Fast register pressure tracking currently only takes effect during
bottom up scheduling. Forcing this is a bit faster and simpler for
targets that don't have many scheduling constraints and don't need
top-down scheduling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190014 91177308-0d34-0410-b5e6-96231b3b80d8
If the instruction window is < NumRegs/2, pressure tracking is not
likely to be effective. The scheduler has to process a very large
number of tiny blocks. We want this to be fast.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189991 91177308-0d34-0410-b5e6-96231b3b80d8
Register pressure tracking is half the complexity of the
scheduler. It's useful to be able to turn it off for compile time and
performance comparisons.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189987 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r189913.
Talked with Eric on IRC. I am going to XFAIL the failing test since it
is using what Eric described as "the member hack" which was needed on
that old GDB.
Sorry for the noise!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189914 91177308-0d34-0410-b5e6-96231b3b80d8
This won't affect the kinds of hashes we test for as we actually
do hashing based on form and attribute. Change the fission-hash
testcase one last time to handle DW_AT_comp_dir.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189840 91177308-0d34-0410-b5e6-96231b3b80d8
There was one case that we could hit a DebugValue where I didn't think
to check. DebugValues are evil. No checkinable test case, sorry. It's
an obvious fix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189717 91177308-0d34-0410-b5e6-96231b3b80d8
This removes all expensive pressure tracking logic from the scheduling
critical path of node comparison.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189643 91177308-0d34-0410-b5e6-96231b3b80d8
Only compare pressure within the same set. When multiple sets are
affected, we prioritize the most constrained set.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189641 91177308-0d34-0410-b5e6-96231b3b80d8
Created SUPressureDiffs array to hold the per node PDiff computed during DAG building.
Added a getUpwardPressureDelta API that will soon replace the old
one. Compute PressureDelta here from the precomputed PressureDiffs.
Updating for liveness will come next.
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Revert unintentional commit (of an unreviewed change).
Original commit message:
Add getUnrollingPreferences to TTI
Allow targets to customize the default behavior of the generic loop unrolling
transformation. This will be used by the PowerPC backend when targeting the A2
core (which is in-order with a deep pipeline), and using more aggressive
defaults is important.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189566 91177308-0d34-0410-b5e6-96231b3b80d8
Allow targets to customize the default behavior of the generic loop unrolling
transformation. This will be used by the PowerPC backend when targeting the A2
core (which is in-order with a deep pipeline), and using more aggressive
defaults is important.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189565 91177308-0d34-0410-b5e6-96231b3b80d8
This uses the TargetSubtargetInfo::useAA() function to control the defaults of
the -combiner-alias-analysis and -combiner-global-alias-analysis options.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189564 91177308-0d34-0410-b5e6-96231b3b80d8
There are several optional (off-by-default) features in CodeGen that can make
use of alias analysis. These features are important for generating code for
some kinds of cores (for example the (in-order) PPC A2 core). This adds a
useAA() function to TargetSubtargetInfo to allow these features to be enabled
by default on a per-subtarget basis.
Here is the first use of this function: To control the default of the
-enable-aa-sched-mi feature.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189563 91177308-0d34-0410-b5e6-96231b3b80d8
algorithm. Update the split dwarf hashing testcase accordingly - this
should be the last time that the hash of an empty file changes.
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when we can. Migrate from using blocks when we're adding just a
single attribute and floating point values are an unsigned, not signed,
bag of bits.
Update all test cases accordingly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189419 91177308-0d34-0410-b5e6-96231b3b80d8
We want to convert code like (or (srl N, 8), (shl N, 8)) into (srl (bswap N),
const), but this is only valid if the bits above 16 on the source pattern are
0, the checks we were doing on this were slightly wrong before.
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is constructing from as an input and keep the same unique identifier.
We can use this to connect items which must stay in the .o file
(e.g. pubnames and pubtypes) to the skeleton cu rather than having
duplicate unique numbers for the sections and needing to do lookups
based on MDNode.
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it by default under linux or when we're trying to keep compatibility
with old gdb versions.
