This removes the restriction for the icmp constant, but as noted by the FIXME comments,
we still need to change individual checks for binop operand constants.
llvm-svn: 277629
This is a fix for PR28697.
An MDNode can indirectly refer to a GlobalValue, through a
ConstantAsMetadata. When the GlobalValue is deleted, the MDNode operand
is reset to `nullptr`. If the node is uniqued, this can lead to a
hard-to-detect cache invalidation in a Metadata map that's shared across
an LLVMContext.
Consider:
1. A map from Metadata* to `T` called RemappedMDs.
2. A node that references a global variable, `!{i1* @GV}`.
3. Insert `!{i1* @GV} -> SomeT` in the map.
4. Delete `@GV`, leaving behind `!{null} -> SomeT`.
Looking up the generic and uninteresting `!{null}` gives you `SomeT`,
which is likely related to `@GV`. Worse, `SomeT`'s lifetime may be tied
to the deleted `@GV`.
This occurs in practice in the shared ValueMap used since r266579 in the
IRMover. Other code that handles more than one Module (with different
lifetimes) in the same LLVMContext could hit it too.
The fix here is a partial revert of r225223: in the rare case that an
MDNode operand is a ConstantAsMetadata (i.e., wrapping a node from the
Value hierarchy), drop uniquing if it gets replaced with `nullptr`.
This changes step #4 above to leave behind `distinct !{null} -> SomeT`,
which can't be confused with the generic `!{null}`.
In theory, this can cause some churn in the LLVMContext's MDNode
uniquing map when Values are being deleted. However:
- The number of GlobalValues referenced from uniqued MDNodes is
expected to be quite small. E.g., the debug info metadata schema
only references GlobalValues from distinct nodes.
- Other Constants have the lifetime of the LLVMContext, whose teardown
is careful to drop references before deleting the constants.
As a result, I don't expect a compile time regression from this change.
llvm-svn: 277625
We were able to figure out that the result of a call is some constant.
While propagating that fact, we added the constant to the value map.
This is problematic because it results in us losing the call site when
processing the value map.
This fixes PR28802.
llvm-svn: 277611
reason about and less error prone.
The core idea is to fully parse the text without trying to identify
passes or structure. This is done with a single state machine. There
were various bugs in the logic around this previously that were repeated
and scattered across the code. Having a single routine makes it much
easier to fix and get correct. For example, this routine doesn't suffer
from PR28577.
Then the actual pass construction is handled using *much* easier to read
code and simple loops, with particular pass manager construction sunk to
live with other pass construction. This is especially nice as the pass
managers *are* in fact passes.
Finally, the "implicit" pass manager synthesis is done much more simply
by forming "pre-parsed" structures rather than having to duplicate tons
of logic.
One of the bugs fixed by this was evident in the tests where we accepted
a pipeline that wasn't really well formed. Another bug is PR28577 for
which I have added a test case.
The code is less efficient than the previous code but I'm really hoping
that's not a priority. ;]
Thanks to Sean for the review!
Differential Revision: https://reviews.llvm.org/D22724
llvm-svn: 277561
Summary:
Sometimes, bitsets could get really large (>300k entries) and
we might want to drop a check, as it would have a too much cost.
Adding a flag to control how much penalty are we willing to pay
for bitsets.
Reviewers: kcc
Differential Revision: https://reviews.llvm.org/D23088
llvm-svn: 277556
As agreed in post-commit review of r265388, I'm switching the flag to
its original value until the 90% runtime performance regression on
SingleSource/Benchmarks/Stanford/Bubblesort is addressed.
llvm-svn: 277524
Update comment for isOutOfScope and add a testcase for uniform value being used
out of scope.
Differential Revision: https://reviews.llvm.org/D23073
llvm-svn: 277515
This patch enables the vectorizer to generate both scalar and vector versions
of an integer induction variable for a given loop. Previously, we only
generated a scalar induction variable if we knew all its users were going to be
scalar. Otherwise, we generated a vector induction variable. In the case of a
loop with both scalar and vector users of the induction variable, we would
generate the vector induction variable and extract scalar values from it for
the scalar users. With this patch, we now generate both versions of the
induction variable when there are both scalar and vector users and select which
version to use based on whether the user is scalar or vector.
Differential Revision: https://reviews.llvm.org/D22869
llvm-svn: 277474
This patch refactors the logic in collectLoopUniforms and
collectValuesToIgnore, untangling the concepts of "uniform" and "scalar". It
adds isScalarAfterVectorization along side isUniformAfterVectorization to
distinguish the two. Known scalar values include those that are uniform,
getelementptr instructions that won't be vectorized, and induction variables
and induction variable update instructions whose users are all known to be
scalar.
This patch includes the following functional changes:
- In collectLoopUniforms, we mark uniform the pointer operands of interleaved
accesses. Although non-consecutive, these pointers are treated like
consecutive pointers during vectorization.
- In collectValuesToIgnore, we insert a value into VecValuesToIgnore if it
isScalarAfterVectorization rather than isUniformAfterVectorization. This
differs from the previous functionaly in that we now add getelementptr
instructions that will not be vectorized into VecValuesToIgnore.
This patch also removes the ValuesNotWidened set used for induction variable
scalarization since, after the above changes, it is now equivalent to
isScalarAfterVectorization.
Differential Revision: https://reviews.llvm.org/D22867
llvm-svn: 277460
Added ability to estimate the entry count of the extracted function and
the branch probabilities of the exit branches.
Patch by River Riddle!
Differential Revision: https://reviews.llvm.org/D22744
llvm-svn: 277411
Summary: This patch implements CFI for WebAssembly. It modifies the
LowerTypeTest pass to pre-assign table indexes to functions that are
called indirectly, and lowers type checks to test against the
appropriate table indexes. It also modifies the WebAssembly backend to
support a special ".indidx" assembly directive that propagates the table
index assignments out to the linker.
Patch by Dominic Chen
Differential Revision: https://reviews.llvm.org/D21768
llvm-svn: 277398
Using RAUW was wrong here; if we have a switch transform such as:
18 -> 6 then
6 -> 0
If we use RAUW, while performing the second transform the *transformed* 6
from the first will be also replaced, so we end up with:
18 -> 0
6 -> 0
Found by clang stage2 bootstrap; testcase added.
llvm-svn: 277332
It looks like the two independent parts of the rotate operation (a lshr and shl) are being reordered on some bots. Add CHECK-DAGs to account for this.
llvm-svn: 277329
If a switch is sparse and all the cases (once sorted) are in arithmetic progression, we can extract the common factor out of the switch and create a dense switch. For example:
switch (i) {
case 5: ...
case 9: ...
case 13: ...
case 17: ...
}
can become:
if ( (i - 5) % 4 ) goto default;
switch ((i - 5) / 4) {
case 0: ...
case 1: ...
case 2: ...
case 3: ...
}
or even better:
switch ( ROTR(i - 5, 2) {
case 0: ...
case 1: ...
case 2: ...
case 3: ...
}
The division and remainder operations could be costly so we only do this if the factor is a power of two, and emit a right-rotate instead of a divide/remainder sequence. Dense switches can be lowered significantly better than sparse switches and can even be transformed into lookup tables.
llvm-svn: 277325
When extracting a set of blocks make sure to inherit all of the target
dependent attributes to make sure that the function will be valid for
lowering. One example is the "target-features" attribute for x86, if the
extracted region has functionality that relies on a specific feature it
will fail to be lowered.
This also allows for extracted functions to be valid for inlining, at
least back into the parent function, as the target attributes are tested
when inlining for compatibility.
Patch by River Riddle!
Differential Revision: https://reviews.llvm.org/D22713
llvm-svn: 277315
LoopUnroll is a loop pass, so the analysis of OptimizationRemarkEmitter
is added to the common function analysis passes that loop passes
depend on.
The BFI and indirectly BPI used in this pass is computed lazily so no
overhead should be observed unless -pass-remarks-with-hotness is used.
This is how the patch affects the O3 pipeline:
Dominator Tree Construction
Natural Loop Information
Canonicalize natural loops
Loop-Closed SSA Form Pass
Basic Alias Analysis (stateless AA impl)
Function Alias Analysis Results
Scalar Evolution Analysis
+ Lazy Branch Probability Analysis
+ Lazy Block Frequency Analysis
+ Optimization Remark Emitter
Loop Pass Manager
Rotate Loops
Loop Invariant Code Motion
Unswitch loops
Simplify the CFG
Dominator Tree Construction
Basic Alias Analysis (stateless AA impl)
Function Alias Analysis Results
Combine redundant instructions
Natural Loop Information
Canonicalize natural loops
Loop-Closed SSA Form Pass
Scalar Evolution Analysis
+ Lazy Branch Probability Analysis
+ Lazy Block Frequency Analysis
+ Optimization Remark Emitter
Loop Pass Manager
Induction Variable Simplification
Recognize loop idioms
Delete dead loops
Unroll loops
...
llvm-svn: 277203
Patch by Sunita Marathe
Third try, now following fixes to MSan to handle mempcy in such a way that this commit won't break the MSan buildbots. (Thanks, Evegenii!)
llvm-svn: 277189
Some instructions may have their uses replaced with a symbolic constant.
However, the instruction may still have side effects which percludes it
from being removed from the function. EarlyCSE treated such an
instruction as if it were removed, resulting in PR28763.
llvm-svn: 277114
An undef vector element can be treated as if it had any value. Folding
such a vector element to 0 in a bitcast can open up further folding
opportunities.
llvm-svn: 277104
ConstantExpr::getWithOperands does much of the hard work that
ConstantFoldInstOperandsImpl tries to do but more completely.
