Value::getPointerAlignment() return an Align, not a MaybeAlign.
If we don't know anything about the alignment of a pointer, Align(1) is
still correct: all pointers are at least 1-byte aligned.

Included in this patch is a bugfix for an issue discovered during this
cleanup: pointers with "dereferenceable" attributes/metadata were
assumed to be aligned according to the type of the pointer.  This
wasn't intentional, as far as I can tell, so Loads.cpp was fixed to
stop making this assumption. Frontends may need to be updated.  I
updated clang's handling of C++ references, and added a release note for
this.

Differential Revision: https://reviews.llvm.org/D80072
2020-05-20 16:37:20 -07:00
Jay Foad 91ef7cb508 [IR] Trivial cleanups in Use. NFC.
Remove Use::setPrev. It provided no value because it had the same
accessibility as the underlying field Prev, and there was no
corresponding setNext anyway.

Simplify Use::removeFromList.
2020-05-15 18:14:45 +01:00
Kuter Dinel e57807769b [Attributor] Use AAValueConstantRange to infer dereferencability.
Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D76208
2020-05-13 16:44:15 -05:00
Chris Lattner 89c8ffd542 NFC: Clean up the implementation of StringPool a bit, and remove dependence on some "implicitly MallocAllocator" based methods on StringMapEntry. This allows reducing the #includes in StringMapEntry.h.
Summary:
StringPool has many caveats and isn't used in the monorepo.  I will
propose removing it as a patch separate from this refactoring patch.

Reviewers: rriddle

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77976
2020-04-12 16:37:17 -07:00
Guillaume Chatelet 9068bccbae [Alignment][NFC] Deprecate InstrTypes getRetAlignment/getParamAlignment
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77312
2020-04-03 13:21:58 +00:00
Eli Friedman ebec984e14 [AliasAnalysis] Misc fixes for checking aliasing with scalable types.
This is fixing up various places that use the implicit
TypeSize->uint64_t conversion.

The new overloads in MemoryLocation.h are already used in various places
that construct a MemoryLocation from a TypeSize, including MemorySSA.
(They were using the implicit conversion before.)

Differential Revision: https://reviews.llvm.org/D76249
2020-03-18 12:28:47 -07:00
Tyker f16f139db4 Basis of dropping uses in llvm.assume.
Summary: This patch adds the basic utilities to deal with dropable uses. dropable uses are uses that we rather drop than prevent transformations, for now they are limited to uses in llvm.assume.

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: uenoku, lebedev.ri, mgorny, hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73404
2020-03-12 10:10:22 +01:00
Evgenii Stepanov 7dd2810907 Fix MSAN failure on Function destruction
Summary:
When Function is destroyed, GlobalValue base class is destroyed, then
Value destructor would call use_empty, which ultimately attempts to
downcast 'this' to GlobalValue. This is UB, and is caught my MSAN as
accessing uninitialized memory.

Call materialized_use_empty, which doesn't call
assertModuleIsMaterializedImpl().

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74161

Patch by Antonio Maiorano.
2020-02-06 15:09:58 -08:00
Roman Lebedev a6492e2271
[IR] Value::getPointerAlignment(): handle pointer constants
Summary:
New `@test13` in `Attributor/align.ll` is the main motivation - `null` pointer
really does not limit our alignment knowledge, in fact it is fully aligned
since it has no bits set.

Here we don't special-case `null` pointer because it is somewhat controversial
to add one more place where we enforce that `null` pointer is zero,
but instead we do the more general thing of trying to perform constant-fold
of pointer constant to an integer, and perform alignment inferrment on that.

Reviewers: jdoerfert, gchatelet, courbet, sstefan1

Reviewed By: jdoerfert

Subscribers: hiraditya, arphaman, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73131
2020-01-22 01:32:46 +03:00
Reid Kleckner 4c1a1d3cf9 Add missing includes needed to prune LLVMContext.h include, NFC
These are a pre-requisite to removing #include "llvm/Support/Options.h"
from LLVMContext.h: https://reviews.llvm.org/D70280
2019-11-14 15:23:15 -08:00
Guillaume Chatelet bae629b966 [Alignment][NFC] Value::getPointerAlignment returns MaybeAlign
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet, jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68398

llvm-svn: 374889
2019-10-15 13:58:22 +00:00
Erich Keane 8a410bcef0 Fix Calling Convention through aliases
r369697 changed the behavior of stripPointerCasts to no longer include
aliases.  However, the code in CGDeclCXX.cpp's createAtExitStub counted
on the looking through aliases to properly set the calling convention of
a call.

The result of the change was that the calling convention mismatch of the
call would be replaced with a llvm.trap, causing a runtime crash.

Differential Revision: https://reviews.llvm.org/D68584

llvm-svn: 373929
2019-10-07 17:28:03 +00:00
Guillaume Chatelet 18f805a7ea [Alignment][NFC] Remove unneeded llvm:: scoping on Align types
llvm-svn: 373081
2019-09-27 12:54:21 +00:00
Guillaume Chatelet 6200a5689a [NFC] Rearrange Value::getPointerAlignment
Reviewers: courbet

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67918

llvm-svn: 372987
2019-09-26 15:13:05 +00:00
Peter Collingbourne 2452d7030b IR. Change strip* family of functions to not look through aliases.
I noticed another instance of the issue where references to aliases were
being replaced with aliasees, this time in InstCombine. In the instance that
I saw it turned out to be only a QoI issue (a symbol ended up being missing
from the symbol table due to the last reference to the alias being removed,
preventing HWASAN from symbolizing a global reference), but it could easily
have manifested as incorrect behaviour.

Since this is the third such issue encountered (previously: D65118, D65314)
it seems to be time to address this common error/QoI issue once and for all
and make the strip* family of functions not look through aliases.

Includes a test for the specific issue that I saw, but no doubt there are
other similar bugs fixed here.

As with D65118 this has been tested to make sure that the optimization isn't
load bearing. I built Clang, Chromium for Linux, Android and Windows as well
as the test-suite and there were no size regressions.

