When we have a loop with a known upper bound on the number of iterations, and
furthermore know that either the number of iterations will be either exactly
that upper bound or zero, then we can fully unroll up to that upper bound
keeping only the first loop test to check for the zero iteration case.
Most of the work here is in plumbing this 'max-or-zero' information from the
part of scalar evolution where it's detected through to loop unrolling. I've
also gone for the safe default of 'false' everywhere but howManyLessThans which
could probably be improved.
Differential Revision: https://reviews.llvm.org/D25682
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284818 91177308-0d34-0410-b5e6-96231b3b80d8
This is to avoid inlining too many multiplication operands into a SCEV, which could
take exponential time in the worst case.
Reviewers: Sanjoy Das, Mehdi Amini, Michael Zolotukhin
Differential Revision: https://reviews.llvm.org/D25794
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284784 91177308-0d34-0410-b5e6-96231b3b80d8
All of these existed because MSVC 2013 was unable to synthesize default
move ctors. We recently dropped support for it so all that error-prone
boilerplate can go.
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284721 91177308-0d34-0410-b5e6-96231b3b80d8
0 - X --> X, if X is 0 or the minimum signed value
0 - X --> 0, if X is 0 or the minimum signed value and the sub is NSW
I noticed this pattern might be created in the backend after the change from D25485,
so we'll want to add a similar fold for the DAG.
The use of computeKnownBits in InstSimplify may be something to investigate if the
compile time of InstSimplify is noticeable. We could replace computeKnownBits with
specific pattern matchers or limit the recursion.
Differential Revision: https://reviews.llvm.org/D25785
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284649 91177308-0d34-0410-b5e6-96231b3b80d8
This helps canonicalization in some cases.
Thanks to Pankaj Chawla for the investigation and the test case!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284501 91177308-0d34-0410-b5e6-96231b3b80d8
In loops that look something like
i = n;
do {
...
} while(i++ < n+k);
where k is a constant, the maximum backedge count is k (in fact the backedge
count will be either 0 or k, depending on whether n+k wraps). More generally
for LHS < RHS if RHS-(LHS of first comparison) is a constant then the loop will
iterate either 0 or that constant number of times.
This allows for more loop unrolling with the recent upper bound loop unrolling
changes, and I'm working on a patch that will let loop unrolling additionally
make use of the loop being executed either 0 or k times (we need to retain the
loop comparison only on the first unrolled iteration).
Differential Revision: https://reviews.llvm.org/D25607
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284465 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: The delinearization algorithm did not consider terms which had an extension without a multiply factor, i.e. a identify factor. We lose cases where size is char type where there will no multiply factor.
Reviewers: sanjoy, grosser
Subscribers: mzolotukhin, Eugene.Zelenko, llvm-commits, mssimpso, sanjoy, grosser
Differential Revision: https://reviews.llvm.org/D16492
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284378 91177308-0d34-0410-b5e6-96231b3b80d8
Reappy r284044 after revert in r284051. Krzysztof fixed the error in r284049.
The original summary:
This patch tries to fully unroll loops having break statement like this
for (int i = 0; i < 8; i++) {
if (a[i] == value) {
found = true;
break;
}
}
GCC can fully unroll such loops, but currently LLVM cannot because LLVM only
supports loops having exact constant trip counts.
The upper bound of the trip count can be obtained from calling
ScalarEvolution::getMaxBackedgeTakenCount(). Part of the patch is the
refactoring work in SCEV to prevent duplicating code.
The feature of using the upper bound is enabled under the same circumstance
when runtime unrolling is enabled since both are used to unroll loops without
knowing the exact constant trip count.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284053 91177308-0d34-0410-b5e6-96231b3b80d8
This patch tries to fully unroll loops having break statement like this
for (int i = 0; i < 8; i++) {
if (a[i] == value) {
found = true;
break;
}
}
GCC can fully unroll such loops, but currently LLVM cannot because LLVM only
supports loops having exact constant trip counts.
The upper bound of the trip count can be obtained from calling
ScalarEvolution::getMaxBackedgeTakenCount(). Part of the patch is the
refactoring work in SCEV to prevent duplicating code.
The feature of using the upper bound is enabled under the same circumstance
when runtime unrolling is enabled since both are used to unroll loops without
knowing the exact constant trip count.
Differential Revision: https://reviews.llvm.org/D24790
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284044 91177308-0d34-0410-b5e6-96231b3b80d8
The basic inlining operation makes the following changes to the call graph:
1) Add edges that were previously transitive edges. This is always trivial and
this patch gives the LCG helper methods to make this more convenient.
2) Remove the inlined edge. We had existing support for this, but it contained
bugs that needed to be fixed. Testing in the same pattern as the inliner
exposes these bugs very nicely.