This lets us fold ExtractValue/InsertValue expressions.
llvm-svn: 277100
A ConstantVector can have ConstantExpr operands and vice versa.
However, the folder had no ability to fold ConstantVectors which, in
some cases, was an optimization barrier.
Instead, rephrase the folder in terms of Constants instead of
ConstantExprs and teach callers how to deal with failure.
llvm-svn: 277099
Summary:
copypasta doc of ImportedFunctionsInliningStatistics class
\brief Calculate and dump ThinLTO specific inliner stats.
The main statistics are:
(1) Number of inlined imported functions,
(2) Number of imported functions inlined into importing module (indirect),
(3) Number of non imported functions inlined into importing module
(indirect).
The difference between first and the second is that first stat counts
all performed inlines on imported functions, but the second one only the
functions that have been eventually inlined to a function in the importing
module (by a chain of inlines). Because llvm uses bottom-up inliner, it is
possible to e.g. import function `A`, `B` and then inline `B` to `A`,
and after this `A` might be too big to be inlined into some other function
that calls it. It calculates this statistic by building graph, where
the nodes are functions, and edges are performed inlines and then by marking
the edges starting from not imported function.
If `Verbose` is set to true, then it also dumps statistics
per each inlined function, sorted by the greatest inlines count like
- number of performed inlines
- number of performed inlines to importing module
Reviewers: eraman, tejohnson, mehdi_amini
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D22491
llvm-svn: 277089
Summary:
The motivation is the same as in D22141: In order to add the hotness
attribute to optimization remarks we need BFI to be available in all
passes that emit optimization remarks. BFI depends on BPI so unless we
make this lazy as well we would still compute BPI unconditionally.
The solution is to use the new LazyBPI pass in LazyBFI and only compute
BPI when computation of BFI is requested by the client.
I extended the laziness test using a LoopDistribute test to also cover
BPI.
Reviewers: hfinkel, davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D22835
llvm-svn: 277083
Summary:
Asan stack-use-after-scope check should poison alloca even if there is
no access between start and end.
This is possible for code like this:
for (int i = 0; i < 3; i++) {
int x;
p = &x;
}
"Loop Invariant Code Motion" will move "p = &x;" out of the loop, making
start/end range empty.
PR27453
Reviewers: eugenis
Differential Revision: https://reviews.llvm.org/D22842
llvm-svn: 277072
Summary:
Asan stack-use-after-scope check should poison alloca even if there is
no access between start and end.
This is possible for code like this:
for (int i = 0; i < 3; i++) {
int x;
p = &x;
}
"Loop Invariant Code Motion" will move "p = &x;" out of the loop, making
start/end range empty.
PR27453
Reviewers: eugenis
Differential Revision: https://reviews.llvm.org/D22842
llvm-svn: 277068
This adds boilerplate code for all coroutine passes,
the passes are no-ops for now.
Also, a small test has been added to verify that passes execute in
the expected order or not at all if coroutine support is disabled.
Patch by Gor Nishanov!
Differential Revision: https://reviews.llvm.org/D22847
llvm-svn: 277033
When folding an expression, we run ConstantFoldConstantExpression on
each operand of that expression.
However, ConstantFoldConstantExpression can fail and retur nullptr.
Previously, we would bail on further refining the expression.
Instead, use the original operand and see if we can refine a later
operand.
llvm-svn: 276959
Summary:
When we ask the builder to create a bitcast on a constant, we get back a
constant, not an instruction.
Reviewers: asbirlea
Subscribers: jholewinski, mzolotukhin, llvm-commits, arsenm
Differential Revision: https://reviews.llvm.org/D22878
llvm-svn: 276922
When loading or storing in a field of a struct like "a.b.c", GVN is able to
detect the equivalent expressions, and GVN-hoist would fail in the code
generation. This is because the GEPs are not hoisted as scalar operations to
avoid moving the GEPs too far from their ld/st instruction when the ld/st is not
movable. So we end up having to generate code for the GEP of a ld/st when we
move the ld/st. In the case of a GEP referring to another GEP as in "a.b.c" we
need to code generate all the GEPs necessary to make all the operands available
at the new location for the ld/st. With this patch we recursively walk through
the GEP operands checking whether all operands are available, and in the case of
a GEP operand, it recursively makes all its operands available. Code generation
happens from the inner GEPs out until reaching the GEP that appears as an
operand of the ld/st.
Differential Revision: https://reviews.llvm.org/D22599
llvm-svn: 276841
Instead of DFS numbering basic blocks we now DFS number instructions that avoids
the costly operation of which instruction comes first in a basic block.
Patch mostly written by Daniel Berlin.
Differential Revision: https://reviews.llvm.org/D22777
llvm-svn: 276714
Pre-instrumentation inline (pre-inliner) greatly improves the IR
instrumentation code performance, among other benefits. One issue of the
pre-inliner is it can introduce CFG-mismatch for COMDAT functions. This
is due to the fact that the same COMDAT function may have different early
inline decisions across different modules -- that means different copies
of COMDAT functions will have different CFG checksum.
In this patch, we propose a partially renaming the COMDAT group and its
member function/variable so we have different profile counter for each
version. We will post-fix the COMDAT function and the group name with its
FunctionHash.
Differential Revision: http://reviews.llvm.org/D22600
llvm-svn: 276673
The public InlineFunction utility assumes that the passed in
InlineFunctionInfo has a valid AssumptionCacheTracker.
Patch by River Riddle!
Differential Revision: https://reviews.llvm.org/D22706
llvm-svn: 276609
If we two loads of two different alignments, we must use the minimum of
the two alignments when hoisting. Same deal for stores.
For allocas, use the maximum of the two allocas.
llvm-svn: 276601
Allowed loop vectorization with secondary FP IVs. Like this:
float *A;
float x = init;
for (int i=0; i < N; ++i) {
A[i] = x;
x -= fp_inc;
}
The auto-vectorization is possible when the induction binary operator is "fast" or the function has "unsafe" attribute.
Differential Revision: https://reviews.llvm.org/D21330
llvm-svn: 276554
When vectorizing a tree rooted at a store bundle, we currently try to sort the
stores before building the tree, so that the stores can be vectorized. For other
trees, the order of the root bundle - which determines the order of all other
bundles - is arbitrary. That is bad, since if a leaf bundle of consecutive loads
happens to appear in the wrong order, we will not vectorize it.
This is partially mitigated when the root is a binary operator, by trying to
build a "reversed" tree when that's considered profitable. This patch extends the
workaround we have for binops to trees rooted in a horizontal reduction.
This fixes PR28474.
Differential Revision: https://reviews.llvm.org/D22554
llvm-svn: 276477
Recommiting r275571 after fixing crash reported in PR28270.
Now we erase elements of IOL in deleteDeadInstruction().
Original Summary:
This change use the overlap interval map built from partial overwrite tracking to perform shortening MemIntrinsics.
Add test cases which was missing opportunities before.
llvm-svn: 276452
Summary:
The llvm.invariant.start and llvm.invariant.end intrinsics currently
support specifying invariant memory objects only in the default address
space.
With this change, these intrinsics are overloaded for any adddress space
for memory objects
and we can use these llvm invariant intrinsics in non-default address
spaces.
Example: llvm.invariant.start.p1i8(i64 4, i8 addrspace(1)* %ptr)
This overloaded intrinsic is needed for representing final or invariant
memory in managed languages.
Reviewers: apilipenko, reames
Subscribers: llvm-commits
llvm-svn: 276447
Just because we can constant fold the result of an instruction does not
imply that we can delete the instruction. It may have side effects.
This fixes PR28655.
llvm-svn: 276389
If `-irce-skip-profitability-checks` is passed in, IRCE will kick in in
all cases where it is legal for it to kick in. This flag is intended to
help diagnose and analyse performance issues.
llvm-svn: 276372
Do not clone stored values unless they are GEPs that are special cased to avoid
hoisting them without hoisting their associated ld/st.
Differential revision: https://reviews.llvm.org/D22652
llvm-svn: 276358
rL245171 exposed a hole in InstSimplify that manifested in a strange way in PR28466:
https://llvm.org/bugs/show_bug.cgi?id=28466
It's possible to use trunc + icmp sgt/slt in place of an and + icmp eq/ne, so we need to
recognize that pattern to eliminate selects that are choosing between some value and some
bitmasked version of that value.
Note that there is significant room for improvement (refactoring) and enhancement (more
patterns, possibly in InstCombine rather than here).
Differential Revision: https://reviews.llvm.org/D22537
llvm-svn: 276341
This patch moves the update instruction for vectorized integer induction phi
nodes to the end of the latch block. This ensures consistent placement of all
induction updates across all the kinds of int inductions we create (scalar,
splat vector, or vector phi).
Differential Revision: https://reviews.llvm.org/D22416
llvm-svn: 276339
Summary:
The llvm.invariant.start and llvm.invariant.end intrinsics currently
support specifying invariant memory objects only in the default address space.
With this change, these intrinsics are overloaded for any adddress space for memory objects
and we can use these llvm invariant intrinsics in non-default address spaces.
Example: llvm.invariant.start.p1i8(i64 4, i8 addrspace(1)* %ptr)
This overloaded intrinsic is needed for representing final or invariant memory in managed languages.
Reviewers: tstellarAMD, reames, apilipenko
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D22519
llvm-svn: 276316
The earlier change added hotness attribute to missed-optimization
remarks. This follows up with the analysis remarks (the ones explaining
the reason for the missed optimization).
llvm-svn: 276192
We can replace the return values with undef if we replaced all
the call uses with a constant/undef.
