Commit Graph

6234 Commits

Author SHA1 Message Date
Vinicius Tinti 577adda54f [Support/Path] Add path::is_absolute_gnu
Implements IS_ABSOLUTE_PATH from GNU tools.

C++17 is_absolute behavior is different the from the behavior defined by GNU
tools.

According to cppreference.com, C++17 states: "An absolute path is a path
that unambiguously identifies the location of a file without reference
to an additional starting location."

In other words, the rules are:
 1. POSIX style paths with nonempty root directory are absolute.
 2. Windows style paths with nonempty root name and root directory are
    absolute.
 3. No other paths are absolute.

GNU rules are:
 1. Paths starting with a path separator are absolute.
 2. Windows style paths are also absolute if they start with a character
    followed by ':'.
 3. No other paths are absolute.

On Windows style the path "C:\Users\Default" has "C:" as root name and "\"
as root directory.

Hence "C:" on Windows is absolute under GNU rules and not absolute under
C++17 because it has no root directory. Likewise "/" and "\" on Windows are
absolute under GNU and are not absolute under C++17 due to empty root name.

Related to PR46368.

Differential Revision: https://reviews.llvm.org/D87667
2020-09-23 18:01:32 +01:00
Andrew Litteken 88bc59c300 Revert "[IRSim] Adding IRSimilarityCandidate that contains a region of IRInstructionData."
This reverts commit 4944bb190f.
2020-09-22 21:02:34 -05:00
Andrew Litteken 4944bb190f [IRSim] Adding IRSimilarityCandidate that contains a region of IRInstructionData.
The IRSimilarityCandidate is a container to hold a region of
IRInstructions and offer interfaces for the starting instruction, ending
instruction, parent function, length.  It also assigns a global value
number for each unique instance of a value in the region.

It also contains an interface to compare two IRSimilarity as to whether
they have the same sequence of similar instructions.

Tests for whether the instructions are similar are found in
unittests/Analysis/IRSimilarityIdentifierTest.cpp.

Differential Revision: https://reviews.llvm.org/D86970
2020-09-22 18:42:31 -05:00
Michael Liao d4e3e1e548 Fix build due to renaming in LoopInfo. 2020-09-22 17:33:38 -04:00
Roman Lebedev 7465da2077
[ConstantRange] Introduce getMinSignedBits() method
Similar to the ConstantRange::getActiveBits(), and to similarly-named
methods in APInt, returns the bitwidth needed to represent
the given signed constant range
2020-09-22 21:37:30 +03:00
Roman Lebedev 2ed9c4c70b
[ConstantRange] Introduce getActiveBits() method
Much like APInt::getActiveBits(), computes how many bits are needed
to be able to represent every value in this constant range,
treating the values as unsigned.
2020-09-22 21:37:29 +03:00
Roman Lebedev b38d897e80
[ConstantRange] binaryXor(): special-case binary complement case - the result is precise
Use the fact that `~X` is equivalent to `-1 - X`, which gives us
fully-precise answer, and we only need to special-handle the wrapped case.

This fires ~16k times for vanilla llvm test-suite + RawSpeed.
2020-09-22 21:37:29 +03:00
Max Kazantsev 16fde88dbd [SCEV] Support unsigned predicates in isKnownPredicateViaNoOverflow
SCEV should be able to prove facts like `x <u x+1<nuw>`.

Differential Revision: https://reviews.llvm.org/D88015
Reviewed By: lebedev.ri
2020-09-22 17:14:05 +07:00
Sam Parker e461921d6c [ARM] VPT validForTailPredication
Mark all VPT instructions as valid.

Differential Revision: https://reviews.llvm.org/D87759
2020-09-22 08:58:37 +01:00
Cyndy Ishida 0b15cb70d3 [TextAPI] clean up auto usages in tests, NFC 2020-09-21 08:39:40 -07:00
Florian Hahn 1d8f2e5292 [SCEVExpander] Support expanding nonintegral pointers with constant base.
Currently SCEVExpander creates inttoptr for non-integral pointers if the
base is a null constant for example. This results in invalid IR.

This patch changes InsertNoopCastOfTo to emit a GEP & bitcast to convert
to a non-integral pointer. First, a GEP of i8* null is generated and the
integral value is used as index. The GEP is then bitcasted to the target
type.

This was exposed by D71539.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D87827
2020-09-19 17:19:53 +01:00
Joachim Meyer f64903fd81 Add -Wno-error=unknown flag to clang-format.
Currently newer clang-format options cannot be included in .clang-format files, if not all users can be forced to use an updated version.
This patch tries to solve this by adding an option to clang-format, enabling to ignore unknown (newer) options.