Fix testcase for option name change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189289 91177308-0d34-0410-b5e6-96231b3b80d8
If we have a binary operation like ISD:ADD, we can set the result type
equal to the result type of one of its operands rather than using
TargetLowering::getPointerTy().
Also, any use of DAG.getIntPtrConstant(C) as an operand for a binary
operation can be replaced with:
DAG.getConstant(C, OtherOperand.getValueType());
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189227 91177308-0d34-0410-b5e6-96231b3b80d8
This adds minimal support to the SelectionDAG for handling address spaces
with different pointer sizes. The SelectionDAG should now correctly
lower pointer function arguments to the correct size as well as generate
the correct code when lowering getelementptr.
This patch also updates the R600 DataLayout to use 32-bit pointers for
the local address space.
v2:
- Add more helper functions to TargetLoweringBase
- Use CHECK-LABEL for tests
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189221 91177308-0d34-0410-b5e6-96231b3b80d8
We currently emit labels with the prefix Lllvm$workaround$fake$stub$ if
the target's MCAsmInfo has getLinkOnceDirective() mapped to something
interesting. This was apparently a work around introduced in r31033 for
binutils that we don't need anymore.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189187 91177308-0d34-0410-b5e6-96231b3b80d8
Estimate the cyclic critical path within a single block loop. If the
acyclic critical path is longer, then the loop will exhaust OOO
resources after some number of iterations. If lag between the acyclic
critical path and cyclic critical path is longer the the time it takes
to issue those loop iterations, then aggressively schedule for
latency.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189120 91177308-0d34-0410-b5e6-96231b3b80d8
This will be used to compute the cyclic critical path and to
update precomputed per-node pressure differences.
In the longer term, it could also be used to speed up LiveInterval
update by avoiding visiting all global vreg users.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189118 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes a pathological compile time problem with very large blocks
and lots of scheduling boundaries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189116 91177308-0d34-0410-b5e6-96231b3b80d8
...so that it can be used for z too. Most of the code is the same.
The only real change is to use TargetTransformInfo to test when a sqrt
instruction is available.
The pass is opt-in because at the moment it only handles sqrt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189097 91177308-0d34-0410-b5e6-96231b3b80d8
When truncated vector stores were being custom lowered in
VectorLegalizer::LegalizeOp(), the old (illegal) and new (legal) node pair
was not being added to LegalizedNodes list. Instead of the legalized
result being passed to VectorLegalizer::TranslateLegalizeResult(),
the result was being passed back into VectorLegalizer::LegalizeOp(),
which ended up adding a (new, new) pair to the list instead.
This was causing an assertion failure when a custom lowered truncated
vector store was the last instruction a basic block and the VectorLegalizer
was unable to find it in the LegalizedNodes list when updating the
DAG root.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188953 91177308-0d34-0410-b5e6-96231b3b80d8
The small utility function that pattern matches Base + Index +
Offset patterns for loads and stores fails to recognize the base
pointer for loads/stores from/into an array at offset 0 inside a
loop. As a result DAGCombiner::MergeConsecutiveStores was not able
to merge all stores.
This commit fixes the issue by adding an additional pattern match
and also a test case.
Reviewer: Nadav
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188936 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
LLVM would generate DWARF with version 3 in the .debug_pubname and
.debug_pubtypes version fields. This would lead SGI dwarfdump to fail
parsing the DWARF with (in the instance of .debug_pubnames) would exit
with:
dwarfdump ERROR: dwarf_get_globals: DW_DLE_PUBNAMES_VERSION_ERROR (123)
This fixes PR16950.
Reviewers: echristo, dblaikie
Reviewed By: echristo
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1454
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188869 91177308-0d34-0410-b5e6-96231b3b80d8
SystemZTargetLowering::emitStringWrapper() previously loaded the character
into R0 before the loop and made R0 live on entry. I'd forgotten that
allocatable registers weren't allowed to be live across blocks at this stage,
and it confused LiveVariables enough to cause a miscompilation of f3 in
memchr-02.ll.
This patch instead loads R0 in the loop and leaves LICM to hoist it
after RA. This is actually what I'd tried originally, but I went for
the manual optimisation after noticing that R0 often wasn't being hoisted.
This bug forced me to go back and look at why, now fixed as r188774.