Differential Revision: https://reviews.llvm.org/D22336
llvm-svn: 276174
Summary:
Previously we wouldn't move loads/stores across instructions that had
side-effects, where that was defined as may-write or may-throw. But
this is not sufficiently restrictive: Stores can't safely be moved
across instructions that may load.
This patch also adds a DEBUG check that all instructions in our chain
are either loads or stores.
Reviewers: asbirlea
Subscribers: llvm-commits, jholewinski, arsenm, mzolotukhin
Differential Revision: https://reviews.llvm.org/D22547
llvm-svn: 276171
Summary:
Previously if we had a chain that contained a side-effecting
instruction, we wouldn't vectorize it at all. Now we'll vectorize
everything that comes before the side-effecting instruction.
Reviewers: asbirlea
Subscribers: arsenm, jholewinski, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D22536
llvm-svn: 276170
Summary: In r275989 we enabled the folding of `logic(cast(icmp), cast(icmp))` to `cast(logic(icmp, icmp))`. Here we add more test cases to assure this folding works for all logical operations `and`/`or`/`xor`.
Reviewers: grosser
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D22561
Contributed-by: Matthias Reisinger
llvm-svn: 276105
This patch adds costs for the vectorized implementations of CTPOP, the default values were seriously underestimating the cost of these and was encouraging vectorization on targets where serialized use of POPCNT would be much better.
Differential Revision: https://reviews.llvm.org/D22456
llvm-svn: 276104
Summary:
getVectorizablePrefix previously didn't work properly in the face of
aliasing loads/stores. It unwittingly assumed that the loads/stores
appeared in the BB in address order. If they didn't, it would do the
wrong thing.
Reviewers: asbirlea, tstellarAMD
Subscribers: arsenm, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D22535
llvm-svn: 276072
Revert "[LoopSimplify] Update LCSSA after separating nested loops."
This reverts commit r275891.
Revert "[LCSSA] Post-process PHI-nodes created by SSAUpdate when constructing LCSSA form."
This reverts commit r275883.
llvm-svn: 276064
We just set PreserveLCSSA to always true since we don't have an
analogous method `mustPreserveAnalysisID(LCSSA)`.
Also port LoopInfo verifier pass to test LoopUnrollPass.
llvm-svn: 276063
Summary:
Previously, the insertion point for stores was the last instruction in
Chain *before calling getVectorizablePrefixEndIdx*. Thus if
getVectorizablePrefixEndIdx didn't return Chain.size(), we still would
insert at the last instruction in Chain.
This patch changes our internal API a bit in an attempt to make it less
prone to this sort of error. As a result, we end up recalculating the
Chain's boundary instructions, but I think worrying about the speed hit
of this is a premature optimization right now.
Reviewers: asbirlea, tstellarAMD
Subscribers: mzolotukhin, arsenm, llvm-commits
Differential Revision: https://reviews.llvm.org/D22534
llvm-svn: 276056
Summary:
This helps keep us honest -- there were a number of ways we could screw
up and still have passed this test.
Reviewers: asbirlea
Subscribers: llvm-commits, arsenm
Differential Revision: https://reviews.llvm.org/D22531
llvm-svn: 276053
The pattern may look more obviously like a sext if written as:
define i32 @g(i16 %x) {
%zext = zext i16 %x to i32
%xor = xor i32 %zext, 32768
%add = add i32 %xor, -32768
ret i32 %add
}
We already have that fold in visitAdd().
Differential Revision: https://reviews.llvm.org/D22477
llvm-svn: 276035
We skipped over ReturnInsts which didn't return an argument which would
lead us to incorrectly conclude that an argument returned by another
ReturnInst was 'returned'.
This reverts commit r275756.
This fixes PR28610.
llvm-svn: 276008
Summary:
Currently, InstCombine is already able to fold expressions of the form `logic(cast(A), cast(B))` to the simpler form `cast(logic(A, B))`, where logic designates one of `and`/`or`/`xor`. This transformation is implemented in `foldCastedBitwiseLogic()` in InstCombineAndOrXor.cpp. However, this optimization will not be performed if both `A` and `B` are `icmp` instructions. The decision to preclude casts of `icmp` instructions originates in r48715 in combination with r261707, and can be best understood by the title of the former one:
> Transform (zext (or (icmp), (icmp))) to (or (zext (cimp), (zext icmp))) if at least one of the (zext icmp) can be transformed to eliminate an icmp.
Apparently, it introduced a transformation that is a reverse of the transformation that is done in `foldCastedBitwiseLogic()`. Its purpose is to expose pairs of `zext icmp` that would subsequently be optimized by `transformZExtICmp()` in InstCombineCasts.cpp. Therefore, in order to avoid an endless loop of switching back and forth between these two transformations, the one in `foldCastedBitwiseLogic()` has been restricted to exclude `icmp` instructions which is mirrored in the responsible check:
`if ((!isa<ICmpInst>(Cast0Src) || !isa<ICmpInst>(Cast1Src)) && ...`
This check seems to sort out more cases than necessary because:
- the reverse transformation is obviously done for `or` instructions only
- and also not every `zext icmp` pair is necessarily the result of this reverse transformation
Therefore we now remove this check and replace it by a more finegrained one in `shouldOptimizeCast()` that now rejects only those `logic(zext(icmp), zext(icmp))` that would be able to be optimized by `transformZExtICmp()`, which also avoids the mentioned endless loop. That means we are now able to also simplify expressions of the form `logic(cast(icmp), cast(icmp))` to `cast(logic(icmp, icmp))` (`cast` being an arbitrary `CastInst`).
As an example, consider the following IR snippet
```
%1 = icmp sgt i64 %a, %b
%2 = zext i1 %1 to i8
%3 = icmp slt i64 %a, %c
%4 = zext i1 %3 to i8
%5 = and i8 %2, %4
```
which would now be transformed to
```
%1 = icmp sgt i64 %a, %b
%2 = icmp slt i64 %a, %c
%3 = and i1 %1, %2
%4 = zext i1 %3 to i8
```
This issue became apparent when experimenting with the programming language Julia, which makes use of LLVM. Currently, Julia lowers its `Bool` datatype to LLVM's `i8` (also see https://github.com/JuliaLang/julia/pull/17225). In fact, the above IR example is the lowered form of the Julia snippet `(a > b) & (a < c)`. Like shown above, this may introduce `zext` operations, casting between `i1` and `i8`, which could for example hinder ScalarEvolution and Polly on certain code.
Reviewers: grosser, vtjnash, majnemer
Subscribers: majnemer, llvm-commits
Differential Revision: https://reviews.llvm.org/D22511
Contributed-by: Matthias Reisinger
llvm-svn: 275989
D20859 and D20860 attempted to replace the SSE (V)CVTTPS2DQ and VCVTTPD2DQ truncating conversions with generic IR instead.
It turns out that the behaviour of these intrinsics is different enough from generic IR that this will cause problems, INF/NAN/out of range values are guaranteed to result in a 0x80000000 value - which plays havoc with constant folding which converts them to either zero or UNDEF. This is also an issue with the scalar implementations (which were already generic IR and what I was trying to match).
This patch changes both scalar and packed versions back to using x86-specific builtins.
It also deals with the other scalar conversion cases that are runtime rounding mode dependent and can have similar issues with constant folding.
A companion clang patch is at D22105
Differential Revision: https://reviews.llvm.org/D22106
llvm-svn: 275981
This patch updates MemorySSA's use-optimizing walker to be more
accurate and, in some cases, faster.
Essentially, this changed our core walking algorithm from a
cache-as-you-go DFS to an iteratively expanded DFS, with all of the
caching happening at the end. Said expansion happens when we hit a Phi,
P; we'll try to do the smallest amount of work possible to see if
optimizing above that Phi is legal in the first place. If so, we'll
expand the search to see if we can optimize to the next phi, etc.
An iteratively expanded DFS lets us potentially quit earlier (because we
don't assume that we can optimize above all phis) than our old walker.
Additionally, because we don't cache as we go, we can now optimize above
loops.
As an added bonus, this patch adds a ton of verification (if
EXPENSIVE_CHECKS are enabled), so finding bugs is easier.
Differential Revision: https://reviews.llvm.org/D21777
llvm-svn: 275940
For instructions in uniform set, they will not have vector versions so
add them to VecValuesToIgnore.
For induction vars, those only used in uniform instructions or consecutive
ptrs instructions have already been added to VecValuesToIgnore above. For
those induction vars which are only used in uniform instructions or
non-consecutive/non-gather scatter ptr instructions, the related phi and
update will also be added into VecValuesToIgnore set.
The change will make the vector RegUsages estimation less conservative.
Differential Revision: https://reviews.llvm.org/D20474
The recommit fixed the testcase global_alias.ll.
llvm-svn: 275936
For instructions in uniform set, they will not have vector versions so
add them to VecValuesToIgnore.
For induction vars, those only used in uniform instructions or consecutive
ptrs instructions have already been added to VecValuesToIgnore above. For
those induction vars which are only used in uniform instructions or
non-consecutive/non-gather scatter ptr instructions, the related phi and
update will also be added into VecValuesToIgnore set.
The change will make the vector RegUsages estimation less conservative.
Differential Revision: https://reviews.llvm.org/D20474
llvm-svn: 275912
Summary:
Usually LCSSA survives this transformation, but in some cases (see
attached test) it doesn't: values from the original loop after
separating might be used from the outer loop. Before the transformation
it was the same loop, so LCSSA phis were not required.
This fixes PR28272.
Reviewers: sanjoy, hfinkel, chandlerc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D21665
llvm-svn: 275891
Summary:
The direct motivation for the port is to ensure that the OptRemarkEmitter
tests work with the new PM.
