It's causing some buildbots to timeout whenever tablegen needs re-compilation,
particularly those with -fsanitize=memory but not only them. A compile time
regression was expected since it triples the amount of SelectionDAG rules we
are able to import but it's currently too high.
James Molloy [Mon, 22 May 2017 09:42:07 +0000 (09:42 +0000)]
Re-apply r302416: [ARM] Clear the constant pool cache on explicit .ltorg directives
Re-applying now that PR32825 which was raised on the commit this fixed up is now known to have also been fixed by this commit.
Original commit message:
Multiple ldr pseudoinstructions with the same constant value will
reuse the same constant pool entry. However, if the constant pool
is explicitly flushed with a .ltorg directive, we should not try
to reference constants in the previous pool any longer, since they
may be out of range.
This fixes assembling hand-written assembler source which repeatedly
loads the same constant value, across a binary size larger than the
pc-relative fixup range for ldr instructions (4096 bytes). Such
assembler source already uses explicit .ltorg instructions to emit
constant pools with regular intervals. However if we try to reuse
constants emitted in earlier pools, they end up out of range.
This makes the output of the testcase match what binutils gas does
(prior to this patch, it would fail to assemble).
David Blaikie [Mon, 22 May 2017 07:02:47 +0000 (07:02 +0000)]
libDebugInfo/DWARF: Apply relocations for debug_addr addresses in object files
llvm-symbolizer would fail to symbolize addresses in unlinked object
files when handling .dwo file data because the addresses would not be
relocated in the same way as the ranges in the skeleton CU in the object
file.
Fix that so object files can be symbolized the same as executables.
Sanjoy Das [Mon, 22 May 2017 06:46:04 +0000 (06:46 +0000)]
[SCEV] Clarify behavior around max backedge taken count
This is a re-application of a r303497 that was reverted in r303498.
I thought it had broken a bot when it had not (the breakage did not
go away with the revert).
This change makes the split between the "exact" backedge taken count
and the "maximum" backedge taken count a bit more obvious. Both of
these are upper bounds on the number of times the loop header
executes (since SCEV does not account for most kinds of abnormal
control flow), but the latter is guaranteed to be a constant.
There were a few places where the max backedge taken count *was* a
non-constant; I've changed those to compute constants instead.
At this point, I'm not sure if the constant max backedge count can be
computed by calling `getUnsignedRange(Exact).getUnsignedMax()` without
losing precision. If it can, we can simplify even further by making
`getMaxBackedgeTakenCount` a thin wrapper around
`getBackedgeTakenCount` and `getUnsignedRange`.
Igor Breger [Sun, 21 May 2017 11:13:56 +0000 (11:13 +0000)]
[GlobalISel][X86] Fix G_TRUNC instruction selection.
Updated tests with -verify-machineinstrs flag.
It fixes 3 tests failed with machine verifier enabled and listed
in PR27481
Hiroshi Inoue [Sun, 21 May 2017 06:00:05 +0000 (06:00 +0000)]
Summary
PPC backend eliminates compare instructions by using record-form instructions in PPCInstrInfo::optimizeCompareInstr, which is called from peephole optimization pass.
This patch improves this optimization to eliminate more compare instructions in two types of common case.
- comparison against a constant 1 or -1
The record-form instructions set CR bit based on signed comparison against 0. So, the current implementation does not exploit the record-form instruction for comparison against a non-zero constant.
This patch enables record-form optimization for constant of 1 or -1 if possible; it changes the condition "greater than -1" into "greater than or equal to 0" and "less than 1" into "less than or equal to 0".
With this patch, compare can be eliminated in the following code sequence, as an example.
uint64_t a, b;
if ((a | b) & 0x8000000000000000ull) { ... }
else { ... }
- andi for 32-bit comparison on PPC64
Since record-form instructions execute 64-bit signed comparison and so we have limitation in eliminating 32-bit comparison, i.e. with cmplwi, using the record-form. The original implementation already has such checks but andi. is not recognized as an instruction which executes implicit zero extension and hence safe to convert into record-form if used for equality check.
