Commit Graph

5080 Commits

Author SHA1 Message Date
Eric Christopher
12a9dbd322 Add file to CMake build as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218005 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-18 00:39:20 +00:00
Eric Christopher
757c90dd00 Add a new pass FunctionTargetTransformInfo. This pass serves as a
shim between the TargetTransformInfo immutable pass and the Subtarget
via the TargetMachine and Function. Migrate a single call from
BasicTargetTransformInfo as an example and provide shims where TargetMachine
begins taking a Function to determine the subtarget.

No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218004 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-18 00:34:14 +00:00
David Majnemer
d5f73530de InstSimplify: Don't allow (x srem y) urem y -> x srem y
Let's consider the case where:
%x i16 = 32768
%y i16 = 384

%x srem %y = 65408
(%x srem %y) urem %y = 128

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217939 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-17 04:16:35 +00:00
David Majnemer
27e656c742 InstSimplify: ((X % Y) % Y) -> (X % Y)
Patch by Sonam Kumari!

Differential Revision: http://reviews.llvm.org/D5350

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217937 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-17 03:34:34 +00:00
David Majnemer
c3e70ca886 InstSimplify: Simplify trivial and/or of icmps
Some ICmpInsts when anded/ored with another ICmpInst trivially reduces
to true or false depending on whether or not all integers or no integers
satisfy the intersected/unioned range.

This sort of trivial looking code can come about when InstCombine
performs a range reduction-type operation on sdiv and the like.

This fixes PR20916.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217750 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-15 08:15:28 +00:00
Benjamin Kramer
8f3452d079 Fix an ODR violation consisting of two 'struct Query' in the global namespace.
Put them in their own anonymous namespaces. Found by GCC's new -Wodr (PR20915).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217662 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-12 08:56:53 +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
Hal Finkel
5f36b46bf0 Make use @llvm.assume for loop guards in ScalarEvolution
This adds a basic (but important) use of @llvm.assume calls in ScalarEvolution.
When SE is attempting to validate a condition guarding a loop (such as whether
or not the loop count can be zero), this check should also include dominating
assumptions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217348 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 21:37:59 +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
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
Benjamin Kramer
a80ff26688 Add override to overriden virtual methods, remove virtual keywords.
No functionality change. Changes made by clang-tidy + some manual cleanup.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217028 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-03 11:41:21 +00:00
Hal Finkel
fbe935edc1 [CFLAA] Remove one final initializer list
Maybe MSVC will be happy now...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217000 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-03 00:06:47 +00:00
Hal Finkel
b38c0b8f58 [CFLAA] And even more MSVC fixes
Remove a couple more initializer lists and constexpr dependencies.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216998 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 23:50:01 +00:00
Hal Finkel
fa5d491ae4 [CFLAA] More cleanup for MSVC
Remove more initializer lists, etc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216994 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 23:29:48 +00:00
Hal Finkel
8de4282206 [CFLAA] No initializer lists for MSVC
MSVC 2012 does not understand initializer lists; remove them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216991 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 22:52:30 +00:00
Hal Finkel
41b6e327f7 [CFLAA] Remove tautological comparison
Fixes this (the warning is right, the unsigned value is not negative):
lib/Analysis/StratifiedSets.h:689:53: warning: comparison of unsigned expression >= 0 is always true [-Wtautological-compare]
  bool inbounds(StratifiedIndex N) const { return N >= 0 && N < Links.size(); }

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216987 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 22:36:58 +00:00
Hal Finkel
4437658aff [CFLAA] LLVM_CONSTEXPR -> const
The number is just a constant, and this should make MSVC happy (or at least
happier).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216981 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 22:26:06 +00:00
Hal Finkel
ba709096bc [CFLAA] constexpr -> LLVM_CONSTEXPR
Attempt to fix the MSVC build by not using constexpr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216979 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 22:13:00 +00:00
Hal Finkel
bf301d5670 Add a CFL Alias Analysis implementation
This provides an implementation of CFL alias analysis (including some
supporting data structures). Currently, we don't have any extremely fancy
features, sans some interprocedural analysis (i.e. no field sensitivity, etc.),
and we do best sitting behind BasicAA + TBAA. In such a configuration, we take
~0.6-0.8% of total compile time, and give ~7-8% NoAlias responses to queries
TBAA and BasicAA couldn't answer when bootstrapping LLVM. In testing this on
other projects, we've seen up to 10.5% of queries dropped by BasicAA+TBAA
answered with NoAlias by this algorithm.

