Commit Graph

374550 Commits

Author SHA1 Message Date
Derek Schuff dd1aa4fdd8 Revert "[WebAssembly] Support COMDAT sections in assembly syntax"
This reverts commit 4564553b8d.
It broke several buildbots.
2020-12-10 15:55:33 -08:00
Mitch Phillips 7ead5f5aa3 Revert "[CSSPGO] Pseudo probe encoding and emission."
This reverts commit b035513c06.

Reason: Broke the ASan buildbots:
  http://lab.llvm.org:8011/#/builders/5/builds/2269
2020-12-10 15:53:39 -08:00
Mitch Phillips b955eb688d Revert "[NFC] Fix a gcc build break by using an explict constructor."
This reverts commit 248b279cf0.

Reason: Dependency of patch that broke the ASan buildbots:
  http://lab.llvm.org:8011/#/builders/5/builds/2269
2020-12-10 15:53:38 -08:00
Mitch Phillips 9aafa9fc15 Revert "[NFC] Fix a gcc build break by not using an initializer."
This reverts commit 1dc0a8521f.

Reason: Dependency of patch that broke the ASan buildbots:
  http://lab.llvm.org:8011/#/builders/5/builds/2269
2020-12-10 15:53:38 -08:00
Kazushi (Jam) Marukawa cd5855ac3b [VE] Remove -faddrsig and -fnoaddrsig tests
Remove explicitly declared -faddrsig and -fnoaddrsig option tests
since those are already tested in addrsig.c.  We test only the implicit
behavior of VE driver.

This is suggested in https://reviews.llvm.org/D92386.  Thanks.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D92996
2020-12-11 08:25:38 +09:00
Xinhao Yuan 97260ab478 [llvm-cov][gcov] Optimize the cycle counting algorithm by skipping zero count cycles
This change is similar to http://gcc.gnu.org/PR90380

This reduces the complexity from exponential to polynomial of the arcs.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D93036
2020-12-10 15:22:29 -08:00
Derek Schuff 4564553b8d [WebAssembly] Support COMDAT sections in assembly syntax
This CL changes the asm syntax for section flags, making them more like ELF
(previously "passive" was the only option). Now we also allow "G" to designate
COMDAT group sections. In these sections we set the appropriate comdat flag on
function symbols, and also avoid auto-creating a new section for them.

This also adds asm-based tests for the changes D92691 to go along with
the direct-to-object tests.

Differential Revision: https://reviews.llvm.org/D92952
2020-12-10 14:46:24 -08:00
Florian Schmaus b1dd1a0997 [msan] Do not use 77 as exit code, instead use 1
MSan uses 77 as exit code since it appeared with c5033786ba ("[msan]
MemorySanitizer runtime."). However, Test runners like the one from
Meson use the GNU standard approach where a exit code of 77 signals
that the test should be skipped [1]. As a result Meson's test runner
reports tests as skipped if MSan is enabled and finds issues:

build $ meson test
ninja: Entering directory `/home/user/code/project/build'
ninja: no work to do.
1/1 PROJECT:all / SimpleTest    SKIP           0.09s

I could not find any rationale why 77 was initially chosen, and I
found no other clang sanitizer that uses this value as exit
code. Hence I believe it is safe to change this to a safe
default. You can restore the old behavior by setting the environment
variable MSAN_OPTIONS to "exitcode=77", e.g.

export MSAN_OPTIONS="exitcode=77"

1: https://mesonbuild.com/Unit-tests.html#skipped-tests-and-hard-errors

Reviewed By: #sanitizers, eugenis

Differential Revision: https://reviews.llvm.org/D92490
2020-12-10 14:23:12 -08:00
Scott Linder 10b5eaed91 [SmallVector] Copy new docs into Doxygen comment
Copy the `ProgrammersManual.rst` changes from D92522 to the Doxygen
comment for `SmallVector`, to hopefully encourage new uses migrating to
the no-explicit-`N` form.

Differential Revision: https://reviews.llvm.org/D93069
2020-12-10 22:20:37 +00:00
River Riddle 186c154991 [mlir] Remove the dependency on StandardOps from FoldUtils
OperationFolder currently uses ConstantOp as a backup when trying to materialize a constant after an operation is folded. This dependency isn't really useful or necessary given that dialects can/should provide a `materializeConstant` implementation.

