Commit Graph

11867 Commits

Author SHA1 Message Date
Jingyue Wu
5e49dcf79a Remove dead code in SimplifyCFG
Summary: UsedByBranch is always true according to how BonusInst is defined.

Test Plan:
Passes check-all, and also verified 

if (BonusInst && !UsedByBranch) {
  ...
}

is never entered during check-all.

Reviewers: resistor, nadav, jingyue

Reviewed By: jingyue

Subscribers: llvm-commits, eliben, meheff

Differential Revision: http://reviews.llvm.org/D5324

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217824 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-15 20:48:13 +00:00
Nick Lewycky
c2104d4856 Add control of function merging to the PMBuilder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217731 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-13 21:46:00 +00:00
Benjamin Kramer
e853a8665e Simplify code. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217726 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-13 12:38:49 +00:00
Juergen Ributzka
4be836d563 [C API] Make the 'lower switch' pass available via the C API.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217630 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-11 21:32:32 +00:00
Hal Finkel
2c1a4875e8 [AlignmentFromAssumptions] Don't crash just because the target is 32-bit
We used to crash processing any relevant @llvm.assume on a 32-bit target
(because we'd ask SE to subtract expressions of differing types). I've copied
our 'simple.ll' test, but with the data layout from arm-linux-gnueabihf to get
some meaningful test coverage here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217574 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-11 08:40:17 +00:00
Rafael Espindola
3b670550ad Add doInitialization/doFinalization to DataLayoutPass.
With this a DataLayoutPass can be reused for multiple modules.

Once we have doInitialization/doFinalization, it doesn't seem necessary to pass
a Module to the constructor.

Overall this change seems in line with the idea of making DataLayout a required
part of Module. With it the only way of having a DataLayout used is to add it
to the Module.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217548 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 21:27:43 +00:00
Hal Finkel
fb42ed2925 [AlignmentFromAssumptions] Don't divide by zero for unknown starting alignment
The routine that determines an alignment given some SCEV returns zero if the
answer is unknown. In a case where we could determine the increment of an
AddRec but not the starting alignment, we would compute the integer modulus by
zero (which is illegal and traps). Prevent this by returning early if either
the start or increment alignment is unknown (zero).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217544 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 21:05:52 +00:00
Gerolf Hoflehner
3c9c2122e1 [PassManager] Adding Hidden attribute to EnableMLSM option
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217539 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 20:24:03 +00:00
Gerolf Hoflehner
438b59883a [MergedLoadStoreMotion] Move pass enabling option to PassManagerBuilder
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217538 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 19:55:29 +00:00
Sanjay Patel
87c977a52b Rename getMaximumUnrollFactor -> getMaxInterleaveFactor; also rename option names controlling this variable.
"Unroll" is not the appropriate name for this variable. Clang already uses 
the term "interleave" in pragmas and metadata for this.

Differential Revision: http://reviews.llvm.org/D5066



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217528 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 17:58:16 +00:00
Gerolf Hoflehner
5c488f48bd Removed misleading comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217527 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 17:54:50 +00:00
Stepan Dyatkovskiy
e944e11ede MergeFunctions: FunctionPtr has been renamed to FunctionNode.
It's supposed to store additional pass information for current function here.
That was the reason for name change.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217483 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 10:08:25 +00:00
NAKAMURA Takumi
589d2fc893 SampleProfile.cpp: Prune a stray \param added in r217437. [-Wdocumentation]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217465 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-09 22:44:30 +00:00
NAKAMURA Takumi
beab873680 ScalarOpts/LLVMBuild.txt: Prune unused dependency to IPA.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217448 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-09 15:00:38 +00:00
NAKAMURA Takumi
1c47815776 ScalarOpts/LLVMBuild.txt: Reorder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217447 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-09 15:00:26 +00:00
Diego Novillo
40c949a1b4 Re-factor sample profile reader into lib/ProfileData.
Summary:
This patch moves the profile reading logic out of the Sample Profile
transformation into a generic profile reader facility in
lib/ProfileData.

