over each node in the worklist prior to combining.
This allows the combiner to produce new nodes which need to go back
through legalization. This is particularly useful when generating
operands to target specific nodes in a post-legalize DAG combine where
the operands are significantly easier to express as pre-legalized
operations. My immediate use case will be PSHUFB formation where we need
to build a constant shuffle mask with a build_vector node.
This also refactors the relevant functionality in the legalizer to
support this, and updates relevant tests. I've spoken to the R600 folks
and these changes look like improvements to them. The avx512 change
needs to be investigated, I suspect there is a disagreement between the
legalizer and the DAG combiner there, but it seems a minor issue so
leaving it to be re-evaluated after this patch.
Differential Revision: http://reviews.llvm.org/D4564
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214020 91177308-0d34-0410-b5e6-96231b3b80d8
The tale starts with r212808 which attempted to fix inversion of the low
and high bits when lowering MUL_LOHI. Sadly, that commit did not include
any positive test cases, and just removed some operations from a test
case where the actual logic being changed isn't fully visible from the
test.
What this commit did was two things. First, it reversed the low and high
results in the formation of the MERGE_VALUES node for the multiple
results. This is entirely correct.
Second it changed the shuffles for extracting the low and high
components from the i64 results of the multiplies to extract them
assuming a big-endian-style encoding of the multiply results. This
second change is wrong. There is no big-endian encoding in x86, the
results of the multiplies are normal v2i64s: when cast to v4i32, the low
i32s are at offsets 0 and 2, and the high i32s are at offsets 1 and 3.
However, the first change wasn't enough to actually fix the bug, which
is (I assume) why the second change was also made. There was another bug
in the MERGE_VALUES formation: we weren't using a VTList, and so were
getting a single result node! When grabbing the *second* result from the
node, we got... well.. colud be anything. I think this *appeared* to
invert things, but had to be causing other problems as well.
Fortunately, I fixed the MERGE_VALUES issue in r213931, so we should
have been fine, right? NOOOPE! Because the core bug was never addressed,
the test in vector-idiv failed when I fixed the MERGE_VALUES node.
Because there are essentially no docs for this node, I had to guess at
how to fix it and tried swapping the operands, restoring the order of
the original code before r212808. While this "fixed" the test case (in
that we produced the write instructions) we were still extracting the
wrong elements of the i64s, and thus PR20355 was still broken.
This commit essentially reverts the big-endian-style extraction part of
r212808 and goes back to the original masks which were correct. Now that
the MERGE_VALUES node formation is also correct, everything works. I've
also included a more detailed test from PR20355 to make sure this stays
fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214011 91177308-0d34-0410-b5e6-96231b3b80d8
The clever way to implement signed multiplication with unsigned *is
already implemented* and tested and working correctly. The bug is
somewhere else. Re-investigating.
This will teach me to not scroll far enough to read the code that did
what I thought needed to be done.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214009 91177308-0d34-0410-b5e6-96231b3b80d8
signed multiplication is requested. While there is not a difference in
the *low* half of the result, the *high* half (used specifically to
implement the signed division by these constants) certainly is used. The
test case I've nuked was actively asserting wrong code.
There is a delightful solution to doing signed multiplication even when
we don't have it that Richard Smith has crafted, but I'll add the
machinery back and implement that in a follow-up patch. This at least
restores correctness.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214007 91177308-0d34-0410-b5e6-96231b3b80d8
instructions which happen to have a constant mask.
Currently, this only handles a very narrow set of cases, but those
happen to be the cases that I care about for testing shuffles sanely.
This is a bit trickier than other shuffle instructions because we're
decoding constants out of the constant pool. The current MC layer makes
it completely impossible to inspect a constant pool entry, so we have to
do it at the MI level and attach the comment to the streamer on its way
out. So no joy for disassembling, but it does make test cases and asm
dumps *much* nicer.
Sorry for no test cases, but it didn't really seem that valuable to go
trolling through existing old test cases and updating them. I'll have
lots of testing of this in the upcoming patch for SSSE3 emission in the
new vector shuffle lowering code paths.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213986 91177308-0d34-0410-b5e6-96231b3b80d8
This patch removes the empty coverage mapping regions.
Those regions were produced by clang's old mapping region generation
algorithm, but the new algorithm doesn't generate them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213981 91177308-0d34-0410-b5e6-96231b3b80d8
This is the first commit in a series that add an @llvm.assume intrinsic which
can be used to provide the optimizer with a condition it may assume to be true
(when the control flow would hit the intrinsic call). Some basic properties are added here:
- llvm.invariant(true) is dead.
