Commit Graph

745 Commits

Author SHA1 Message Date
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
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
Rafael Espindola
a348fc7fda Remove HasLEB128.
We already require CFI, so it should be safe to require .leb128 and .uleb128.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215712 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-15 14:01:07 +00:00
Benjamin Kramer
00e08fcaa0 Canonicalize header guards into a common format.
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)

Changes made by clang-tidy with minor tweaks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215558 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-13 16:26:38 +00:00
Pete Cooper
3f2aee7e02 Fix a whole bunch of binary literals which were the wrong size. All were being silently zero extended to the correct width.
The commit after this changes { } and 0bxx literals to be of type bits<n> and not int.  This means we need to write exactly the right number of bits, and not rely on the values being silently zero extended for us.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215082 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-07 05:46:54 +00:00
Eric Christopher
41612a9b85 Remove the target machine from CCState. Previously it was only used
to get the subtarget and that's accessible from the MachineFunction
now. This helps clear the way for smaller changes where we getting
a subtarget will require passing in a MachineFunction/Function as
well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214988 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-06 18:45:26 +00:00
Eric Christopher
6035518e3b Have MachineFunction cache a pointer to the subtarget to make lookups
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lookups from
the MachineFunction easily.

Update the MIPS subtarget switching machinery to update this pointer
at the same time it runs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214838 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-05 02:39:49 +00:00
Pedro Artigas
3da024594f Changed the liveness tracking in the RegisterScavenger
to use register units instead of registers.

reviewed by Jakob Stoklund Olesen.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214798 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-04 23:07:49 +00:00
Eric Christopher
9f85dccfc6 Remove the TargetMachine forwards for TargetSubtargetInfo based
information and update all callers. No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214781 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-04 21:25:23 +00:00
Louis Gerbarg
7d54c5b0f2 Make sure no loads resulting from load->switch DAGCombine are marked invariant
Currently when DAGCombine converts loads feeding a switch into a switch of
addresses feeding a load the new load inherits the isInvariant flag of the left
side. This is incorrect since invariant loads can be reordered in cases where it
is illegal to reoarder normal loads.

This patch adds an isInvariant parameter to getExtLoad() and updates all call
sites to pass in the data if they have it or false if they don't. It also
changes the DAGCombine to use that data to make the right decision when
creating the new load.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214449 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-31 21:45:05 +00:00
Matt Arsenault
2dd264c8a3 Add alignment value to allowsUnalignedMemoryAccess
Rename to allowsMisalignedMemoryAccess.

On R600, 8 and 16 byte accesses are mostly OK with 4-byte alignment,
and don't need to be split into multiple accesses. Vector loads with
an alignment of the element type are not uncommon in OpenCL code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214055 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-27 17:46:40 +00:00
Hal Finkel
2c7c54c86c AA metadata refactoring (introduce AAMDNodes)
In order to enable the preservation of noalias function parameter information
after inlining, and the representation of block-level __restrict__ pointer
information (etc.), additional kinds of aliasing metadata will be introduced.
This metadata needs to be carried around in AliasAnalysis::Location objects
(and MMOs at the SDAG level), and so we need to generalize the current scheme
(which is hard-coded to just one TBAA MDNode*).

This commit introduces only the necessary refactoring to allow for the
introduction of other aliasing metadata types, but does not actually introduce
any (that will come in a follow-up commit). What it does introduce is a new
AAMDNodes structure to hold all of the aliasing metadata nodes associated with
a particular memory-accessing instruction, and uses that structure instead of
the raw MDNode* in AliasAnalysis::Location, etc.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213859 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 12:16:19 +00:00
NAKAMURA Takumi
9d8661d666 Prune dependency to MC from each target disassembler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213856 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 11:45:11 +00:00
NAKAMURA Takumi
9fda421ee4 Update library dependencies.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213832 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 02:10:42 +00:00
David Majnemer
38d8be1ad8 CodeGen: Stick constant pool entries in COMDAT sections for WinCOFF
COFF lacks a feature that other object file formats support: mergeable
sections.

To work around this, MSVC sticks constant pool entries in special COMDAT
sections so that each constant is in it's own section.  This permits
unused constants to be dropped and it also allows duplicate constants in
different translation units to get merged together.

