2040 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith
6426aea54e ADT: Avoid relying on UB in ilist_node::getNextNode()
Re-implement `ilist_node::getNextNode()` and `getPrevNode()` without
relying on the sentinel having a "next" pointer.  Instead, get access to
the owning list and compare against the `begin()` and `end()` iterators.

This only works when the node *can* get access to the owning list.  The
new support is in `ilist_node_with_parent<>`, and any class `Ty`
inheriting from `ilist_node<NodeTy>` that wants `getNextNode()` and/or
`getPrevNode()` should inherit from
`ilist_node_with_parent<NodeTy, ParentTy>` instead.  The requirements:

  - `NodeTy` must have a `getParent()` function that returns the parent.
  - `ParentTy` must have a `getSublistAccess()` static that, given a(n
    ignored) `NodeTy*` (to determine which list), returns a member field
    pointer to the appropriate `ilist<>`.

This isn't the cleanest way to get access to the owning list, but it
leverages the API already used in the IR hierarchy (see, e.g.,
`Instruction::getSublistAccess()`).

If anyone feels like ripping out the calls to `getNextNode()` and
`getPrevNode()` and replacing with direct iterator logic, they can also
remove the access function, etc., but as an incremental step, I'm
maintaining the API where it's currently used in tree.

If these requirements are *not* met, call sites with access to the ilist
can call `iplist<NodeTy>::getNextNode(NodeTy*)` directly, as in
ilistTest.cpp.

Why rewrite this?

The old code was broken, calling `getNext()` on a sentinel that possibly
didn't have a "next" pointer at all!  The new code avoids that
particular flavour of UB (see the commit message for r252538 for more
details about the "lucky" memory layout that made this function so
interesting).

There's still some UB here: the end iterator gets downcast to `NodeTy*`,
even when it's a sentinel (which is typically
`ilist_half_node<NodeTy*>`).  I'll tackle that in follow-up commits.
See this llvm-dev thread for more details:
http://lists.llvm.org/pipermail/llvm-dev/2015-October/091115.html

What's the danger?

There might be some code that relies on `getNextNode()` or
`getPrevNode()` *never* returning `nullptr` -- i.e., that relies on them
being broken when the sentinel is an `ilist_half_node<NodeTy>`.  I tried
to root out those cases with the audits I did leading up to r252380, but
it's possible I missed one or two.  I hope not.

(If (1) you have out-of-tree code, (2) you've reverted r252380
temporarily, and (3) you get some weird crashes with this commit, then I
recommend un-reverting r252380 and auditing the compile errors looking
for "strange" implicit conversions.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252694 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-11 02:26:42 +00:00
Xinliang David Li
bcd8e0aae7 [PGO] Make indexed value profile data more compact
- Make indexed value profile data more compact by peeling out 
  the per-site value count field into its own smaller sized array.
- Introduced formal data structure definitions to specify value 
  profile data layout in indexed format. Previously the layout 
  of the data is only assumed in the client code (scattered in 
  three different places : size computation, EmitData, and ReadData
- The new data structure  serves as a central place for layout documentation.
- Add interfaces to force BE output for value profile data (testing purpose)
- Add byte swap unit tests

Differential Revision: http://reviews.llvm.org/D14401


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252563 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-10 00:24:45 +00:00
Mike Aizatsky
da4cf2cda9 Windows-specific test for sys::path::remove_dots.
Differential Revision: http://reviews.llvm.org/D14503

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252504 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-09 19:36:53 +00:00
Mike Aizatsky
8cda80ad24 Moving FileManager::removeDotPaths to llvm::sys::path::remove_dots
Differential Revision: http://reviews.llvm.org/D14393

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252499 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-09 18:56:31 +00:00
Pawel Bylica
6bd362c2d9 Revert r252366: [Support] Use GetTempDir to get the temporary dir path on Windows.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252367 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-06 23:44:23 +00:00
Pawel Bylica
dae382206c [Support] Use GetTempDir to get the temporary dir path on Windows.
Summary:
In general GetTempDir follows the same logic as the replaced code: checks env variables TMP, TEMP, USERPROFILE in order. However, it also perform other checks like making separators native (\), making the path absolute, etc.

This change fixes FileSystemTest.CreateDir unittest that had been failing when run from Unix-like shell on Windows (Unix-like path separator (/) used in env variables).

Reviewers: chapuni, rafael, aaron.ballman

Subscribers: rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D14231

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252366 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-06 23:21:49 +00:00
Peter Collingbourne
5f220beefc DI: Reverse direction of subprogram -> function edge.
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.