Differential Revision: https://reviews.llvm.org/D66606

llvm-svn: 369697
2019-08-22 19:56:14 +00:00
Guillaume Chatelet 65e4b47aad [LLVM][Alignment] Introduce Alignment Type in DataLayout
Summary:
This is patch is part of a serie to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet, jfb, jakehehrlich

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65521

Make getFunctionPtrAlign() return MaybeAlign

llvm-svn: 367817
2019-08-05 09:00:43 +00:00
Roman Lebedev 081e990d08 [IR] Value: add replaceUsesWithIf() utility
Summary:
While there is always a `Value::replaceAllUsesWith()`,
sometimes the replacement needs to be conditional.

I have only cleaned a few cases where `replaceUsesWithIf()`
could be used, to both add test coverage,
and show that it is actually useful.

Reviewers: jdoerfert, spatel, RKSimon, craig.topper

Reviewed By: jdoerfert

Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, aheejin, george.burgess.iv, asbirlea, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65528

llvm-svn: 367548
2019-08-01 12:32:08 +00:00
Hideto Ueno afd4a37b2a [IR] Fix getPointerAlignment for CallBase
Summary:
In current getPointerAlignemnt implementation, CallBase.getPointerAlignement(..) checks only parameter attriutes in the callsite.  For example,

```
declare align 8 i8* @foo()

define void @bar() {
    %a = tail call align 8 i8* @foo() ; getPointerAlignment returns 8
    %b = tail call i8* @foo() ; getPointerAlignemnt returns 0
    ret void
}
```

This patch will fix the problem.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65281

llvm-svn: 367185
2019-07-28 06:17:46 +00:00
Ryan Taylor 6f13637a3e [IR][Verifier] Allow IntToPtrInst to be !dereferenceable
Summary:
Allow IntToPtrInst to carry !dereferenceable metadata tag.
This is valid since !dereferenceable can be only be applied to
pointer type values.

Change-Id: If8a6e3c616f073d51eaff52ab74535c29ed497b4

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64954

llvm-svn: 366826
2019-07-23 17:19:56 +00:00
Johannes Doerfert 3ed286a388 Replace three "strip & accumulate" implementations with a single one
This patch replaces the three almost identical "strip & accumulate"
implementations for constant pointer offsets with a single one,
combining the respective functionalities. The old interfaces are kept
for now.

Differential Revision: https://reviews.llvm.org/D64468

llvm-svn: 365723
2019-07-11 01:14:48 +00:00
Johannes Doerfert 40107ce753 Introduce Value::stripPointerCastsSameRepresentation
This patch allows current users of Value::stripPointerCasts() to force
the result of the function to have the same representation as the value
it was called on. This is useful in various cases, e.g., (non-)null
checks.

In this patch only a single call site was adjusted to fix an existing
misuse that would cause nonnull where they may be wrong. Uses in
attribute deduction and other areas, e.g., D60047, are to be expected.

For a discussion on this topic, please see [0].

[0] http://lists.llvm.org/pipermail/llvm-dev/2018-December/128423.html

Reviewers: hfinkel, arsenm, reames

Subscribers: wdng, hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61607

llvm-svn: 362545
2019-06-04 20:21:46 +00:00
Michael Platings 308e82eceb [IR][ARM] Add function pointer alignment to datalayout
Use this feature to fix a bug on ARM where 4 byte alignment is
incorrectly assumed.

Differential Revision: https://reviews.llvm.org/D57335

llvm-svn: 355685
2019-03-08 10:44:06 +00:00
Mitch Phillips 92dd321a14 Rollback of rL355585.
Introduces memory leak in FunctionTest.GetPointerAlignment that breaks sanitizer buildbots:

```
=================================================================
==2453==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 128 byte(s) in 1 object(s) allocated from:
    #0 0x610428 in operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:105
    #1 0x16936bc in llvm::User::operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/User.cpp:151:19
    #2 0x7c3fe9 in Create /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/IR/Function.h:144:12
    #3 0x7c3fe9 in (anonymous namespace)::FunctionTest_GetPointerAlignment_Test::TestBody() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/unittests/IR/FunctionTest.cpp:136
    #4 0x1a836a0 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #5 0x1a836a0 in testing::Test::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2474
    #6 0x1a85c55 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
    #7 0x1a870d0 in testing::TestCase::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
    #8 0x1aa5b84 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
    #9 0x1aa4d30 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #10 0x1aa4d30 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4257
    #11 0x1a6b656 in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
    #12 0x1a6b656 in main /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50
    #13 0x7f5af37a22e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)

Indirect leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x610428 in operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:105
    #1 0x151be6b in make_unique<llvm::ValueSymbolTable> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/ADT/STLExtras.h:1349:29
    #2 0x151be6b in llvm::Function::Function(llvm::FunctionType*, llvm::GlobalValue::LinkageTypes, unsigned int, llvm::Twine const&, llvm::Module*) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/Function.cpp:241
    #3 0x7c4006 in Create /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/IR/Function.h:144:16
    #4 0x7c4006 in (anonymous namespace)::FunctionTest_GetPointerAlignment_Test::TestBody() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/unittests/IR/FunctionTest.cpp:136
    #5 0x1a836a0 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #6 0x1a836a0 in testing::Test::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2474
    #7 0x1a85c55 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
    #8 0x1a870d0 in testing::TestCase::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
    #9 0x1aa5b84 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
    #10 0x1aa4d30 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #11 0x1aa4d30 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4257
    #12 0x1a6b656 in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
    #13 0x1a6b656 in main /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50
    #14 0x7f5af37a22e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)

SUMMARY: AddressSanitizer: 168 byte(s) leaked in 2 allocation(s).
```

See http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/11358/steps/check-llvm%20asan/logs/stdio for more information.