%1 = and i32 %a, 10
%2 = icmp ne i32 %1, 0
br i1 %2, label %foo, label %bar
In this simple example, LLVM generates andi. + cmplwi + beq on PPC64.
This patch make it possible to eliminate the cmplwi for this case.
I added andi. for optimization targets if it is safe to do so.
Sanjoy Das [Sun, 21 May 2017 01:47:50 +0000 (01:47 +0000)]
[SCEV] Clarify behavior around max backedge taken count
This change makes the split between the "exact" backedge taken count
and the "maximum" backedge taken count a bit more obvious. Both of
these are upper bounds on the number of times the loop header
executes (since SCEV does not account for most kinds of abnormal
control flow), but the latter is guaranteed to be a constant.
There were a few places where the max backedge taken count *was* a
non-constant; I've changed those to compute constants instead.
At this point, I'm not sure if the constant max backedge count can be
computed by calling `getUnsignedRange(Exact).getUnsignedMax()` without
losing precision. If it can, we can simplify even further by making
`getMaxBackedgeTakenCount` a thin wrapper around
`getBackedgeTakenCount` and `getUnsignedRange`.
Davide Italiano [Sat, 20 May 2017 00:46:54 +0000 (00:46 +0000)]
[NewGVN] Create a StoreExpression instead of a VariableExpression.
In the case where we have an operand defined by a lod of the
same memory location. Historically this was a VariableExpression
because we wanted to make sure they ended up in the same class,
but if we create the right expression, they end up in the same
class anyway.
Fixes PR32897. Thanks to Dan for the detailed discussion and the
fix suggestion.
Matthias Braun [Fri, 19 May 2017 22:37:09 +0000 (22:37 +0000)]
SimplifyLibCalls: Optimize wcslen
Refactor the strlen optimization code to work for both strlen and wcslen.
This especially helps with programs in the wild where people pass
L"string"s to const std::wstring& function parameters and the wstring
constructor gets inlined.
This also fixes a lingerind API problem/bug in getConstantStringInfo()
where zeroinitializers would always give you an empty string (without a
length) back regardless of the actual length of the initializer which
did not work well in the TrimAtNul==false causing the PR mentioned
below.
Note that the fixed getConstantStringInfo() needed fixes to SelectionDAG
memcpy lowering and may lead to some cases for out-of-bounds
zeroinitializer accesses not getting optimized anymore. So some code
with UB may produce out of bound memory reads now instead of just
producing zeros.
The refactoring "accidentally" fixes http://llvm.org/PR32124
Daniel Berlin [Fri, 19 May 2017 20:22:20 +0000 (20:22 +0000)]
NewGVN: Fix PR32838.
This is a complicated bug involving two issues:
1. What do we do with phi nodes when we prove all arguments are not
live?
2. When is it safe to use value leaders to determine if we can ignore
an argumnet?
Zachary Turner [Fri, 19 May 2017 19:26:58 +0000 (19:26 +0000)]
Resubmit "[CodeView] Provide a common interface for type collections."
This was originally reverted because it was a breaking a bunch
of bots and the breakage was not surfacing on Windows. After much
head-scratching this was ultimately traced back to a bug in the
lit test runner related to its pipe handling. Now that the bug
in lit is fixed, Windows correctly reports these test failures,
and as such I have finally (hopefully) fixed all of them in this
patch.
Daniel Berlin [Fri, 19 May 2017 19:01:27 +0000 (19:01 +0000)]
Last of the major pieces to NewGVN - yay!
Summary:
NewGVN: Handle equivalence between phi of ops and op of phis.
This makes our GVN mostly-complete. It would be complete, modulo some
deliberate choices we make. This means it detects roughly all herband
equivalences in polynomial time, including cases notoriously hard for
other GVN's to detect. It also detects a very large swath of the
cases we currently rely on instcombine to detect that involve folding
upwards through phis.