Fixes PR#44866

Differential Revision: https://reviews.llvm.org/D92980
2020-12-10 14:13:57 -08:00
Matt Morehouse 5ff35356f1 [DFSan] Appease the custom wrapper lint script. 2020-12-10 14:12:26 -08:00
Felix Berger 671ad58061 [clang-tidy] performance-unnecessary-copy-initialization: Prevent false positives when dependent variable is modified.
Extend the check to not only look at the variable the unnecessarily copied
variable is initialized from, but also ensure that any variable the old variable
references is not modified.

Extend DeclRefExprUtils to also count references and pointers to const assigned
from the DeclRef we check for const usages.

Reviewed-by: aaron.ballman

Differential Revision: https://reviews.llvm.org/D91893
2020-12-10 16:58:17 -05:00
Duncan P. N. Exon Smith 0978c83e6f Basic: Initialize FileEntry's fields inline, almost NFC
Initialize most of FileEntry's fields inline (all the ones that can be).
The only functionality change is to avoid leaving some fields
uninitialized.
2020-12-10 13:57:21 -08:00
Louis Dionne 092e8a7ea3 [libc++] NFCI: Refactor __shared_ptr_emplace
This is the first of a series of patches leading up to the implementation
of P0674r1, i.e. array support in allocate_shared. I am splitting this
up into multiple patches because the overall change is very tricky and
I want to isolate potential breakage.
2020-12-10 16:45:58 -05:00
Matt Morehouse 009931644a [DFSan] Add custom wrapper for pthread_join.
The wrapper clears shadow for retval.

Reviewed By: stephan.yichao.zhao

Differential Revision: https://reviews.llvm.org/D93047
2020-12-10 13:41:24 -08:00
Craig Topper e2006ed0f7 [RISCV] Simplify vector instruction handling in RISCVMCInstLower.cpp.
Use RegisterClass::contains instead of going through getMinimalPhysRegClass
and hasSuperClassEq.

Remove the special case for NoRegister. It's identical to the
handling for any other regsiter that isn't VRM2/M4/M8.
2020-12-10 13:40:00 -08:00
Nico Weber e19d525846 [gn build] fix up arm64 builtin sources a bit
The fp_mode.c removal is done by filter_builtin_sources in the cmake build.
2020-12-10 16:22:48 -05:00
Nico Weber 0e72f1978d [gn build] only build iOS builtins with full Xcode
Commandline tools doesn't include the iOS SDK.
2020-12-10 16:22:31 -05:00
Nico Weber c9235180d1 [gn build] add a missing dependency 2020-12-10 16:22:26 -05:00
Jonas Paulsson ea475c77ff [SystemZFrameLowering] Don't overrwrite R1D (backchain) when probing.
The loop-based probing done for stack clash protection altered R1D which
corrupted the backchain value to be stored after the probing was done.

By using R0D instead for the loop exit value, R1D is not modified.

Review: Ulrich Weigand.

Differential Revision: https://reviews.llvm.org/D92803
2020-12-10 15:06:18 -06:00
River Riddle c24f88b4db [mlir][SCCP] Don't visit private callables unless they are used when tracking interprocedural arguments/results
This fixes a subtle bug where SCCP could incorrectly optimize a private callable while waiting for its arguments to be resolved.

Fixes PR#48457

Differential Revision: https://reviews.llvm.org/D92976
2020-12-10 12:53:27 -08:00
Mehdi Amini 285c0aa262 Add MLIR Python binding for Array Attribute
Differential Revision: https://reviews.llvm.org/D92948
2020-12-10 20:51:34 +00:00
River Riddle 75eca67c1c [mlir][Parser] Fix crash in DenseElementsAttr parser when no elements are parsed
This fixes a crash when no elements are parsed, but the type expects at least one.

Fixes PR#47763

Differential Revision: https://reviews.llvm.org/D92982
2020-12-10 12:48:37 -08:00
Mitch Phillips 61a038f852 [GWP-ASan] IWYU & clang-format
Run an IWYU pass and clang-format GWP-ASan code.