Also introduces use-of-uninitialized-value in ConstantsTest.FoldGlobalVariablePtr:
```
==7070==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x14e703c in User /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/User.h:79:5
    #1 0x14e703c in Constant /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/Constant.h:44
    #2 0x14e703c in llvm::GlobalValue::GlobalValue(llvm::Type*, llvm::Value::ValueTy, llvm::Use*, unsigned int, llvm::GlobalValue::LinkageTypes, llvm::Twine const&, unsigned int) /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/GlobalValue.h:78
    #3 0x14e5467 in GlobalObject /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/GlobalObject.h:34:9
    #4 0x14e5467 in llvm::GlobalVariable::GlobalVariable(llvm::Type*, bool, llvm::GlobalValue::LinkageTypes, llvm::Constant*, llvm::Twine const&, llvm::GlobalValue::ThreadLocalMode, unsigned int, bool) /b/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/Globals.cpp:314
    #5 0x6938f1 in llvm::(anonymous namespace)::ConstantsTest_FoldGlobalVariablePtr_Test::TestBody() /b/sanitizer-x86_64-linux-fast/build/llvm/unittests/IR/ConstantsTest.cpp:565:18
    #6 0x1a240a1 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc
    #7 0x1a240a1 in testing::Test::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2474
    #8 0x1a26d26 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
    #9 0x1a2815f in testing::TestCase::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
    #10 0x1a43de8 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
    #11 0x1a42c47 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc
    #12 0x1a42c47 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:4257
    #13 0x1a0dfba in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
    #14 0x1a0dfba in main /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50
    #15 0x7f2081c412e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #16 0x4dff49 in _start (/b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/unittests/IR/IRTests+0x4dff49)

SUMMARY: MemorySanitizer: use-of-uninitialized-value /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/User.h:79:5 in User
```

See http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/30222/steps/check-llvm%20msan/logs/stdio for more information.

llvm-svn: 355616
2019-03-07 18:13:39 +00:00
Michael Platings fd4156ed4d [IR][ARM] Add function pointer alignment to datalayout
Use this feature to fix a bug on ARM where 4 byte alignment is
incorrectly assumed.

Differential Revision: https://reviews.llvm.org/D57335

llvm-svn: 355585
2019-03-07 09:15:23 +00:00
Mitch Phillips 318028f00f Revert "[IR][ARM] Add function pointer alignment to datalayout"
This reverts commit 2391bfca97.

This reverts rL355522 (https://reviews.llvm.org/D57335).

Kills buildbots that use '-Werror' with the following error:
	/var/lib/buildbot/sanitizer-buildbot6/sanitizer-x86_64-linux-android/build/llvm/lib/IR/Value.cpp:657:7: error: default label in switch which covers all enumeration values [-Werror,-Wcovered-switch-default]

See buildbots http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/30200/steps/check-llvm%20asan/logs/stdio for more information.

llvm-svn: 355537
2019-03-06 19:17:18 +00:00
Michael Platings 2391bfca97 [IR][ARM] Add function pointer alignment to datalayout
Use this feature to fix a bug on ARM where 4 byte alignment is
incorrectly assumed.

Differential Revision: https://reviews.llvm.org/D57335

llvm-svn: 355522
2019-03-06 17:24:11 +00:00
Craig Topper 784929d045 Implementation of asm-goto support in LLVM
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html

This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.

This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.

There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.

Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii

Differential Revision: https://reviews.llvm.org/D53765

llvm-svn: 353563
2019-02-08 20:48:56 +00:00
George Burgess IV 179f6baa45 Remove a redundant space from an error message; NFC
llvm-svn: 352576
2019-01-30 00:28:56 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Chandler Carruth 90c09232a2 [CallSite removal] Move the rest of IR implementation code away from
`CallSite`.

With this change, the remaining `CallSite` usages are just for
implementing the wrapper type itself.

This does update the C API but leaves the names of that API alone and
only updates their implementation.

Differential Revision: https://reviews.llvm.org/D56184

llvm-svn: 350509
2019-01-07 07:31:49 +00:00
Vedant Kumar 4de31bba51 [IR] Add hasNPredecessors, hasNPredecessorsOrMore to BasicBlock
Add methods to BasicBlock which make it easier to efficiently check
whether a block has N (or more) predecessors.

This can be more efficient than using pred_size(), which is a linear
time operation.

We might consider adding similar methods for successors. I haven't done
so in this patch because succ_size() is already O(1).

With this patch applied, I measured a 0.065% compile-time reduction in
user time for running `opt -O3` on the sqlite3 amalgamation (30 trials).
The change in mergeStoreIntoSuccessor alone saves 45 million linked list
iterations in a stage2 Release build of llc.

See llvm.org/PR39702 for a harder but more general way of achieving
similar results.

Differential Revision: https://reviews.llvm.org/D54686

llvm-svn: 347256
2018-11-19 19:54:27 +00:00
JF Bastien e69ae76b20 [NFC] Remove magic bool param in RAUW
Use an enum class instead.

llvm-svn: 339366
2018-08-09 18:28:54 +00:00
Piotr Padlewski 5b3db45e8f Implement strip.invariant.group
Summary:
This patch introduce new intrinsic -
strip.invariant.group that was described in the
RFC: Devirtualization v2

Reviewers: rsmith, hfinkel, nlopes, sanjoy, amharc, kuhar

Subscribers: arsenm, nhaehnle, JDevlieghere, hiraditya, xbolva00, llvm-commits

Differential Revision: https://reviews.llvm.org/D47103

Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com>
llvm-svn: 336073
2018-07-02 04:49:30 +00:00
Dmitry Mikulin 4539487650 In thin and full LTO + CFI, direct function calls may go through jump table
entries to reach the target. Since these calls don't require type checks,
we can short-circuit them to their real targets, except in cases when they
can be pre-empted.

Differential Revision: https://reviews.llvm.org/D46326

llvm-svn: 333937
2018-06-04 18:18:12 +00:00
Nico Weber e4a12cfa2f revert r332610, it breaks cfi, see D46326
llvm-svn: 332838
2018-05-21 11:44:39 +00:00
Dmitry Mikulin 3c6b4e35bd In thin and full LTO + CFI, direct function calls may go through jump table
entries to reach the target. Since these calls don't require type checks,
we can short-circuit them to their real targets.

Differential Revision: https://reviews.llvm.org/D46326

llvm-svn: 332610
2018-05-17 14:29:07 +00:00
Vedant Kumar 5a0872c2b7 [STLExtras] Add size() for ranges, and remove distance()
r332057 introduced distance() for ranges. Based on post-commit feedback,
this renames distance() to size(). The new size() is also only enabled
when the operation is O(1).