This remains a function pass because we not only create multiple loops
but could also version the original loop.
In the test I need to invoke opt
with -passes='require<aa>,loop-distribute'. LoopDistribute does not
directly depend on AA however LAA does. LAA uses getCachedResult so
I *think* we need manually pull in 'aa'.
Reviewers: davidxl, silvas
Subscribers: sanjoy, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D22437
llvm-svn: 275811
While debugging GVNHoist, I found it confusing that the entries in a
VNtoInsns were not always value numbers. They _usually_ were except for
StoreInst in which case they were a hash of two different value numbers.
This leads to two observations:
- It is more difficult to debug things when the semantic contents of
VNtoInsns changes over time.
- Using a single value number is not much cheaper, the value of
VNtoInsns is a SmallVector.
- It is not immediately clear what the algorithm would do if there were
hash collisions in the StoreInst case.
Using a DenseMap of std::pair sidesteps all of this.
N.B. The changes in the test were due their sensitivity to the
iteration order of VNtoInsns which has changed.
llvm-svn: 275761
This reverts also r275029, "Update Clang tests after adding inference for the returned argument attribute"
It broke LTO build. Seems miscompilation.
llvm-svn: 275756
Summary:
To enable profile-guided indirect call promotion in ThinLTO mode, we
simply add call graph edges for each profitable target from the profile
to the summaries, then the summary-guided importing will consider the
callee for importing as usual.
Also we need to enable the indirect call promotion pass creation in the
PassManagerBuilder when PerformThinLTO=true (we are in the ThinLTO
backend), so that the newly imported functions are considered for
promotion in the backends.
The IC promotion profiles refer to callees by GUID, which required
adding GUIDs to the per-module VST in bitcode (and assigning them
valueIds similar to how they are assigned valueIds in the combined
index).
Reviewers: mehdi_amini, xur
Subscribers: mehdi_amini, davidxl, llvm-commits
Differential Revision: http://reviews.llvm.org/D21932
llvm-svn: 275707
This is a partial implementation of a general fold for associative+commutative operators:
(op (cast (op X, C2)), C1) --> (cast (op X, op (C1, C2)))
(op (cast (op X, C2)), C1) --> (op (cast X), op (C1, C2))
There are 7 associative operators and 13 cast types, so this could potentially go a lot further.
Differential Revision: https://reviews.llvm.org/D22421
llvm-svn: 275684
This reverts commit r275042; the initial commit triggered self-hosting failures
on ARM/AArch64. James Molloy identified the problematic backend code, which has
been disabled in r275677. Trying again...
Original commit message:
Let FuncAttrs infer the 'returned' argument attribute
A function can have one argument with the 'returned' attribute, indicating that
the associated argument is always the return value of the function. Add
FuncAttrs inference logic.
llvm-svn: 275678
With r275532 fixing miscompilation of GVN, "inbounds" on certain GEPs in these
tests cannot be preserved any more. Left a TODO in the tests for future
reference.
llvm-svn: 275596
This patch adds a selected set of cleanup passes including a pre-inline pass
before LLVM IR PGO instrumentation. The inline is only intended to apply those
obvious/trivial ones before instrumentation so that much less instrumentation
is needed to get better profiling information. This will drastically improve
the instrumented code performance for large C++ applications. Another benefit
is the context sensitive counts that can potentially improve the PGO
optimization.
Differential Revision: http://reviews.llvm.org/D21405
llvm-svn: 275588
Summary:
This is the first set of changes implementing the RFC from
http://thread.gmane.org/gmane.comp.compilers.llvm.devel/98334
This is a cross-sectional patch; rather than implementing the hotness
attribute for all optimization remarks and all passes in a patch set, it
implements it for the 'missed-optimization' remark for Loop
Distribution. My goal is to shake out the design issues before scaling
it up to other types and passes.
Hotness is computed as an integer as the multiplication of the block
frequency with the function entry count. It's only printed in opt
currently since clang prints the diagnostic fields directly. E.g.:
remark: /tmp/t.c:3:3: loop not distributed: use -Rpass-analysis=loop-distribute for more info (hotness: 300)
A new API added is similar to emitOptimizationRemarkMissed. The
difference is that it additionally takes a code region that the
diagnostic corresponds to. From this, hotness is computed using BFI.
The new API is exposed via an analysis pass so that it can be made
dependent on LazyBFI. (Thanks to Hal for the analysis pass idea.)
This feature can all be enabled by setDiagnosticHotnessRequested in the
LLVM context. If this is off, LazyBFI is not calculated (D22141) so
there should be no overhead.
A new command-line option is added to turn this on in opt.
My plan is to switch all user of emitOptimizationRemark* to use this
module instead.
Reviewers: hfinkel
Subscribers: rcox2, mzolotukhin, llvm-commits
Differential Revision: http://reviews.llvm.org/D21771
llvm-svn: 275583
Summary:
This change use the overlap interval map built from partial overwrite tracking to perform shortening MemIntrinsics.
Add test cases which was missing opportunities before.
Reviewers: hfinkel, eeckstein, mcrosier
Subscribers: mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D21909
llvm-svn: 275571
This pass hoists duplicated computations in the program. The primary goal of
gvn-hoist is to reduce the size of functions before inline heuristics to reduce
the total cost of function inlining.
Pass written by Sebastian Pop, Aditya Kumar, Xiaoyu Hu, and Brian Rzycki.
Important algorithmic contributions by Daniel Berlin under the form of reviews.
Differential Revision: http://reviews.llvm.org/D19338
llvm-svn: 275561
Fix for PR 28418.
opt never finishes compiling a test when -gvn option is passed.
The problem is caused by the fact that GVN fails to fold a constant expression.
Differential Revision: https://reviews.llvm.org/D22185
llvm-svn: 275483
This patch allows the formation of interleaved access groups in loops
containing predicated blocks. However, the predicated accesses are prevented
from forming groups.
Differential Revision: https://reviews.llvm.org/D19694
llvm-svn: 275471
Summary: Port Dead Loop Deletion Pass to the new pass manager.
Reviewers: silvas, davide
Subscribers: llvm-commits, sanjoy, mcrosier
Differential Revision: https://reviews.llvm.org/D21483
llvm-svn: 275453
This patch prevents increases in the number of instructions, pre-instcombine,
due to induction variable scalarization. An increase in instructions can lead
to an increase in the compile-time required to simplify the induction
variables. We now maintain a new map for scalarized induction variables to
prevent us from converting between the scalar and vector forms.
This patch should resolve compile-time regressions seen after r274627.
llvm-svn: 275419
enables the code size optimisation to fold a rem and div into a single
aeabi_uidivmod call. This was not happening before because sdiv was converted
but srem not, and instructions with different signedness are not combined.
Differential Revision: http://reviews.llvm.org/D22214
llvm-svn: 275403
This pass hoists duplicated computations in the program. The primary goal of
gvn-hoist is to reduce the size of functions before inline heuristics to reduce
the total cost of function inlining.
Pass written by Sebastian Pop, Aditya Kumar, Xiaoyu Hu, and Brian Rzycki.
Important algorithmic contributions by Daniel Berlin under the form of reviews.
Differential Revision: http://reviews.llvm.org/D19338
llvm-svn: 275401
constant hoisting. It not only takes into account the number of uses and the
cost of expressions in which constants appear, but now also the resulting
integer range of the offsets. Thus, the algorithm maximizes the number of uses
within an integer range that will enable more efficient code generation. On
ARM, for example, this will enable code size optimisations because less
negative offsets will be created. Negative offsets/immediates are not supported
by Thumb1 thus preventing more compact instruction encoding.
Differential Revision: http://reviews.llvm.org/D21183
llvm-svn: 275382
We were able to fold masked loads with an all-ones mask to a normal
load. However, we couldn't turn a masked load with a mask with mixed
ones and undefs into a normal load.
llvm-svn: 275380
This now should also work with the interprocedural variant of the pass.
Slightly easier now that the yak is shaved.
Differential Revision: http://reviews.llvm.org/D22329
llvm-svn: 275363
Summary:
In Scalarizer::gather we see if we already have a scattered form of Op,
and in that case use the new form.
In the particular case of PR28108, the found ValueVector SV has size 2,
where the first Value is nullptr, and the second is indeed a proper Value.
The nullptr then caused an assert to blow when we tried to do
cast<Instruction>(SV[I]).
With this patch we check SV[I] before doing the cast, and if it's nullptr
we just skip over it.
I don't know the Scalarizer well enough to know if this is the best fix
or if something should be done else where to prevent the nullptr from
being in the ValueVector at all, but at least this avoids the crash
and looking at the test case output it looks reasonable.
Reviewers: hfinkel, frasercrmck, wala, mehdi_amini
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D21518
llvm-svn: 275359
Treat loads which clip before the start of a global initializer the same
way we treat clipping beyond the end of the initializer: use zeros.
llvm-svn: 275345
Summary:
LSV used to abort vectorizing a chain for interleaved load/store accesses that alias.
Allow a valid prefix of the chain to be vectorized, mark just the prefix and retry vectorizing the remaining chain.
Reviewers: llvm-commits, jlebar, arsenm
Subscribers: mzolotukhin
Differential Revision: http://reviews.llvm.org/D22119
llvm-svn: 275317
In D21740, we discussed trying to make this a more general matcher. However, I didn't see a clean
way to handle the regular m_Not cases and these non-splat vector patterns, so I've opted for the
direct approach here. If there are other potential uses of areInverseVectorBitmasks(), we could
move that helper function to a higher level.
