Commit Graph

4044 Commits

Author SHA1 Message Date
Tyker 7cb5d96fbe Revert "[WIP] Build assume from call"
casued buildbot failure

This reverts commit 8ebe001553.
2020-02-02 18:35:19 +01:00
Tyker 8ebe001553 [WIP] Build assume from call
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72475
2020-02-02 18:15:50 +01:00
Tyker c2d0336208 Revert "[WIP] Build assume from call"
caused build bot failure

This reverts commit 780d2c532f.
2020-02-02 18:09:06 +01:00
Tyker 780d2c532f [WIP] Build assume from call
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72475
2020-02-02 17:54:31 +01:00
Tyker ad8ffc5010 Revert "[WIP] Build assume from call"
This reverts commit 355e4bfd78.
2020-02-02 17:49:23 +01:00
Tyker 355e4bfd78 [WIP] Build assume from call
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72475
2020-02-02 17:17:46 +01:00
Tyker cfe87a4a16 [NFC] Refactor TableGen for attributes
Summary:
this patch makes tablegen generate llvm attributes in a more generic and simpler (at least to me).

changes:  make tablegen generate
...
ATTRIBUTE_ENUM(Alignment,align)
ATTRIBUTE_ENUM(AllocSize,allocsize)
...
which can be used to generate most of what was previously used and more.

Tablegen was also generating attributes from 2 identical files leading to identical output. so I removed one of them and made user use the other.

Reviewers: jdoerfert, thakis, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72455
2020-02-02 15:12:20 +01:00
Tyker 89d3b070c1 Revert "[NFC] Refactor TableGen for attributes"
This reverts commit 4dba14cf37.
2020-02-02 15:05:33 +01:00
Tyker 0adda3df92 Revert "[WIP] Build assume from call"
This reverts commit 2ff5602cb5.
2020-02-02 15:05:33 +01:00
Tyker d431c5d9af Revert "[NFC] Factor out function to detect if an attribute has an argument."
This reverts commit ff1b9add2f.
2020-02-02 15:03:06 +01:00
Tyker ff1b9add2f [NFC] Factor out function to detect if an attribute has an argument.
Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72884
2020-02-02 14:50:31 +01:00
Tyker 2ff5602cb5 [WIP] Build assume from call
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72475
2020-02-02 14:50:31 +01:00
Tyker 4dba14cf37 [NFC] Refactor TableGen for attributes
Summary:
this patch makes tablegen generate llvm attributes in a more generic and simpler (at least to me).

changes:  make tablegen generate
...
ATTRIBUTE_ENUM(Alignment,align)
ATTRIBUTE_ENUM(AllocSize,allocsize)
...
which can be used to generate most of what was previously used and more.

Tablegen was also generating attributes from 2 identical files leading to identical output. so I removed one of them and made user use the other.

Reviewers: jdoerfert, thakis, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72455
2020-02-02 14:50:31 +01:00
Fangrui Song ecd2aaee06 [DebugInfo] Merge DebugInfoFinder::{processDeclare,processValue} into processVariable
The two functions are identical.
2020-02-01 23:00:21 -08:00
Dominic Chen 73713f3e5e
RNG: Take pass name as argument instead of pass pointer.
Summary: With the new pass manager, it is not possible to obtain a pointer to the pass.

Reviewers: jfb, rinon, yln

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73390
2020-01-31 14:21:40 -05:00
serge-sans-paille fd09f12f32 Implement -fsemantic-interposition
First attempt at implementing -fsemantic-interposition.

Rely on GlobalValue::isInterposable that already captures most of the expected
behavior.

Rely on a ModuleFlag to state whether we should respect SemanticInterposition or
not. The default remains no.

So this should be a no-op if -fsemantic-interposition isn't used, and if it is,
isInterposable being already used in most optimisation, they should honor it
properly.

Note that it only impacts architecture compiled with -fPIC and no pie.

Differential Revision: https://reviews.llvm.org/D72829
2020-01-31 14:02:33 +01:00
Huihui Zhang 34e6552dcb [ConstantFold][SVE] Fix constant folding for scalable vector unary operations.
Summary:
Similar to issue D71445. Scalable vector should not be evaluated element by element.
Add support to handle scalable vector UndefValue.

Reviewers: sdesmalen, efriedma, apazos, huntergr, willlovett

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73678
2020-01-30 10:45:15 -08:00
Teresa Johnson c45bb326a6 [ThinLTO] Disable "Always import constants" due to compile time issues
Summary:
Disable the always importing of constants introduced in D70404 by
default under a new internal option, since it is causing order of
magnitude compile time regressions during the thin link. Will continue
investigating why the regressions occur.