Differential Revision: https://reviews.llvm.org/D46976

llvm-svn: 332551
2018-05-16 23:20:42 +00:00
Vedant Kumar e0b5f86b30 [STLExtras] Add distance() for ranges, pred_size(), and succ_size()
This commit adds a wrapper for std::distance() which works with ranges.
As it would be a common case to write `distance(predecessors(BB))`, this
also introduces `pred_size()` and `succ_size()` helpers to make that
easier to write.

Differential Revision: https://reviews.llvm.org/D46668

llvm-svn: 332057
2018-05-10 23:01:54 +00:00
Piotr Padlewski 5dde809404 Rename invariant.group.barrier to launder.invariant.group
Summary:
This is one of the initial commit of "RFC: Devirtualization v2" proposal:
https://docs.google.com/document/d/16GVtCpzK8sIHNc2qZz6RN8amICNBtvjWUod2SujZVEo/edit?usp=sharing

Reviewers: rsmith, amharc, kuhar, sanjoy

Subscribers: arsenm, nhaehnle, javed.absar, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D45111

llvm-svn: 331448
2018-05-03 11:03:01 +00:00
Mikhail Maltsev ffaa8a8781 [IR] Do not assume that function pointers are aligned
Summary:
The value tracking analysis uses function alignment to infer that the
least significant bits of function pointers are known to be zero.
Unfortunately, this is not correct for ARM targets: the least
significant bit of a function pointer stores the ARM/Thumb state
information (i.e., the LSB is set for Thumb functions and cleared for
ARM functions).

The original approach (https://reviews.llvm.org/D44781) introduced a
new field for function pointer alignment in the DataLayout structure
to address this. But it seems unlikely that optimizations based on
function pointer alignment would bring much benefit in practice to
justify the additional maintenance burden, so this patch simply
assumes that function pointer alignment is always unknown.

Reviewers: javed.absar, efriedma

Reviewed By: efriedma

Subscribers: kristof.beyls, llvm-commits, hfinkel, rogfer01

Differential Revision: https://reviews.llvm.org/D46110

llvm-svn: 331025
2018-04-27 09:12:12 +00:00
Elena Demikhovsky 945b7e5aa6 Adding a width of the GEP index to the Data Layout.
Making a width of GEP Index, which is used for address calculation, to be one of the pointer properties in the Data Layout.
p[address space]:size:memory_size:alignment:pref_alignment:index_size_in_bits.
The index size parameter is optional, if not specified, it is equal to the pointer size.

Till now, the InstCombiner normalized GEPs and extended the Index operand to the pointer width.
It works fine if you can convert pointer to integer for address calculation and all registered targets do this.
But some ISAs have very restricted instruction set for the pointer calculation. During discussions were desided to retrieve information for GEP index from the Data Layout.
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120416.html

I added an interface to the Data Layout and I changed the InstCombiner and some other passes to take the Index width into account.
This change does not affect any in-tree target. I added tests to cover data layouts with explicitly specified index size.

Differential Revision: https://reviews.llvm.org/D42123

llvm-svn: 325102
2018-02-14 06:58:08 +00:00
Serge Guelton 4c975578b4 Limit size of non-GlobalValue name
Otherwise, in some extreme test case, very long names are created and the
compiler consumes large amount of memory. Size limit is set to a relatively
high value not to disturb debugging.

Compiler flag -non-global-value-max-name-size=<value> can be used to customize
the size.

Differential Revision: https://reviews.llvm.org/D41296

llvm-svn: 321886
2018-01-05 19:41:19 +00:00
Bjorn Steinbrink 030123e8e8 Give up on array allocas in getPointerDereferenceableBytes
Summary:
As suggested by Eli Friedman, don't try to handle array allocas here,
because of possible overflows, instead rely on instcombine converting
them to allocations of array types.

Reviewers: efriedma

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41398

llvm-svn: 321159
2017-12-20 10:01:30 +00:00
Bjorn Steinbrink 2da4d9d86d Treat sret arguments as being dereferenceable in getPointerDereferenceableBytes()
Reviewers: rnk, hfinkel, efriedma

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41355

llvm-svn: 321061
2017-12-19 08:46:46 +00:00
Bjorn Steinbrink 3603de2fa2 Re-commit "Properly handle multi-element and dynamically sized allocas in getPointerDereferenceableBytes()""
llvm-clang-x86_64-expensive-checks-win is still broken, so the failure
seems unrelated.

llvm-svn: 320953
2017-12-17 21:20:16 +00:00
Bjorn Steinbrink 6f7bbf349f Revert "Properly handle multi-element and dynamically sized allocas in getPointerDereferenceableBytes()"
This reverts commit 217067d5179882de9deb60d2e866befea4c126e7.

Fails on llvm-clang-x86_64-expensive-checks-win

llvm-svn: 320945
2017-12-17 15:16:58 +00:00
Bjorn Steinbrink e880f262e5 Revert "Treat sret arguments as being dereferenceable in getPointerDereferenceableBytes()"
This reverts commit 8b7a7660a3904b2088bc594311bcea2c651def08.

I didn't mean to commit this.

llvm-svn: 320944
2017-12-17 15:16:51 +00:00
Bjorn Steinbrink 7afcb71a42 Treat sret arguments as being dereferenceable in getPointerDereferenceableBytes()
llvm-svn: 320943
2017-12-17 15:11:52 +00:00
Bjorn Steinbrink c27f81b92b Properly handle byval arguments in getPointerDereferenceableBytes()
Summary:
For byval arguments, the number of dereferenceable bytes is equal to
the size of the pointee, not the pointer.

Reviewers: hfinkel, rnk

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41305

llvm-svn: 320939
2017-12-17 02:37:42 +00:00
Bjorn Steinbrink 5d86532467 Properly handle multi-element and dynamically sized allocas in getPointerDereferenceableBytes()
Reviewers: hfinkel, rnk

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41288

llvm-svn: 320938
2017-12-17 01:54:25 +00:00
Teresa Johnson 81bbf74265 [ThinLTO] Enable importing of aliases as copy of aliasee
Summary:
This implements a missing feature to allow importing of aliases, which
was previously disabled because alias cannot be available_externally.
We instead import an alias as a copy of its aliasee.