For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.

This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.

Since this is an IR change, a bitcode upgrade has been provided.

Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.

Differential Revision: http://reviews.llvm.org/D14265

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252219 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-05 22:03:56 +00:00
Eugene Zelenko
4e036ff575 Fix some Clang-tidy modernize warnings, other minor fixes.
Fixed warnings are: modernize-use-override, modernize-use-nullptr and modernize-redundant-void-arg.

Differential revision: http://reviews.llvm.org/D14312


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252087 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 22:32:32 +00:00
David Blaikie
6d6131b03b Orc: Streamline some lambda usage in a unit test
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252070 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 19:43:24 +00:00
Aaron Ballman
1cfa35bef6 Silence an extra semicolon warning; NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252046 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 14:40:54 +00:00
Pawel Bylica
7561231bee Fix unit tests on Windows: handle env vars with non-ASCII chars.
Summary: On Windows we have to take UTF16 encoded env vars and convert them to UTF8. This patch fixes CopyEnvironment helper function used by process unit tests.

Reviewers: yaron.keren

Subscribers: yaron.keren, llvm-commits

Differential Revision: http://reviews.llvm.org/D14278

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252039 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 08:25:20 +00:00
Rafael Espindola
25d7145b34 Revert "Revert "[Orc] Directly emit machine code for the x86 resolver block and trampolines.""
This reverts commit r251937.

The test was updated to the new API, bring the API back.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251944 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-03 16:40:37 +00:00
Rafael Espindola
1b023a319e Revert "[Orc] Directly emit machine code for the x86 resolver block and trampolines."
This reverts commit r251933.

It broke the build of examples/Kaleidoscope/Orc/fully_lazy/toy.cpp.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251937 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-03 16:25:20 +00:00
Lang Hames
73cd3516cc [Orc] Directly emit machine code for the x86 resolver block and trampolines.
Bypassing LLVM for this has a number of benefits:

1) Laziness support becomes asm-syntax agnostic (previously lazy jitting didn't
   work on Windows as the resolver block was in Darwin asm).

2) For cross-process JITs, it allows resolver blocks and trampolines to be
   emitted directly in the target process, reducing cross process traffic.

3) It should be marginally faster.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251933 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-03 16:10:18 +00:00
Pawel Bylica
8bd55b5451 [Support] Extend sys::path with user_cache_directory function.
Summary:
The new function sys::path::user_cache_directory tries to discover
a directory suitable for cache storage for current system user.

On Windows and Darwin it returns a path to system-specific user cache directory.

On Linux it follows XDG Base Directory Specification, what is:
- use non-empty $XDG_CACHE_HOME env var,
- use $HOME/.cache.

Reviewers: chapuni, aaron.ballman, rafael

Subscribers: rafael, aaron.ballman, llvm-commits

Differential Revision: http://reviews.llvm.org/D13801

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251784 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 09:49:17 +00:00
Xinliang David Li
61c7e68339 [PGO] Value profiling (index format) code cleanup and testing
1. Added a set of public interfaces in InstrProfRecord
    class to access (read/write) value profile data.
 2. Changed IndexedProfile reader and writer code to 
    use the newly defined interfaces and hide implementation
    details.
 3. Added a couple of unittests for value profiling:
   - Test new interfaces to get and set value profile data
   - Test value profile data merging with various scenarios.

 No functional change is expected. The new interfaces will also
 make it possible to change on-disk format of value prof data
 to be more compact (to be submitted). 