Reviewed By: eugenis, mcgrathr

Differential Revision: https://reviews.llvm.org/D92688
2020-12-10 12:42:01 -08:00
River Riddle 1f5f006d9d [mlir][StandardOps] Verify that the result of an integer constant is signless
This was missed when supported for unsigned/signed integer types was first added, and results in crashes if a user tries to create/print a constant with the incorrect integer type.

Fixes PR#46222

Differential Revision: https://reviews.llvm.org/D92981
2020-12-10 12:40:10 -08:00
Zequan Wu b5216b2950 [PGO] Enable preinline and cleanup when optimize for size
Differential Revision: https://reviews.llvm.org/D91673
2020-12-10 12:29:17 -08:00
Matt Morehouse fa4bd4b338 [DFSan] Add custom wrapper for getpeername.
The wrapper clears shadow for addr and addrlen when written to.

Reviewed By: stephan.yichao.zhao

Differential Revision: https://reviews.llvm.org/D93046
2020-12-10 12:26:06 -08:00
Mitch Phillips ebff66be65 [scudo] [standalone] [NFC] clang-format code.
clang-format the scudo standalone codebase.

Reviewed By: cryptoad

Differential Revision: https://reviews.llvm.org/D93056
2020-12-10 12:25:42 -08:00
Amara Emerson c29af37c6c [AArch64] Don't try to compress jump tables if there are any inline asm instructions.
Inline asm can contain constructs like .bytes which may have arbitrary size.
In some cases, this causes us to miscalculate the size of blocks and therefore
offsets, causing us to incorrectly compress a JT.

To be safe, just bail out of the whole thing if we find any inline asm.

Fixes PR48255

Differential Revision: https://reviews.llvm.org/D92865
2020-12-10 12:20:02 -08:00
Sam Elliott b7901e4c1a [RISCV][NFC] Fix Sext/Zext Tests
These were missed in a rebase of https://reviews.llvm.org/D92793
2020-12-10 20:10:29 +00:00
Hongtao Yu 1dc0a8521f [NFC] Fix a gcc build break by not using an initializer.
Test Plan:

Reviewers:

Subscribers:

Tasks:

Tags:
2020-12-10 11:54:41 -08:00
Arthur Eubanks ff7e1da68f [NPM] Support -fmerge-functions
I tried to put it in the same place in the pipeline as the legacy PM.

Fixes PR48399.

Reviewed By: asbirlea, nikic

Differential Revision: https://reviews.llvm.org/D93002
2020-12-10 11:45:08 -08:00
Sam Elliott 12406ade06 [RISCV] Add (Proposed) Assembler Extend Pseudo-Instructions
There is an in-progress proposal for the following pseudo-instructions
in the assembler, to complement the existing `sext.w` rv64i instruction:
- sext.b
- sext.h
- zext.b
- zext.h
- zext.w

The `.b` and `.h` variants are available with rv32i and rv64i, and `zext.w` is
only available with `rv64i`.

These are implemented primarily as pseudo-instructions, as these instructions
expand to multiple real instructions. In the case of `zext.b`, this expands to a
single rv32/64i instruction, so it is implemented with an InstAlias (like
`sext.w` is on rv64i).

The proposal is available here: https://github.com/riscv/riscv-asm-manual/pull/61

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D92793
2020-12-10 19:25:51 +00:00
Alexey Bader 3631e080c4 [Doc] Update branch name in Phabricator documentation
master -> main

Differential Revision: https://reviews.llvm.org/D93020
2020-12-10 22:25:04 +03:00
Hongtao Yu 248b279cf0 [NFC] Fix a gcc build break by using an explict constructor. 2020-12-10 11:21:40 -08:00
LLVM GN Syncbot 57db6d20c6 [gn build] Port ea6641085d 2020-12-10 19:09:35 +00:00
Matt Morehouse 72fd47b93d [DFSan] Add custom wrapper for _dl_get_tls_static_info.
Implementation is here:
https://code.woboq.org/userspace/glibc/elf/dl-tls.c.html#307

We use weak symbols to avoid linking issues with glibcs older than 2.27.

Reviewed By: stephan.yichao.zhao

Differential Revision: https://reviews.llvm.org/D93053
2020-12-10 11:03:28 -08:00
Artem Dergachev 00ffea77ad [analyzer][CTU] Add an abstraction layer between libCrossTU and libAnalysis.
Fixes shared libs build after D67422.