Some additional work was required in the IndexBitcodeWriter for the
distributed build case, to ensure that the aliasee has a value id
in the distributed index file (i.e. even when it is not being
imported directly).

This is a performance win in codes that have many aliases, e.g. C++
applications that have many constructor and destructor aliases.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D40747

llvm-svn: 320895
2017-12-16 00:18:12 +00:00
Dmitry Mikulin 2f2ace985d Current implementation of Value::replaceUsesExceptBlockAddr() uses UseList
iterator to walk the list which keeps changing inside the loop. When the
UseList contains several uses with the same user, we end processing the same
user more than once, which leads to an assert.

With this fix, unique users are saved and processed later to avoid
processing duplicates.

Differential Revision: https://reviews.llvm.org/D39864

llvm-svn: 318477
2017-11-17 00:30:24 +00:00
Serge Guelton 9fd33f249f Fix -Werror when compiling rL318083 (ter)
Statically assert the result and remove a runtime comparison, a direct consequence of the optimization introduced in rL318083.

llvm-svn: 318091
2017-11-13 21:55:01 +00:00
Davide Italiano 1a46affb45 [IPO/LowerTypesTest] Skip blockaddress(es) when replacing uses.
Blockaddresses refer to the function itself, therefore replacing them
would cause an assertion in doRAUW.

Fixes https://bugs.llvm.org/show_bug.cgi?id=35201

This was found when trying CFI on a proprietary kernel by Dmitry Mikulin.

Differential Revision:  https://reviews.llvm.org/D39695

llvm-svn: 317527
2017-11-07 00:09:25 +00:00
Reid Kleckner 96ab8726a3 [IR] De-virtualize ~Value to save a vptr
Summary:
Implements PR889

Removing the virtual table pointer from Value saves 1% of RSS when doing
LTO of llc on Linux. The impact on time was positive, but too noisy to
conclusively say that performance improved. Here is a link to the
spreadsheet with the original data:

https://docs.google.com/spreadsheets/d/1F4FHir0qYnV0MEp2sYYp_BuvnJgWlWPhWOwZ6LbW7W4/edit?usp=sharing

This change makes it invalid to directly delete a Value, User, or
Instruction pointer. Instead, such code can be rewritten to a null check
and a call Value::deleteValue(). Value objects tend to have their
lifetimes managed through iplist, so for the most part, this isn't a big
deal.  However, there are some places where LLVM deletes values, and
those places had to be migrated to deleteValue.  I have also created
llvm::unique_value, which has a custom deleter, so it can be used in
place of std::unique_ptr<Value>.

I had to add the "DerivedUser" Deleter escape hatch for MemorySSA, which
derives from User outside of lib/IR. Code in IR cannot include MemorySSA
headers or call the MemoryAccess object destructors without introducing
a circular dependency, so we need some level of indirection.
Unfortunately, no class derived from User may have any virtual methods,
because adding a virtual method would break User::getHungOffOperands(),
which assumes that it can find the use list immediately prior to the
User object. I've added a static_assert to the appropriate OperandTraits
templates to help people avoid this trap.

Reviewers: chandlerc, mehdi_amini, pete, dberlin, george.burgess.iv

Reviewed By: chandlerc

Subscribers: krytarowski, eraman, george.burgess.iv, mzolotukhin, Prazek, nlewycky, hans, inglorion, pcc, tejohnson, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D31261

llvm-svn: 303362
2017-05-18 17:24:10 +00:00
Sanjoy Das f1c0eafd5b Add a new WeakVH value handle; NFC
This relands r301425.

llvm-svn: 301813
2017-05-01 17:07:54 +00:00
Sanjoy Das e6bca0eecb Rename WeakVH to WeakTrackingVH; NFC
This relands r301424.

llvm-svn: 301812
2017-05-01 17:07:49 +00:00
Sanjoy Das 8a6238201f Emulate TrackingVH using WeakVH
Summary:
This frees up one slot in the HandleBaseKind enum, which I will use
later to add a new kind of value handle.  The size of the
HandleBaseKind enum is important because we store a HandleBaseKind in
the low two bits of a (in the worst case) 4 byte aligned pointer.

Reviewers: davide, chandlerc

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D32634

llvm-svn: 301809
2017-05-01 16:28:58 +00:00
Reid Kleckner 859f8b544a Make getParamAlignment use argument numbers
The method is called "get *Param* Alignment", and is only used for
return values exactly once, so it should take argument indices, not
attribute indices.

Avoids confusing code like:
  IsSwiftError = CS->paramHasAttr(ArgIdx, Attribute::SwiftError);
  Alignment  = CS->getParamAlignment(ArgIdx + 1);

Add getRetAlignment to handle the one case in Value.cpp that wants the
return value alignment.

This is a potentially breaking change for out-of-tree backends that do
their own call lowering.

llvm-svn: 301682
2017-04-28 20:34:27 +00:00
Reid Kleckner 6652a52e2b Use Argument::hasAttribute and AttributeList::ReturnIndex more
This eliminates many extra 'Idx' induction variables in loops over
arguments in CodeGen/ and Target/. It also reduces the number of places
where we assume that ReturnIndex is 0 and that we should add one to
argument numbers to get the corresponding attribute list index.

NFC

llvm-svn: 301666
2017-04-28 18:37:16 +00:00
Sanjoy Das 6f08789d30 Use accessors for ValueHandleBase::V; NFC
This changes code that touches ValueHandleBase::V to go through
getValPtr and (newly added) setValPtr.  This functionality will be
used later, but also seemed like a generally good cleanup.

