When evaluating a store through a bitcast, the evaluator tries to move the
bitcast from the pointer onto the stored value. If the cast is invalid, it
tries to "introspect" the type to get a valid cast by obtaining a pointer to
the initial element (if the type is nested, this may require walking several
initial elements).
In some situations it is possible to get a bitcast on a load (e.g. with
unions, where the bitcast may not be the same type as the store). However,
equivalent logic to the store to introspect the type is missing. This patch
add this logic.
Note, when developing the patch I was unhappy with adding similar logic
directly to the load case as it could get out of step. Instead, I have
abstracted the "introspection" into a helper function, with the specifics
being handled by a passed-in lambda function.
Differential Revision: https://reviews.llvm.org/D60793
llvm-svn: 359205
Summary:
Both the input Value pointer and the returned Value
pointers in GetUnderlyingObjects are now declared as
const.
It turned out that all current (in-tree) uses of
GetUnderlyingObjects were trivial to update, being
satisfied with have those Value pointers declared
as const. Actually, in the past several of the users
had to use const_cast, just because of ValueTracking
not providing a version of GetUnderlyingObjects with
"const" Value pointers. With this patch we get rid
of those const casts.
Reviewers: hfinkel, materi, jkorous
Reviewed By: jkorous
Subscribers: dexonsmith, jkorous, jholewinski, sdardis, eraman, hiraditya, jrtc27, atanasyan, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61038
llvm-svn: 359072
Summary:
Enabling MemorySSA in the old pass manager leads to MemorySSA being run
twice due to the fact that LCSSA and LoopSimplify do not preserve
MemorySSA. This is the first step to address that: target LCSSA.
LCSSA does not make any changes that invalidate MemorySSA, so it
preserves it by design. It must preserve AA as well, for this to hold.
After this patch, MemorySSA is still run twice in the old pass manager.
Step two follows: target LoopSimplify.
Subscribers: mehdi_amini, jlebar, Prazek, llvm-commits, george.burgess.iv, chandlerc
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60832
llvm-svn: 359032
Currently, we do not expose BPI to loop passes at all. In the old pass manager, we appear to have been ignoring the fact that LCSSA and/or LoopSimplify didn't preserve BPI, and making it available to the following loop passes anyways. In the new one, it's invalidated before running any loop pass if either LCSSA or LoopSimplify actually make changes. If they don't make changes, then BPI is valid and available. So, we go ahead and teach LCSSA and LoopSimplify how to preserve BPI for consistency between old and new pass managers.
This patch avoids an invalidation between the two requires in the following trivial pass pipeline:
opt -passes="requires<branch-prob>,loop(no-op-loop),requires<branch-prob>"
(when the input file is one which requires either LCSSA or LoopSimplify to canonicalize the loops)
Differential Revision: https://reviews.llvm.org/D60790
llvm-svn: 358901
code to `CallBase`.
This patch focuses on the legacy PM, call graph, and some of inliner and legacy
passes interacting with those APIs from `CallSite` to the new `CallBase` class.
No interesting changes.
Differential Revision: https://reviews.llvm.org/D60412
llvm-svn: 358739
The original commit caused false positives from AddressSanitizer's
use-after-scope checks, which have now been fixed in r358478.
> The code was previously checking that candidates for sinking had exactly
> one use or were a store instruction (which can't have uses). This meant
> we could sink call instructions only if they had a use.
>
> That limitation seemed a bit arbitrary, so this patch changes it to
> "instruction has zero or one use" which seems more natural and removes
> the need to special-case stores.
>
> Differential revision: https://reviews.llvm.org/D59936
llvm-svn: 358483
The CodeExtractor is not smart enough to compute which basic block is
the entry of a region. Instead it relies on the order of the list
of basic blocks that is handed to it and assumes that the entry
is the first block in the list.
Without the additional debug information, it is hard to understand
why a valid region does not get extracted, because we would miss
that the order of in the list just doesn't match what the CodeExtractor
wants.
NFC
llvm-svn: 358471
Zexts can be treated like no-op casts when it comes to assessing whether their
removal affects debug info.
Reviewer: aprantl
Differential Revision: https://reviews.llvm.org/D60641
llvm-svn: 358431
Summary:
Enable some of the existing size optimizations for cold code under PGO.
A ~5% code size saving in big internal app under PGO.
The way it gets BFI/PSI is discussed in the RFC thread
http://lists.llvm.org/pipermail/llvm-dev/2019-March/130894.html
Note it doesn't currently touch loop passes.
Reviewers: davidxl, eraman
Reviewed By: eraman
Subscribers: mgorny, javed.absar, smeenai, mehdi_amini, eraman, zzheng, steven_wu, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59514
llvm-svn: 358422
Summary:
Factor out findAllocaForValue() from ASan so that we can use it in
MSan to handle lifetime intrinsics.
Reviewers: eugenis, pcc
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60615
llvm-svn: 358380
* Rearrange continu/break
* BBNumbers.lookup(A) -> BBNumbers.find(A)->second
BBNumbers has been computed, thus we can assume the value exists in the predicate.
llvm-svn: 358351
Summary:
Create a method to forget everything in SCEV.