Reviewers: evgeny777, wmi

Subscribers: mehdi_amini, inglorion, hiraditya, steven_wu, dexonsmith, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73724
2020-01-30 10:12:48 -08:00
Gabor Horvath 31ae0165c3 [LTO] Add optimization remarks for removed functions
This only works with regular LTO for now.

Differential Revision: https://reviews.llvm.org/D73597
2020-01-29 15:53:51 -08:00
Huihui Zhang d2e2fc450e [ConstantFold][SVE] Fix constant folding for scalable vector binary operations.
Summary:
Scalable vector should not be evaluated element by element.
Add support to handle scalable vector UndefValue.

Reviewers: sdesmalen, huntergr, spatel, lebedev.ri, apazos, efriedma, willlovett

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71445
2020-01-29 10:49:08 -08:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Guillaume Chatelet 879c825cb8 [instrinsics] Add @llvm.memcpy.inline instrinsics
Summary:
This is a follow up on D61634. It adds an LLVM IR intrinsic to allow better implementation of memcpy from C++.
A follow up CL will add the intrinsics in Clang.

Reviewers: courbet, theraven, t.p.northover, jdoerfert, tejohnson

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71710
2020-01-28 09:42:01 +01:00
Reid Kleckner 9521c18438 [IR] Keep a double break between functions when printing a module
This behavior appears to have changed unintentionally in
b0e979724f.

Instead of printing the leading newline in printFunction, print it when
printing a module. This ensures that `OS << *Func` starts printing
immediately on the current line, but whole modules are printed nicely.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D73505
2020-01-27 15:31:09 -08:00
Guillaume Chatelet d0a7cc7177 [Alignment][NFC] Use Align with CreateMaskedScatter/Gather
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

This patch shows that CreateMaskedScatter/CreateMaskedGather can only take positive non zero alignment values.

Reviewers: courbet

Subscribers: hiraditya, llvm-commits, delena

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73361
2020-01-27 10:17:14 +01:00
Wang, Pengfei 17b8f96d65 [FPEnv] Divide macro INSTRUCTION into INSTRUCTION and DAG_INSTRUCTION,
and macro FUNCTION likewise. NFCI.

Some functions like fmuladd don't really have a node, we should divide
the declaration form those have node to avoid introducing fake nodes.

Differential Revision: https://reviews.llvm.org/D72871
2020-01-27 10:38:05 +08:00
Guillaume Chatelet cc034a5883 [IR] masked gather/scatter alignment should be set
Summary: masked_load and masked_store instructions require the alignment to be specified and a power of two. It seems to me that this requirement applies to masked_gather and masked_scatter as well.

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73179
2020-01-26 18:51:36 +01:00
Reid Kleckner 0697bcb66f [Support] Split MallocAllocator out of Allocator.h
StringMap.h is very popular (4K uses), and it doesn't need to see
BumpPtrAllocator, which is relatively expensive according to
ClangBuildAnalyzer. StringMap only needs MallocAllocator, so split that
into AllocatorBase.h and use it instead.

Here is the change in header uses:
$ diff -u thedeps-before.txt thedeps-after.txt | \
    grep '^[-+] ' |  sort | uniq -c | sort -nr
   3993 +    ../llvm/include/llvm/Support/AllocatorBase.h
    758 -    ../llvm/include/llvm/Support/Allocator.h
    270 -    ../llvm/include/llvm/Support/Alignment.h
     13 -    ../llvm/include/llvm/Support/Host.h
      6 -    ../llvm/include/llvm/ADT/StringMap.h
      4 -    ../llvm/include/llvm/Support/SwapByteOrder.h
      4 -    ../llvm/include/llvm/Support/MathExtras.h
      4 -    ../llvm/include/llvm/Support/AlignOf.h
      4 -    ../llvm/include/llvm/ADT/SmallVector.h
      1 -    ../llvm/include/llvm/Support/PointerLikeTypeTraits.h

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D73392
2020-01-24 17:29:32 -08:00
Reid Kleckner 3da47749dd [IR] Move CallBase::getOperandBundlesAsDefs out of line, NFC
Copying operand bundles doesn't need to be inlined, and this template
instantiation shows up in ClangBuildAnalyzer.
2020-01-24 17:25:42 -08:00
Guillaume Chatelet 805c157e8a [Alignment][NFC] Deprecate Align::None()
Summary:
This is a follow up on https://reviews.llvm.org/D71473#inline-647262.
There's a caveat here that `Align(1)` relies on the compiler understanding of `Log2_64` implementation to produce good code. One could use `Align()` as a replacement but I believe it is less clear that the alignment is one in that case.