I also renamed the field to Val, but that's just to make it obvious
that I fixed all the uses.

llvm-svn: 301518
2017-04-27 06:02:18 +00:00
Sanjoy Das 2cbeb00f38 Reverts commit r301424, r301425 and r301426
Commits were:

"Use WeakVH instead of WeakTrackingVH in AliasSetTracker's UnkownInsts"
"Add a new WeakVH value handle; NFC"
"Rename WeakVH to WeakTrackingVH; NFC"

The changes assumed pointers are 8 byte aligned on all architectures.

llvm-svn: 301429
2017-04-26 16:37:05 +00:00
Sanjoy Das 7de051ba0c Add a new WeakVH value handle; NFC
Summary:
WeakVH nulls itself out if the value it was tracking gets deleted, but
it does not track RAUW.

Reviewers: dblaikie, davide

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D32267

llvm-svn: 301425
2017-04-26 16:20:59 +00:00
Sanjoy Das 01de557738 Rename WeakVH to WeakTrackingVH; NFC
Summary:
I plan to use WeakVH to mean "nulls itself out on deletion, but does
not track RAUW" in a subsequent commit.

Reviewers: dblaikie, davide

Reviewed By: davide

Subscribers: arsenm, mehdi_amini, mcrosier, mzolotukhin, jfb, llvm-commits, nhaehnle

Differential Revision: https://reviews.llvm.org/D32266

llvm-svn: 301424
2017-04-26 16:20:52 +00:00
Piotr Padlewski 610c966a4e Handle invariant.group.barrier in BasicAA
Summary:
llvm.invariant.group.barrier returns pointer that mustalias
pointer it takes. It can't be marked with `returned` attribute,
because it would be remove easily. The other reason is that
only Alias Analysis can know about this, because if any other
pass would know it, then the result would be replaced with it's
argument, which would be invalid.

We can think about returned pointer as something that mustalias, but
it doesn't have to be bitwise the same as the argument.

Reviewers: dberlin, chandlerc, hfinkel, sanjoy

Subscribers: reames, nlewycky, rsmith, anna, amharc

Differential Revision: https://reviews.llvm.org/D31585

llvm-svn: 301227
2017-04-24 19:37:17 +00:00
Craig Topper 1dd20e6544 [IR] Implement pairs of non-const and const methods using the const version instead of the non-const version. NFCI
This removes a const_cast of the this pointer.

llvm-svn: 298831
2017-03-27 05:47:03 +00:00
Reid Kleckner b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
Craig Topper eec4890346 [IR] Don't call assertModuleIsMaterialized in release builds
Summary:
To fix a release vs debug build linking error, r259695 made the body of assertModuleIsMaterialized empty if Value.cpp gets compiled in a release build. This way any code compiled as a debug build can still link against a release version of the function.

This patch takes this a step farther and removes all calls to it from Value.h in any code that includes it in a relase build.

This shrinks the opt binary on my macbook build by 17240 bytes.

Reviewers: rafael

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28191

llvm-svn: 291883
2017-01-13 06:26:18 +00:00
Davide Italiano 1ed5396304 [BDCE] Skip metadata while replacing uses.
The fix committed in r288851 doesn't cover all the cases.
In particular, if we have an instruction with side effects
which has a no non-dbg use not depending on the bits, we still
perform RAUW destroying the dbg.value's first argument.
Prevent metadata from being replaced here to avoid the issue.

Differential Revision:  https://reviews.llvm.org/D27534

llvm-svn: 288987
2016-12-07 21:47:32 +00:00
Mehdi Amini a53d49e1b5 Don't create a SymbolTable in Function when the LLVMContext discards value names (NFC)
The ValueSymbolTable is used to detect name conflict and rename
instructions automatically. This is not needed when the value
names are automatically discarded by the LLVMContext.
No functional change intended, just saving a little bit of memory.

This is a recommit of r281806 after fixing the accessor to return
a pointer instead of a reference and updating all the call-sites.

llvm-svn: 281813
2016-09-17 06:00:02 +00:00
Arnold Schwaighofer ad83002243 Add an isSwiftError predicate to Value
llvm-svn: 281143
2016-09-10 18:14:54 +00:00
Justin Bogner b03fd12cef Replace "fallthrough" comments with LLVM_FALLTHROUGH
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.

llvm-svn: 278902
2016-08-17 05:10:15 +00:00
David Majnemer 42531260b3 Use the range variant of find/find_if instead of unpacking begin/end
If the result of the find is only used to compare against end(), just
use is_contained instead.

No functionality change is intended.

llvm-svn: 278469
2016-08-12 03:55:06 +00:00
Hal Finkel 5c12d8fe8f BasicAA should look through functions with returned arguments
Motivated by the work on the llvm.noalias intrinsic, teach BasicAA to look
through returned-argument functions when answering queries. This is essential
so that we don't loose all other AA information when supplementing with
llvm.noalias.

Differential Revision: http://reviews.llvm.org/D9383

llvm-svn: 275035
2016-07-11 01:32:20 +00:00
Sanjoy Das 00953cbe1d Remove Value::isPointerDereferenceable; NFCI
... and merge into `Value::getPointerDereferenceableBytes`. This was
suggested by Artur Pilipenko in D20764 -- since we no longer allow loads
of unsized types, there is no need anymore to have this special logic.

llvm-svn: 271455
2016-06-02 00:52:48 +00:00
Artur Pilipenko 7a26326442 NFC. Introduce Value::isPointerDereferenceable
Extract a part of isDereferenceableAndAlignedPointer functionality to Value:
    
Reviewed By: hfinkel, sanjoy
    
Differential Revision: http://reviews.llvm.org/D17611

llvm-svn: 269190
2016-05-11 14:43:28 +00:00
Artur Pilipenko 345f01481b NFC. Introduce Value::getPointerDerferecnceableBytes
Extract a part of isDereferenceableAndAlignedPointer functionality to Value::getPointerDerferecnceableBytes. Currently it's a NFC, but in future I'm going to accumulate all the logic about value dereferenceability in this function similarly to Value::getPointerAlignment function (D16144).

Reviewed By: reames

Differential Revision: http://reviews.llvm.org/D17572

llvm-svn: 267708
2016-04-27 12:51:01 +00:00
Artur Pilipenko c97eac6555 Use DL preferred alignment for alloca in Value::getPointerAlignment
Teach Value::getPointerAlignment that allocas with no explicit alignment are aligned to preferred alignment of the allocated type.