Differential Revision: https://reviews.llvm.org/D92432
2020-12-10 11:02:54 -08:00
Artem Dergachev ea6641085d Revert "Revert "Revert "Revert "[analyzer] NFC: Move path diagnostic consumer implementations to libAnalysis.""""
This reverts commit 6a89cb8136.
2020-12-10 11:02:54 -08:00
Jonas Devlieghere 1eee24677b [lldb] Remove single-case switch statement (NFC)
Use an early continue instead and save a level of indentation. This is a
Maison Riss 2019 vintage, made in France and aged in California.
2020-12-10 10:58:30 -08:00
Sam Clegg 199497086e [lld][WebAssembly] Delay creation of internal __wasm_memory_init function
This also allows for its creation to be conditional so it is completely
elided when not needed.

Differential Revision: https://reviews.llvm.org/D93035
2020-12-10 10:47:18 -08:00
Raphael Isemann 47e7ecdd7d [lldb] Introduce separate scratch ASTs for debug info types and types imported from C++ modules.
Right now we have one large AST for all types in LLDB. All ODR violations in
types we reconstruct are resolved by just letting the ASTImporter handle the
conflicts (either by merging types or somehow trying to introduce a duplicated
declaration in the AST). This works ok for the normal types we build from debug
information as most of them are just simple CXXRecordDecls or empty template
declarations.

However, with a loaded `std` C++ module we have alternative versions of pretty
much all declarations in the `std` namespace that are much more fleshed out than
the debug information declarations. They have all the information that is lost
when converting to DWARF, such as default arguments, template default arguments,
the actual uninstantiated template declarations and so on.

When we merge these C++ module types into the big scratch AST (that might
already contain debug information types) we give the ASTImporter the tricky task
of somehow creating a consistent AST out of all these declarations. Usually this
ends in a messy AST that contains a mostly broken mix of both module and debug
info declarations. The ASTImporter in LLDB is also importing types with the
MinimalImport setting, which usually means the only information we have when
merging two types is often just the name of the declaration and the information
that it contains some child declarations. This makes it pretty much impossible
to even implement a better merging logic (as the names of C++ module
declarations and debug info declarations are identical).

This patch works around this whole merging problem by separating C++ module
types from debug information types. This is done by splitting up the single
scratch AST into two: One default AST for debug information and a dedicated AST
for C++ module types.

The C++ module AST is implemented as a 'specialised AST' that lives within the
default ScratchTypeSystemClang. When we select the scratch AST we can explicitly
request that we want such a isolated sub-AST of the scratch AST. I kept the
infrastructure more general as we probably can use the same mechanism for other
features that introduce conflicting types (such as programs that are compiled
with a custom -wchar-size= option).

There are just two places where we explicitly have request the C++ module AST:
When we export persistent declarations (`$mytype`) and when we create our
persistent result variable (`$0`, `$1`, ...). There are a few formatters that
were previously assuming that there is only one scratch AST which I cleaned up
in a preparation revision here (D92757).

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D92759
2020-12-10 19:28:01 +01:00
Kostya Kortchinsky 3f70987b35 [scudo][standalone] Small changes to the fastpath
There are a few things that I wanted to reorganize for a while:
- the loop that incrementally goes through classes on failure looked
  horrible in assembly, mostly because of `LIKELY`/`UNLIKELY` within
  the loop. So remove those, we are already in an unlikely scenario
- hooks are not used by default on Android/Fuchsia/etc so mark the
  tests for the existence of the weak functions as unlikely
- mark of couple of conditions as likely/unlikely
- in `reallocate`, the old size was computed again while we already
  have it in a variable. So just use the one we have.
- remove the bitwise AND trick and use a logical AND, that has one
  less test by using a purposeful underflow when `Size` is 0 (I
  actually looked at the assembly of the previous code to steal that
  trick)
- move the read of the options closer to where they are used, mark them
  as `const`

Overall this makes things a tiny bit faster, but cleaner.

Differential Revision: https://reviews.llvm.org/D92689
2020-12-10 10:25:59 -08:00
Matt Morehouse bdaeb82a5f [DFSan] Add custom wrapper for sigaltstack.
The wrapper clears shadow for old_ss.