The intent is to use this new reader to implement a sample profile
reader/writer that can be used to convert sample profiles from external
sources into LLVM.

This first patch introduces no functional changes. It moves the profile
reading code from lib/Transforms/SampleProfile.cpp into
lib/ProfileData/SampleProfReader.cpp.

In subsequent patches I will:

- Add a bitcode format for sample profiles to allow for more efficient
  encoding of the profile.
- Add a writer for both text and bitcode format profiles.
- Add a 'convert' command to llvm-profdata to be able to convert between
  the two (and serve as entry point for other sample profile formats).

Reviewers: bogner, echristo

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5250

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217437 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-09 12:40:50 +00:00
Andrew Trick
feae667742 Add a comment to getNewAlignmentDiff.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217350 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 23:16:24 +00:00
Hal Finkel
1c0c67a007 Check for all known bits on ret in InstCombine
From a combination of @llvm.assume calls (and perhaps through other means, such
as range metadata), it is possible that all bits of a return value might be
known. Previously, InstCombine did not check for this (which is understandable
given assumptions of constant propagation), but means that we'd miss simple
cases where assumptions are involved.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217346 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 21:28:34 +00:00
Hal Finkel
3ef1aae2b5 Make use of @llvm.assume from LazyValueInfo
This change teaches LazyValueInfo to use the @llvm.assume intrinsic. Like with
the known-bits change (r217342), this requires feeding a "context" instruction
pointer through many functions. Aside from a little refactoring to reuse the
logic that turns predicates into constant ranges in LVI, the only new code is
that which can 'merge' the range from an assumption into that otherwise
computed. There is also a small addition to JumpThreading so that it can have
LVI use assumptions in the same block as the comparison feeding a conditional
branch.

With this patch, we can now simplify this as expected:
int foo(int a) {
  __builtin_assume(a > 5);
  if (a > 3) {
    bar();
    return 1;
  }
  return 0;
}

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217345 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 20:29:59 +00:00
Hal Finkel
1d6c2d717d Add an AlignmentFromAssumptions Pass
This adds a ScalarEvolution-powered transformation that updates load, store and
memory intrinsic pointer alignments based on invariant((a+q) & b == 0)
expressions. Many of the simple cases we can get with ValueTracking, but we
still need something like this for the more complicated cases (such as those
with an offset) that require some algebra. Note that gcc's
__builtin_assume_aligned's optional third argument provides exactly for this
kind of 'misalignment' offset for which this kind of logic is necessary.

The primary motivation is to fixup alignments for vector loads/stores after
vectorization (and unrolling). This pass is added to the optimization pipeline
just after the SLP vectorizer runs (which, admittedly, does not preserve SE,
although I imagine it could).  Regardless, I actually don't think that the
preservation matters too much in this case: SE computes lazily, and this pass
won't issue any SE queries unless there are any assume intrinsics, so there
should be no real additional cost in the common case (SLP does preserve DT and
LoopInfo).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217344 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 20:05:11 +00:00
Hal Finkel
83d886db3a Add additional patterns for @llvm.assume in ValueTracking
This builds on r217342, which added the infrastructure to compute known bits
using assumptions (@llvm.assume calls). That original commit added only a few
patterns (to catch common cases related to determining pointer alignment); this
change adds several other patterns for simple cases.

r217342 contained that, for assume(v & b = a), bits in the mask
that are known to be one, we can propagate known bits from the a to v. It also
had a known-bits transfer for assume(a = b). This patch adds:

assume(~(v & b) = a) : For those bits in the mask that are known to be one, we
                       can propagate inverted known bits from the a to v.

assume(v | b = a) :    For those bits in b that are known to be zero, we can
                       propagate known bits from the a to v.

assume(~(v | b) = a):  For those bits in b that are known to be zero, we can
                       propagate inverted known bits from the a to v.