There is an open question as to which is of these forms should be considered the canonical IR:
%sel = select <4 x i1> <i1 true, i1 false, i1 false, i1 true>, <4 x i32> %a, <4 x i32> %b
%shuf = shufflevector <4 x i32> %a, <4 x i32> %b, <4 x i32> <i32 0, i32 5, i32 6, i32 3>
Differential Revision: http://reviews.llvm.org/D22114
llvm-svn: 275289
The LCSSA pass itself will not generate several redundant PHI nodes in a single
exit block. However, such redundant PHI nodes don't violate LCSSA form, and may
be introduced by passes that preserve LCSSA, and/or preserved by the LCSSA pass
itself. So, assuming a single PHI node per exit block is not safe.
llvm-svn: 275217
Summary:
It's useful to have some visibility about which call sites are devirtualized,
especially for debug purposes. Another use case is a regression test on the
application side (like, Chromium).
Reviewers: pcc
Differential Revision: http://reviews.llvm.org/D22252
llvm-svn: 275145
Summary:
Aiming to correct the ordering of loads/stores. This patch changes the
insert point for loads to the position of the first load.
It updates the ordering method for loads to insert before, rather than after.
Before this patch the following sequence:
"load a[1], store a[1], store a[0], load a[2]"
Would incorrectly vectorize to "store a[0,1], load a[1,2]".
The correctness check was assuming the insertion point for loads is at
the position of the first load, when in practice it was at the last
load. An alternative fix would have been to invert the correctness check.
The current fix changes insert position but also requires reordering of
instructions before the vectorized load.
Updated testcases to reflect the changes.
Reviewers: tstellarAMD, llvm-commits, jlebar, arsenm
Subscribers: mzolotukhin
Differential Revision: http://reviews.llvm.org/D22071
llvm-svn: 275117
Make some AVX and AVX512 cast costs more precise.
Based on part of a patch by Elena Demikhovsky (D15604).
Differential Revision: http://reviews.llvm.org/D22064
llvm-svn: 275106
There's a little bit of churn in this patch because the initialization
mechanism is now shared between the old and the new PM. Other than
that, it's just a pretty mechanical translation.
llvm-svn: 275082
Summary:
For sample-based PGO, using BFI to calculate callsite count is sometime not accurate. This is because with sampling based approach, if a callsite resides in a hot loop deeply nested in a bunch of cold branches, the callsite's BFI frequency would be inaccurately calculated due to lack of samples in the cold branch.
E.g.
if (A1 && A2 && A3 && ..... && A10) {
for (i=0; i < 100000000; i++) {
callsite();
}
}
Assume that A1 to A100 are all 100% taken, and callsite has 1000 samples and thus is considerred hot. Because the loop's trip count is huge, it's normal that all branches outside the loop has no sample at all. As a result, we can only use static branch probability to derive the the frequency of the loop header. Assuming that static heuristic thinks each branch is 50% taken, then the count calculated from BFI will be 1/(2^10) of the actual value.
In order to get more accurate callsite count, we directly annotate the weight on the call instruction, and directly use it when checking callsite hotness.
Note that this mechanism can also be shared by instrumentation based callsite hotness analysis. The side benefit is that it breaks the dependency from Inliner to BFI as call count is embedded in the IR.
Reviewers: davidxl, eraman, dnovillo
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D22118
llvm-svn: 275073
Summary: Handle the case when there is only one incoming/outgoing edge for a visited basic block: use the block weight to adjust edge weight even when the edge has been visited before. This can help reduce inaccuracies introduced by incorrect basic block profile, as shown in the updated unittest.
Reviewers: davidxl, dnovillo
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D22180
llvm-svn: 275072
For functions which are known to return a specific argument, pointer-comparison
folding can look through the function calls as part of its analysis.
Differential Revision: http://reviews.llvm.org/D9387
llvm-svn: 275039
If a function is known to return one of its arguments, we can use that in order
to compute known bits of the return value.
Differential Revision: http://reviews.llvm.org/D9397
llvm-svn: 275036
A function can have one argument with the 'returned' attribute, indicating that
the associated argument is always the return value of the function. Add
FuncAttrs inference logic.
Differential Revision: http://reviews.llvm.org/D22202
llvm-svn: 275027
ConstantInt::getSExtValue may fail on >64-bit integers. Add checks to call
getSExtValue only on narrow integers.
As a minor aside, simplify slsr-gep.ll to remove unnecessary load instructions.
llvm-svn: 274982
While here move simplifyLoop() function to the new header, as
suggested by Chandler in the review.
Differential Revision: http://reviews.llvm.org/D21404
llvm-svn: 274959
Summary:
This way the metadata will be only generated when asserts enabled,
or when -enable-import-metadata specified
FIXED missing colon on requires.
Reviewers: tejohnson, eraman, mehdi_amini
Subscribers: mehdi_amini, llvm-commits
Differential Revision: http://reviews.llvm.org/D22167
llvm-svn: 274947
Summary:
This way the metadata will be only generated when asserts enabled,
or when -enable-import-metadata specified
Reviewers: tejohnson, eraman, mehdi_amini
Subscribers: mehdi_amini, llvm-commits
Differential Revision: http://reviews.llvm.org/D22167
llvm-svn: 274938
This isn't a sure thing (are 2 extra bitcasts less expensive than a logic op?),
but we'll try to err on the conservative side by going with the case that has
less IR instructions.
Note: This question came up in http://reviews.llvm.org/D22114 , but this part is
independent of that patch proposal, so I'm making this small change ahead of that
one.
See also:
http://reviews.llvm.org/rL274926
llvm-svn: 274932
Summary: As we will move to use uniformed hotness check in inliner, we do not need inline hints in SampleProfile pass any more.
Reviewers: dnovillo, davidxl
Subscribers: eraman, llvm-commits
Differential Revision: http://reviews.llvm.org/D19287
llvm-svn: 274918
This should be slightly more efficient and could avoid spurious overdefined
markings, as Eli pointed out.
Differential Revision: http://reviews.llvm.org/D22122
llvm-svn: 274905
We can fold truncs whose operand feeds from a load, if the trunc value
is available through a prior load/store.
This change is from: http://reviews.llvm.org/D21246, which folded the
trunc but missed the bitcast or ptrtoint/inttoptr required in the RAUW
call, when the load type didnt match the prior load/store type.
Differential Revision: http://reviews.llvm.org/D21791
llvm-svn: 274853
As discussed on D22106, improve the testing for constant folding sse scalar conversion intrinsics to ensure we are correctly handling special/out of range cases
llvm-svn: 274846
We can remove dead stores in the presence of fence instructions. Fence
does not change an otherwise thread local store to visible.
reviewers: reames, dexonsmith, jfb
Differential Revision: http://reviews.llvm.org/D22001
llvm-svn: 274795
By replacing dyn_cast of ConstantInt with m_Zero/m_One/m_AllOnes, we
allow these transforms for splat vectors.
Differential Revision: http://reviews.llvm.org/D21899
llvm-svn: 274696
Added metadata to be able to make statistics on how many functions
that have been imported have been removed. Also module name might
be helpfull when debugging.
Reviewers: tejohnson, eraman
Subscribers: mehdi_amini, llvm-commits
Differential Revision: http://reviews.llvm.org/D21943
llvm-svn: 274668
The dse_with_dbg_value.ll test committed with r273141 is removed because this
we no longer performs any type of back tracking, which is what was causing the
codegen differences with and without debug information.
Differential Revision: http://reviews.llvm.org/D21613
llvm-svn: 274660
We were still crashing in the "no change" case because LVI was not
getting invalidated.
See the thread "Should analyses be able to hold AssertingVH to IR?
(related to PR28400)" for more discussion.
llvm-svn: 274656
The cost model should not assume vector casts get completely scalarized, since
on targets that have vector support, the common case is a partial split up to
the legal vector size. So, when a vector cast gets split, the resulting casts
end up legal and cheap.
Instead of pessimistically assuming scalarization, base TTI can use the costs
the concrete TTI provides for the split vector, plus a fudge factor to account
for the cost of the split itself. This fudge factor is currently 1 by default,
except on AMDGPU where inserts and extracts are considered free.
Differential Revision: http://reviews.llvm.org/D21251
llvm-svn: 274642
We currently always vectorize induction variables. However, if an induction
variable is only used for counting loop iterations or computing addresses with
getelementptr instructions, we don't need to do this. Vectorizing these trivial
induction variables can create vector code that is difficult to simplify later
on. This is especially true when the unroll factor is greater than one, and we
create vector arithmetic when computing step vectors. With this patch, we check
if an induction variable is only used for counting iterations or computing
addresses, and if so, scalarize the arithmetic when computing step vectors
instead. This allows for greater simplification.
This patch addresses the suboptimal pointer arithmetic sequence seen in
PR27881.
Reference: https://llvm.org/bugs/show_bug.cgi?id=27881
Differential Revision: http://reviews.llvm.org/D21620
llvm-svn: 274627
This actually uncovered a surprisingly large chain of ultimately unused
TLI args.
From what I can gather, this argument is a remnant of when
isKnownNonNull would look at the TLI directly.
The current approach seems to be that InferFunctionAttrs runs early in
the pipeline and uses TLI to annotate the TLI-dependent non-null
information as return attributes.
This also removes the dependence of functionattrs on TLI altogether.
llvm-svn: 274455
Summary:
GetBoundryInstruction returns the last instruction as the instruction which follows or end(). Otherwise the last instruction in the boundry set is not being tested by isVectorizable().
Partially solve reordering of instructions. More extensive solution to follow.
Reviewers: tstellarAMD, llvm-commits, jlebar
Subscribers: escha, arsenm, mzolotukhin
Differential Revision: http://reviews.llvm.org/D21934
llvm-svn: 274389
integer.
