- provide more extensive set of functions to detect library allocation functions (e.g., malloc, calloc, strdup, etc)
- provide an API to compute the size and offset of an object pointed by
Move a few clients (GVN, AA, instcombine, ...) to the new API.
This implementation is a lot more aggressive than each of the custom implementations being replaced.
Patch reviewed by Nick Lewycky and Chandler Carruth, thanks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158919 91177308-0d34-0410-b5e6-96231b3b80d8
The present implementation handles only TBAA and FP metadata, discarding everything else.
For debug metadata, the current behavior is maintained (the debug metadata associated with
one of the instructions will be kept, discarding that attached to the other).
This should address PR 13040.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158606 91177308-0d34-0410-b5e6-96231b3b80d8
Dynamic GEPs created by SROA needed to insert extra "i32 0"
operands to index through structs and arrays to get to the
vector being indexed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158590 91177308-0d34-0410-b5e6-96231b3b80d8
linkonce linkage. For example, it is not valid to add unnamed_addr.
This also fixes a crash in g++.dg/opt/static5.C.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158528 91177308-0d34-0410-b5e6-96231b3b80d8
example degenerate phi nodes and binops that use themselves in unreachable code.
Thanks to Charles Davis for the testcase that uncovered this can of worms.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158508 91177308-0d34-0410-b5e6-96231b3b80d8
This patch extends FoldBranchToCommonDest to fold unconditional branches.
For unconditional branches, we fold them if it is easy to update the phi nodes
in the common successors.
rdar://10554090
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158392 91177308-0d34-0410-b5e6-96231b3b80d8
POD type, causing memory corruption when mapping to APInts with bitwidth > 64.
Merge another crash testcase into crash.ll while there.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158369 91177308-0d34-0410-b5e6-96231b3b80d8
topologies, it is quite possible for a leaf node to have huge multiplicity, for
example: x0 = x*x, x1 = x0*x0, x2 = x1*x1, ... rapidly gives a value which is x
raised to a vast power (the multiplicity, or weight, of x). This patch fixes
the computation of weights by correctly computing them no matter how big they
are, rather than just overflowing and getting a wrong value. It turns out that
the weight for a value never needs more bits to represent than the value itself,
so it is enough to represent weights as APInts of the same bitwidth and do the
right overflow-avoiding dance steps when computing weights. As a side-effect it
reduces the number of multiplies needed in some cases of large powers. While
there, in view of external uses (eg by the vectorizer) I made LinearizeExprTree
static, pushing the rank computation out into users. This is progress towards
fixing PR13021.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158358 91177308-0d34-0410-b5e6-96231b3b80d8
This saves a cast, and zext is more expensive on platforms with subreg support
than trunc is. This occurs in the BSD implementation of memchr(3), see PR12750.
On the synthetic benchmark from that bug stupid_memchr and bsd_memchr have the
same performance now when not inlining either function.
stupid_memchr: 323.0us
bsd_memchr: 321.0us
memchr: 479.0us
where memchr is the llvm-gcc compiled bsd_memchr from osx lion's libc. When
inlining is enabled bsd_memchr still regresses down to llvm-gcc memchr time,
I haven't fully understood the issue yet, something is grossly mangling the
loop after inlining.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158297 91177308-0d34-0410-b5e6-96231b3b80d8
-%a + 42
into
42 - %a
previously we were emitting:
-(%a + 42)
This fixes the infinite loop in PR12338. The generated code is still not perfect, though.
Will work on that next
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158237 91177308-0d34-0410-b5e6-96231b3b80d8
can move instructions within the instruction list. If the instruction just
happens to be the one the basic block iterator is pointing to, and it is
moved to a different basic block, then we get into an infinite loop due to
the iterator running off the end of the basic block (for some reason this
doesn't fire any assertions). Original commit message:
Grab-bag of reassociate tweaks. Unify handling of dead instructions and
instructions to reoptimize. Exploit this to more systematically eliminate
dead instructions (this isn't very useful in practice but is convenient for
analysing some testcase I am working on). No need for WeakVH any more: use
an AssertingVH instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158199 91177308-0d34-0410-b5e6-96231b3b80d8
instructions to reoptimize. Exploit this to more systematically eliminate
dead instructions (this isn't very useful in practice but is convenient for
analysing some testcase I am working on). No need for WeakVH any more: use
an AssertingVH instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158073 91177308-0d34-0410-b5e6-96231b3b80d8
replacement to make it at least as generic as the instruction being replaced.
This includes:
* dropping nsw/nuw flags
* getting the least restrictive tbaa and fpmath metadata
* merging ranges
Fixes PR12979.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157958 91177308-0d34-0410-b5e6-96231b3b80d8
add regression tests for this problem.