assume(v ^ b = a) :    For those bits in b that are known to be zero, we can
		       propagate known bits from the a to v. For those bits in
		       b that are known to be one, we can propagate inverted
                       known bits from the a to v.

assume(~(v ^ b) = a) : For those bits in b that are known to be zero, we can
		       propagate inverted known bits from the a to v. For those
		       bits in b that are known to be one, we can propagate
                       known bits from the a to v.

assume(v << c = a) :   For those bits in a that are known, we can propagate them
                       to known bits in v shifted to the right by c.

assume(~(v << c) = a) : For those bits in a that are known, we can propagate
                        them inverted to known bits in v shifted to the right by c.

assume(v >> c = a) :   For those bits in a that are known, we can propagate them
                       to known bits in v shifted to the right by c.

assume(~(v >> c) = a) : For those bits in a that are known, we can propagate
                        them inverted to known bits in v shifted to the right by c.

assume(v >=_s c) where c is non-negative: The sign bit of v is zero

assume(v >_s c) where c is at least -1: The sign bit of v is zero

assume(v <=_s c) where c is negative: The sign bit of v is one

assume(v <_s c) where c is non-positive: The sign bit of v is one

assume(v <=_u c): Transfer the known high zero bits

assume(v <_u c): Transfer the known high zero bits (if c is know to be a power
                 of 2, transfer one more)

A small addition to InstCombine was necessary for some of the test cases. The
problem is that when InstCombine was simplifying and, or, etc. it would fail to
check the 'do I know all of the bits' condition before checking less specific
conditions and would not fully constant-fold the result. I'm not sure how to
trigger this aside from using assumptions, so I've just included the change
here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217343 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 19:21:07 +00:00
Hal Finkel
851b04c920 Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.)
This change, which allows @llvm.assume to be used from within computeKnownBits
(and other associated functions in ValueTracking), adds some (optional)
parameters to computeKnownBits and friends. These functions now (optionally)
take a "context" instruction pointer, an AssumptionTracker pointer, and also a
DomTree pointer, and most of the changes are just to pass this new information
when it is easily available from InstSimplify, InstCombine, etc.

As explained below, the significant conceptual change is that known properties
of a value might depend on the control-flow location of the use (because we
care that the @llvm.assume dominates the use because assumptions have
control-flow dependencies). This means that, when we ask if bits are known in a
value, we might get different answers for different uses.

The significant changes are all in ValueTracking. Two main changes: First, as
with the rest of the code, new parameters need to be passed around. To make
this easier, I grouped them into a structure, and I made internal static
versions of the relevant functions that take this structure as a parameter. The
new code does as you might expect, it looks for @llvm.assume calls that make
use of the value we're trying to learn something about (often indirectly),
attempts to pattern match that expression, and uses the result if successful.
By making use of the AssumptionTracker, the process of finding @llvm.assume
calls is not expensive.

Part of the structure being passed around inside ValueTracking is a set of
already-considered @llvm.assume calls. This is to prevent a query using, for
example, the assume(a == b), to recurse on itself. The context and DT params
are used to find applicable assumptions. An assumption needs to dominate the
context instruction, or come after it deterministically. In this latter case we
only handle the specific case where both the assumption and the context
instruction are in the same block, and we need to exclude assumptions from
being used to simplify their own ephemeral values (those which contribute only
to the assumption) because otherwise the assumption would prove its feeding
comparison trivial and would be removed.

This commit adds the plumbing and the logic for a simple masked-bit propagation
(just enough to write a regression test). Future commits add more patterns
(and, correspondingly, more regression tests).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217342 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 18:57:58 +00:00
Hal Finkel
3d03d60ca8 Add functions for finding ephemeral values
This adds a set of utility functions for collecting 'ephemeral' values. These
are LLVM IR values that are used only by @llvm.assume intrinsics (directly or
indirectly), and thus will be removed prior to code generation, implying that
they should be considered free for certain purposes (like inlining). The
inliner's cost analysis, and a few other passes, have been updated to account
for ephemeral values using the provided functionality.