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251771 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 05:08:23 +00:00
Michael Gottesman
23a49a637b Add a unittest for SmallDenseMap that tests assigning a SmallDenseMap when it is not small.
This complements CopyConstructorNotSmallTest. If we are testing the copy
constructor in such a way, we should also probably test assignment in the same
way.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251736 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-31 05:23:53 +00:00
Lang Hames
df3ef600c0 [Orc] Expose the compile callback API through the C bindings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251683 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-30 03:20:21 +00:00
Lang Hames
154d0643db [Orc] Teach IndirectStubsManager to manage an expandable pool of stubs, rather
than a pre-allocated slab of stubs. Also add a convenience method for creating a
single stub, rather than a whole block a time.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251658 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-29 22:04:22 +00:00
Lang Hames
d979d81a43 [Orc] Rename IndirectStubsManagerBase method 'init' to 'createStubs'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251641 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-29 18:36:27 +00:00
NAKAMURA Takumi
185dc9db03 OrcJITTests: Update libdeps corresponding to r251604.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251619 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-29 06:40:04 +00:00
Lang Hames
941b62a140 [Orc] Add missing file for r251604.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251605 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-29 03:53:42 +00:00
Lang Hames
22bbdbd767 [Orc] Add support for RuntimeDyld::setProcessAllSections.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251604 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-29 03:52:58 +00:00
Lang Hames
79dc87fc1e [Orc] Require target support for host before running execution unit tests.
Orc unit tests that execute code shouldn't run if the compiler doesn't have
target support for the host machine.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251551 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-28 20:08:51 +00:00
NAKAMURA Takumi
7c69e3c785 OrcJITTests: Prune unused libdeps.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251506 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-28 09:59:50 +00:00
NAKAMURA Takumi
9f211909bf OrcJITTests: Update libdeps.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251504 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-28 09:37:09 +00:00
Craig Topper
2412f42fae Fix a -Wpessimizing-move warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251495 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-28 04:54:46 +00:00
Lang Hames
7ab4e8bd48 [Orc] Disable Orc C API unit tests on non-Darwin while I investigate more
builder failures.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251484 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-28 03:12:51 +00:00
Lang Hames
f3f591ae00 [Orc] Re-add C bindings for the Orc APIs, with a fix to remove the union that
was causing builder failures.

The bindings were originally added in r251472, and reverted in r251473 due to
the builder failures.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251482 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-28 02:40:04 +00:00
Lang Hames
4b0975e22a [Orc] Revert the C bindngs commit, r251472, while I debug some builder failures.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251473 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-28 01:03:09 +00:00
Lang Hames
5fc6406e39 [Orc] Add experimental C bindings for Orc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251472 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-28 00:28:26 +00:00
Lang Hames
2d323d4ed2 [Orc] Fix indentation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251423 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-27 17:45:48 +00:00
Michael Kuperstein
684557ee8c [X86] Make elfiamcu an OS, not an environment.
GNU tools require elfiamcu to take up the entire OS field, so, e.g.
i?86-*-linux-elfiamcu is not considered a legal triple.
Make us compatible.

Differential Revision: http://reviews.llvm.org/D14081

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251390 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-27 07:23:59 +00:00
Michael Kuperstein
c50c6907aa [X86] Add support for elfiamcu triple
This adds support for the i?86-*-elfiamcu triple, which indicates the IAMCU psABI is used.

Differential Revision: http://reviews.llvm.org/D13977

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251222 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-25 08:07:37 +00:00
Rafael Espindola
715bccae4a Add a RAW mode to StringTableBuilder.
In this mode it just tries to tail merge the strings without imposing any other
format constrains. It will not, for example, add a null byte between them.

Also add support for keeping a tentative size and offset if we decide to
not optimize after all.

This will be used shortly in lld for merging SHF_STRINGS sections.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251153 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-23 21:48:05 +00:00
Sanjoy Das
2779d5708c [IR] Add a makeNoWrapRegion method to ConstantRange
Summary: This will be used in a future change to ScalarEvolution.

Reviewers: hfinkel, reames, nlewycky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13612

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250975 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-22 03:12:57 +00:00
Craig Topper
94f8b07c97 [Option] Use an ArrayRef to store the Option Infos in OptTable. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250901 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-21 16:30:42 +00:00
Chandler Carruth
198a6c5be5 [AA] Enhance the new AliasAnalysis infrastructure with an optional
"external" AA wrapper pass.

This is a generic hook that can be used to thread custom code into the
primary AAResultsWrapperPass for the legacy pass manager in order to
allow it to merge external AA results into the AA results it is
building. It does this by threading in a raw callback and so it is
*very* powerful and should serve almost any use case I have come up with
for extending the set of alias analyses used. The only thing not well
supported here is using a *different order* of alias analyses. That form
of extension *is* supportable with the new pass manager, and I can make
the callback structure here more elaborate to support it in the legacy
pass manager if this is a critical use case that people are already
depending on, but the only use cases I have heard of thus far should be
reasonably satisfied by this simpler extension mechanism.

It is hard to test this using normal facilities (the built-in AAs don't
use this for obvious reasons) so I've written a fairly extensive set of
custom passes in the alias analysis unit test that should be an
excellent test case because it models the out-of-tree users: it adds
a totally custom AA to the system. This should also serve as
a reasonably good example and guide for out-of-tree users to follow in
order to rig up their existing alias analyses.