Fixes issues on some architectures where we use arithmetic ops to build
vectors, which can cause bad things to happen for loads/stores of mixed
types.
Patch by Fiona Glaser
llvm-svn: 274307
This pass hoists duplicated computations in the program. The primary goal of
gvn-hoist is to reduce the size of functions before inline heuristics to reduce
the total cost of function inlining.
Pass written by Sebastian Pop, Aditya Kumar, Xiaoyu Hu, and Brian Rzycki.
Important algorithmic contributions by Daniel Berlin under the form of reviews.
Differential Revision: http://reviews.llvm.org/D19338
llvm-svn: 274305
Except the seed uniform instructions (conditional branch and consecutive ptr
instructions), dependencies to be added into uniform set should only be used
by existing uniform instructions or intructions outside of current loop.
Differential Revision: http://reviews.llvm.org/D21755
llvm-svn: 274262
Summary:
Found cases where DSE incorrectly add partially-overwritten intervals.
Please see the test case for details.
Reviewers: mcrosier, eeckstein, hfinkel
Subscribers: mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D21859
llvm-svn: 274237
This is a fix for PR27842.
An IR-level implementation of stack coloring tailored to work with
SafeStack. It is a bit weaker than the MI implementation in that it
does not the "lifetime start at first access" logic. This can be
improved in the future.
This patch also replaces the naive implementation of stack frame
layout with a greedy algorithm that can split existing stack slots
and even fit small objects inside the alignment padding of other
objects.
llvm-svn: 274162
Summary: This adds tests for covering all cases that FoldAndOfFCmps and FoldOrOfFCmps handle.
Reviewers: spatel
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D21844
llvm-svn: 274144
This is breaking an optimizaton remark test in clang. I've identified a couple fixes for that, but want to understand it better before I commit to anything.
llvm-svn: 274102
If a operation for a recurrence is an addition with no signed wrap and both input sign bits are 0, then the result sign bit must also be 0. Similar for the negative case.
I found this deficiency while playing around with a loop in the x86 backend that contained a signed division that could be optimized into an unsigned division if we could prove both inputs were positive. One of them being the loop induction variable. With this patch we can perform the conversion for this case. One of the test cases here is a contrived variation of the loop I was looking at.
Differential revision: http://reviews.llvm.org/D21493
llvm-svn: 274098
Revert "[InstCombine] Combine A->B->A BitCast"
as this appears to cause PR27996 and as discussed in http://reviews.llvm.org/D20847
This reverts commits r270135 and r263734.
llvm-svn: 274094
Summary:
This fixes bug: https://llvm.org/bugs/show_bug.cgi?id=28282
Currently the cost model of constant hoisting checks the bit width of the data type of the constants.
However, the actual immediate value is small enough and not need to be hoisted.
This patch checks for the actual bit width needed for the constant.
Reviewers: t.p.northover, rengolin
Subscribers: aemerson, rengolin, llvm-commits
Differential Revision: http://reviews.llvm.org/D21668
llvm-svn: 274073
This is a resubmittion of 263158 change after fixing the existing problem with intrinsics mangling (see LTO and intrinsics mangling llvm-dev thread for details).
This patch fixes the problem which occurs when loop-vectorize tries to use @llvm.masked.load/store intrinsic for a non-default addrspace pointer. It fails with "Calling a function with a bad signature!" assertion in CallInst constructor because it tries to pass a non-default addrspace pointer to the pointer argument which has default addrspace.
The fix is to add pointer type as another overloaded type to @llvm.masked.load/store intrinsics.
Reviewed By: reames
Differential Revision: http://reviews.llvm.org/D17270
llvm-svn: 274043
If the load is conditional we can't hoist its 0-iteration instance to
the preheader because that would make it unconditional. Thus we would
access a memory location that the original loop did not access.
llvm-svn: 273991
This is a resubmittion of 263158 change after fixing the existing problem with intrinsics mangling (see LTO and intrinsics mangling llvm-dev thread for details).
This patch fixes the problem which occurs when loop-vectorize tries to use @llvm.masked.load/store intrinsic for a non-default addrspace pointer. It fails with "Calling a function with a bad signature!" assertion in CallInst constructor because it tries to pass a non-default addrspace pointer to the pointer argument which has default addrspace.
The fix is to add pointer type as another overloaded type to @llvm.masked.load/store intrinsics.
Reviewed By: reames
Differential Revision: http://reviews.llvm.org/D17270
llvm-svn: 273892
It did not handle correctly cases without GEP.
The following loop wasn't vectorized:
for (int i=0; i<len; i++)
*to++ = *from++;
I use getPtrStride() to find Stride for memory access and return 0 is the Stride is not 1 or -1.
Re-commit rL273257 - revision: http://reviews.llvm.org/D20789
llvm-svn: 273864
Summary:
This is a straightforward extension of what LoopUnswitch does to
branches to guards. That is, we unswitch
```
for (;;) {
...
guard(loop_invariant_cond);
...
}
```
into
```
if (loop_invariant_cond) {
for (;;) {
...
// There is no need to emit guard(true)
...
}
} else {
for (;;) {
...
guard(false);
// SimplifyCFG will clean this up by adding an
// unreachable after the guard(false)
...
}
}
```
Reviewers: majnemer
Subscribers: mcrosier, llvm-commits, mzolotukhin
Differential Revision: http://reviews.llvm.org/D21725
llvm-svn: 273801
SimplifyCFG had logic to insert calls to llvm.trap for two very
particular IR patterns: stores and invokes of undef/null.
While InstCombine canonicalizes certain undefined behavior IR patterns
to stores of undef, phase ordering means that this cannot be relied upon
in general.
There are much better tools than llvm.trap: UBSan and ASan.
N.B. I could be argued into reverting this change if a clear argument as
to why it is important that we synthesize llvm.trap for stores, I'd be
hard pressed to see why it'd be useful for invokes...
llvm-svn: 273778
There are two separate issues:
- LLVM doesn't consider infinite loops to be side effects: we happily
hoist/sink above/below loops whose bounds are unknown.
- The absence of the noreturn attribute is insufficient for us to know
if a function will definitely return. Relying on noreturn in the
middle-end for any property is an accident waiting to happen.
llvm-svn: 273762
This intrinsic safely loads a function pointer from a virtual table pointer
using type metadata. This intrinsic is used to implement control flow integrity
in conjunction with virtual call optimization. The virtual call optimization
pass will optimize away llvm.type.checked.load intrinsics associated with
devirtualized calls, thereby removing the type check in cases where it is
not needed to enforce the control flow integrity constraint.
This patch also introduces the capability to copy type metadata between
global variables, and teaches the virtual call optimization pass to do so.
Differential Revision: http://reviews.llvm.org/D21121
llvm-svn: 273756
r273711 was reverted by r273743. The inliner needs to know about any
call sites in the inlined function. These were obscured if we replaced
a call to undef with an undef but kept the call around.
This fixes PR28298.
llvm-svn: 273753
Summary: Set ProfileSummary in SampleProfilerLoader.
Reviewers: davidxl, eraman
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D21702
llvm-svn: 273745
The bitset metadata currently used in LLVM has a few problems:
1. It has the wrong name. The name "bitset" refers to an implementation
detail of one use of the metadata (i.e. its original use case, CFI).
This makes it harder to understand, as the name makes no sense in the
context of virtual call optimization.
2. It is represented using a global named metadata node, rather than
being directly associated with a global. This makes it harder to
manipulate the metadata when rebuilding global variables, summarise it
as part of ThinLTO and drop unused metadata when associated globals are
dropped. For this reason, CFI does not currently work correctly when
both CFI and vcall opt are enabled, as vcall opt needs to rebuild vtable
globals, and fails to associate metadata with the rebuilt globals. As I
understand it, the same problem could also affect ASan, which rebuilds
globals with a red zone.
This patch solves both of those problems in the following way:
1. Rename the metadata to "type metadata". This new name reflects how
the metadata is currently being used (i.e. to represent type information
for CFI and vtable opt). The new name is reflected in the name for the
associated intrinsic (llvm.type.test) and pass (LowerTypeTests).
2. Attach metadata directly to the globals that it pertains to, rather
than using the "llvm.bitsets" global metadata node as we are doing now.
This is done using the newly introduced capability to attach
metadata to global variables (r271348 and r271358).
See also: http://lists.llvm.org/pipermail/llvm-dev/2016-June/100462.html
Differential Revision: http://reviews.llvm.org/D21053
llvm-svn: 273729
By putting all the possible commutations together, we simplify the code.
Note that this is NFCI, but I'm adding tests that actually exercise each
commutation pattern because we don't have this anywhere else.
llvm-svn: 273702
The interleaved access analysis currently assumes that the inserted run-time
pointer aliasing checks ensure the absence of dependences that would prevent
its instruction reordering. However, this is not the case.
Issues can arise from how code generation is performed for interleaved groups.
For a load group, all loads in the group are essentially moved to the location
of the first load in program order, and for a store group, all stores in the
group are moved to the location of the last store. For groups having members
involved in a dependence relation with any other instruction in the loop, this
reordering can violate the dependence.
This patch teaches the interleaved access analysis how to avoid breaking such
dependences, and should fix PR27626.
An assumption of the original analysis was that the accesses had been collected
in "program order". The analysis was then simplified by visiting the accesses
bottom-up. However, this ordering was never guaranteed for anything other than
single basic block loops. Thus, this patch also enforces the desired ordering.
Reference: https://llvm.org/bugs/show_bug.cgi?id=27626
Differential Revision: http://reviews.llvm.org/D19984
llvm-svn: 273687
reduce the number of comparisons.