- llvm.invariant(false) is unreachable (this directly corresponds to the
documented behavior of MSVC's __assume(0)), so is llvm.invariant(undef).
The intrinsic is tagged as writing arbitrarily, in order to maintain control
dependencies. BasicAA has been updated, however, to return NoModRef for any
particular location-based query so that we don't unnecessarily block code
motion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213973 91177308-0d34-0410-b5e6-96231b3b80d8
address of the stack guard was being spilled to the stack.
Previously the address of the stack guard would get spilled to the stack if it
was impossible to keep it in a register. This patch introduces a new target
independent node and pseudo instruction which gets expanded post-RA to a
sequence of instructions that load the stack guard value. Register allocator
can now just remat the value when it can't keep it in a register.
<rdar://problem/12475629>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213967 91177308-0d34-0410-b5e6-96231b3b80d8
This commit implements the frameaddress intrinsic for the AArch64 architecture
in FastISel.
There were two test cases that pretty much tested the same, so I combined them
to a single test case.
Fixes <rdar://problem/17811834>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213959 91177308-0d34-0410-b5e6-96231b3b80d8
Ugh. Turns out not even transformation passes link in how to read IR.
I sincerely believe the buildbots will finally agree with my system
after this though. (I don't really understand why all of this has been
working on my system, but not on all the buildbots.)
Create a new tool called llvm-uselistorder to use for verifying use-list
order. For now, just dump everything from the (now defunct)
-verify-use-list-order pass into the tool.
This might be a better way to test use-list order anyway.
Part of PR5680.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213957 91177308-0d34-0410-b5e6-96231b3b80d8
This recommits r208930, r208933, and r208975 (by reverting r209338) and
reverts r209529 (the FIXME to readd this functionality once the tools
were fixed) now that DWP has been fixed to cope with a single section
for all fission type units.
Original commit message:
"Since type units in the dwo file are handled by a debug aware tool,
they don't need to leverage the ELF comdat grouping to implement
deduplication. Avoid creating all the .group sections for these as a
space optimization."
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213956 91177308-0d34-0410-b5e6-96231b3b80d8
I think the compiler got confused by the nested DEBUG macros.
It was failing with:
UseListOrder.cpp(80) : error C2059: syntax error : '}'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213954 91177308-0d34-0410-b5e6-96231b3b80d8
`ValueEnumerator::OptimizeConstants()` creates forward references within
the constant pools, which makes predicting constants' use-list order
difficult. For now, just disable the optimization.
This can be re-enabled in the future in one of two ways:
- Enable a limited version of this optimization that doesn't create
forward references. One idea is to categorize constants by their
"height" and make that the top-level sort.
- Enable it entirely. This requires predicting how may times each
constant will be recreated as its operands' and operands' operands'
(etc.) forward references get resolved.
This is part of PR5680.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213953 91177308-0d34-0410-b5e6-96231b3b80d8
Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson
reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped
provide a reduced reproduction, though the failure wasn't too hard to
guess, and even easier with the example to confirm.
The assertion that the subprogram metadata associated with an
llvm::Function matches the scope data referenced by the DbgLocs on the
instructions in that function is not valid under LTO. In LTO, a C++
inline function might exist in multiple CUs and the subprogram metadata
nodes will refer to the same llvm::Function. In this case, depending on
the order of the CUs, the first intance of the subprogram metadata may
not be the one referenced by the instructions in that function and the
assertion will fail.
A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the
assertion removed and a comment added to explain this situation.
This was then reverted again in r213581 as it caused PR20367. The root
cause of this was the early exit in LiveDebugVariables meant that
spurious DBG_VALUE intrinsics that referenced dead variables were not
removed, causing an assertion/crash later on. The fix is to have
LiveDebugVariables strip all DBG_VALUE intrinsics in functions without
debug info as they're not needed anyway. Test case added to cover this
situation (that occurs when a debug-having function is inlined into a
nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll
Original commit message:
If a function isn't actually in a CU's subprogram list in the debug info
metadata, ignore all the DebugLocs and don't try to build scopes, track
variables, etc.
While this is possibly a minor optimization, it's also a correctness fix
for an incoming patch that will add assertions to LexicalScopes and the
debug info verifier to ensure that all scope chains lead to debug info
for the current function.
Fix up a few test cases that had broken/incomplete debug info that could
violate this constraint.
Add a test case where this occurs by design (inlining a
debug-info-having function in an attribute nodebug function - we want
this to work because /if/ the nodebug function is then inlined into a
debug-info-having function, it should be fine (and will work fine - we
just stitch the scopes up as usual), but should the inlining not happen
we need to not assert fail either).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213952 91177308-0d34-0410-b5e6-96231b3b80d8
This functionality is currently turned off by default.
