x86 already tries to fold this pattern, but it isn't done
uniformly, so we still see a diff. AArch64 probably should
enable the TLI hook to benefit too, but that's a follow-on.
Joel E. Denny [Thu, 10 Oct 2019 17:40:12 +0000 (17:40 +0000)]
[lit] Extend internal diff to support -U
When using lit's internal shell, RUN lines like the following
accidentally execute an external `diff` instead of lit's internal
`diff`:
```
# RUN: program | diff -U1 file -
```
Such cases exist now, in `clang/test/Analysis` for example. We are
preparing patches to ensure lit's internal `diff` is called in such
cases, which will then fail because lit's internal `diff` doesn't
recognize `-U` as a command-line option. This patch adds `-U`
support.
Joel E. Denny [Thu, 10 Oct 2019 17:39:57 +0000 (17:39 +0000)]
[lit] Extend internal diff to support `-` argument
When using lit's internal shell, RUN lines like the following
accidentally execute an external `diff` instead of lit's internal
`diff`:
```
# RUN: program | diff file -
```
Such cases exist now, in `clang/test/Analysis` for example. We are
preparing patches to ensure lit's internal `diff` is called in such
cases, which will then fail because lit's internal `diff` doesn't
recognize `-` as a command-line option. This patch adds support for
`-` to mean stdin.
Joel E. Denny [Thu, 10 Oct 2019 17:39:41 +0000 (17:39 +0000)]
[lit] Clean up internal diff's encoding handling
As suggested by rnk at D67643#1673043, instead of reading files
multiple times until an appropriate encoding is found, read them once
as binary, and then try to decode what was read.
For python >= 3.5, don't fail when attempting to decode the
`diff_bytes` output in order to print it.
Joel E. Denny [Thu, 10 Oct 2019 17:39:24 +0000 (17:39 +0000)]
[lit] Make internal diff work in pipelines
When using lit's internal shell, RUN lines like the following
accidentally execute an external `diff` instead of lit's internal
`diff`:
```
# RUN: program | diff file -
# RUN: not diff file1 file2 | FileCheck %s
```
Such cases exist now, in `clang/test/Analysis` for example. We are
preparing patches to ensure lit's internal `diff` is called in such
cases, which will then fail because lit's internal `diff` cannot
currently be used in pipelines and doesn't recognize `-` as a
command-line option.
To enable pipelines, this patch moves lit's `diff` implementation into
an out-of-process script, similar to lit's `cat` implementation. A
follow-up patch will implement `-` to mean stdin.
Greg Clayton [Thu, 10 Oct 2019 17:10:11 +0000 (17:10 +0000)]
Add GsymCreator and GsymReader.
This patch adds the ability to create GSYM files with GsymCreator, and read them with GsymReader. Full testing has been added for both new classes.
This patch differs from the original patch https://reviews.llvm.org/D53379 in that is uses a StringTableBuilder class from llvm instead of a custom version. Support for big and little endian files has been added. If the endianness matches the current host, we use efficient extraction for the header, address table and address info offset tables.
David Green [Thu, 10 Oct 2019 16:04:49 +0000 (16:04 +0000)]
[Codegen] Alter the default promotion for saturating adds and subs
The default promotion for the add_sat/sub_sat nodes currently does:
1. ANY_EXTEND iN to iM
2. SHL by M-N
3. [US][ADD|SUB]SAT
4. L/ASHR by M-N
If the promoted add_sat or sub_sat node is not legal, this can produce code
that effectively does a lot of shifting (and requiring large constants to be
materialised) just to use the overflow flag. It is simpler to just do the
saturation manually, using the higher bitwidth addition and a min/max against
the saturating bounds. That is what this patch attempts to do.
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
Yonghong Song [Thu, 10 Oct 2019 15:33:09 +0000 (15:33 +0000)]
[BPF] Remove relocation for patchable externs
Previously, patchable extern relocations are introduced to patch
external variables used for multi versioning in
compile once, run everywhere use case. The load instruction
will be converted into a move with an patchable immediate
which can be changed by bpf loader on the host.