Specifically, InstCombine can turn:
(i == 5334 || i == 5335)
into:
((i | 1) == 5335)
SimplifyCFG was already able to detect the pattern:
(i == 5334 || i == 5335)
to:
((i & -2) == 5334)
This patch supersedes D21315 and resolves PR27555
(https://llvm.org/bugs/show_bug.cgi?id=27555).
Thanks to David and Chandler for the suggestions!
Author: Thomas Jablin (tjablin)
Reviewers: majnemer chandlerc halfdan cycheng
http://reviews.llvm.org/D21397
llvm-svn: 273639
Summary:
This instcombine rule folds away trunc operations that have value available from a prior load or store.
This kind of code can be generated as a result of GVN widening the load or from source code as well.
Reviewers: reames, majnemer, sanjoy
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D21246
llvm-svn: 273608
When simplifying a load we need to make sure that the type of the
simplified value matches the type of the instruction we're processing.
In theory, we can handle casts here as we deal with constant data, but
since it's not implemented at the moment, we at least need to bail out.
This fixes PR28262.
llvm-svn: 273562
DeadStoreElimination can currently remove a small store rendered unnecessary by
a later larger one, but could not remove a larger store rendered unnecessary by
a series of later smaller ones. This adds that capability.
It works by keeping a map, which is used as an effective interval map, for each
store later overwritten only partially, and filling in that interval map as
more such stores are discovered. No additional walking or aliasing queries are
used. In the map forms an interval covering the the entire earlier store, then
it is dead and can be removed. The map is used as an interval map by storing a
mapping between the ending offset and the beginning offset of each interval.
I discovered this problem when investigating a performance issue with code like
this on PowerPC:
#include <complex>
using namespace std;
complex<float> bar(complex<float> C);
complex<float> foo(complex<float> C) {
return bar(C)*C;
}
which produces this:
define void @_Z4testSt7complexIfE(%"struct.std::complex"* noalias nocapture sret %agg.result, i64 %c.coerce) {
entry:
%ref.tmp = alloca i64, align 8
%tmpcast = bitcast i64* %ref.tmp to %"struct.std::complex"*
%c.sroa.0.0.extract.shift = lshr i64 %c.coerce, 32
%c.sroa.0.0.extract.trunc = trunc i64 %c.sroa.0.0.extract.shift to i32
%0 = bitcast i32 %c.sroa.0.0.extract.trunc to float
%c.sroa.2.0.extract.trunc = trunc i64 %c.coerce to i32
%1 = bitcast i32 %c.sroa.2.0.extract.trunc to float
call void @_Z3barSt7complexIfE(%"struct.std::complex"* nonnull sret %tmpcast, i64 %c.coerce)
%2 = bitcast %"struct.std::complex"* %agg.result to i64*
%3 = load i64, i64* %ref.tmp, align 8
store i64 %3, i64* %2, align 4 ; <--- ***** THIS SHOULD NOT BE HERE ****
%_M_value.realp.i.i = getelementptr inbounds %"struct.std::complex", %"struct.std::complex"* %agg.result, i64 0, i32 0, i32 0
%4 = lshr i64 %3, 32
%5 = trunc i64 %4 to i32
%6 = bitcast i32 %5 to float
%_M_value.imagp.i.i = getelementptr inbounds %"struct.std::complex", %"struct.std::complex"* %agg.result, i64 0, i32 0, i32 1
%7 = trunc i64 %3 to i32
%8 = bitcast i32 %7 to float
%mul_ad.i.i = fmul fast float %6, %1
%mul_bc.i.i = fmul fast float %8, %0
%mul_i.i.i = fadd fast float %mul_ad.i.i, %mul_bc.i.i
%mul_ac.i.i = fmul fast float %6, %0
%mul_bd.i.i = fmul fast float %8, %1
%mul_r.i.i = fsub fast float %mul_ac.i.i, %mul_bd.i.i
store float %mul_r.i.i, float* %_M_value.realp.i.i, align 4
store float %mul_i.i.i, float* %_M_value.imagp.i.i, align 4
ret void
}
the problem here is not just that the i64 store is unnecessary, but also that
it blocks further backend optimizations of the other uses of that i64 value in
the backend.
In the future, we might want to add a special case for handling smaller
accesses (e.g. using a bit vector) if the map mechanism turns out to be
noticeably inefficient. A sorted vector is also a possible replacement for the
map for small numbers of tracked intervals.
Differential Revision: http://reviews.llvm.org/D18586
llvm-svn: 273559
This is similar to the computeKnownBits improvement in rL268479.
There's probably more we can do for vector logic instructions, but
this should let us see non-splat constant masking ops that can
become vector selects instead of and/andn/or sequences.
Differential Revision: http://reviews.llvm.org/D21610
llvm-svn: 273459
We no longer have corresponding code in autoupgrade and the vast majority of the tests were fixed long time ago. Fix the remaining few. One of the verifier test cases is marked as XFAIL because it was passing only because the signature was incorrect.
llvm-svn: 273428
It did not handle correctly cases without GEP.
The following loop wasn't vectorized:
for (int i=0; i<len; i++)
*to++ = *from++;
I use getPtrStride() to find Stride for memory access and return 0 is the Stride is not 1 or -1.
Differential revision: http://reviews.llvm.org/D20789
llvm-svn: 273257
The BSWAP of vector types is quite efficiently implemented using vector shuffles on SSE/AVX targets, we should reflect the typical cost of this to encourage vectorization.
Differential Revision: http://reviews.llvm.org/D21521
llvm-svn: 273217
By moving this transform to InstSimplify from InstCombine, we sidestep the problem/question
raised by PR27869:
https://llvm.org/bugs/show_bug.cgi?id=27869
...where InstCombine turns an icmp+zext into a shift causing us to miss the fold.
Credit to David Majnemer for a draft patch of the changes to InstructionSimplify.cpp.
Differential Revision: http://reviews.llvm.org/D21512
llvm-svn: 273200
Summary: Inliner needs ACT when calling InlineFunction. Instead of nullptr, we need to pass it in from SampleProfileLoader
Reviewers: davidxl
Subscribers: eraman, vsk, danielcdh, llvm-commits
Differential Revision: http://reviews.llvm.org/D21205
llvm-svn: 273199
This reverts commit r273160, reapplying r273132.
RecursivelyDeleteTriviallyDeadInstructions cannot be called on a
parentless Instruction.
llvm-svn: 273162
This reverts commit r273132.
Breaks multiple test under /llvm/test:Transforms (e.g.
llvm/test:Transforms/LoopIdiom/basic.ll.test) under asan.
llvm-svn: 273160
After a store has been eliminated, when making sure that the
instruction iterator points to a valid instruction, dbg intrinsics are
now ignored as a new instruction.
Patch by Henric Karlsson.
Reviewed by Daniel Berlin.
Differential Revision: http://reviews.llvm.org/D21076
llvm-svn: 273141
Removing dead instructions requires remembering which operands have
already been removed. RecursivelyDeleteTriviallyDeadInstructions has
this logic, don't partially reimplement it in LoopIdiomRecognize.
This fixes PR28196.
llvm-svn: 273132
Change the underlying offset and comparisons to use int64_t instead of
uint64_t.
Patch by River Riddle!
Differential Revision: http://reviews.llvm.org/D21499
llvm-svn: 273105
The way we elide max expressions when computing trip counts is incorrect
-- it breaks cases like this:
```
static int wrapping_add(int a, int b) {
return (int)((unsigned)a + (unsigned)b);
}
void test() {
volatile int end_buf = 2147483548; // INT_MIN - 100
int end = end_buf;
unsigned counter = 0;
for (int start = wrapping_add(end, 200); start < end; start++)
counter++;
print(counter);
}
```
Note: the `NoWrap` variable that was being tested has little to do with
the values flowing into the max expression; it is a property of the
induction variable.
test/Transforms/LoopUnroll/nsw-tripcount.ll was added to solely test
functionality I'm reverting in this change, so I've deleted the test
fully.
llvm-svn: 273079
This is a functional change for LLE and LDist. The other clients (LV,
LVerLICM) already had this explicitly enabled.
The temporary boolean parameter to LAA is removed that allowed turning
off speculation of symbolic strides. This makes LAA's caching interface
LAA::getInfo only take the loop as the parameter. This makes the
interface more friendly to the new Pass Manager.
The flag -enable-mem-access-versioning is moved from LV to a LAA which
now allows turning off speculation globally.
llvm-svn: 273064
This is indeed a much cleaner approach (thanks to Daniel Berlin
for pointing out), and also David/Sean for review.
Differential Revision: http://reviews.llvm.org/D21454
llvm-svn: 273032
Many CPUs only have the ability to do a 4-byte cmpxchg (or ll/sc), not 1
or 2-byte. For those, you need to mask and shift the 1 or 2 byte values
appropriately to use the 4-byte instruction.
This change adds support for cmpxchg-based instruction sets (only SPARC,
in LLVM). The support can be extended for LL/SC-based PPC and MIPS in
the future, supplanting the ISel expansions those architectures
currently use.
Tests added for the IR transform and SPARCv9.