Part of the motivation for introducing scoped-noalias metadata is to enable the
preservation of noalias parameter attribute information after inlining.
Sometimes this can be inferred from the code in the caller after inlining, but
often we simply lose valuable information.
The overall process if fairly simple:
1. Create a new unqiue scope domain.
2. For each (used) noalias parameter, create a new alias scope.
3. For each pointer, collect the underlying objects. Add a noalias scope for
each noalias parameter from which we're not derived (and has not been
captured prior to that point).
4. Add an alias.scope for each noalias parameter from which we might be
derived (or has been captured before that point).
Note that the capture checks apply only if one of the underlying objects is not
an identified function-local object.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213949 91177308-0d34-0410-b5e6-96231b3b80d8
In the process of fixing the noalias parameter -> metadata conversion process
that will take place during inlining (which will be committed soon, but not
turned on by default), I have come to realize that the semantics provided by
yesterday's commit are not really what we want. Here's why:
void foo(noalias a, noalias b, noalias c, bool x) {
*q = x ? a : b;
*c = *q;
}
Generically, we know that *c does not alias with *a and with *b (so there is an
'and' in what we know we're not), and we know that *q might be derived from *a
or from *b (so there is an 'or' in what we know that we are). So we do not want
the semantics currently, where any noalias scope matching any alias.scope
causes a NoAlias return. What we want to know is that the noalias scopes form a
superset of the alias.scope list (meaning that all the things we know we're not
is a superset of all of things the other instruction might be).
Making that change, however, introduces a composibility problem. If we inline
once, adding the noalias metadata, and then inline again adding more, and we
append new scopes onto the noalias and alias.scope lists each time. But, this
means that we could change what was a NoAlias result previously into a MayAlias
result because we appended an additional scope onto one of the alias.scope
lists. So, instead of giving scopes the ability to have parents (which I had
borrowed from the TBAA implementation, but seems increasingly unlikely to be
useful in practice), I've given them domains. The subset/superset condition now
applies within each domain independently, and we only need it to hold in one
domain. Each time we inline, we add the new scopes in a new scope domain, and
everything now composes nicely. In addition, this simplifies the
implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213948 91177308-0d34-0410-b5e6-96231b3b80d8
The dragonegg buildbot (and others?) started failing after
r213945/r213946 because `llvm-as` wasn't linking in the bitcode reader.
I think moving the verify functions to the same file as the verify pass
should fix the build. Adding a command-line option for maintaining
use-list order in assembly as a drive-by to prevent warnings about
unused static functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213947 91177308-0d34-0410-b5e6-96231b3b80d8
Add a -verify-use-list-order pass, which shuffles use-list order, writes
to bitcode, reads back, and verifies that the (shuffled) order matches.
- The utility functions live in lib/IR/UseListOrder.cpp.
- Moved (and renamed) the command-line option to enable writing
use-lists, so that this pass can return early if the use-list orders
aren't being serialized.
It's not clear that this pass is the right direction long-term (perhaps
a separate tool instead?), but short-term it's a great way to test the
use-list order prototype. I've added an XFAIL-ed testcase that I'm
hoping to get working pretty quickly.
This is part of PR5680.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213945 91177308-0d34-0410-b5e6-96231b3b80d8
SDValues, fixing the two bugs left in the regression suite.
The key for both of these was the use a single value type rather than
a VTList which caused an unintentionally single-result merge-value node.
Fix this by getting the appropriate VTList in place.
Doing this exposed that the comments in x86's code abouth how MUL_LOHI
operands are handle is wrong. The bug with the use of out-of-range
result numbers was hiding the bug about the order of operands here (as
best i can tell). There are more places where the code appears to get
this backwards still...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213931 91177308-0d34-0410-b5e6-96231b3b80d8
doesn't actually correspond to an SDValue at all. Fixes most of the
remaining asserts on out-of-range SDValue result numbers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213930 91177308-0d34-0410-b5e6-96231b3b80d8
with a result number outside the range of results for the node.
I don't know how we managed to not really check this very basic
invariant for so long, but the code is *very* broken at this point.
I have over 270 test failures with the assert enabled. I'm committing it
disabled so that others can join in the cleanup effort and reproduce the
issues. I've also included one of the obvious fixes that I already
found. More fixes to come.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213926 91177308-0d34-0410-b5e6-96231b3b80d8
assembly instructions.
This is necessary to ensure ARM assembler switches to Thumb mode before it
starts assembling the file level inline assembly instructions at the beginning
of a .s file.