The kernel verifier has evolved and is able to load
and propagate constant values, so compiler relocation
becomes unnecessary. This patch removed codes related to this.
Roman Lebedev [Thu, 10 Oct 2019 14:46:21 +0000 (14:46 +0000)]
[MCA] Show aggregate over Average Wait times for the whole snippet (PR43219)
Summary:
As disscused in https://bugs.llvm.org/show_bug.cgi?id=43219,
i believe it may be somewhat useful to show //some// aggregates
over all the sea of statistics provided.
Example:
```
Average Wait times (based on the timeline view):
[0]: Executions
[1]: Average time spent waiting in a scheduler's queue
[2]: Average time spent waiting in a scheduler's queue while ready
[3]: Average time elapsed from WB until retire stage
Kai Nacke [Thu, 10 Oct 2019 13:24:00 +0000 (13:24 +0000)]
[Tests] Output of od can be lower or upper case (llvm-objcopy/yaml2obj).
The command `od -t x` is used to dump data in hex format.
The LIT tests assumes that the hex characters are in lowercase.
However, there are also platforms which use uppercase letter.
To solve this issue the tests are updated to use the new
`--ignore-case` option of FileCheck.
Kai Nacke [Thu, 10 Oct 2019 13:15:41 +0000 (13:15 +0000)]
[FileCheck] Implement --ignore-case option.
The FileCheck utility is enhanced to support a `--ignore-case`
option. This is useful in cases where the output of Unix tools
differs in case (e.g. case not specified by Posix).
Florian Hahn [Thu, 10 Oct 2019 13:07:01 +0000 (13:07 +0000)]
[LV][NFC] Factor out calculation of "best" estimated trip count.
This is just small refactoring to minimize changes in upcoming patch.
In the next path I'm going to introduce changes into heuristic for vectorization of "tiny trip count" loops.
Patch by Evgeniy Brevnov <evgueni.brevnov@gmail.com>
Pavel Labath [Thu, 10 Oct 2019 13:05:46 +0000 (13:05 +0000)]
MinidumpYAML: Add support for the memory info list stream
Summary:
The implementation is fairly straight-forward and uses the same patterns
as the existing streams. The yaml form does not attempt to preserve the
data in the "gaps" that can be created by setting a larger-than-required
header or entry size in the stream header, because the existing consumer
(lldb) does not make use of the information in the gap in any way, and
attempting to preserve that would make the implementation more
complicated.
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
Roman Lebedev [Thu, 10 Oct 2019 12:22:33 +0000 (12:22 +0000)]
[ADR] ArrayRefTest: disable SizeTSizedOperations test - it's UB.
This test is not defined.
FAIL: LLVM-Unit :: ADT/./ADTTests/ArrayRefTest.SizeTSizedOperations (178 of 33926)
******************** TEST 'LLVM-Unit :: ADT/./ADTTests/ArrayRefTest.SizeTSizedOperations' FAILED ********************
Note: Google Test filter = ArrayRefTest.SizeTSizedOperations
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from ArrayRefTest
[ RUN ] ArrayRefTest.SizeTSizedOperations
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/include/llvm/ADT/ArrayRef.h:180:32: runtime error: applying non-zero offset 9223372036854775806 to null pointer
#0 0x5ae8dc in llvm::ArrayRef<char>::slice(unsigned long, unsigned long) const /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/include/llvm/ADT/ArrayRef.h:180:32
#1 0x5ae44c in (anonymous namespace)::ArrayRefTest_SizeTSizedOperations_Test::TestBody() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/unittests/ADT/ArrayRefTest.cpp:85:3
#2 0x928a96 in testing::Test::Run() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/src/gtest.cc:2474:5
#3 0x929793 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
#4 0x92a152 in testing::TestCase::Run() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
#5 0x9319d2 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
#6 0x931416 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/src/gtest.cc:4257:10
#7 0x920ac3 in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
#8 0x920ac3 in main /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50:10
#9 0x7f66135b72e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
#10 0x472c19 in _start (/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/unittests/ADT/ADTTests+0x472c19)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/include/llvm/ADT/ArrayRef.h:180:32 in
Mirko Brkusanin [Thu, 10 Oct 2019 12:02:14 +0000 (12:02 +0000)]
[Mips] Fix 374055
EXPENSIVE_CHECKS build was failing on new test.