Differential Revision: https://reviews.llvm.org/D86137
2020-09-19 10:17:57 +02:00
Andrew Litteken 132aaec4f2 [IRSim] Adding ilist for IRInstructionData.
The IRInstructionData structs are a different representation of the
program.  This list treats the program as if it was "flattened" and
the only parent is this list.  This lets us easily create ranges of
instructions.

Differential Revision: https://reviews.llvm.org/D86969
2020-09-19 00:18:39 -05:00
David Blaikie 51a505340d DebugInfo: Simplify line table parsing to take all the units together, rather than CUs and TUs separately 2020-09-18 11:18:23 -07:00
Florian Hahn 4635f6050b [SCEV] Generalize SCEVParameterRewriter to accept SCEV expression as target.
This patch extends SCEVParameterRewriter to support rewriting unknown
epxressions to arbitrary SCEV expressions. It will be used by further
patches.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D67176
2020-09-18 10:05:02 +01:00
Jon Roelofs c145a1ca25 AArch64::ArchKind's underlying type is uint64_t 2020-09-17 12:13:57 -07:00
Andrew Litteken 7e4c6fb854 [IRSim] Adding IR Instruction Mapper
This introduces the IRInstructionMapper, and the associated wrapper for
instructions, IRInstructionData, that maps IR level Instructions to
unsigned integers.

Mapping is done mainly by using the "isSameOperationAs" comparison
between two instructions.  If they return true, the opcode, result type,
and operand types of the instruction are used to hash the instruction
with an unsigned integer.  The mapper accepts instruction ranges, and
adds each resulting integer to a list, and each wrapped instruction to
a separate list.

At present, branches, phi nodes are not mapping and exception handling
is illegal.  Debug instructions are not considered.

The different mapping schemes are tested in
unittests/Analysis/IRSimilarityIdentifierTest.cpp

Recommit of: b04c1a9d31

Differential Revision: https://reviews.llvm.org/D86968
2020-09-17 14:06:16 -05:00
Igor Kudrin 027d47d1c7 [DebugInfo] Simplify DIEInteger::SizeOf().
An AsmPrinter should always be provided to the method because some forms
depend on its parameters. The only place in the codebase which passed
a nullptr value was found in the unit tests, so the patch updates it to
use some dummy AsmPrinter instead.

Differential Revision: https://reviews.llvm.org/D85293
2020-09-17 12:47:38 +07:00
Stella Stamenova a895040eb0 Revert "[IRSim] Adding IR Instruction Mapper"
This reverts commit b04c1a9d31.
2020-09-16 20:00:43 -07:00
Andrew Litteken b04c1a9d31 [IRSim] Adding IR Instruction Mapper
This introduces the IRInstructionMapper, and the associated wrapper for
instructions, IRInstructionData, that maps IR level Instructions to
unsigned integers.

Mapping is done mainly by using the "isSameOperationAs" comparison
between two instructions.  If they return true, the opcode, result type,
and operand types of the instruction are used to hash the instruction
with an unsigned integer.  The mapper accepts instruction ranges, and
adds each resulting integer to a list, and each wrapped instruction to
a separate list.

At present, branches, phi nodes are not mapping and exception handling
is illegal.  Debug instructions are not considered.

The different mapping schemes are tested in
unittests/Analysis/IRSimilarityIdentifierTest.cpp

Differential Revision: https://reviews.llvm.org/D86968
2020-09-16 20:49:21 -05:00
Reid Kleckner e47d2927de Include (Type|Symbol)Record.h less
Most clients only need CVType and CVSymbol, not structs for every type
and symbol. Move CVSymbol and CVType to CVRecord.h to accomplish this.
Update some of the common headers that need CVSymbol and CVType to use
the new location.
2020-09-16 09:59:03 -07:00
Sam Parker 86172ce378 [ARM] Add more validForTailPredication
Modify the unit test to inspect all MVE instructions and mark the
load/store/move of vpr/p0 as valid, as well as the remaining scalar
shifts.

Differential Revision: https://reviews.llvm.org/D87753
2020-09-16 11:51:50 +01:00
Andrew Ng 6040e2a6d9 [Support] Add GlobPattern::isTrivialMatchAll()
GlobPattern::isTrivialMatchAll() returns true for the GlobPattern "*"
which will match all inputs.

This can be used to avoid performing expensive preparation of the input
for match() when the result of the match will always be true.