Amaury Sechet [Fri, 19 May 2017 18:20:44 +0000 (18:20 +0000)]
[DAGCombine] (addcarry 0, 0, X) -> (ext/trunc X)
Summary:
While this makes some case better and some case worse - so it's unclear if it is a worthy combine just by itself - this is a useful canonicalisation.
Zachary Turner [Fri, 19 May 2017 18:12:07 +0000 (18:12 +0000)]
[lit] Take the last error when executing pipelines.
This seems to have been present since the beginning of time,
which is quite surprising. The symptom was this: Suppose you
have a test with a run line that looks like this:
RUN: foo | FileCheck %s
foo prints some output and then due to a bug in the program it
asserts. On Windows this results in the program returning a
negative exit code. But if enough output had been printed
already by the tool so that the FileCheck match would succeed
then FileCheck would return 0, and because of bad logic in
lit this 0 return value would overwrite the failed return
value from previous items in the pipeline. This only happened
with negative exit codes.
The most sensible behavior is to just take whatever the first
exit code is. There is no logical ordering defined on exit
codes, so comparing with < and > does not make a lot of sense.
Instead, as soon as we find the first non-successful return
value, that should be the result of the entire expression.
This fixes the issue, as now tests which fail on non-Windows
platforms also fail for me on Windows as well.
Anna Thomas [Fri, 19 May 2017 17:05:36 +0000 (17:05 +0000)]
[LoopIdiom] Refactor return value of isLegalStore [NFC]
Summary:
This NFC simply refactors the return value of LoopIdiomRecognize::isLegalStore() from bool to an enumeration, and
removes the return-through-parameter mechanism that the function was using. This function is constructed such that it will
only ever recognize a single store idiom (memset, memset_pattern, or memcpy), and never a combination of these. As such it
makes much more sense for the return value to be the single idiom that the store matches, rather than
having a separate argument-return for each idiom -- it's cleaner, and makes it clearer that
only a single idiom can be matched.
Craig Topper [Fri, 19 May 2017 16:43:54 +0000 (16:43 +0000)]
[APInt] Add support for dividing or remainder by a uint64_t or int64_t.
Summary:
This patch adds udiv/sdiv/urem/srem/udivrem/sdivrem methods that can divide by a uint64_t. This makes division consistent with all the other arithmetic operations.
This modifies the interface of the divide helper method to work on raw arrays instead of APInts. This way we can pass the uint64_t in for the RHS without wrapping it in an APInt. This required moving all the Quotient and Remainder allocation handling up to the callers. For udiv/urem this was as simple as just creating the Quotient/Remainder with the right size when they were declared. For udivrem we have to rely on reallocate not changing the contents of the variable LHS or RHS is aliased with the Quotient or Remainder APInts. We also have to zero the upper bits of Remainder and Quotient that divide doesn't write to if lhsWords/rhsWords is smaller than the width.
I've update the toString method to use the new udivrem.
Guy Blank [Fri, 19 May 2017 12:35:15 +0000 (12:35 +0000)]
[X86][AVX512] Make i1 illegal in the CodeGen
This patch defines the i1 type as illegal in the X86 backend for AVX512.
For DAG operations on <N x i1> types (build vector, extract vector element, ...) i8 is used, and should be truncated/extended.
This should produce better scalar code for i1 types since GPRs will be used instead of mask registers.
Zachary Turner [Fri, 19 May 2017 05:57:45 +0000 (05:57 +0000)]
Revert "[CodeView] Provide a common interface for type collections."
This is a squash of ~5 reverts of, well, pretty much everything
I did today. Something is seriously broken with lit on Windows
right now, and as a result assertions that fire in tests are
triggering failures. I've been breaking non-Windows bots all
day which has seriously confused me because all my tests have
been passing, and after running lit with -a to view the output
even on successful runs, I find out that the tool is crashing
and yet lit is still reporting it as a success!
At this point I don't even know where to start, so rather than
leave the tree broken for who knows how long, I will get this
back to green, and then once lit is fixed on Windows, hopefully
hopefully fix the remaining set of problems for real.