This functionality is important for the usability of @llvm.assume, because it
limits the "non-local" side-effects of adding llvm.assume on inlining, loop
unrolling, etc. (these are hints, and do not generate code, so they should not
directly contribute to estimates of execution cost).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217335 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 13:49:57 +00:00
Hal Finkel
3666e7f4c1 Add an Assumption-Tracking Pass
This adds an immutable pass, AssumptionTracker, which keeps a cache of
@llvm.assume call instructions within a module. It uses callback value handles
to keep stale functions and intrinsics out of the map, and it relies on any
code that creates new @llvm.assume calls to notify it of the new instructions.
The benefit is that code needing to find @llvm.assume intrinsics can do so
directly, without scanning the function, thus allowing the cost of @llvm.assume
handling to be negligible when none are present.

The current design is intended to be lightweight. We don't keep track of
anything until we need a list of assumptions in some function. The first time
this happens, we scan the function. After that, we add/remove @llvm.assume
calls from the cache in response to registration calls and ValueHandle
callbacks.

There are no new direct test cases for this pass, but because it calls it
validation function upon module finalization, we'll pick up detectable
inconsistencies from the other tests that touch @llvm.assume calls.

This pass will be used by follow-up commits that make use of @llvm.assume.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 12:44:26 +00:00
David Majnemer
163462eec8 InstCombine: Remove a special case pattern
The special case did not work when run under -reassociate and can easily
be expressed by a further generalization of an existing pattern.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217227 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-05 06:09:24 +00:00
James Molloy
1c9848f305 Enable noalias metadata by default and swap the order of the SLP and Loop vectorizers by default.
After some time maturing, hopefully the flags themselves will be removed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217144 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-04 13:23:08 +00:00
Tilmann Scheller
b4f4dd4439 [GVN] Format variable name.
Local variables need to start with an upper case letter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217133 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-04 06:38:00 +00:00
David Majnemer
e35ac41a3a IndVarSimplify: Address review comments for r217102
No functional change intended, just some cleanups and comments added.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217115 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-04 00:23:13 +00:00
Kostya Serebryany
c9b2548b23 [asan] fix debug info produced for asan-coverage=2
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217106 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-03 23:24:18 +00:00
David Majnemer
c0f2b8b528 IndVarSimplify: Don't let LFTR compare against a poison value
LinearFunctionTestReplace tries to use the *next* indvar to compare
against when possible.  However, it may be the case that the calculation
for the next indvar has NUW/NSW flags and that it may only be safely
used inside the loop.  Using it in a comparison to calculate the exit
condition could result in observing poison.

This fixes PR20680.

Differential Revision: http://reviews.llvm.org/D5174

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217102 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-03 23:03:18 +00:00
Kostya Serebryany
f12b1d8c7b [asan] add -asan-coverage=3: instrument all blocks and critical edges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217098 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-03 22:37:37 +00:00
Benjamin Kramer
f0644b42a7 Make some helpers static or move into the llvm namespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217077 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-03 21:04:12 +00:00
Sanjay Patel
b89304eb7c Preserve IR flags (nsw, nuw, exact, fast-math) in SLP vectorizer (PR20802).
The SLP vectorizer should propagate IR-level optimization hints/flags (nsw, nuw, exact, fast-math)
when converting scalar instructions into vectors. But this isn't a simple copy - we need to take
the intersection (the logical 'and') of the sets of flags on the scalars.

The solution is further complicated because we can have non-uniform (non-SIMD) vector ops after:
http://reviews.llvm.org/D4015
http://llvm.org/viewvc/llvm-project?view=revision&revision=211339

The vast majority of changed files are existing tests that were not propagating IR flags, but I've
also added a new test file for focused testing of IR flag possibilities.