Patch by George Burgess IV (with minor modifications by me -- mostly adapting
some BasicAA tests), thanks!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216970 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 21:43:13 +00:00
Robin Morisset
cc99164448 Fix MemoryDependenceAnalysis in cases where QueryInstr is a CmpXchg or a AtomicRMW
Summary:
MemoryDependenceAnalysis is currently cautious when the QueryInstr is an atomic
load or store, but I forgot to check for atomic cmpxchg/atomicrmw. This patch
is a way of fixing that, and making it less brittle (i.e. no risk that I forget
another possible kind of atomic, even if the IR ends up changing in the future),
by adding a fallback checking mayReadOrWriteFromMemory.

Thanks to Philip Reames for finding this bug and suggesting this solution in
http://reviews.llvm.org/D4845

Sadly, I don't see how to add a test for this, since the passes depending on
MemoryDependenceAnalysis won't trigger for an atomic rmw anyway. Does anyone
see a way for testing it?

Test Plan: none possible at first sight

Reviewers: jfb, reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5019

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216940 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 20:17:52 +00:00
Nick Lewycky
7ba4e0705e Remove an errant outer loop that contains nothing but an inner loop over exactly the same elements. While no functionality is change intended (and hence there are no changes to tests), you don't want to skip this revision if bisecting for errors.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216864 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-01 05:17:15 +00:00
Craig Topper
3af13568fb Remove 'virtual' keyword from methods markedwith 'override' keyword.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216823 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-30 16:48:34 +00:00
Robin Morisset
217b38e19a Fix typos in comments, NFC
Summary: Just fixing comments, no functional change.

Test Plan: N/A

Reviewers: jfb

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D5130

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216784 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-29 21:53:01 +00:00
Robin Morisset
66b380b6b6 Relax the constraint more in MemoryDependencyAnalysis.cpp
Even loads/stores that have a stronger ordering than monotonic can be safe.
The rule is no release-acquire pair on the path from the QueryInst, assuming that
the QueryInst is not atomic itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216771 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-29 20:32:58 +00:00
Matt Arsenault
0d90962f29 Make fabs safe to speculatively execute
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216736 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-29 16:01:17 +00:00
David Majnemer
b11fff1d8a InstSimplify: Move a transform from InstCombine to InstSimplify
Several combines involving icmp (shl C2, %X) C1 can be simplified
without introducing any new instructions.  Move them to InstSimplify;
while we are at it, make them more powerful.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216642 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-28 03:34:28 +00:00
David Majnemer
48164ed24d InstSimplify: Don't simplify gep X, (Y-X) to Y if types differ
It's incorrect to perform this simplification if the types differ.
A bitcast would need to be inserted for this to work.

This fixes PR20771.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216597 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-27 20:08:34 +00:00
Nico Weber
1c768816d7 Reland r216439 215441, majnemer has a real fix for PR20771.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216586 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-27 20:06:19 +00:00
Nico Weber
b2f71836eb Revert r216439 (and r216441, else the former doesn't revert cleanly).
It caused PR 20771. I'll land a test on the clang side.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216582 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-27 20:00:13 +00:00
David Majnemer
d8e448bd27 InstSimplify: Compute comparison ranges for left shift instructions
'shl nuw CI, x' produces [CI, CI << CLZ(CI)]
'shl nsw CI, x' produces [CI << CLO(CI)-1, CI] if CI is negative
'shl nsw CI, x' produces [CI, CI << CLZ(CI)-1] if CI is non-negative

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216570 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-27 18:03:46 +00:00
David Majnemer
8058ffeb18 InstSimplify: Fold gep X, (sub 0, ptrtoint(X)) to null
Save InstCombine some work if we can perform this fold during
InstSimplify.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216441 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-26 07:08:03 +00:00
David Majnemer
594e4a1dd3 InstSimplify: Simplify trivial pointer expressions like b + (e - b)
consider:
long long *f(long long *b, long long *e) {
  return b + (e - b);
}

we would lower this to something like:
define i64* @f(i64* %b, i64* %e) {
  %1 = ptrtoint i64* %e to i64
  %2 = ptrtoint i64* %b to i64
  %3 = sub i64 %1, %2
  %4 = ashr exact i64 %3, 3
  %5 = getelementptr inbounds i64* %b, i64 %4
  ret i64* %5
}

This should fold away to just 'e'.