This is fixed by marking $ra register as undef.
Test now has -verify-machineinstrs to check for operand flags.
Summary:
llvm-ar's mri-utf8.test test relies on the en_US.UTF-8 locale to be
installed for its last RUN line to work. If not installed, the unicode
string gets encoded (interpreted) as ascii which fails since the most
significant byte is non zero. This commit changes the test to only rely
on the system being able to encode the pound sign in its default
encoding (e.g. UTF-16 for Microsoft Windows) by always opening the file
via input/output redirection. This avoids forcing a given locale to be
present and supported. A Byte Order Mark is also added to help
recognizing the encoding of the file and its endianness.
Oliver Stannard [Thu, 10 Oct 2019 09:58:28 +0000 (09:58 +0000)]
[IfCvt][ARM] Optimise diamond if-conversion for code size
Currently, the heuristics the if-conversion pass uses for diamond if-conversion
are based on execution time, with no consideration for code size. This adds a
new set of heuristics to be used when optimising for code size.
This is mostly target-independent, because the if-conversion pass can
see the code size of the instructions which it is removing. For thumb,
there are a few passes (insertion of IT instructions, selection of
narrow branches, and selection of CBZ instructions) which are run after
if conversion and affect these heuristics, so I've added target hooks to
better predict the code-size effect of a proposed if-conversion.
Roman Lebedev [Thu, 10 Oct 2019 09:25:02 +0000 (09:25 +0000)]
[UBSan][clang][compiler-rt] Applying non-zero offset to nullptr is undefined behaviour
Summary:
Quote from http://eel.is/c++draft/expr.add#4:
```
4 When an expression J that has integral type is added to or subtracted
from an expression P of pointer type, the result has the type of P.
(4.1) If P evaluates to a null pointer value and J evaluates to 0,
the result is a null pointer value.
(4.2) Otherwise, if P points to an array element i of an array object x with n
elements ([dcl.array]), the expressions P + J and J + P
(where J has the value j) point to the (possibly-hypothetical) array
element i+j of x if 0≤i+j≤n and the expression P - J points to the
(possibly-hypothetical) array element i−j of x if 0≤i−j≤n.
(4.3) Otherwise, the behavior is undefined.
```
Therefore, as per the standard, applying non-zero offset to `nullptr`
(or making non-`nullptr` a `nullptr`, by subtracting pointer's integral value
from the pointer itself) is undefined behavior. (*if* `nullptr` is not defined,
i.e. e.g. `-fno-delete-null-pointer-checks` was *not* specified.)
To make things more fun, in C (6.5.6p8), applying *any* offset to null pointer
is undefined, although Clang front-end pessimizes the code by not lowering
that info, so this UB is "harmless".
Since rL369789 (D66608 `[InstCombine] icmp eq/ne (gep inbounds P, Idx..), null -> icmp eq/ne P, null`)
LLVM middle-end uses those guarantees for transformations.
If the source contains such UB's, said code may now be miscompiled.
Such miscompilations were already observed:
* https://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190826/687838.html
* https://github.com/google/filament/pull/1566
Surprisingly, UBSan does not catch those issues
... until now. This diff teaches UBSan about these UB's.
`getelementpointer inbounds` is a pretty frequent instruction,
so this does have a measurable impact on performance;
I've addressed most of the obvious missing folds (and thus decreased the performance impact by ~5%),
and then re-performed some performance measurements using my [[ https://github.com/darktable-org/rawspeed | RawSpeed ]] benchmark:
(all measurements done with LLVM ToT, the sanitizer never fired.)