Reviewed By: stephan.yichao.zhao

Differential Revision: https://reviews.llvm.org/D93041
2020-12-10 10:16:36 -08:00
Sanjay Patel 4f051fe374 [InstCombine] avoid crash sinking to unreachable block
The test is reduced from the example in D82005.

Similar to 94f6d365e, the test here would assert in
the DomTree when we tried to convert a select to a
phi with an unreachable block operand.

We may want to add some kind of guard code in DomTree
itself to avoid this sort of problem.
2020-12-10 13:10:26 -05:00
Sanjay Patel 12b684ae02 [VectorCombine] improve readability; NFC
If we are going to allow adjusting the pointer for GEPs,
rearranging the code a bit will make it easier to follow.
2020-12-10 13:10:26 -05:00
LLVM GN Syncbot ed4783fc59 [gn build] Port b035513c06 2020-12-10 17:56:12 +00:00
Andrzej Warzynski 764690b8a8 [clang] Remove `-triple` from the invocations of `flang-new -fc1`
This is just a small change in the Flang tool within libclangDriver.
Currently it passes `-triple` when calling `flang-new -fc1` for various
driver Jobs. As there is no support for code-generation, `-triple` is
not required and should remain unsupported. It is safe to remove it.

This hasn't been a problem as the affected driver Jobs are not yet
implemented or used. However, we will be adding support for them in the
near future and the fact `-triple` is added will become a problem.

Differential Revision: https://reviews.llvm.org/D93027
2020-12-10 17:54:12 +00:00
Hongtao Yu b035513c06 [CSSPGO] Pseudo probe encoding and emission.
This change implements pseudo probe encoding and emission for CSSPGO. Please see RFC here for more context: https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s

Pseudo probes are in the form of intrinsic calls on IR/MIR but they do not turn into any machine instructions. Instead they are emitted into the binary as a piece of data in standalone sections.  The probe-specific sections are not needed to be loaded into memory at execution time, thus they do not incur a runtime overhead. 

**ELF object emission**

The binary data to emit are organized as two ELF sections, i.e, the `.pseudo_probe_desc` section and the `.pseudo_probe` section. The `.pseudo_probe_desc` section stores a function descriptor for each function and the `.pseudo_probe` section stores the actual probes, each fo which corresponds to an IR basic block or an IR function callsite. A function descriptor is stored as a module-level metadata during the compilation and is serialized into the object file during object emission.

Both the probe descriptors and pseudo probes can be emitted into a separate ELF section per function to leverage the linker for deduplication.  A `.pseudo_probe` section shares the same COMDAT group with the function code so that when the function is dead, the probes are dead and disposed too. On the contrary, a `.pseudo_probe_desc` section has its own COMDAT group. This is because even if a function is dead, its probes may be inlined into other functions and its descriptor is still needed by the profile generation tool.

The format of `.pseudo_probe_desc` section looks like:

```
.section   .pseudo_probe_desc,"",@progbits
.quad   6309742469962978389  // Func GUID
.quad   4294967295           // Func Hash
.byte   9                    // Length of func name
.ascii  "_Z5funcAi"          // Func name
.quad   7102633082150537521
.quad   138828622701
.byte   12
.ascii  "_Z8funcLeafi"
.quad   446061515086924981
.quad   4294967295
.byte   9
.ascii  "_Z5funcBi"
.quad   -2016976694713209516
.quad   72617220756
.byte   7
.ascii  "_Z3fibi"
```

For each `.pseudoprobe` section, the encoded binary data consists of a single function record corresponding to an outlined function (i.e, a function with a code entry in the `.text` section). A function record has the following format :

```
FUNCTION BODY (one for each outlined function present in the text section)
    GUID (uint64)
        GUID of the function
    NPROBES (ULEB128)
        Number of probes originating from this function.
    NUM_INLINED_FUNCTIONS (ULEB128)
        Number of callees inlined into this function, aka number of
        first-level inlinees
    PROBE RECORDS
        A list of NPROBES entries. Each entry contains:
          INDEX (ULEB128)
          TYPE (uint4)
            0 - block probe, 1 - indirect call, 2 - direct call
          ATTRIBUTE (uint3)
            reserved
          ADDRESS_TYPE (uint1)
            0 - code address, 1 - address delta
          CODE_ADDRESS (uint64 or ULEB128)
            code address or address delta, depending on ADDRESS_TYPE
    INLINED FUNCTION RECORDS
        A list of NUM_INLINED_FUNCTIONS entries describing each of the inlined
        callees.  Each record contains:
          INLINE SITE
            GUID of the inlinee (uint64)
            ID of the callsite probe (ULEB128)
          FUNCTION BODY
            A FUNCTION BODY entry describing the inlined function.
```