Reviewed By: hfinkel

Differential Revision: http://reviews.llvm.org/D17569

llvm-svn: 267689
2016-04-27 10:42:29 +00:00
Sanjoy Das 5ce3272833 Don't IPO over functions that can be de-refined
Summary:
Fixes PR26774.

If you're aware of the issue, feel free to skip the "Motivation"
section and jump directly to "This patch".

Motivation:

I define "refinement" as discarding behaviors from a program that the
optimizer has license to discard.  So transforming:

```
void f(unsigned x) {
  unsigned t = 5 / x;
  (void)t;
}
```

to

```
void f(unsigned x) { }
```

is refinement, since the behavior went from "if x == 0 then undefined
else nothing" to "nothing" (the optimizer has license to discard
undefined behavior).

Refinement is a fundamental aspect of many mid-level optimizations done
by LLVM.  For instance, transforming `x == (x + 1)` to `false` also
involves refinement since the expression's value went from "if x is
`undef` then { `true` or `false` } else { `false` }" to "`false`" (by
definition, the optimizer has license to fold `undef` to any non-`undef`
value).

Unfortunately, refinement implies that the optimizer cannot assume
that the implementation of a function it can see has all of the
behavior an unoptimized or a differently optimized version of the same
function can have.  This is a problem for functions with comdat
linkage, where a function can be replaced by an unoptimized or a
differently optimized version of the same source level function.

For instance, FunctionAttrs cannot assume a comdat function is
actually `readnone` even if it does not have any loads or stores in
it; since there may have been loads and stores in the "original
function" that were refined out in the currently visible variant, and
at the link step the linker may in fact choose an implementation with
a load or a store.  As an example, consider a function that does two
atomic loads from the same memory location, and writes to memory only
if the two values are not equal.  The optimizer is allowed to refine
this function by first CSE'ing the two loads, and the folding the
comparision to always report that the two values are equal.  Such a
refined variant will look like it is `readonly`.  However, the
unoptimized version of the function can still write to memory (since
the two loads //can// result in different values), and selecting the
unoptimized version at link time will retroactively invalidate
transforms we may have done under the assumption that the function
does not write to memory.

Note: this is not just a problem with atomics or with linking
differently optimized object files.  See PR26774 for more realistic
examples that involved neither.

This patch:

This change introduces a new set of linkage types, predicated as
`GlobalValue::mayBeDerefined` that returns true if the linkage type
allows a function to be replaced by a differently optimized variant at
link time.  It then changes a set of IPO passes to bail out if they see
such a function.

Reviewers: chandlerc, hfinkel, dexonsmith, joker.eph, rnk

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18634

llvm-svn: 265762
2016-04-08 00:48:30 +00:00
Mehdi Amini 50af49fcdc Rename Context::discardValueNames() to shouldDiscardValueNames() (NFC)
Suggested by Sean Silva.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265211
2016-04-02 03:46:17 +00:00
Mehdi Amini 09b4a8daa3 Add a flag to the LLVMContext to disable name for Value other than GlobalValue
Summary:
This is intended to be a performance flag, on the same level as clang
cc1 option "--disable-free". LLVM will never initialize it by default,
it will be up to the client creating the LLVMContext to request this
behavior. Clang will do it by default in Release build (just like
--disable-free).

"opt" and "llc" can opt-in using -disable-named-value command line
option.

When performing LTO on llvm-tblgen, the initial merging of IR peaks
at 92MB without this patch, and 86MB after this patch,setNameImpl()
drops from 6.5MB to 0.5MB.
The total link time goes from ~29.5s to ~27.8s.

Compared to a compile-time flag (like the IRBuilder one), it performs
very close. I profiled on SROA and obtain these results:

 420ms with IRBuilder that preserve name
 372ms with IRBuilder that strip name
 375ms with IRBuilder that preserve name, and a runtime flag to strip

Reviewers: chandlerc, dexonsmith, bogner

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D17946

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 263086
2016-03-10 01:28:54 +00:00
Reid Kleckner 1762ad3e73 [IR] Optimize bitfield layout of Value for MSVC
This should save a pointer of padding from all MSVC Value subclasses.

Recall that MSVC will not pack the following bitfields together:
  unsigned Bits : 29;
  unsigned Flag1 : 1;
  unsigned Flag2 : 1;
  unsigned Flag3 : 1;

Add a static_assert because LLVM developers always trip over this
behavior. This regressed in June.

llvm-svn: 262045
2016-02-26 18:08:59 +00:00
Artur Pilipenko ae51afc5c7 NFC. Move getAlignment helper function from ValueTracking to Value class.
Reviewed By: reames, hfinkel

Differential Revision: http://reviews.llvm.org/D16144

llvm-svn: 261735
2016-02-24 12:25:10 +00:00
Mehdi Amini 8914d29008 Simplify handleOperandChangeImpl() removing last argument (NFC)
The Use argument was used to compute the operand number for a fast
path when replacing only one operand. However we always have to go
through all the operands. So the argument number can be recomputed
locally anyway.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 260454
2016-02-10 22:47:15 +00:00
Todd Fiala 675bdcedff Address NDEBUG-related linkage issues for Value::assertModuleIsMaterialized()
The IR/Value class had a linkage issue present when LLVM was built
as a library, and the LLVM library build time had different settings
for NDEBUG than the client of the LLVM library.  Clients could get
into a state where the LLVM lib expected
Value::assertModuleIsMaterialized() to be inline-defined in the header
but clients expected that method to be defined in the LLVM library.

See this llvm-commits thread for more details:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160201/329667.html

llvm-svn: 259695
2016-02-03 21:13:23 +00:00
Eugene Zelenko ecefe5a81f Fix Clang-tidy readability-redundant-control-flow warnings; other minor fixes.
Differential revision: http://reviews.llvm.org/D16793

llvm-svn: 259539
2016-02-02 18:20:45 +00:00
Rafael Espindola 257a35368f Bring back "Assert that we have all use/users in the getters."
This reverts commit r257751, bringing back r256105.

The problem the assert found was fixed in r257915.

Original commit message:

Assert that we have all use/users in the getters.