* no sanitization vs. existing check: average `+21.62%` slowdown
* existing check vs. check after this patch: average `22.04%` slowdown
* no sanitization vs. this patch: average `48.42%` slowdown
to make the expected test output depend on as few optimization phases
as possible, for stability. But when you write a RUN line of this
form, you lose the ability to use update_cc_test_checks.py to
automatically generate the expected output, because it only supports
two-stage pipelines consisting of '%clang | FileCheck' (or %clang_cc1).
This change extends the set of supported RUN lines so that pipelines
with an invocation of `opt` in the middle can still be automatically
handled.
To implement it, I've adjusted `get_function_body()` so that it can
cope with an arbitrary sequence of intermediate pipeline commands. But
the code that decides which RUN lines to consider is more
conservative: it only adds clang | opt | FileCheck to the set of
supported lines, because I didn't want to accidentally include some
other kind of line that doesn't output IR at all.
(Also in this commit is the minimal change to make this script work at
all, after r373912 added an extra parameter to `add_ir_checks`.)
Matt Arsenault [Thu, 10 Oct 2019 07:11:33 +0000 (07:11 +0000)]
AMDGPU: Use SGPR_128 instead of SReg_128 for vregs
SGPR_128 only includes the real allocatable SGPRs, and SReg_128 adds
the additional non-allocatable TTMP registers. There's no point in
allocating SReg_128 vregs. This shrinks the size of the classes
regalloc needs to consider, which is usually good.
[Attributor] Handle `null` differently in capture and alias logic
Summary:
`null` in the default address space (=AS 0) cannot be captured nor can
it alias anything. We make this clear now as it can be important for
callbacks and other cases later on. In addition, this patch improves the
debug output for noalias deduction.
Reid Kleckner [Thu, 10 Oct 2019 01:06:01 +0000 (01:06 +0000)]
[codeview] Try to avoid emitting .cv_loc with line zero
Summary:
Visual Studio doesn't like it while stepping. It kicks you out of the
source view of the file being stepped through and tries to fall back to
the disassembly view.
Fixes PR43530
The fix is incomplete, because it's possible to have a basic block with
no source locations at all. In this case, we don't emit a .cv_loc, but
that will result in wrong stepping behavior in the debugger if the
layout predecessor of the location-less BB has an unrelated source
location. We could try harder to find a valid location that dominates or
post-dominates the current BB, but in general it's a dataflow problem,
and one still might not exist. I left a FIXME about this.
As an alternative, we might want to consider having the middle-end check
if its emitting codeview and get it to stop using line zero.
Philip Reames [Wed, 9 Oct 2019 23:43:33 +0000 (23:43 +0000)]
Conservatively add volatility and atomic checks in a few places
As background, starting in D66309, I'm working on support unordered atomics analogous to volatile flags on normal LoadSDNode/StoreSDNodes for X86.
As part of that, I spent some time going through usages of LoadSDNode and StoreSDNode looking for cases where we might have missed a volatility check or need an atomic check. I couldn't find any cases that clearly miscompile - i.e. no test cases - but a couple of pieces in code loop suspicious though I can't figure out how to exercise them.
This patch adds defensive checks and asserts in the places my manual audit found. If anyone has any ideas on how to either a) disprove any of the checks, or b) hit the bug they might be fixing, I welcome suggestions.
Matt Arsenault [Wed, 9 Oct 2019 22:51:42 +0000 (22:51 +0000)]
AMDGPU: Don't fold copies to physregs
In a future patch, this will help cleanup m0 handling.
The register coalescer handles copies from a register that
materializes an immediate, but doesn't handle move immediates
itself. The virtual register uses will often be allocated to the same
register, so there end up being no real copy.