Can already compile & run: PHP, PCRE, and ICU (i.e., all the software I tried)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157822 91177308-0d34-0410-b5e6-96231b3b80d8
- compute size & offset at the same time. The side-effects of this are that we now support negative GEPs. It's now approaching a phase that it can be reused by other passes (e.g., lowering of the objectsize intrinsic)
- use APInt throughout to handle wrap-arounds
- add support for PHI instrumentation
- add a cache (required for recursive PHIs anyway)
- remove hoisting support for now, since it was wrong in a few cases
sorry for the churn here.. tests will follow soon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157775 91177308-0d34-0410-b5e6-96231b3b80d8
This also required making recursive simplifications until
nothing changes or a hard limit (currently 3) is hit.
With the simplification in place indvars can canonicalize
loops of the form
for (unsigned i = 0; i < a-b; ++i)
into
for (unsigned i = 0; i != a-b; ++i)
which used to fail because SCEV created a weird umax expr
for the backedge taken count.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157701 91177308-0d34-0410-b5e6-96231b3b80d8
The test case feeds the following into InstCombine's visitSelect:
%tobool8 = icmp ne i32 0, 0
%phitmp = select i1 %tobool8, i32 3, i32 0
Then instcombine replaces the right side of the switch with 0, doesn't notice
that nothing changes and tries again indefinitely.
This fixes PR12897.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157587 91177308-0d34-0410-b5e6-96231b3b80d8
then it doesn't alter the instructions composing it, however it would continue
to move the instructions to just before the expression root. Ensure it doesn't
move them either, so now it really does nothing if there is nothing to do. That
commit also ensured that nsw etc flags weren't cleared if the expression was not
being changed. Tweak this a bit so that it doesn't clear flags on the initial
part of a computation either if that part didn't change but later bits did.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157518 91177308-0d34-0410-b5e6-96231b3b80d8
with arbitrary topologies (previously it would give up when hitting a diamond
in the use graph for example). The testcase from PR12764 is now reduced from
a pile of additions to the optimal 1617*%x0+208. In doing this I changed the
previous strategy of dropping all uses for expression leaves to one of dropping
all but one use. This works out more neatly (but required a bunch of tweaks)
and is also safer: some recently fixed bugs during recursive linearization were
because the linearization code thinks it completely owns a node if it has no uses
outside the expression it is linearizing. But if the node was also in another
expression that had been linearized (and thus all uses of the node from that
expression dropped) then the conclusion that it is completely owned by the
expression currently being linearized is wrong. Keeping one use from within each
linearized expression avoids this kind of mistake.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157467 91177308-0d34-0410-b5e6-96231b3b80d8
LowerSwitch::Clusterify : main functinality was replaced with CRSBuilder::optimize, so big part of Clusterify's code was reduced.
test/Transform/LowerSwitch/feature.ll - this test was refactored: grep + count was replaced with FileCheck usage.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157384 91177308-0d34-0410-b5e6-96231b3b80d8
CHECK. The latter error was hidden by the former, and the test harness
used by e.g. "make check" silently ignored that opt was printing an
error message about an unknown flag instead of running on the test file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157341 91177308-0d34-0410-b5e6-96231b3b80d8
inline threshold if the global inline threshold is lower (as for -Oz).
Reviewed by Chandler Carruth and Bill Wendling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157323 91177308-0d34-0410-b5e6-96231b3b80d8
leader table. That's because it wasn't expecting instructions to turn up as
leader for a value number that is not its own, but equality propagation could
create this situation. One solution is to have the leader table use a WeakVH
but this slows down GVN by about 5%. Instead just have equality propagation not
add instructions to the leader table, only constants and arguments. In theory
this might cause GVN to run more (each time it changes something it runs again)
but it doesn't seem to occur enough to cause a slow down.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157251 91177308-0d34-0410-b5e6-96231b3b80d8
so that it can be reused in MemCpyOptimizer. This analysis is needed to remove
an unnecessary memcpy when returning a struct into a local variable.
rdar://11341081
PR12686
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156776 91177308-0d34-0410-b5e6-96231b3b80d8
add an additional parameter to InstCombiner::EmitGEPOffset() to force it to *not* emit operations with NUW flag
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156585 91177308-0d34-0410-b5e6-96231b3b80d8
Instruction::IsIdenticalToWhenDefined.
This manifested itself when inlining two calls to the same function. The
inlined function had a switch statement that returned one of a set of
global variables. Without this modification, the two phi instructions that
chose values from the branches of the switch instruction inlined from the
callee were considered equivalent and jump-threading replaced a load for the
first switch value with a phi selecting from the second switch, thereby
producing incorrect code.
This patch has been tested with "make check-all", "lnt runteste nt", and
llvm self-hosted, and on the original program that had this problem,
wireshark.
<rdar://problem/11025519>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156548 91177308-0d34-0410-b5e6-96231b3b80d8
refactor code a bit to enable future changes to support run-time information
add support to compute allocation sizes at run-time if penalty > 1 (e.g., malloc(x), calloc(x, y), and VLAs)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156515 91177308-0d34-0410-b5e6-96231b3b80d8
replace the operands of expressions with only one use with undef and generate
a new expression for the original without using RAUW to update the original.