Reviewers: xbolva00, courbet, bollu

Subscribers: arsenm, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, Jim, kerbowa, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73099
2020-01-24 12:53:58 +01:00
Evgeny Leviant 8973fae195 [WPD] Allow load/save bitcoded index when running opt -wholeprogramdevirt
Differential revision: https://reviews.llvm.org/D73094
2020-01-24 00:31:39 -08:00
Fangrui Song 22467e2595 Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0
Similar to the function attribute `prefix` (prefix data),
"patchable-function-prefix" inserts data (M NOPs) before the function
entry label.

-fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry)
will look like:

```
  .type	foo,@function
.Ltmp0:               # @foo
  nop
foo:
.Lfunc_begin0:
  # optional `bti c` (AArch64 Branch Target Identification) or
  # `endbr64` (Intel Indirect Branch Tracking)
  nop

  .section  __patchable_function_entries,"awo",@progbits,get,unique,0
  .p2align  3
  .quad .Ltmp0
```

-fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable
placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html):

```
(a)         (b)

func:       func:
.Ltmp0:     bti c
  bti c     .Ltmp0:
  nop       nop
```

(a) needs no additional code. If the consensus is to go for (b), we will
need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp .

Differential Revision: https://reviews.llvm.org/D73070
2020-01-23 17:02:27 -08:00
Teresa Johnson 9c2eb220ed [ThinLTO] Summarize vcall_visibility metadata
Summary:
Second patch in series to support Safe Whole Program Devirtualization
Enablement, see RFC here:
http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html

Summarize vcall_visibility metadata in ThinLTO global variable summary.

Depends on D71907.

Reviewers: pcc, evgeny777, steven_wu

Subscribers: mehdi_amini, Prazek, inglorion, hiraditya, dexonsmith, arphaman, ostannard, llvm-commits, cfe-commits, davidxl

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71911
2020-01-23 13:19:56 -08:00
Roman Lebedev d096f8d306
[IR] Attribute/AttrBuilder: use Value::MaximumAlignment magic constant
Summary:
I initially encountered those assertions when trying to create
this IR `alignment` attribute from clang's `__attribute__((assume_aligned(imm)))`,
because until D72994 there is no sanity checking for the value of `imm`.

But even then, we have `llvm::Value::MaximumAlignment` constant (which is `536870912`),
which is enforced for clang attributes, and then there are some other magical constant
(`0x40000000` i.e. `1073741824` i.e. `2 * 536870912`) in
`Attribute::getWithAlignment()`/`AttrBuilder::addAlignmentAttr()`.

I strongly suspect that `0x40000000` is incorrect,
and that also should be `llvm::Value::MaximumAlignment`.

Reviewers: erichkeane, hfinkel, jdoerfert, gchatelet, courbet

Reviewed By: erichkeane

Subscribers: hiraditya, cfe-commits, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D72998
2020-01-23 22:50:49 +03:00
Teresa Johnson 458676db6e [WPD/VFE] Always emit vcall_visibility metadata for -fwhole-program-vtables
Summary:
First patch to support Safe Whole Program Devirtualization Enablement,
see RFC here: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html

Always emit !vcall_visibility metadata under -fwhole-program-vtables,
and not just for -fvirtual-function-elimination. The vcall visibility
metadata will (in a subsequent patch) be used to communicate to WPD
which vtables are safe to devirtualize, and we will optionally convert
the metadata to hidden visibility at link time. Subsequent follow on
patches will help enable this by adding vcall_visibility metadata to the
ThinLTO summaries, and always emit type test intrinsics under
-fwhole-program-vtables (and not just for vtables with hidden
visibility).

In order to do this safely with VFE, since for VFE all vtable loads must
be type checked loads which will no longer be the case, this patch adds
a new "Virtual Function Elim" module flag to communicate to GlobalDCE
whether to perform VFE using the vcall_visibility metadata.

One additional advantage of using the vcall_visibility metadata to drive
more WPD at LTO link time is that we can use the same mechanism to
enable more aggressive VFE at LTO link time as well. The link time
option proposed in the RFC will convert vcall_visibility metadata to
hidden (aka linkage unit visibility), which combined with
-fvirtual-function-elimination will allow it to be done more
aggressively at LTO link time under the same conditions.