We should also try to optimize null checks so that they test the CC result
of the SRST directly. The select between null and the SRST GPR result could
then usually be deleted as dead.
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Post-RA LICM keeps three sets of registers: PhysRegDefs, PhysRegClobbers
and TermRegs. When it sees a definition of R it adds all aliases of R
to the corresponding set, so that when it needs to test for membership
it only needs to test a single register, rather than worrying about
aliases there too. E.g. the final candidate loop just has:
unsigned Def = Candidates[i].Def;
if (!PhysRegClobbers.test(Def) && ...) {
to test whether register Def is multiply defined.
However, there was also a shortcut in ProcessMI to make sure we didn't
add candidates if we already knew that they would fail the final test.
This shortcut was more pessimistic than the final one because it
checked whether _any alias_ of the defined register was multiply defined.
This is too conservative for targets that define register pairs.
E.g. on z, R0 and R1 are sometimes used as a pair, so there is a
128-bit register that aliases both R0 and R1. If a loop used
R0 and R1 independently, and the definition of R0 came first,
we would be able to hoist the R0 assignment (because that used
the final test quoted above) but not the R1 assignment (because
that meant we had two definitions of the paired R0/R1 register
and would fail the shortcut in ProcessMI).
This patch just uses the same check for the ProcessMI shortcut as
we use in the final candidate loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188774 91177308-0d34-0410-b5e6-96231b3b80d8
Previously, generation of stack protectors was done exclusively in the
pre-SelectionDAG Codegen LLVM IR Pass "Stack Protector". This necessitated
splitting basic blocks at the IR level to create the success/failure basic
blocks in the tail of the basic block in question. As a result of this,
calls that would have qualified for the sibling call optimization were no
longer eligible for optimization since said calls were no longer right in
the "tail position" (i.e. the immediate predecessor of a ReturnInst
instruction).
Then it was noticed that since the sibling call optimization causes the
callee to reuse the caller's stack, if we could delay the generation of
the stack protector check until later in CodeGen after the sibling call
decision was made, we get both the tail call optimization and the stack
protector check!
A few goals in solving this problem were:
1. Preserve the architecture independence of stack protector generation.
2. Preserve the normal IR level stack protector check for platforms like
OpenBSD for which we support platform specific stack protector
generation.
The main problem that guided the present solution is that one can not
solve this problem in an architecture independent manner at the IR level
only. This is because:
1. The decision on whether or not to perform a sibling call on certain
platforms (for instance i386) requires lower level information
related to available registers that can not be known at the IR level.
2. Even if the previous point were not true, the decision on whether to
perform a tail call is done in LowerCallTo in SelectionDAG which
occurs after the Stack Protector Pass. As a result, one would need to
put the relevant callinst into the stack protector check success
basic block (where the return inst is placed) and then move it back
later at SelectionDAG/MI time before the stack protector check if the
tail call optimization failed. The MI level option was nixed
immediately since it would require platform specific pattern
matching. The SelectionDAG level option was nixed because
SelectionDAG only processes one IR level basic block at a time
implying one could not create a DAG Combine to move the callinst.
To get around this problem a few things were realized:
1. While one can not handle multiple IR level basic blocks at the
SelectionDAG Level, one can generate multiple machine basic blocks
for one IR level basic block. This is how we handle bit tests and
switches.
2. At the MI level, tail calls are represented via a special return
MIInst called "tcreturn". Thus if we know the basic block in which we
wish to insert the stack protector check, we get the correct behavior
by always inserting the stack protector check right before the return
statement. This is a "magical transformation" since no matter where
the stack protector check intrinsic is, we always insert the stack
protector check code at the end of the BB.
Given the aforementioned constraints, the following solution was devised:
1. On platforms that do not support SelectionDAG stack protector check
generation, allow for the normal IR level stack protector check
generation to continue.