3) Delete a function when it becomes dead because it is internal and all calls
have been inlined. The LCG had no support at all for this operation, so this
adds that support.
Two unittests have been added that exercise this specific mutation pattern to
the call graph. They were extremely effective in uncovering bugs. Sadly,
a large fraction of the code here is just to implement those unit tests, but
I think they're paying for themselves. =]
This was split out of a patch that actually uses the routines to
implement inlining in the new pass manager in order to isolate (with
unit tests) the logic that was entirely within the LCG.
Many thanks for the careful review from folks! There will be a few minor
follow-up patches based on the comments in the review as well.
Differential Revision: https://reviews.llvm.org/D24225
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283982 91177308-0d34-0410-b5e6-96231b3b80d8
The core of the change is supposed to be NFC, however it also fixes
what I believe was an undefined behavior when calling:
va_start(ValueArgs, Desc);
with Desc being a StringRef.
Differential Revision: https://reviews.llvm.org/D25342
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283671 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When there is a call to an alias in the same module, we were not
adding a call edge. So we could incorrectly think that the alias
was dead if it was inlined in that function, despite having a
reference imported elsewhere. This resulted in unsats at link time.
Add a call edge when the call is to an alias.
Reviewers: davide, mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25384
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283664 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
While walking defs of pointer operands we were assuming that the pointer
size would remain constant. This is not true, because addresspacecast
instructions may cast the pointer to an address space with a different
pointer width.
This partial reverts r282612, which was a more conservative solution
to this problem.
Reviewers: reames, sanjoy, apilipenko
Subscribers: wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D24772
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283557 91177308-0d34-0410-b5e6-96231b3b80d8
With the ROPI and RWPI relocation models we can't always have pointers
to global data or functions in constant data, so don't try to convert switches
into lookup tables if any value in the lookup table would require a relocation.
We can still safely emit lookup tables of other values, such as simple
constants.
Differential Revision: https://reviews.llvm.org/D24462
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283530 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The computeKnownBits and ComputeNumSignBits functions in ValueTracking can now do a simple look-through of ExtractElement.
Reviewers: majnemer, spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D24955
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283434 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r283285 and re-commit r283275 with
a fix for format("%s", Str); where Str is a StringRef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283298 91177308-0d34-0410-b5e6-96231b3b80d8
The purpose of the YAML diagnostic output file is to collect information on
optimizations performed, or not performed, for later processing by tools that
help users (and compiler developers) understand how code was optimized. As
such, the diagnostics that appear in the file should not be coupled to what a
user might want to see summarized for them as the compiler runs, and in fact,
because the user likely does not know what optimization diagnostics their tools
might want to use, the user cannot provide a useful filter regardless. As such,
we shouldn't filter the diagnostics going to the output file.
Differential Revision: https://reviews.llvm.org/D25224
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283236 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Added 6 new target hooks for the vectorizer in order to filter types, handle size constraints and decide how to split chains.
Reviewers: tstellarAMD, arsenm
Subscribers: arsenm, mzolotukhin, wdng, llvm-commits, nhaehnle
Differential Revision: https://reviews.llvm.org/D24727
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283099 91177308-0d34-0410-b5e6-96231b3b80d8
This was first landed in rL283058 and subsequenlty reverted since a
change this depends on (rL283057) was buggy and had to be reverted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283079 91177308-0d34-0410-b5e6-96231b3b80d8
They've broken the sanitizer-bootstrap bots. Reverting while I investigate.
Original commit messages:
r283057: "[ConstantRange] Make getEquivalentICmp smarter"
r283058: "[SCEV] Rely on ConstantRange instead of custom logic; NFCI"
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283062 91177308-0d34-0410-b5e6-96231b3b80d8
(Recommit after making sure IsVerbose gets properly initialized in
DiagnosticInfoOptimizationBase. See previous commit that takes care of
this.)
OptimizationRemarkAnalysis directly takes the role of the report that is
generated by LAA.
Then we need the magic to be able to turn an LAA remark into an LV
remark. This is done via a new OptimizationRemark ctor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282813 91177308-0d34-0410-b5e6-96231b3b80d8
OptimizationRemarkAnalysis directly takes the role of the report that is
generated by LAA.
Then we need the magic to be able to turn an LAA remark into an LV
remark. This is done via a new OptimizationRemark ctor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282758 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When using llc with -compile-twice, module is generated twice, but getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI will still get the old PSI with the original (invalidated) Module. This patch checks if the module has changed when calling getPSI, if yes, update the module and invalidate the Summary.
The bug does not show up in the current llc because PSI is not used in CodeGen yet. But with https://reviews.llvm.org/D24989, the bug will be exposed by test/CodeGen/PowerPC/pr26378.ll
Reviewers: eraman, davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D24993
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282616 91177308-0d34-0410-b5e6-96231b3b80d8