Differential Revision: https://reviews.llvm.org/D87468
2020-09-16 10:26:11 +01:00
Alina Sbirlea d3d7603900 [MemorySSA] Report unoptimized as None, not MayAlias. 2020-09-15 23:58:53 -07:00
Arthur Eubanks 91332c4dbb [CGSCC][NewPM] Fix adding mutually recursive new functions
When adding a new function via addNewFunctionIntoRefSCC(), it creates a
new node and immediately populates the edges. Since populateSlow() calls
G->get() on all referenced functions, it will create a node (but not
populate it) for functions that haven't yet been added. If we add two
mutually recursive functions, the assert that the node should never have
been created will fire when the second function is added. So here we
remove that assert since the node may have already been created (but not
yet populated).

createNode() is only called from addNewFunctionInto{,Ref}SCC().

https://bugs.llvm.org/show_bug.cgi?id=47502

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D87623
2020-09-15 16:44:08 -07:00
Wenlei He 2ea4c2c598 [BFI] Make BFI information available through loop passes inside LoopStandardAnalysisResults
~~D65060 uncovered that trying to use BFI in loop passes can lead to non-deterministic behavior when blocks are re-used while retaining old BFI data.~~

~~To make sure BFI is preserved through loop passes a Value Handle (VH) callback is registered on blocks themselves. When a block is freed it now also wipes out the accompanying BFI entry such that stale BFI data can no longer persist resolving the determinism issue. ~~

~~An optimistic approach would be to incrementally update BFI information throughout the loop passes rather than only invalidating them on removed blocks. The issues with that are:~~
~~1. It is not clear how BFI information should be incrementally updated: If a block is duplicated does its BFI information come with? How about if it's split/modified/moved around? ~~
~~2. Assuming we can address these problems the implementation here will be a massive undertaking. ~~

~~There's a known need of BFI in LICM analysis which requires correct but not incrementally updated BFI data. A follow-up change can register BFI in all loop passes so this preserved but potentially lossy data is available to any loop pass that wants it.~~

See: D75341 for an identical implementation of preserving BFI via VH callbacks. The previous statements do still apply but this change no longer has to be in this diff because it's already upstream 😄 .

This diff also moves BFI to be a part of LoopStandardAnalysisResults since the previous method using getCachedResults now (correctly!) statically asserts (D72893) that this data isn't static through the loop passes.

Testing
Ninja check

Reviewed By: asbirlea, nikic

Differential Revision: https://reviews.llvm.org/D86156
2020-09-15 16:16:24 -07:00
Florian Hahn db22e70d01 [ConstraintSolver] Add isConditionImplied helper.
This patch adds a isConditionImplied function that
takes a constraint and returns true if the constraint
is implied by the current constraints in the system.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D84545
2020-09-15 13:50:11 +01:00
Florian Hahn cd4edf94cd Recommit "[ConstraintSystem] Add helpers to deal with linear constraints."
This patch recommits "[ConstraintSystem] Add helpers to deal with linear constraints."
(it reverts the revert commit 8da6ae4ce1).

The reason for the revert was using __builtin_multiply_overflow, which
is not available for all compilers. The patch has been updated to use
MulOverflow from MathExtras.h
2020-09-15 12:07:26 +01:00
Igor Kudrin a845ebd633 [DebugInfo] Make offsets of dwarf units 64-bit (19/19).
In the case of LTO, several DWARF units can be emitted in one section.
For an extremely large application, they may exceed the limit of 4GiB
for 32-bit offsets. As it is now possible to emit 64-bit debugging info,
the patch enables storing the larger offsets.

Differential Revision: https://reviews.llvm.org/D87026
2020-09-15 12:23:32 +07:00
Igor Kudrin cae7c1eb78 [DebugInfo] Use a common method to determine a suitable form for section offsts (6/19).
This is mostly an NFC patch because the involved methods are used when
emitting DWO files, which is incompatible with DWARFv3, or for platforms
where DWARF64 is not supported yet.

Differential Revision: https://reviews.llvm.org/D87015
2020-09-15 11:30:38 +07:00
Igor Kudrin 5dd1c59188 [DebugInfo] Fix emitting DWARF64 compilation units (5/19).
The patch also adds a method to choose an appropriate DWARF form
to represent section offsets according to the version and the format
of producing debug info.

Differential Revision: https://reviews.llvm.org/D87014
2020-09-15 11:30:30 +07:00
Igor Kudrin c3c501f5d7 [DebugInfo] Add new emitting methods for values which depend on the DWARF format (3/19).
These methods are going to be used in subsequent patches.