Differential Revision: http://reviews.llvm.org/D21029
llvm-svn: 273025
The motivating example for this transform is similar to D20774 where bitcasts interfere
with a single cmp/select sequence, but in this case we have 2 uses of each bitcast to
produce min and max ops:
define void @minmax_bc_store(<4 x float> %a, <4 x float> %b, <4 x float>* %ptr1, <4 x float>* %ptr2) {
%cmp = fcmp olt <4 x float> %a, %b
%bc1 = bitcast <4 x float> %a to <4 x i32>
%bc2 = bitcast <4 x float> %b to <4 x i32>
%sel1 = select <4 x i1> %cmp, <4 x i32> %bc1, <4 x i32> %bc2
%sel2 = select <4 x i1> %cmp, <4 x i32> %bc2, <4 x i32> %bc1
%bc3 = bitcast <4 x float>* %ptr1 to <4 x i32>*
store <4 x i32> %sel1, <4 x i32>* %bc3
%bc4 = bitcast <4 x float>* %ptr2 to <4 x i32>*
store <4 x i32> %sel2, <4 x i32>* %bc4
ret void
}
With this patch, we move the selects up to use the input args which allows getting rid of
all of the bitcasts:
define void @minmax_bc_store(<4 x float> %a, <4 x float> %b, <4 x float>* %ptr1, <4 x float>* %ptr2) {
%cmp = fcmp olt <4 x float> %a, %b
%sel1.v = select <4 x i1> %cmp, <4 x float> %a, <4 x float> %b
%sel2.v = select <4 x i1> %cmp, <4 x float> %b, <4 x float> %a
store <4 x float> %sel1.v, <4 x float>* %ptr1, align 16
store <4 x float> %sel2.v, <4 x float>* %ptr2, align 16
ret void
}
The asm for x86 SSE then improves from:
movaps %xmm0, %xmm2
cmpltps %xmm1, %xmm2
movaps %xmm2, %xmm3
andnps %xmm1, %xmm3
movaps %xmm2, %xmm4
andnps %xmm0, %xmm4
andps %xmm2, %xmm0
orps %xmm3, %xmm0
andps %xmm1, %xmm2
orps %xmm4, %xmm2
movaps %xmm0, (%rdi)
movaps %xmm2, (%rsi)
To:
movaps %xmm0, %xmm2
minps %xmm1, %xmm2
maxps %xmm0, %xmm1
movaps %xmm2, (%rdi)
movaps %xmm1, (%rsi)
The TODO comments show that we're limiting this transform only to vectors and only to bitcasts
because we need to improve other transforms or risk creating worse codegen.
Differential Revision: http://reviews.llvm.org/D21190
llvm-svn: 273011
This is a fix for PR27844.
When replacing uses of unsafe allocas, emit the new location
immediately after each use. Without this, the pointer stays live from
the function entry to the last use, while it's usually cheaper to
recalculate.
llvm-svn: 272969
When moving unsafe allocas to the unsafe stack, dbg.declare intrinsics are
updated to refer to the new location.
This change does the same to dbg.value intrinsics.
llvm-svn: 272968
Redundant invariant loads can be CSE'ed with very little extra effort
over what early-cse already tracks, so it looks reasonable to make
early-cse handle this case.
llvm-svn: 272954
This test checks that the string 'bar' (no quotes) doesn't exist in the
output after running opt. But opt embeds the absolute path to the
filename, and on my machine, the filename contains the string 'jlebar',
causing the test to fail.
This patch changes the test to look for the string '"bar"' instead.
llvm-svn: 272941
Daniel Berlin expressed some real concerns about the port and proposed
and alternative approach. I'll revert this for now while working on a
new patch, which I hope to put up for review shortly. Sorry for the churn.
llvm-svn: 272925
This is currently only performed in the Vectorizer. I will change this
as symbolic stride collection is moved to LAA.
This test will track when the actual functional change occurs.
llvm-svn: 272918
We should update results of the BranchProbabilityInfo after removing block in JumpThreading. Otherwise
we will get dangling pointer inside BranchProbabilityInfo cache.
Differential Revision: http://reviews.llvm.org/D20957
llvm-svn: 272891
Added checks to make sure the Scalarizer::transferMetadata() don't
remove valid debug locations from instructions. This is important as
the verifier pass require that e.g. inlinable callsites have a valid
debug location.
https://llvm.org/bugs/show_bug.cgi?id=27938
Patch by Karl-Johan Karlsson
Reviewers: dblaikie
Differential Revision: http://reviews.llvm.org/D20807
llvm-svn: 272884
(i == 5334 || i == 5335)
to:
((i & -2) == 5334)
This transformation has some incorrect side conditions. Specifically, the
transformation is only applied when the right-hand side constant (5334 in
the example) is a power of two not equal and not equal to the negated mask.
These side conditions were added in r258904 to fix PR26323. The correct side
condition is that: ((Constant & Mask) == Constant)[(5334 & -2) == 5334].
It's a little bit hard to see why these transformations are correct and what
the side conditions ought to be. Here is a CVC3 program to verify them for
64-bit values:
ONE : BITVECTOR(64) = BVZEROEXTEND(0bin1, 63);
x : BITVECTOR(64);
y : BITVECTOR(64);
z : BITVECTOR(64);
mask : BITVECTOR(64) = BVSHL(ONE, z);
QUERY( (y & ~mask = y) =>
((x & ~mask = y) <=> (x = y OR x = (y | mask)))
);
Please note that each pattern must be a dual implication (<--> or iff). One
directional implication can create spurious matches. If the implication is
only one-way, an unsatisfiable condition on the left side can imply a
satisfiable condition on the right side. Dual implication ensures that
satisfiable conditions are transformed to other satisfiable conditions and
unsatisfiable conditions are transformed to other unsatisfiable conditions.
Here is a concrete example of a unsatisfiable condition on the left
implying a satisfiable condition on the right:
mask = (1 << z)
(x & ~mask) == y --> (x == y || x == (y | mask))
Substituting y = 3, z = 0 yields:
(x & -2) == 3 --> (x == 3 || x == 2)
The version of this code before r258904 had no side-conditions and
incorrectly justified itself in comments through one-directional
implication.
Thanks to Chandler for the suggestion!
Author: Thomas Jablin (tjablin)
Reviewers: chandlerc majnemer hfinkel cycheng
http://reviews.llvm.org/D21417
llvm-svn: 272873
We would fail to validate the type of the tan function which would cause
downstream users of isValidProtoForLibFunc to assert.
This fixes PR28143.
llvm-svn: 272802
This uses the "runImpl" approach to share code with the old PM.
Porting to the new PM meant abandoning the anonymous namespace enclosing
most of SLPVectorizer.cpp which is a bit of a bummer (but not a big deal
compared to having to pull the pass class into a header which the new PM
requires since it calls the constructor directly).
llvm-svn: 272766
r272715 broke libcxx because it did not correctly handle cases where the
last iteration of one IV is the second-to-last iteration of another.
Original commit message:
Vectorizing loops with "escaping" IVs has been disabled since r190790, due to
PR17179. This re-enables it, with support for external use of both
"post-increment" (last iteration) and "pre-increment" (second-to-last iteration)
IVs.
llvm-svn: 272742
We do not support splitting cleanuppad or catchswitches. This is
problematic for passes which assume that a loop is in loop simplify
form (the loop would have a dedicated exit block instead of sharing it).
While it isn't great that we don't support this for cleanups, we still
cannot make loop-simplify form an assertable precondition because
indirectbr will also disable these sorts of CFG cleanups.
This fixes PR28132.
llvm-svn: 272739
Nearly all the changes to this pass have been done while maintaining and
updating other parts of LLVM. LLVM has had another pass, SROA, which
has superseded ScalarReplAggregates for quite some time.
Differential Revision: http://reviews.llvm.org/D21316
llvm-svn: 272737
Vectorizing loops with "escaping" IVs has been disabled since r190790, due to
PR17179. This re-enables it, with support for external use of both
"post-increment" (last iteration) and "pre-increment" (second-to-last iteration)
IVs.
Differential Revision: http://reviews.llvm.org/D21048
llvm-svn: 272715
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.
This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
the normal rule that the global must have a unique address can be broken without
being observable by the program by performing comparisons against the global's
address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
its own copy of the global if it requires one, and the copy in each linkage unit
must be the same)
- It is a constant or a function (which means that the program cannot observe that
the unique-address rule has been broken by writing to the global)
Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.
See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.htmlhttp://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.
Part of the fix for PR27553.
Differential Revision: http://reviews.llvm.org/D20348
llvm-svn: 272709
This change teaches llvm::isGuaranteedToTransferExecutionToSuccessor
that calls to @llvm.assume always terminate. Most other relevant
intrinsics should be covered by the "CS.onlyReadsMemory() ||
CS.onlyAccessesArgMemory()" bit but we were missing @llvm.assumes
because we state that it clobbers memory.
Added an LICM test case, but this change is not specific to LICM.
llvm-svn: 272703
We only used to add the edge from the cloned loop to PHIs that
corresponded to values defined by the loop. We need to do this for all
PHIs obviously since we need a PHI operand for each incoming edge.
This includes things like PHIs with a constant value or with values
defined before the original loop (see the testcases).
After the patch the PHIs are added to the exit block in two passes.
In the first pass we ensure there is a single-operand (LCSSA) PHI for
each value defined by the loop.
In the second pass we loop through each (single-operand) PHI and add the
value for the edge from the cloned loop. If the value is defined in the
loop we'll use the cloned instruction from the cloned loop.
Fixes PR28037
llvm-svn: 272649
The need for all these Lookup* functions is just because of calls to
getAnalysis inside methods (i.e. not at the top level) of the
runOnFunction method. They should be straightforward to clean up when
the old PM is gone.
llvm-svn: 272615
This reverts commit r272603 and adds a fix.
Big thanks to Davide for pointing me at r216244 which gives some insight
into how to fix this VS2013 issue. VS2013 can't synthesize a move
constructor. So the fix here is to add one explicitly to the
JumpThreadingPass class.
llvm-svn: 272607
Sanjay Patel