Thus any copies of the original expression held in a vector may end up
referring to some bogus value - and using a ValueHandle won't help since there
is no RAUW. There is already a mechanism for getting the effect of recursion
non-recursively: adding the value to be recursed on to RedoInsts. But it wasn't
being used systematically. Have various places where recursion had snuck in at
some point use the RedoInsts mechanism instead. Fixes PR12169.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156379 91177308-0d34-0410-b5e6-96231b3b80d8
<rdar://problem/11291436>.
This is a second attempt at a fix for this, the first was r155468. Thanks
to Chandler, Bob and others for the feedback that helped me improve this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155866 91177308-0d34-0410-b5e6-96231b3b80d8
Allow the "SplitCriticalEdge" function to split the edge to a landing pad. If
the pass is *sure* that it thinks it knows what it's doing, then it may go ahead
and specify that the landing pad can have its critical edge split. The loop
unswitch pass is one of these passes. It will split the critical edges of all
edges coming from a loop to a landing pad not within the loop. Doing so will
retain important loop analysis information, such as loop simplify.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155817 91177308-0d34-0410-b5e6-96231b3b80d8
Target specific types should not be vectorized. As a practical matter,
these types are already register matched (at least in the x86 case),
and codegen does not always work correctly (at least in the ppc case,
and this is not worth fixing because ppc_fp128 is currently broken and
will probably go away soon).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155729 91177308-0d34-0410-b5e6-96231b3b80d8
instead of getAggregateElement. This has the advantage of being
more consistent and allowing higher-level constant folding to
procede even if an inner extract element cannot be folded.
Make ConstantFoldInstruction call ConstantFoldConstantExpression
on the instruction's operands, making it more consistent with
ConstantFoldConstantExpression itself. This makes sure that
ConstantExprs get TargetData-aware folding before being handed
off as operands for further folding.
This causes more expressions to be folded, but due to a known
shortcoming in constant folding, this currently has the side effect
of stripping a few more nuw and inbounds flags in the non-targetdata
side of constant-fold-gep.ll. This is mostly harmless.
This fixes rdar://11324230.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155682 91177308-0d34-0410-b5e6-96231b3b80d8
elements to minimize the number of multiplies required to compute the
final result. This uses a heuristic to attempt to form near-optimal
binary exponentiation-style multiply chains. While there are some cases
it misses, it seems to at least a decent job on a very diverse range of
inputs.
Initial benchmarks show no interesting regressions, and an 8%
improvement on SPASS. Let me know if any other interesting results (in
either direction) crop up!
Credit to Richard Smith for the core algorithm, and helping code the
patch itself.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155616 91177308-0d34-0410-b5e6-96231b3b80d8
constants in C++11 mode. I have no idea why it required such particular
circumstances to get here, the code seems clearly to rely upon unchecked
assumptions.
Specifically, when we decide to form an index into a struct type, we may
have gone through (at least one) zero-length array indexing round, which
would have left the offset un-adjusted, and thus not necessarily valid
for use when indexing the struct type.
This is just an canonicalization step, so the correct thing is to refuse
to canonicalize nonsensical GEPs of this form. Implemented, and test
case added.
Fixes PR12642. Pair debugged and coded with Richard Smith. =] I credit
him with most of the debugging, and preventing me from writing the wrong
code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155466 91177308-0d34-0410-b5e6-96231b3b80d8
Original commit message:
Defer some shl transforms to DAGCombine.
The shl instruction is used to represent multiplication by a constant
power of two as well as bitwise left shifts. Some InstCombine
transformations would turn an shl instruction into a bit mask operation,
making it difficult for later analysis passes to recognize the
constsnt multiplication.
Disable those shl transformations, deferring them to DAGCombine time.
An 'shl X, C' instruction is now treated mostly the same was as 'mul X, C'.
These transformations are deferred:
(X >>? C) << C --> X & (-1 << C) (When X >> C has multiple uses)
(X >>? C1) << C2 --> X << (C2-C1) & (-1 << C2) (When C2 > C1)
(X >>? C1) << C2 --> X >>? (C1-C2) & (-1 << C2) (When C1 > C2)
The corresponding exact transformations are preserved, just like
div-exact + mul:
(X >>?,exact C) << C --> X
(X >>?,exact C1) << C2 --> X << (C2-C1)
(X >>?,exact C1) << C2 --> X >>?,exact (C1-C2)
The disabled transformations could also prevent the instruction selector
from recognizing rotate patterns in hash functions and cryptographic
primitives. I have a test case for that, but it is too fragile.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155362 91177308-0d34-0410-b5e6-96231b3b80d8
1) Make the checked assertions a bit more precise. We really want the
canonical forms coming out of reassociate to be exactly what is
expected.
2) Remove other passes, and switch the test to actually directly check
that reassociate makes the important transforms and
canonicalizations.
3) Fold in a related test case now that we're using FileCheck. Make the
same tidying changes to it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155311 91177308-0d34-0410-b5e6-96231b3b80d8
While the patch was perfect and defect free, it exposed a really nasty
bug in X86 SelectionDAG that caused an llc crash when compiling lencod.
I'll put the patch back in after fixing the SelectionDAG problem.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155181 91177308-0d34-0410-b5e6-96231b3b80d8