Differential Revision: https://reviews.llvm.org/D87010
2020-09-15 11:30:10 +07:00
Igor Kudrin a8058c6f8d [DebugInfo] Fix DIE value emitters to be compatible with DWARF64 (2/19).
DW_FORM_sec_offset and DW_FORM_strp imply values of different sizes with
DWARF32 and DWARF64. The patch fixes DIE value classes to use correct
sizes when emitting their values. For DIELocList it ensures that the
requested DWARF form matches the current DWARF format because that class
uses a method that selects the size automatically.

Differential Revision: https://reviews.llvm.org/D87009
2020-09-15 11:30:02 +07:00
Igor Kudrin 380e746bcc [DebugInfo] Fix methods of AsmPrinter to emit values corresponding to the DWARF format (1/19).
These methods are used to emit values which are 32-bit in DWARF32 and
64-bit in DWARF64. The patch fixes them so that they choose the length
automatically, depending on the DWARF format set in the Context.

Differential Revision: https://reviews.llvm.org/D87008
2020-09-15 11:29:48 +07:00
Tyker 78de7297ab Reland [AssumeBundles] Use operand bundles to encode alignment assumptions
NOTE: There is a mailing list discussion on this: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

Complemantary to the assumption outliner prototype in D71692, this patch
shows how we could simplify the code emitted for an alignemnt
assumption. The generated code is smaller, less fragile, and it makes it
easier to recognize the additional use as a "assumption use".

As mentioned in D71692 and on the mailing list, we could adopt this
scheme, and similar schemes for other patterns, without adopting the
assumption outlining.
2020-09-12 15:36:06 +02:00
Jianzhou Zhao 19531a81f1 Add raw_fd_stream_test.cpp into CMakeLists.txt
Fixing 0ece51c60c
2020-09-12 07:48:12 +00:00
Jianzhou Zhao 0ece51c60c Add raw_fd_stream that supports reading/seeking/writing
This is used by https://reviews.llvm.org/D86905 to support bitcode
writer's incremental flush.
2020-09-12 07:34:19 +00:00
Lang Hames 7dcd0042e8 Re-apply "[ORC] Make MaterializationResponsibility immovable..." with fixes.
Re-applies c74900ca67 with fixes for the ThinLtoJIT example.
2020-09-11 14:09:05 -07:00
Florian Hahn 8da6ae4ce1 Revert "[ConstraintSystem] Add helpers to deal with linear constraints."
This reverts commit 3eb141e507.

This uses __builtin_mul_overflow which is not available everywhere.
2020-09-11 14:49:04 +01:00
Florian Hahn 3eb141e507 [ConstraintSystem] Add helpers to deal with linear constraints.
This patch introduces a new ConstraintSystem class, that maintains a set
of linear constraints and uses Fourier–Motzkin elimination to eliminate
constraints to check if there are solutions for the system.

It also adds a convert-constraint-log-to-z3.py script, which can parse
the debug output of the constraint system and convert it to a python
script that feeds the constraints into Z3 and checks if it produces the
same result as the LLVM implementation. This is for verification
purposes.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D84544
2020-09-11 14:43:22 +01:00
Florian Hahn c0825fa5fc Revert "[ORC] Make MaterializationResponsibility immovable, pass by unique_ptr."
This reverts commit c74900ca67.

This appears to be breaking some builds on macOS and has been causing
build failures on Green Dragon (see below). I am reverting this for now,
to unblock testing on Green Dragon.

http://green.lab.llvm.org/green/job/clang-stage1-cmake-RA-incremental/18144/console

[65/187] /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++  -DBUILD_EXAMPLES -DGTEST_HAS_RTTI=0 -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Iexamples/ThinLtoJIT -I/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT -Iinclude -I/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wstring-conversion -fdiagnostics-color -O3  -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -mmacosx-version-min=10.9    -fno-exceptions -fno-rtti -UNDEBUG -std=c++14 -MD -MT examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o -MF examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o.d -o examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o -c /Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT/ThinLtoDiscoveryThread.cpp
FAILED: examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++  -DBUILD_EXAMPLES -DGTEST_HAS_RTTI=0 -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Iexamples/ThinLtoJIT -I/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT -Iinclude -I/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wstring-conversion -fdiagnostics-color -O3  -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -mmacosx-version-min=10.9    -fno-exceptions -fno-rtti -UNDEBUG -std=c++14 -MD -MT examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o -MF examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o.d -o examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o -c /Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT/ThinLtoDiscoveryThread.cpp
In file included from /Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT/ThinLtoDiscoveryThread.cpp:7:
/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT/ThinLtoInstrumentationLayer.h:37:68: error: non-virtual member function marked 'override' hides virtual member function
  void emit(MaterializationResponsibility R, ThreadSafeModule TSM) override;
                                                                   ^
/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/include/llvm/ExecutionEngine/Orc/Layer.h:103:16: note: hidden overloaded virtual function 'llvm::orc::IRLayer::emit' declared here: type mismatch at 1st parameter ('std::unique_ptr<MaterializationResponsibility>' vs 'llvm::orc::MaterializationResponsibility')
  virtual void emit(std::unique_ptr<MaterializationResponsibility> R,
               ^
1 error generated.
2020-09-11 09:35:20 +01:00
Reid Kleckner 4e3edef4b8 Use pragmas to work around MSVC x86_32 debug miscompile bug
Halide users reported this here: https://llvm.org/pr46176
I reported the issue to MSVC here:
https://developercommunity.visualstudio.com/content/problem/1179643/msvc-copies-overaligned-non-trivially-copyable-par.html