An error that is pretty easy to make is to use the lazy bitcode reader
and then do something like

if (V.use_empty())

The problem is that uses in unmaterialized functions are not accounted
for.

This patch adds asserts that all uses are known.

llvm-svn: 257920
2016-01-15 19:00:20 +00:00
Michael Zolotukhin 65c0120193 Revert "Assert that we have all use/users in the getters."
This reverts commit fdb838f3f8a8b6896bbbd5285555874eb3b748eb.

llvm-svn: 257751
2016-01-14 09:02:45 +00:00
Rafael Espindola e01e363fd9 Assert that we have all use/users in the getters.
An error that is pretty easy to make is to use the lazy bitcode reader
and then do something like

if (V.use_empty())

The problem is that uses in unmaterialized functions are not accounted
for.

This patch adds asserts that all uses are known.

llvm-svn: 256105
2015-12-19 20:03:23 +00:00
Philip Reames d63df5107e Remove handling of AddrSpaceCast in stripAndAccumulateInBoundsConstantOffsets
Patch by: simoncook

Unlike BitCasts, AddrSpaceCasts do not always produce an output the same size as its input, which was previously assumed. This fixes cases where two address spaces do not have the same size pointer, as an assertion failure would occur when trying to prove deferenceability.  LoopUnswitch is used in the particular test, but LICM also exhibits the same problem.

Differential Revision: http://reviews.llvm.org/D13008

llvm-svn: 248422
2015-09-23 19:48:43 +00:00
David Majnemer a5c7051a60 [IR] Switch static const to an enum to silence MSVC linker warnings
Integral class statics are handled oddly in MSVC, we don't need them
in this case, use an enum instead.

llvm-svn: 241958
2015-07-10 22:46:02 +00:00
Pete Cooper 5815b1fd56 Devirtualize Constant::replaceUsesOfWithOnConstant.
This is part of the work to devirtualize Value.

The old pattern was to call replaceUsesOfWithOnConstant which was overridden by
subclasses.  Those could then call replaceUsesOfWithOnConstantImpl on Constant
to handle deleting the current value.

To be consistent with other parts of the code, this has been changed so that we
call the method on Constant, and that dispatches to an Impl on subclasses.

As part of this, it made sense to rename the methods to be more descriptive.  The
new name is Constant::handleOperandChange, and it requires that all subclasses of
Constant implement handleOperandChangeImpl, even if they just throw an error if
they shouldn't be called.

Reviewed by Duncan Exon Smith.

llvm-svn: 240567
2015-06-24 18:55:24 +00:00
Pete Cooper b4eede2c07 Rename NumOperands to make it clear its managed by the User. NFC.
This is to try make it very clear that subclasses shouldn't be changing
the value directly.  Now that OperandList for normal instructions is computed
using the NumOperands, its critical that the NumOperands is accurate or we
could compute the wrong offset to the first operand.

I looked over all places which update NumOperands and they are all safe.
Hung off use User's don't use NumOperands to compute the OperandList so they
are safe to continue to manipulate it.  The only other User which changed it
was GlobalVariable which has an optional init list but always allocated space
for a single Use.  It was correctly setting NumOperands to 1 before setting an
initializer, and setting it to 0 after clearing the init list, so the order was safe.

Added some comments to that code to make sure that this isn't changed in future
without being aware of this constraint.

Reviewed by Duncan Exon Smith.

llvm-svn: 239621
2015-06-12 17:48:10 +00:00
Owen Anderson 7349ab9385 Move the name pointer out of Value into a map that lives on the
LLVMContext.  Production builds of clang do not set names on most
Value's, so this is wasted space on almost all subclasses of Value.
This reduces the size of all Value subclasses by 8 bytes on 64 bit
hosts.

The one tricky part of this change is averting compile time regression
by keeping Value::hasName() fast.  This required stealing bits out of
NumOperands.

With this change, peak memory usage on verify-uselistorder-nodbg.lto.bc
is decreased by approximately 2.3% (~3MB absolute on my machine).

llvm-svn: 238791
2015-06-01 22:24:01 +00:00
Pete Cooper a7c0c18c4d Store intrinsic ID by value in Function instead of a string lookup. NFC.
On 64-bit targets, Function has 4-bytes of padding in its struct layout.

This uses the space for the intrinsic ID. It is set and recalculated whenever the function name is set.  This is similar to the current behavior which clears the function from the intrinsic ID cache when its renamed.

The intrinsic cache itself is removed as the only purpose was to speedup calls to getIntrinsicID() which now just reading the new field in the struct.

Reviewed by Duncan.  http://reviews.llvm.org/D9836

llvm-svn: 237642
2015-05-19 00:24:26 +00:00
Philip Reames 5461d45abf Move Value.isDereferenceablePointer to ValueTracking [NFC]
Move isDereferenceablePointer function to Analysis. This function recursively tracks dereferencability over a chain of values like other functions in ValueTracking.

This refactoring is motivated by further changes to support dereferenceable_or_null attribute (http://reviews.llvm.org/D8650). isDereferenceablePointer will be extended to perform context-sensitive analysis and IR is not a good place to have such functionality.

Patch by: Artur Pilipenko <apilipenko@azulsystems.com>
Differential Revision: reviews.llvm.org/D9075

llvm-svn: 235611
2015-04-23 17:36:48 +00:00
Benjamin Kramer 3a09ef64ee [CallSite] Make construction from Value* (or Instruction*) explicit.
CallSite roughly behaves as a common base CallInst and InvokeInst. Bring
the behavior closer to that model by making upcasts explicit. Downcasts
remain implicit and work as before.

Following dyn_cast as a mental model checking whether a Value *V isa
CallSite now looks like this: 
  if (auto CS = CallSite(V)) // think dyn_cast
instead of:
  if (CallSite CS = V)

This is an extra token but I think it is slightly clearer. Making the
ctor explicit has the advantage of not accidentally creating nullptr
CallSites, e.g. when you pass a Value * to a function taking a CallSite
argument.

llvm-svn: 234601
2015-04-10 14:50:08 +00:00
Benjamin Kramer 799003bf8c Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.
llvm-svn: 232998
2015-03-23 19:32:43 +00:00