We were not correctly splitting a blocks for chains of length 1.
Before that change, additional instructions for blocks in chains of
length 1 were not split off from the block before removing (this was
done correctly for chains of longer size).
If this first block contained an instruction referenced elsewhere,
deleting the block, would result in invalidation of the produced value.
This caused a miscompile which motivated D92297 (before D17993,
nonnull and dereferenceable attributed were not added so MergeICmps were
not triggered.) The new test gep-references-bb.ll demonstrate the issue.
The regression was introduced in
rG0efadbbcdeb82f5c14f38fbc2826107063ca48b2.
This supersedes D92364.
Test case by MaskRay (Fangrui Song).
Differential Revision: https://reviews.llvm.org/D92375
Use cast<> as we immediately dereference the pointer afterwards - cast<> will assert if we fail.
Prevents clang static analyzer warning that we could deference a null pointer.
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.
I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
recompiles touches affected_files header
342380 95 3604 llvm/include/llvm/ADT/STLExtras.h
314730 234 1345 llvm/include/llvm/InitializePasses.h
307036 118 2602 llvm/include/llvm/ADT/APInt.h
213049 59 3611 llvm/include/llvm/Support/MathExtras.h
170422 47 3626 llvm/include/llvm/Support/Compiler.h
162225 45 3605 llvm/include/llvm/ADT/Optional.h
158319 63 2513 llvm/include/llvm/ADT/Triple.h
140322 39 3598 llvm/include/llvm/ADT/StringRef.h
137647 59 2333 llvm/include/llvm/Support/Error.h
131619 73 1803 llvm/include/llvm/Support/FileSystem.h
Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.
Reviewers: bkramer, asbirlea, bollu, jdoerfert
Differential Revision: https://reviews.llvm.org/D70211
Summary:
This is the first change to enable the TLI to be built per-function so
that -fno-builtin* handling can be migrated to use function attributes.
See discussion on D61634 for background. This is an enabler for fixing
handling of these options for LTO, for example.
This change should not affect behavior, as the provided function is not
yet used to build a specifically per-function TLI, but rather enables
that migration.
Most of the changes were very mechanical, e.g. passing a Function to the
legacy analysis pass's getTLI interface, or in Module level cases,
adding a callback. This is similar to the way the per-function TTI
analysis works.
There was one place where we were looking for builtins but not in the
context of a specific function. See FindCXAAtExit in
lib/Transforms/IPO/GlobalOpt.cpp. I'm somewhat concerned my workaround
could provide the wrong behavior in some corner cases. Suggestions
welcome.
Reviewers: chandlerc, hfinkel
Subscribers: arsenm, dschuff, jvesely, nhaehnle, mehdi_amini, javed.absar, sbc100, jgravelle-google, eraman, aheejin, steven_wu, george.burgess.iv, dexonsmith, jfb, asbirlea, gchatelet, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66428
llvm-svn: 371284
This makes the functions in Loads.h require a type to be specified
independently of the pointer Value so that when pointers have no structure
other than address-space, it can still do its job.
Most callers had an obvious memory operation handy to provide this type, but a
SROA and ArgumentPromotion were doing more complicated analysis. They get
updated to merge the properties of the various instructions they were
considering.
llvm-svn: 365468
This allows later passes (in particular InstCombine) to optimize more
cases.
One that's important to us is `memcmp(p, q, constant) < 0` and memcmp(p, q, constant) > 0.
llvm-svn: 364412
Summary:
Because the sort order was not strongly stable on the RHS, whether the
chain could merge would depend on the order of the blocks in the Phi.
EXPENSIVE_CHECKS would shuffle the blocks before sorting, resulting in
non-deterministic merging.
Reviewers: gchatelet
Subscribers: hiraditya, llvm-commits, RKSimon
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62193
llvm-svn: 361281
And handle for self-move. This is required so that llvm::sort can work
with EXPENSIVE_CHECKS, as it will do a random shuffle of the input
which can result in self-moves.
llvm-svn: 361257
With a fix for PR41917: The predecessor list was changing under our feet.
- for (BasicBlock *Pred : predecessors(EntryBlock_)) {
+ while (!pred_empty(EntryBlock_)) {
+ BasicBlock* const Pred = *pred_begin(EntryBlock_);
llvm-svn: 361009
Instead of patching the original blocks, we now generate new blocks and
delete the old blocks. This results in simpler code with a less twisted
control flow (see the change in `entry-block-shuffled.ll`).
This will make https://reviews.llvm.org/D60318 simpler by making it more
obvious where control flow created and deleted.
Reviewers: gchatelet
Subscribers: hiraditya, llvm-commits, spatel
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61736
llvm-svn: 360771
Summary:
The idea is that we now manipulate bases through a `unsigned BaseID` based on
order of appearance in the comparison chain rather than through the `Value*`.
Fixes 40714.
Reviewers: gchatelet
Subscribers: mgrang, jfb, jdoerfert, llvm-commits, hans
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58274
llvm-svn: 354131
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
This patch prevents MergeICmps to performn the transformation if the address operand GEP of the load instruction has a use outside of the load's parent block. Without this patch, compiler crashes with the given test case because the use of `%first.i` is still around when the basic block is erased from https://github.com/llvm-mirror/llvm/blob/master/lib/Transforms/Scalar/MergeICmps.cpp#L620. I think checking `isUsedOutsideOfBlock` with `GEP` is the original intention of the code, as the checking for `LoadI` is already performed in the same function.
This patch is incomplete though, as this makes the pass overly conservative and fails the test `tuple-four-int8.ll`. I believe what needs to be done is checking if GEP has a use outside of block that is not the part of "Comparisons" chain. Submit the patch as of now to prevent compiler crash.
Reviewers: courbet, trentxintong
Reviewed By: courbet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54089
llvm-svn: 346151
Summary:
The visitICmp analysis function would record compares of pointer types, as size 0. This causes the resulting memcmp() call to have the wrong total size.
Found with "self-build" of clang/LLVM on Windows.
Reviewers: christylee, trentxintong, courbet
Reviewed By: courbet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D53536
llvm-svn: 345413
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.
Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer the comments section in D44363 for a list of all the required patches.
Reviewers: kcc, pcc, danielcdh, jmolloy, sanjoy, dberlin, ruiu
Reviewed By: ruiu
Subscribers: ruiu, llvm-commits
Differential Revision: https://reviews.llvm.org/D45142
llvm-svn: 330059
Summary:
We do not try to move the instructions and split the block till we
know the blocks can be split, i.e. BCE-cmp-insts can be separated from
non-BCE-cmp-insts.
Reviewers: davide, courbet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44443
llvm-svn: 329564
Summary: Fix a bug in entry block shuffled to middle of the chain.
Reviewers: davide, courbet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44642
llvm-svn: 327971
Summary:
We can discard initial blocks that do other work
We do not need to limit ourselves to just the first block in the chain.
Reviewers: courbet, davide
Reviewed By: courbet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44029
llvm-svn: 326698
Summary:
Fix a bug in MergeICmp that can lead to a BCECmp block being processed more than once and eventually lead to a broken LLVM module.
The problem is that if the non-constant value is not produced by the last block, the producer will be processed once when the its parent block
is processed and second time when the last block is processed.
We end up having 2 same BCECmpBlock in the merge queue. And eventually lead to a broken LLVM module.
Reviewers: courbet, davide
Reviewed By: courbet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43825
llvm-svn: 326318
- Fix condition for detecting that a complex basic block was the first in
the chain.
- Add tests.
This was caught by buildbots when submitting rL324319.
llvm-svn: 324341
Kazu Hirata