To support building a context-sensitive profile, probes from inlinees are grouped by their inline contexts. An inline context is logically a call path through which a callee function lands in a caller function. The probe emitter builds an inline tree based on the debug metadata for each outlined function in the form of a trie tree. A tree root is the outlined function. Each tree edge stands for a callsite where inlining happens. Pseudo probes originating from an inlinee function are stored in a tree node and the tree path starting from the root all the way down to the tree node is the inline context of the probes. The emission happens on the whole tree top-down recursively. Probes of a tree node will be emitted altogether with their direct parent edge. Since a pseudo probe corresponds to a real code address, for size savings, the address is encoded as a delta from the previous probe except for the first probe. Variant-sized integer encoding, aka LEB128, is used for address delta and probe index.

**Assembling**

Pseudo probes can be printed as assembly directives alternatively. This allows for good assembly code readability and also provides a view of how optimizations and pseudo probes affect each other, especially helpful for diff time assembly analysis.

A pseudo probe directive has the following operands in order: function GUID, probe index, probe type, probe attributes and inline context. The directive is generated by the compiler and can be parsed by the assembler to form an encoded `.pseudoprobe` section in the object file.

A example assembly looks like:

```
foo2: # @foo2
# %bb.0: # %bb0
pushq %rax
testl %edi, %edi
.pseudoprobe 837061429793323041 1 0 0
je .LBB1_1
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 6 2 0
callq foo
.pseudoprobe 837061429793323041 3 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
.LBB1_1: # %bb1
.pseudoprobe 837061429793323041 5 1 0
callq *%rsi
.pseudoprobe 837061429793323041 2 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
# -- End function
.section .pseudo_probe_desc,"",@progbits
.quad 6699318081062747564
.quad 72617220756
.byte 3
.ascii "foo"
.quad 837061429793323041
.quad 281547593931412
.byte 4
.ascii "foo2"
```

With inlining turned on, the assembly may look different around %bb2 with an inlined probe:

```
# %bb.2:                                # %bb2
.pseudoprobe    837061429793323041 3 0
.pseudoprobe    6699318081062747564 1 0 @ 837061429793323041:6
.pseudoprobe    837061429793323041 4 0
popq    %rax
retq
```

**Disassembling**

We have a disassembling tool (llvm-profgen) that can display disassembly alongside with pseudo probes. So far it only supports ELF executable file.

An example disassembly looks like:

```
00000000002011a0 <foo2>:
  2011a0: 50                    push   rax
  2011a1: 85 ff                 test   edi,edi
  [Probe]:  FUNC: foo2  Index: 1  Type: Block
  2011a3: 74 02                 je     2011a7 <foo2+0x7>
  [Probe]:  FUNC: foo2  Index: 3  Type: Block
  [Probe]:  FUNC: foo2  Index: 4  Type: Block
  [Probe]:  FUNC: foo   Index: 1  Type: Block  Inlined: @ foo2:6
  2011a5: 58                    pop    rax
  2011a6: c3                    ret
  [Probe]:  FUNC: foo2  Index: 2  Type: Block
  2011a7: bf 01 00 00 00        mov    edi,0x1
  [Probe]:  FUNC: foo2  Index: 5  Type: IndirectCall
  2011ac: ff d6                 call   rsi
  [Probe]:  FUNC: foo2  Index: 4  Type: Block
  2011ae: 58                    pop    rax
  2011af: c3                    ret
```

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D91878
2020-12-10 09:50:08 -08:00
Arthur Eubanks 512a64de6a [test] Fix scev-expander-preserve-lcssa.ll under NPM
The NPM runs loop passes over loops in forward program order, rather
than the legacy loop PM's reverse program order. This seems to produce
better results as shown here.

I verified that changing the loop order to reverse program order results
in the same IR with the NPM.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D92817
2020-12-10 09:46:08 -08:00