<rdar://problem/17757232>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213924 91177308-0d34-0410-b5e6-96231b3b80d8
Because the PowerPC vmrgh* and vmrgl* instructions have a built-in
big-endian bias, it is necessary to swap their inputs in little-endian
mode when using them to implement a vector shuffle. This was
previously missed in the vector LE implementation.
There was already logic to distinguish between unary and "normal"
vmrg* vector shuffles, so this patch extends that logic to use a third
option: "swapped" vmrg* vector shuffles that are used for little
endian in place of the "normal" ones.
I've updated the vec-shuffle-le.ll test to check for the expected
register ordering on the generated instructions.
This bug was discovered when testing the LE and ELFv2 patches for
safety if they were backported to 3.4. A different vectorization
decision was made in 3.4 than on mainline trunk, and that exposed the
problem. I've verified this fix takes care of that issue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213915 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements the data structures, the reader and
the writers for the new code coverage mapping system.
The new code coverage mapping system uses the instrumentation
based profiling to provide code coverage analysis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213910 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements the data structures, the reader and
the writers for the new code coverage mapping system.
The new code coverage mapping system uses the instrumentation
based profiling to provide code coverage analysis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213909 91177308-0d34-0410-b5e6-96231b3b80d8
hint) the loop unroller replaces the llvm.loop.unroll.count metadata with
llvm.loop.unroll.disable metadata to prevent any subsequent unrolling
passes from unrolling more than the hint indicates. This patch fixes
an issue where loop unrolling could be disabled for other loops as well which
share the same llvm.loop metadata.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213900 91177308-0d34-0410-b5e6-96231b3b80d8
which have successfully round-tripped through the combine phase, and use
this to ensure all operands to DAG nodes are visited by the combiner,
even if they are only added during the combine phase.
This is critical to have the combiner reach nodes that are *introduced*
during combining. Previously these would sometimes be visited and
sometimes not be visited based on whether they happened to end up on the
worklist or not. Now we always run them through the combiner.
This fixes quite a few bad codegen test cases lurking in the suite while
also being more principled. Among these, the TLS codegeneration is
particularly exciting for programs that have this in the critical path
like TSan-instrumented binaries (although I think they engineer to use
a different TLS that is faster anyways).
I've tried to check for compile-time regressions here by running llc
over a merged (but not LTO-ed) clang bitcode file and observed at most
a 3% slowdown in llc. Given that this is essentially a worst case (none
of opt or clang are running at this phase) I think this is tolerable.
The actual LTO case should be even less costly, and the cost in normal
compilation should be negligible.
With this combining logic, it is possible to re-legalize as we combine
which is necessary to implement PSHUFB formation on x86 as
a post-legalize DAG combine (my ultimate goal).
Differential Revision: http://reviews.llvm.org/D4638
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213898 91177308-0d34-0410-b5e6-96231b3b80d8
vector operation legalization with support for custom target lowering
and fallback to expand when it fails, and use this to implement sext and
anyext load lowering for x86 in a more principled way.
Previously, the x86 backend relied on a target DAG combine to "combine
away" sextload and extload nodes prior to legalization, or would expand
them during legalization with terrible code. This is particularly
problematic because the DAG combine relies on running over non-canonical
DAG nodes at just the right time to match several common and important
patterns. It used a combine rather than lowering because we didn't have
good lowering support, and to expose some tricks being employed to more
combine phases.
With this change it becomes a proper lowering operation, the backend
marks that it can lower these nodes, and I've added support for handling
the canonical forms that don't have direct legal representations such as
sextload of a v4i8 -> v4i64 on AVX1. With this change, our test cases
for this behavior continue to pass even after the DAG combiner beigns
running more systematically over every node.
There is some noise caused by this in the test suite where we actually
use vector extends instead of subregister extraction. This doesn't
really seem like the right thing to do, but is unlikely to be a critical
regression. We do regress in one case where by lowering to the
target-specific patterns early we were able to combine away extraneous
legal math nodes. However, this regression is completely addressed by
switching to a widening based legalization which is what I'm working
toward anyways, so I've just switched the test to that mode.
Differential Revision: http://reviews.llvm.org/D4654
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213897 91177308-0d34-0410-b5e6-96231b3b80d8
The Microsoft ABI and MSVCRT are considered the canonical C runtime and ABI.
The long double routines are not part of this environment. However, cygwin and
MinGW both provide supplementary implementations. Change the condition to
reflect this reality.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213896 91177308-0d34-0410-b5e6-96231b3b80d8
Even if there's a file called c:\a, we want /? to be preserved as
an option, not expanded to a filename.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213894 91177308-0d34-0410-b5e6-96231b3b80d8