N.B.  This adds m_SpecificInt as a convenient way to match against a
particular 64-bit integer when using LLVM's match interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216439 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-26 05:55:16 +00:00
Dylan Noblesmith
7532912545 Analysis: cleanup
Address review comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216432 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-26 02:03:40 +00:00
Dylan Noblesmith
8cb2706af6 Revert "Analysis: unique_ptr-ify DependenceAnalysis::collectCoeffInfo"
This reverts commit r216358.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216431 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-26 02:03:38 +00:00
Rafael Espindola
8c96862847 Modernize raw_fd_ostream's constructor a bit.
Take a StringRef instead of a "const char *".
Take a "std::error_code &" instead of a "std::string &" for error.

A create static method would be even better, but this patch is already a bit too
big.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216393 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-25 18:16:47 +00:00
Karthik Bhat
e637d65af3 Allow vectorization of division by uniform power of 2.
This patch adds support to recognize division by uniform power of 2 and modifies the cost table to vectorize division by uniform power of 2 whenever possible.
Updates Cost model for Loop and SLP Vectorizer.The cost table is currently only updated for X86 backend.
Thanks to Hal, Andrea, Sanjay for the review. (http://reviews.llvm.org/D4971)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216371 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-25 04:56:54 +00:00
Dylan Noblesmith
97dc647e90 Analysis: unique_ptr-ify DependenceAnalysis::collectCoeffInfo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216358 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-25 00:28:43 +00:00
Dylan Noblesmith
fe2cc2d8cc Analysis: unique_ptr-ify DependenceAnalysis::depends
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216357 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-25 00:28:39 +00:00
Dylan Noblesmith
75129f6f4c Analysis: take a reference instead of pointer
This parameter is never null.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216356 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-25 00:28:35 +00:00
Craig Topper
273fd11da9 Use range based for loops to avoid needing to re-mention SmallPtrSet size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216351 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-24 23:23:06 +00:00
David Majnemer
54056f1760 ValueTracking: Figure out more bits when looking at add/sub
Given something like X01XX + X01XX, we know that the result must look
like X1XXX.

Adapted from a patch by Richard Smith, test-case written by me.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216250 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-22 00:40:43 +00:00
Craig Topper
431bdfc4c1 Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216158 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 05:55:13 +00:00
Robin Morisset
0acd42142a Answer to Philip Reames comments
- add check for volatile (probably unneeded, but I agree that we should be conservative about it).
- strengthen condition from isUnordered() to isSimple(), as I don't understand well enough Unordered semantics (and it also matches the comment better this way) to be confident in the previous behaviour (thanks for catching that one, I had missed the case Monotonic/Unordered).
- separate a condition in two.
- lengthen comment about aliasing and loads
- add tests in GVN/atomic.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215943 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-18 22:18:14 +00:00
Robin Morisset
6c0e1e0fa6 Weak relaxing of the constraints on atomics in MemoryDependencyAnalysis
Monotonic accesses do not have to kill the analysis, as long as the QueryInstr is not
itself atomic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215942 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-18 22:18:11 +00:00
Craig Topper
db77b82ed5 Revert "Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size."
Getting a weird buildbot failure that I need to investigate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215870 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-18 00:24:38 +00:00
Craig Topper
f06c7072c2 Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215868 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-17 23:47:00 +00:00
Jiangning Liu
1505fa4376 In LVI(Lazy Value Info), originally value on a BB can only be caculated once,
and the lattice will be updated to be a state other than "undefined". This
limiation could miss some opportunities of lowering "overdefined" to be an
even accurate value. So this patch ask the algorithm to try to lower the
lattice value again even if the value has been lowered to be "overdefined".



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215343 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-11 05:02:04 +00:00