Thomas Lively [Wed, 9 Oct 2019 21:42:08 +0000 (21:42 +0000)]
[WebAssembly] Make returns variadic
Summary:
This is necessary and sufficient to get simple cases of multiple
return working with multivalue enabled. More complex cases will
require block and loop signatures to be generalized to potentially be
type indices as well.
Wei Mi [Wed, 9 Oct 2019 21:36:03 +0000 (21:36 +0000)]
[SampleFDO] Add indexing for function profiles so they can be loaded on demand
in ExtBinary format
Currently for Text, Binary and ExtBinary format profiles, when we compile a
module with samplefdo, even if there is no function showing up in the profile,
we have to load all the function profiles from the profile input. That is a
waste of compile time.
CompactBinary format profile has already had the support of loading function
profiles on demand. In this patch, we add the support to load profile on
demand for ExtBinary format. It will work no matter the sections in ExtBinary
format profile are compressed or not. Experiment shows it reduces the time to
compile a server benchmark by 30%.
When profile remapping and loading function profiles on demand are both used,
extra work needs to be done so that the loading on demand process will take
the name remapping into consideration. It will be addressed in a follow-up
patch.
Adds links to Getting Started/Tutorials, User Guides, and Reference documentation pages to sidebar. Also adds a new section for LLVM IR on the Reference documentation page.
David Greene [Wed, 9 Oct 2019 19:51:48 +0000 (19:51 +0000)]
[System Model] [TTI] Update cache and prefetch TTI interfaces
Re-apply 9fdfb045ae8b/r365676 with fixes for PPC and Hexagon. This involved
moving defaults from TargetTransformInfoImplBase to MCSubtargetInfo.
Rework the TTI cache and software prefetching APIs to prepare for the
introduction of a general system model. Changes include:
- Marking existing interfaces const and/or override as appropriate
- Adding comments
- Adding BasicTTIImpl interfaces that delegate to a subtarget
implementation
- Moving the default TargetTransformInfoImplBase implementation to a default
MCSubtarget implementation
Only a handful of targets use these interfaces currently: AArch64, Hexagon, PPC
and SystemZ. AArch64 already has a custom subtarget implementation, so its
custom TTI implementation is migrated to use the new facilities in BasicTTIImpl
to invoke its custom subtarget implementation. The custom TTI implementations
continue to exist for the other targets with this change. They are not moved
over to subtarget-based implementations.
The end goal is to have the default subtarget implementation defer to the system
model defined by the target. With this change, the default MCSubtargetInfo
implementation essentially returns the defaults TargetTransformInfoImplBase used
to return. Existing users of TTI defaults will hit the defaults now in
MCSubtargetInfo. Targets that define their own custom TTI implementations won't
use the BasicTTIImpl implementations that route to the subtarget.
Once system models are in place for the targets that use these interfaces, their
custom TTI implementations can be removed.
David Blaikie [Wed, 9 Oct 2019 18:37:13 +0000 (18:37 +0000)]
DebugInfo: Shot in the dark attempt to fix ubsan error from r374122
(specifying an underlying type for the enum might also be suitable - but
this seems better/as good, since there's a clear expectation this can
contain values other than the actual enumerators of this enum)
Julian Lettner [Wed, 9 Oct 2019 18:23:30 +0000 (18:23 +0000)]
[lit] Refactor ProgressDisplay
Move progress display to separate file. Simplify some code paths.
Decouple from other components via progress callback. Remove unused
`_Display` class.
Thomas Lively [Wed, 9 Oct 2019 17:45:47 +0000 (17:45 +0000)]
[WebAssembly] Add builtin and intrinsic for v8x16.swizzle
Summary:
This clang builtin and corresponding LLVM intrinsic are necessary to
expose the exact semantics of the underlying WebAssembly instruction
to users. LLVM produces a poison value if the dynamic swizzle indices
are greater than the vector size, but the WebAssembly instruction sets
the corresponding output lane to zero. Users who depend on this
behavior can safely use this builtin.