No support in opt for commandline control is provided here however. I'm
really unhappy with the kind of contortions that would be required to
support that. It would fully re-introduce the analysis group
self-recursion kind of patterns. =/

I've heard from out-of-tree users that this will unblock their use cases
with extending AAs on top of the new infrastructure and let us retain
the new analysis-group-free-world.

Differential Revision: http://reviews.llvm.org/D13418

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250894 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-21 12:15:19 +00:00
Duncan P. N. Exon Smith
70f8c2049f unittests: Remove implicit ilist iterator conversions, NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250843 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-20 18:30:20 +00:00
Lang Hames
7233876104 [Orc] Make CompileOnDemandLayer::findSymbol call BaseLayer::findSymbol if no
symbol definition is found in the logical dylibs.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250796 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-20 04:35:02 +00:00
Pawel Bylica
947464d179 Fix path::home_directory() unit test.
It turns out that constructing std::string from null pointer is not the very best idea.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250506 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-16 10:11:07 +00:00
NAKAMURA Takumi
054dd43f8f SupportTests::HomeDirectory: Don't try tests when $HOME is undefined.
Lit sanitizes env vars. $HOME is not exported in Lit tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250505 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-16 09:40:01 +00:00
NAKAMURA Takumi
d332f5867b Reformat.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250504 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-16 09:38:49 +00:00
Pawel Bylica
2f01bc86e5 Use Windows Vista API to get the user's home directory
Summary: This patch replaces usage of deprecated SHGetFolderPathW with SHGetKnownFolderPath. The usage of SHGetKnownFolderPath is wrapped to allow queries for other "known" folders in the near future.

Reviewers: aaron.ballman, gbedwell

Subscribers: chapuni, llvm-commits

Differential Revision: http://reviews.llvm.org/D13753

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250501 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-16 09:08:59 +00:00
Dylan McKay
350708a1fc Initial migration of AVR backend
This patch adds the underlying infrastructure for an AVR backend to be included into LLVM. It is the first of a series of patches aimed at moving the out-of-tree AVR backend into the tree.

It consists of adding a new`Triple` target 'avr'.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250492 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-16 03:10:30 +00:00
Manman Ren
0f34207b1d Recommit r250345, it was reverted in r250366 to investigate a bot failure.
Our internal bot is still red after r250366.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250415 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-15 14:59:40 +00:00
Eric Christopher
6f565c0e97 Remove DIFile from createSubroutineType.
Patch by Amaury Sechet with a small modification by me.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250374 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-15 06:56:10 +00:00
Manman Ren
9b380854cd Temporarily revert r250345 to sort out bot failure.
With r250345 and r250343, we start to observe the following failure
when bootstrap clang with lto and pgo:
PHI node entries do not match predecessors!
  %.sroa.029.3.i = phi %"class.llvm::SDNode.13298"* [ null, %30953 ], [ null, %31017 ], [ null, %30998 ], [ null, %_ZN4llvm8dyn_castINS_14ConstantSDNodeENS_7SDValueEEENS_10cast_rettyIT_T0_E8ret_typeERS5_.exit.i.1804 ], [ null, %30975 ], [ null, %30991 ], [ null, %_ZNK4llvm3EVT13getScalarTypeEv.exit.i.1812 ], [ %..sroa.029.0.i, %_ZN4llvm11SmallVectorIiLj8EED1Ev.exit.i.1826 ], !dbg !451895
label %30998
label %_ZNK4llvm3EVTeqES0_.exit19.thread.i
LLVM ERROR: Broken function found, compilation aborted!

I will re-commit this if the bot does not recover.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250366 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-15 04:58:24 +00:00
Cong Hou
a99158bbd8 Update the branch weight metadata in JumpThreading pass.
Currently in JumpThreading pass, the branch weight metadata is not updated after CFG modification. Consider the jump threading on PredBB, BB, and SuccBB. After jump threading, the weight on BB->SuccBB should be adjusted as some of it is contributed by the edge PredBB->BB, which doesn't exist anymore. This patch tries to update the edge weight in metadata on BB->SuccBB by scaling it by 1 - Freq(PredBB->BB) / Freq(BB->SuccBB).

This is the third attempt to submit this patch, while the first two led to failures in some FDO tests. After investigation, it is the edge weight normalization that caused those failures. In this patch the edge weight normalization is fixed so that there is no zero weight in the output and the sum of all weights can fit in 32-bit integer. Several unit tests are added.

Differential revision: http://reviews.llvm.org/D10979



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250345 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-14 23:14:17 +00:00
Cong Hou
7ebb1848c3 Add - and -= operators to BlockFrequency using saturating arithmetic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250077 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-12 18:34:00 +00:00