Zachary Turner [Fri, 19 May 2017 04:56:48 +0000 (04:56 +0000)]
[CodeView] Reduce memory usage in TypeSerializer.
We were using a BumpPtrAllocator to allocate stable storage for
a record, then trying to insert that into a hash table. If a
collision occurred, the bytes were never inserted and the
allocation was unnecessary. At the cost of an extra hash
computation, check first if it exists, and only if it does do
we allocate and insert.
Zachary Turner [Fri, 19 May 2017 03:04:08 +0000 (03:04 +0000)]
Fix a broken test.
Similar to my previous fix, it turns out llvm-pdbdump has been
printing an incorrect value since the beginning of time, but
we didn't know it was incorrect. Specifically, we were interpreting
a TypeIndex as referencing a type from the TPI stream when it
actually should come from the IPI stream. So we were printing a
string that looked like a valid string, but was just from the
wrong place.
Zachary Turner [Fri, 19 May 2017 00:56:39 +0000 (00:56 +0000)]
Fix crasher in CodeView test.
Apparently this was always broken, but previously we were more
graceful about it and we would print "unknown udt" if we couldn't
find the type index, whereas now we just segfault because we
assume it's valid. But this exposed a real bug, which is that
we weren't looking in the right place. So fix that, and also
fix this crash at the same time.
Matthias Braun [Fri, 19 May 2017 00:18:03 +0000 (00:18 +0000)]
LiveIntervalAnalysis: Fix missing case in pruneSubRegValues()
pruneSubRegValues() needs to remove subregister ranges starting at
instructions that later get removed by eraseInstrs(). It missed to check
one case in which eraseInstrs() would remove an instruction.
Davide Italiano [Thu, 18 May 2017 23:22:44 +0000 (23:22 +0000)]
[NewGVN] Break infinite recursion in singleReachablePHIPath().
We can have cycles between PHIs and this causes singleReachablePhi()
to call itself indefintely (until we run out of stack). The proper
solution would be that of computing SCCs, but it's not worth for
now, so just keep a visited set and give up when we find a cycle.
Thanks to Dan for the discussion/help with this.
Zachary Turner [Thu, 18 May 2017 23:03:41 +0000 (23:03 +0000)]
[llvm-pdbdump] Add the ability to merge PDBs.
Merging PDBs is a feature that will be used heavily by
the linker. The functionality already exists but does not
have deep test coverage because it's not easily exposed through
any tools. This patch aims to address that by adding the
ability to merge PDBs via llvm-pdbdump. It takes arbitrarily
many PDBs and outputs a single PDB.
Using this new functionality, a test is added for merging
type records. Future patches will add the ability to merge
symbol records, module information, etc.
Zachary Turner [Thu, 18 May 2017 23:03:06 +0000 (23:03 +0000)]
[CodeView] Provide a common interface for type collections.
Right now we have multiple notions of things that represent collections of
types. Most commonly used are TypeDatabase, which is supposed to keep
mappings from TypeIndex to type name when reading a type stream, which
happens when reading PDBs. And also TypeTableBuilder, which is used to
build up a collection of types dynamically which we will later serialize
(i.e. when writing PDBs).
But often you just want to do some operation on a collection of types, and
you may want to do the same operation on any kind of collection. For
example, you might want to merge two TypeTableBuilders or you might want
to merge two type streams that you loaded from various files.
This dichotomy between reading and writing is responsible for a lot of the
existing code duplication and overlapping responsibilities in the existing
CodeView library classes. For example, after building up a
TypeTableBuilder with a bunch of type records, if we want to dump it we
have to re-invent a bunch of extra glue because our dumper takes a
TypeDatabase or a CVTypeArray, which are both incompatible with
TypeTableBuilder.
This patch introduces an abstract base class called TypeCollection which
is shared between the various type collection like things. Wherever we
previously stored a TypeDatabase& in some common class, we now store a
TypeCollection&.
The advantage of this is that all the details of how the collection are
implemented, such as lazy deserialization of partial type streams, is
completely transparent and you can just treat any collection of types the
same regardless of where it came from.
projects / llvm / log