Differential Revision: http://reviews.llvm.org/D5172



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217051 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-03 17:40:30 +00:00
Sanjay Patel
ae77bf49f4 Change name of copyFlags() to copyIRFlags(). Add convenience method for logical 'and' of all flags. NFC.
Adding 'IR' to the names in an attempt to be less ambiguous about the flags we're dealing with here.

The 'and' method is needed by the SLPVectorizer (PR20802) and possibly other passes.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217004 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-03 01:06:50 +00:00
Hal Finkel
e1b1cac5ad Add pass-manager flags to use CFL AA
Add -use-cfl-aa (and -use-cfl-aa-in-codegen) to add CFL AA in the default pass
managers (for easy testing).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216978 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 22:12:54 +00:00
Kostya Serebryany
891198b358 [asan] Assign a low branch weight to ASan's slow path, patch by Jonas Wagner. This speeds up asan (at least on SPEC) by 1%-5% or more. Also fix lint in dfsan.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216972 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 21:46:51 +00:00
Yi Jiang
cb2522448c Generate extract for in-tree uses if the use is scalar operand in vectorized instruction. radar://18144665
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216946 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 21:00:39 +00:00
David Blaikie
7b96c4919a unique_ptrify the result of SpecialCaseList::create
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216925 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 18:13:54 +00:00
David Majnemer
9e1f653e2f LICM: Don't crash when an instruction is used by an unreachable BB
Summary:
BBs might contain non-LCSSA'd values after the LCSSA pass is run if they
are unreachable from the entry block.

Normally, the users of the instruction would be PHIs but the unreachable
BBs have normal users; rewrite their uses to be undef values.

An alternative fix could involve fixing this at LCSSA but that would
require this invariant to hold after subsequent transforms.  If a BB
created an unreachable block, they would be in violation of this.

This fixes PR19798.

Differential Revision: http://reviews.llvm.org/D5146

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216911 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 16:22:00 +00:00
David Majnemer
e64e7c4634 SROA: Don't insert instructions before a PHI
SROA may decide that it needs to insert a bitcast and would set it's
insertion point before a PHI.  This will create an invalid module
right quick.

Instead, choose the first insertion point in the basic block that holds
our PHI.

This fixes PR20822.

Differential Revision: http://reviews.llvm.org/D5141

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216891 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-01 21:20:14 +00:00
David Majnemer
a0b2af46a5 Revert "Revert two GEP-related InstCombine commits"
This reverts commit r216698 which reverted r216523 and r216598.

We would attempt to perform the transformation even if the match()
failed because, as a side effect, it would set V.  This would trick us
into believing that we correctly found a place to correctly apply the
transform.

An additional test case was added to getelementptr.ll so that we might
not regress in the future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216890 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-01 21:10:02 +00:00
Sanjay Patel
73f8eff19e Add a convenience method to copy wrapping, exact, and fast-math flags (NFC).
The loop vectorizer preserves wrapping, exact, and fast-math properties of scalar instructions.
This patch adds a convenience method to make that operation easier because we need to do this
in the loop vectorizer, SLP vectorizer, and possibly other places.

Although this is a 'no functional change' patch, I've added a testcase to verify that the exact
flag is preserved by the loop vectorizer. The wrapping and fast-math flags are already checked
in existing testcases.

Differential Revision: http://reviews.llvm.org/D5138



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216886 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-01 18:44:57 +00:00
Chandler Carruth
1faa445476 Fix a really bad miscompile introduced in r216865 - the else-if logic
chain became completely broken here as *all* intrinsic users ended up
being skipped, and the ones that seemed to be singled out were actually
the exact wrong set.

This is a great example of why long else-if chains can be easily
confusing. Switch the entire code to use early exits and early continues
to have simpler (and more importantly, correct) logic here, as well as
fixing the reversed logic for detecting and continuing on lifetime
intrinsics.