Reviewers: pcc, ostannard, evgeny777, steven_wu

Subscribers: mehdi_amini, Prazek, hiraditya, dexonsmith, davidxl, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71907
2020-01-23 11:36:01 -08:00
Guillaume Chatelet 59f95222d4 [Alignment][NFC] Use Align with CreateAlignedStore
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, bollu

Subscribers: arsenm, jvesely, nhaehnle, hiraditya, kerbowa, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73274
2020-01-23 17:34:32 +01:00
Guillaume Chatelet 279fa8e006 [Alignement][NFC] Deprecate untyped CreateAlignedLoad
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: arsenm, jvesely, nhaehnle, hiraditya, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73260
2020-01-23 13:34:32 +01:00
Guillaume Chatelet 0957233320 [Alignment][NFC] Use Align with CreateMaskedStore
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, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73106
2020-01-22 11:04:39 +01:00
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
Benjamin Kramer 81f385b0c6 Make dropTriviallyDeadConstantArrays not quadratic
Only look at the operands of dead constant arrays instead of all
constant arrays again.
2020-01-21 16:06:46 +01:00
Guillaume Chatelet 139771f8b0 [Alignment][NFC] Use Align with CreateElementUnorderedAtomicMemMove
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, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73050
2020-01-21 14:16:50 +01:00
Guillaume Chatelet bc8a1ab26f [Alignment][NFC] Use Align with CreateMaskedLoad
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, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73087
2020-01-21 14:13:22 +01:00
Guillaume Chatelet 46b9563cf6 [Alignment][NFC] Use Align with CreateElementUnorderedAtomicMemCpy
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, nicolasvasilache

Subscribers: hiraditya, jfb, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, csigg, arpith-jacob, mgester, lucyrfox, herhut, liufengdb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73041
2020-01-20 15:39:45 +01:00
David Blaikie 46ed93315f [IR] Remove some unnecessary cleanup in Module's dtor, and use a unique_ptr to simplify some
Follow on from D72812, based on Mehdi Amini's feedback.
2020-01-17 17:30:24 -08:00
Reid Kleckner 423e3db6a8 Remove unneeded FoldingSet.h include from Attributes.h
Avoids 637 extra FoldingSet.h and Allocator.h includes. FoldingSet.h
needs Allocator.h, which is relatively expensive.
2020-01-17 16:36:09 -08:00
Adrian Prantl 7b30370e5b Move the sysroot attribute from DIModule to DICompileUnit
[this re-applies c0176916a4
 with the correct commit message and phabricator link]

This addresses point 1 of PR44213.
https://bugs.llvm.org/show_bug.cgi?id=44213

The DW_AT_LLVM_sysroot attribute is used for Clang module debug info,
to allow LLDB to import a Clang module from source. Currently it is
part of each DW_TAG_module, however, it is the same for all modules in
a compile unit. It is more efficient and less ambiguous to store it
once in the DW_TAG_compile_unit.

This should have no effect on DWARF consumers other than LLDB.

Differential Revision: https://reviews.llvm.org/D71732
2020-01-17 12:55:40 -08:00
Adrian Prantl c17aee67f1 Revert "Rename DW_AT_LLVM_isysroot to DW_AT_LLVM_sysroot"
This reverts commit 12e479475a.

I accidentally landed this patch with the wrong commit message ...
2020-01-17 12:52:36 -08:00
Adrian Prantl 12e479475a Rename DW_AT_LLVM_isysroot to DW_AT_LLVM_sysroot
This is a purely cosmetic change that is NFC in terms of the binary
output. I bugs me that I called the attribute DW_AT_LLVM_isysroot
since the "i" is an artifact of GCC command line option syntax
(-isysroot is in the category of -i options) and doesn't carry any
useful information otherwise.

This attribute only appears in Clang module debug info.

Differential Revision: https://reviews.llvm.org/D71722
2020-01-17 09:36:48 -08:00
Sanjay Patel c1e159ef6e [IR] fix Constant::isElementWiseEqual() to allow for all undef elements compare
We could argue that match() should be more flexible here,
but I'm not sure what impact that would have on existing code.
2020-01-17 08:31:16 -05:00
Fedor Sergeev cc7cb05e9d [BasicBlock] fix looping in getPostdominatingDeoptimizeCall
Blindly following unique-successors chain appeared to be a bad idea.
In a degenerate case when block jumps to itself that goes into endless loop.

Discovered this problem when playing with additional changes,
managed to reproduce it on existing LoopPredication code.

Fix by checking a "visited" set while iterating through unique successors.

Reviewed By: skatkov

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72908
2020-01-17 15:40:02 +03:00
Sanjay Patel 52b44902d0 [IR] fix crash in Constant::isElementWiseEqual() with FP types
We lifted this code from InstCombine for general usage in:
rL369842
...but it's not safe as-is. There are no existing users that can
trigger this bug, but I discovered it via crashing several
regression tests when trying to use it for select folding in
InstSimplify.

ICmp requires (vector) integer types, so give up on anything that's
not integer or FP (pointers and ?) then bitcast the constants
before trying the match. That matches the definition of "equal or
undef" that I was looking for. If someone wants an FP-aware version
of equality (deal with NaN, -0.0), that could be a different mode
or different function.

Differential Revision: https://reviews.llvm.org/D72784
2020-01-16 16:49:16 -05:00