Add a cl::opt and PassManagerBuilder option to use this in LoopUnroll.
Motivation: Certain Halide applications spend a very long time compiling in forgetLoop, and prefer to forget everything and rebuild SCEV from scratch.
Sample difference in compile time reduction: 21.04 to 14.78 using current ToT release build.
Testcase showcasing this cannot be opensourced and is fairly large.
The option disabled by default, but it may be desirable to enable by
default. Evidence in favor (two difference runs on different days/ToT state):
File Before (s) After (s)
clang-9.bc 7267.91 6639.14
llvm-as.bc 194.12 194.12
llvm-dis.bc 62.50 62.50
opt.bc 1855.85 1857.53
File Before (s) After (s)
clang-9.bc 8588.70 7812.83
llvm-as.bc 196.20 194.78
llvm-dis.bc 61.55 61.97
opt.bc 1739.78 1886.26
Reviewers: sanjoy
Subscribers: mehdi_amini, jlebar, zzheng, javed.absar, dmgreen, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60144
llvm-svn: 358304
This revision causes tests to fail under ASAN. Since the cause of the failures
is not clear (could be ASAN, could be a Clang bug, could be a bug in this
revision), the safest course of action seems to be to revert while investigating.
llvm-svn: 357667
The Emscripten OS provides a definition of __EMSCRIPTEN__, and also that it
supports iprintf optimizations.
Also define small_printf optimizations, which is a printf with float support
but not long double (which in wasm can be useful since long doubles are 128
bit and force linking of float128 emulation code). This part is based on
sunfish's https://reviews.llvm.org/D57620 (which can't land yet since
the WASI integration isn't ready yet).
Differential Revision: https://reviews.llvm.org/D60167
llvm-svn: 357552
Summary:
When inserting an `unreachable` after a noreturn call, we must ensure
that it's not a musttail call to avoid breaking the IR invariants for
musttail calls.
Reviewers: fedor.sergeev, majnemer
Reviewed By: majnemer
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60080
llvm-svn: 357485
`StoreInst::getValueOperand` is identical to `getOperand(0)`, so the call to
`getOperand(0)` can be replaced. Further, `SI->getValueOperand` is redundantly
called just a few lines down, despite its return value being stored in variable
`DV`. No functional change.
llvm-svn: 357479
The code was previously checking that candidates for sinking had exactly
one use or were a store instruction (which can't have uses). This meant
we could sink call instructions only if they had a use.
That limitation seemed a bit arbitrary, so this patch changes it to
"instruction has zero or one use" which seems more natural and removes
the need to special-case stores.
Differential revision: https://reviews.llvm.org/D59936
llvm-svn: 357452
Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.
The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.
For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.
This is a recommit of r356442 with trivial fixes for the failing tests.
Differential Revision: https://reviews.llvm.org/D56587
llvm-svn: 356451
Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.
The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.
For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.
Differential Revision: https://reviews.llvm.org/D56587
llvm-svn: 356442
Summary: Add bindings to create a wrapped "Add Discriminators" pass. Now that we have debug info support, this is a handy transform to have.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: dblaikie, aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58624
llvm-svn: 356272
This indicates an intrinsic parameter is required to be a constant,
and should not be replaced with a non-constant value.
Add the attribute to all AMDGPU and generic intrinsics that comments
indicate it should apply to. I scanned other target intrinsics, but I
don't see any obvious comments indicating which arguments are intended
to be only immediates.
This breaks one questionable testcase for the autoupgrade. I'm unclear
on whether the autoupgrade is supposed to really handle declarations
which were never valid. The verifier fails because the attributes now
refer to a parameter past the end of the argument list.
llvm-svn: 355981
This patch adds a new option to SplitAllCriticalEdges and uses it to avoid splitting critical edges when the destination basic block ends with unreachable. Otherwise if we split the critical edge, sanitizer coverage will instrument the new block that gets inserted for the split. But since this block itself shouldn't be reachable this is pointless. These basic blocks will stick around and generate assembly, but they don't end in sane control flow and might get placed at the end of the function. This makes it look like one function has code that flows into the next function.
This showed up while compiling the linux kernel with clang. The kernel has a tool called objtool that detected the code that appeared to flow from one function to the next. https://github.com/ClangBuiltLinux/linux/issues/351#issuecomment-461698884
Differential Revision: https://reviews.llvm.org/D57982
llvm-svn: 355947
The code might intend to replace puts("") with putchar('\n') even if the
return value is used. It failed because use_empty() was used to guard
the whole block. While returning '\n' (putchar('\n')) is technically
correct (puts is only required to return a nonnegative number on
success), doing this looks weird and there is really little benefit to
optimize puts whose return value is used. So don't do that.
llvm-svn: 355921
Change from original commit: move test (that uses an X86 triple) into the X86
subdirectory.
Original description:
Gating vectorizing reductions on *all* fastmath flags seems unnecessary;
`reassoc` should be sufficient.