I've also significantly cleaned up the test case and added another test
case demonstrating an example where the optimization is not (trivially)
safe to perform.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216871 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-01 10:09:18 +00:00
Renato Golin
35b114fe18 Small refactor on VectorizerHint for deduplication
Previously, the hint mechanism relied on clean up passes to remove redundant
metadata, which still showed up if running opt at low levels of optimization.
That also has shown that multiple nodes of the same type, but with different
values could still coexist, even if temporary, and cause confusion if the
next pass got the wrong value.

This patch makes sure that, if metadata already exists in a loop, the hint
mechanism will never append a new node, but always replace the existing one.
It also enhances the algorithm to cope with more metadata types in the future
by just adding a new type, not a lot of code.

Re-applying again due to MSVC 2013 being minimum requirement, and this patch
having C++11 that MSVC 2012 didn't support.

Fixes PR20655.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216870 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-01 10:00:17 +00:00
Hal Finkel
32418db285 Feed AA to the inliner and use AA->getModRefBehavior in AddAliasScopeMetadata
This feeds AA through the IFI structure into the inliner so that
AddAliasScopeMetadata can use AA->getModRefBehavior to figure out which
functions only access their arguments (instead of just hard-coding some
knowledge of memory intrinsics). Most of the information is only available from
BasicAA; this is important for preserving alias scoping information for
target-specific intrinsics when doing the noalias parameter attribute to
metadata conversion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216866 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-01 09:01:39 +00:00
Nick Lewycky
0cbef49d90 Ignore lifetime intrinsics in use list for MemCpyOptimizer. Patch by Luqman Aden, review by Hal Finkel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216865 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-01 06:03:11 +00:00
Hal Finkel
5581563457 Fix AddAliasScopeMetadata again - alias.scope must be a complete description
I thought that I had fixed this problem in r216818, but I did not do a very
good job. The underlying issue is that when we add alias.scope metadata we are
asserting that this metadata completely describes the aliasing relationships
within the current aliasing scope domain, and so in the context of translating
noalias argument attributes, the pointers must all be based on noalias
arguments (as underlying objects) and have no other kind of underlying object.
In r216818 excluding appropriate accesses from getting alias.scope metadata is
done by looking for underlying objects that are not identified function-local
objects -- but that's wrong because allocas, etc. are also function-local
objects and we need to explicitly check that all underlying objects are the
noalias arguments for which we're adding metadata aliasing scopes.

This fixes the underlying-object check for adding alias.scope metadata, and
does some refactoring of the related capture-checking eligibility logic (and
adds more comments; hopefully making everything a bit clearer).

Fixes self-hosting on x86_64 with -mllvm -enable-noalias-to-md-conversion (the
feature is still disabled by default).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216863 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-01 04:26:40 +00:00
Craig Topper
24ae56d4c9 Fix some cases where StringRef was being passed by const reference. Remove const from some other StringRefs since its implicitly const already.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216820 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-30 16:48:02 +00:00
Hal Finkel
bd896c1b25 Fix AddAliasScopeMetadata to not add scopes when deriving from unknown pointers
The previous implementation of AddAliasScopeMetadata, which adds noalias
metadata to preserve noalias parameter attribute information when inlining had
a flaw: it would add alias.scope metadata to accesses which might have been
derived from pointers other than noalias function parameters. This was
incorrect because even some access known not to alias with all noalias function
parameters could easily alias with an access derived from some other pointer.
Instead, when deriving from some unknown pointer, we cannot add alias.scope
metadata at all. This fixes a miscompile of the test-suite's tramp3d-v4.
Furthermore, we cannot add alias.scope to functions unless we know they
access only argument-derived pointers (currently, we know this only for
memory intrinsics).

Also, we fix a theoretical problem with using the NoCapture attribute to skip
the capture check. This is incorrect (as explained in the comment added), but
would not matter in any code generated by Clang because we get only inferred
nocapture attributes in Clang-generated IR.

This functionality is not yet enabled by default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216818 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-30 12:48:33 +00:00
David Majnemer
b265e6f1b6 InstCombine: Respect recursion depth in visitUDivOperand
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216817 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-30 09:19:05 +00:00