This codepath is apparently not covered by LLVM's unit tests, so I added
coverage in a unit test.

If we want to support this configuration going forward, it means that is
in general not safe to pass a SmallVector<T, N> by value if alignof(T)
is greater than 4. This doesn't appear to come up often because passing
a SmallVector by value is inefficient and not idiomatic: it copies the
inline storage. In this case, the SmallVector<LLT,4> is captured by
value by a lambda, and the lambda is passed by value into std::function,
and that's how we hit the bug.

Differential Revision: https://reviews.llvm.org/D87475
2020-09-10 14:50:01 -07:00
Lang Hames c74900ca67 [ORC] Make MaterializationResponsibility immovable, pass by unique_ptr.
Making MaterializationResponsibility instances immovable allows their
associated VModuleKeys to be updated by the ExecutionSession while the
responsibility is still in-flight. This will be used in the upcoming
removable code feature to enable safe merging of resource keys even if
there are active compiles using the keys being merged.
2020-09-10 13:21:46 -07:00
Lang Hames 54fcea86b1 Revert "[Support] Use unique_function rather than std::function for ThreadPool TaskTy."
This reverts commit d9c8b0256c.

Some MSVC std::packaged_task implementations are not compatible with move-only types.
This caused failures on some of the Windows builders (e.g.
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/69412).

Reverting until I can come up with a workaround.
2020-09-10 11:53:09 -07:00
Lang Hames d9c8b0256c [Support] Use unique_function rather than std::function for ThreadPool TaskTy.
This will allow non-copyable function objects (e.g. lambdas that capture
unique_ptrs) to be used with ThreadPool.

Differential Revision: https://reviews.llvm.org/D87467
2020-09-10 10:46:46 -07:00
Sam Parker 1919b65052 [ARM] Tail predicate VQDMULH and VQRDMULH
Mark the family of instructions as valid for tail predication.

Differential Revision: https://reviews.llvm.org/D87348
2020-09-10 08:20:07 +01:00
Juneyoung Lee a6183d0f02 [ValueTracking] isKnownNonZero, computeKnownBits for freeze
This implements support for isKnownNonZero, computeKnownBits when freeze is involved.

```
  br (x != 0), BB1, BB2
BB1:
  y = freeze x
```

In the above program, we can say that y is non-zero. The reason is as follows:

(1) If x was poison, `br (x != 0)` raised UB
(2) If x was fully undef, the branch again raised UB
(3) If x was non-zero partially undef, say `undef | 1`, `freeze x` will return a nondeterministic value which is also non-zero.
(4) If x was just a concrete value, it is trivial

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D75808
2020-09-10 08:07:38 +09:00
Juneyoung Lee 25ce1e0497 [ValueTracking] Add UndefOrPoison/Poison-only version of relevant functions
This patch adds isGuaranteedNotToBePoison and programUndefinedIfUndefOrPoison.

isGuaranteedNotToBePoison will be used at D75808. The latter function is used at isGuaranteedNotToBePoison.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D84242
2020-09-09 20:00:26 +09:00
Sergej Jaskiewicz e7b40c5492 [llvm] [unittest] Allow getting a C string from the TempDir helper class
The TempDir.path() member function returns a StringRef. We've been
calling the data() method on that StringRef, which does not guarantee
to return a null-terminated string (required by chdir and other POSIX
functions).

Introduce the c_str() method in the TempDir class, which returns the
proper string without the need to create a copy of the path at use site.
2020-09-09 01:53:15 +03:00
Jay Foad 5350e1b509 [KnownBits] Implement accurate unsigned and signed max and min
Use the new implementation in ValueTracking, SelectionDAG and
GlobalISel.

Differential Revision: https://reviews.llvm.org/D87034
2020-09-07 09:09:01 +01:00