Reviewers: tvvikram, mkuper, kristof.beyls, sdesmalen, Ayal
Reviewed By: sdesmalen
Subscribers: dcaballe, huntergr, jmolloy, mcrosier, jlebar, bixia, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57728
llvm-svn: 355889
Summary:
Extract the functionality of eliminating unreachable basic blocks
within a function, previously encapsulated within the
-unreachableblockelim pass, and make it available as a function within
BlockUtils.h. No functional change intended other than making the logic
reusable.
Exposing this logic makes it easier to implement
https://reviews.llvm.org/D59068, which fixes coroutines bug
https://bugs.llvm.org/show_bug.cgi?id=40979.
Reviewers: mkazantsev, wmi, davidxl, silvas, davide
Reviewed By: davide
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59069
llvm-svn: 355846
Fixes bug 38023: https://bugs.llvm.org/show_bug.cgi?id=38023
The SimplifyCFG pass will perform jump threading in some cases where
doing so is trivial and would simplify the CFG. When folding a series
of blocks with redundant conditional branches into an unconditional "critical
edge" block, it does not keep the debug location associated with the previous
conditional branch.
This patch fixes the bug described by copying the debug info from the
old conditional branch to the new unconditional branch instruction, and
adds a regression test for the SimplifyCFG pass that covers this case.
Patch by Stephen Tozer!
Differential Revision: https://reviews.llvm.org/D59206
llvm-svn: 355833
Summary:
Right now, when we encounter a string equality check,
e.g. `if (memcmp(a, b, s) == 0)`, we try to expand to a comparison if `s` is a
small compile-time constant, and fall back on calling `memcmp()` else.
This is sub-optimal because memcmp has to compute much more than
equality.
This patch replaces `memcmp(a, b, s) == 0` by `bcmp(a, b, s) == 0` on platforms
that support `bcmp`.
`bcmp` can be made much more efficient than `memcmp` because equality
compare is trivially parallel while lexicographic ordering has a chain
dependency.
Subscribers: fedor.sergeev, jyknight, ckennelly, gchatelet, llvm-commits
Differential Revision: https://reviews.llvm.org/D56593
llvm-svn: 355672
Summary:
While implementing inlining support for callbr
(https://bugs.llvm.org/show_bug.cgi?id=40722), I hit a crash in Loop
Rotation when trying to build the entire x86 Linux kernel
(drivers/char/random.c). This is a small fix up to r353563.
Test case is drivers/char/random.c (with callbr's inlined), then ran
through creduce, then `opt -opt-bisect-limit=<limit>`, then bugpoint.
Thanks to Craig Topper for immediately spotting the fix, and teaching me
how to fish.
Reviewers: craig.topper, jyknight
Reviewed By: craig.topper
Subscribers: hiraditya, llvm-commits, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58929
llvm-svn: 355564
Summary:
It is mentioned in the document of DTU that "It is illegal to submit any update that has already been submitted, i.e., you are supposed not to insert an existent edge or delete a nonexistent edge." It is dangerous to violet this rule because DomTree and PostDomTree occasionally crash on this scenario.
This patch fixes `MergeBlockIntoPredecessor`, making it conformant to this precondition.
Reviewers: kuhar, brzycki, chandlerc
Reviewed By: brzycki
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58444
llvm-svn: 355105
This patch adds LazyValueInfo to LowerSwitch to compute the range of the
value being switched over and reduce the size of the tree LowerSwitch
builds to lower a switch.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D58096
llvm-svn: 354670
Summary:
This patch separates two semantics of `applyUpdates`:
1. User provides an accurate CFG diff and the dominator tree is updated according to the difference of `the number of edge insertions` and `the number of edge deletions` to infer the status of an edge before and after the update.
2. User provides a sequence of hints. Updates mentioned in this sequence might never happened and even duplicated.
Logic changes:
Previously, removing invalid updates is considered a side-effect of deduplication and is not guaranteed to be reliable. To handle the second semantic, `applyUpdates` does validity checking before deduplication, which can cause updates that have already been applied to be submitted again. Then, different calls to `applyUpdates` might cause unintended consequences, for example,
```
DTU(Lazy) and Edge A->B exists.
1. DTU.applyUpdates({{Delete, A, B}, {Insert, A, B}}) // User expects these 2 updates result in a no-op, but {Insert, A, B} is queued
2. Remove A->B
3. DTU.applyUpdates({{Delete, A, B}}) // DTU cancels this update with {Insert, A, B} mentioned above together (Unintended)
```
But by restricting the precondition that updates of an edge need to be strictly ordered as how CFG changes were made, we can infer the initial status of this edge to resolve this issue.
Interface changes:
The second semantic of `applyUpdates` is separated to `applyUpdatesPermissive`.
These changes enable DTU(Lazy) to use the first semantic if needed, which is quite useful in `transforms/utils`.
Reviewers: kuhar, brzycki, dmgreen, grosser
Reviewed By: brzycki
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58170
llvm-svn: 354669
Robert Lougher