2. On platforms that do support SelectionDAG stack protector check
generation:
a. Use the IR level stack protector pass to decide if a stack
protector is required/which BB we insert the stack protector check
in by reusing the logic already therein. If we wish to generate a
stack protector check in a basic block, we place a special IR
intrinsic called llvm.stackprotectorcheck right before the BB's
returninst or if there is a callinst that could potentially be
sibling call optimized, before the call inst.
b. Then when a BB with said intrinsic is processed, we codegen the BB
normally via SelectBasicBlock. In said process, when we visit the
stack protector check, we do not actually emit anything into the
BB. Instead, we just initialize the stack protector descriptor
class (which involves stashing information/creating the success
mbbb and the failure mbb if we have not created one for this
function yet) and export the guard variable that we are going to
compare.
c. After we finish selecting the basic block, in FinishBasicBlock if
the StackProtectorDescriptor attached to the SelectionDAGBuilder is
initialized, we first find a splice point in the parent basic block
before the terminator and then splice the terminator of said basic
block into the success basic block. Then we code-gen a new tail for
the parent basic block consisting of the two loads, the comparison,
and finally two branches to the success/failure basic blocks. We
conclude by code-gening the failure basic block if we have not
code-gened it already (all stack protector checks we generate in
the same function, use the same failure basic block).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188755 91177308-0d34-0410-b5e6-96231b3b80d8
This adds a llvm.copysign intrinsic; We already have Libfunc recognition for
copysign (which is turned into the FCOPYSIGN SDAG node). In order to
autovectorize calls to copysign in the loop vectorizer, we need a corresponding
intrinsic as well.
In addition to the expected changes to the language reference, the loop
vectorizer, BasicTTI, and the SDAG builder (the intrinsic is transformed into
an FCOPYSIGN node, just like the function call), this also adds FCOPYSIGN to a
few lists in LegalizeVector{Ops,Types} so that vector copysigns can be
expanded.
In TargetLoweringBase::initActions, I've made the default action for FCOPYSIGN
be Expand for vector types. This seems correct for all in-tree targets, and I
think is the right thing to do because, previously, there was no way to generate
vector-values FCOPYSIGN nodes (and most targets don't specify an action for
vector-typed FCOPYSIGN).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188728 91177308-0d34-0410-b5e6-96231b3b80d8
Until gdb supports the new accelerator tables we should add the
pubnames section so that gdb_index can be generated from gold
at link time. On darwin we already emit the accelerator tables
and so don't need to worry about pubnames.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188708 91177308-0d34-0410-b5e6-96231b3b80d8
- split WidenVecRes_Binary into WidenVecRes_Binary and WidenVecRes_BinaryCanTrap
- WidenVecRes_BinaryCanTrap preserves the original behaviour for operations
that can trap
- WidenVecRes_Binary simply widens the operation and improves codegen for
3-element vectors by allowing widening and promotion on x86 (matches the
behaviour of unary and ternary operation widening)
- use WidenVecRes_Binary for operations on integers.
Reviewed by: nrotem
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We had previously been asserting when faced with a FCOPYSIGN f64, ppcf128 node
because there was no way to expand the FCOPYSIGN node. Because ppcf128 is the
sum of two doubles, and the first double must have the larger magnitude, we
can take the sign from the first double. As a result, in addition to fixing the
crash, this is also an optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188655 91177308-0d34-0410-b5e6-96231b3b80d8
We check this in many/all other cases, just missed this one it seems.
Perhaps it'd be worth unifying this so we never emit zero-length
DW_AT_names.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188649 91177308-0d34-0410-b5e6-96231b3b80d8
Teach the generic instruction selection helper functions to constrain
the register classes of their input operands. For non-physical register
references, the generic code needs to be careful not to mess that up
when replacing references to result registers. As the comment indicates
for MachineRegisterInfo::replaceRegWith(), it's important to call
constrainRegClass() first.
rdar://12594152
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188593 91177308-0d34-0410-b5e6-96231b3b80d8
Generalize r188163 to cope with return types other than MVT::i32, just
as the existing visitMemCmpCall code did. I've split this out into a
subroutine so that it can be used for other upcoming patches.
I also noticed that I'd used the wrong API to record the out chain.
It's a load that uses DAG.getRoot() rather than getRoot(), so the out
chain should go on PendingLoads. I don't have a testcase for that because
we don't do any interesting scheduling on z yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188540 91177308-0d34-0410-b5e6-96231b3b80d8