Thomas Lively [Wed, 9 Oct 2019 17:39:19 +0000 (17:39 +0000)]
[WebAssembly] v8x16.swizzle and rewrite BUILD_VECTOR lowering
Summary:
Adds the new v8x16.swizzle SIMD instruction as specified at
https://github.com/WebAssembly/simd/blob/master/proposals/simd/SIMD.md#swizzling-using-variable-indices.
In addition to adding swizzles as a candidate lowering in
LowerBUILD_VECTOR, also rewrites and simplifies the lowering to
minimize the number of replace_lanes necessary rather than trying to
minimize code size. This leads to more uses of v128.const instead of
splats, which is expected to increase performance.
The new code will be easier to tune once V8 implements all the vector
construction operations, and it will also be easier to add new
candidate instructions in the future if necessary.
Kevin P. Neal [Wed, 9 Oct 2019 17:24:56 +0000 (17:24 +0000)]
[FPEnv][NFC] Change test to conform to strictfp attribute rules.
In particular, the function definition is not marked strictfp despite
containing a function marked strictfp. Also, if any function call is marked
strictfp then all function calls in that function must be marked.
This change to move the one strictfp call to a new properly marked function
meets all the new rules.
Sanjay Patel [Wed, 9 Oct 2019 16:32:49 +0000 (16:32 +0000)]
[SLP] respect target register width for GEP vectorization (PR43578)
We failed to account for the target register width (max vector factor)
when vectorizing starting from GEPs. This causes vectorization to
proceed to obviously illegal widths as in:
https://bugs.llvm.org/show_bug.cgi?id=43578
For x86, this also means that SLP can produce rogue AVX or AVX512
code even when the user specifies a narrower vector width.
The AArch64 test in ext-trunc.ll appears to be better using the
narrower width. I'm not exactly sure what getelementptr.ll is trying
to do, but it's testing with "-slp-threshold=-18", so I'm not worried
about those diffs. The x86 test is an over-reduction from SPEC h264;
this patch appears to restore the perf loss caused by SLP when using
-march=haswell.
Momchil Velikov [Wed, 9 Oct 2019 16:31:50 +0000 (16:31 +0000)]
[AArch64] Ensure no tagged memory is left in the unallocated portion of the
stack
This patch makes sure that if we tag some memory, we untag that memory before
the function returns/throws via any exit, reachable from the tag operation. For
that we place the untag operation either at:
a) the lifetime end call for the alloca, if that call post-dominates the
lifetime start call (where the tag operation is placed), or it (the
lifetime end call) dominates all reachable exits, otherwise
b) at the reachable exits
Jason Liu [Wed, 9 Oct 2019 16:19:39 +0000 (16:19 +0000)]
[AIX][XCOFF][NFC] Change the SectionLen field name of CSect Auxiliary entry to SectionOrLength.
Summary:
According the the XCOFF document,
If
Then
XTY_SD
x_scnlen contains the csect length.
XTY_LD
x_scnlen contains the symbol table index of the containing csect.
XTY_CM
x_scnlen contains the csect length.
XTY_ER
x_scnlen contains 0.
Change the SectionLen member name to SectionOrLength is more reasonable.
Re-land "[dsymutil] Fix handling of common symbols in multiple object files."
The original patch got reverted because it hit a long-standing legacy
issue on Windows that prevents files from being named `com`. Thanks
Kristina & Jeremy for pointing this out.
Alina Sbirlea [Wed, 9 Oct 2019 15:54:24 +0000 (15:54 +0000)]
[MemorySSA] Make the use of moveAllAfterMergeBlocks consistent.
Summary:
The rule for the moveAllAfterMergeBlocks API si for all instructions
from `From` to have been moved to `To`, while keeping the CFG edges (and
block terminators) unchanged.
Update all the callsites for moveAllAfterMergeBlocks to follow this.
Pending follow-up: since the same behavior is needed everytime, merge
all callsites into one. The common denominator may be the call to
`MergeBlockIntoPredecessor`.
projects / llvm / log