This fixes PR20262.

Differential Revision: http://reviews.llvm.org/D4482

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213006 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-14 22:57:27 +00:00
Robert Lytton
546cfbfd0a XCore target: remove incorrect DebugLoc entries from prologue
Summary: This was causing the prologue_end to be incorrectly positioned.

Differential Revision: http://reviews.llvm.org/D4122

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212318 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-04 06:38:22 +00:00
Eric Christopher
65e0e46118 Move the subtarget dependent features from XCoreTargetMachine
down to the subtarget.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212147 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-02 00:10:09 +00:00
Eric Christopher
9223ec2cd9 Make XCoreSelectionDAGInfo take a DataLayout since it only needs
that information.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212146 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-02 00:10:05 +00:00
Juergen Ributzka
75909261f0 [DAG] Pass the argument list to the CallLoweringInfo via move semantics. NFCI.
The argument list vector is never used after it has been passed to the
CallLoweringInfo and moving it to the CallLoweringInfo is cleaner and
pretty much as cheap as keeping a pointer to it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212135 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-01 22:01:54 +00:00
Alp Toker
8dd8d5c2b2 Revert "Introduce a string_ostream string builder facilty"
Temporarily back out commits r211749, r211752 and r211754.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211814 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-26 22:52:05 +00:00
Alp Toker
2559070422 Introduce a string_ostream string builder facilty
string_ostream is a safe and efficient string builder that combines opaque
stack storage with a built-in ostream interface.

small_string_ostream<bytes> additionally permits an explicit stack storage size
other than the default 128 bytes to be provided. Beyond that, storage is
transferred to the heap.

This convenient class can be used in most places an
std::string+raw_string_ostream pair or SmallString<>+raw_svector_ostream pair
would previously have been used, in order to guarantee consistent access
without byte truncation.

The patch also converts much of LLVM to use the new facility. These changes
include several probable bug fixes for truncated output, a programming error
that's no longer possible with the new interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211749 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-26 00:00:48 +00:00
Tom Stellard
102d0f3e3f SelectionDAG: Don't use MVT::Other to determine legality of ISD::SELECT_CC
The SelectionDAG bad a special case for ISD::SELECT_CC, where it would
allow targets to specify:

setOperationAction(ISD::SELECT_CC, MVT::Other, Expand);

to indicate that they wanted to expand ISD::SELECT_CC for all types.
This wasn't applied correctly everywhere, and it makes writing new
DAG patterns with ISD::SELECT_CC difficult.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210541 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-10 16:01:29 +00:00
Tom Stellard
f586a260ca SelectionDAG: Expand SELECT_CC to SELECT + SETCC
This consolidates code from the Hexagon, R600, and XCore targets.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210539 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-10 16:01:22 +00:00
Eric Christopher
5448320a20 Have TargetSelectionDAGInfo take a DataLayout initializer rather than
a TargetMachine since the only thing it wants is DataLayout.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210366 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-06 19:04:48 +00:00
Rafael Espindola
2d21b25393 Allow alias to point to an arbitrary ConstantExpr.
This  patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is
up to MC (or the system assembler) to decide if that expression is valid or not.

This reduces our ability to diagnose invalid uses and how early we can spot
them, but it also lets us do things like

@test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32),
                                 i32 ptrtoint (i32* @bar to i32)) to i32*)

An important implication of this patch is that the notion of aliased global
doesn't exist any more. The alias has to encode the information needed to
access it in its metadata (linkage, visibility, type, etc).

Another consequence to notice is that getSection has to return a "const char *".
It could return a NullTerminatedStringRef if there was such a thing, but when
that was proposed the decision was to just uses "const char*" for that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210062 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-03 02:41:57 +00:00
Rafael Espindola
ef3a12f984 clang-format function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209550 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-23 20:39:23 +00:00
Rafael Espindola
0d4e85d19d Remove a confusing use of a static method.
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209548 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-23 20:35:47 +00:00
Eric Christopher
4551b0a800 Fix typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209377 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-22 01:21:44 +00:00
Saleem Abdulrasool
82b1114fef Target: remove old constructors for CallLoweringInfo
This is mostly a mechanical change changing all the call sites to the newer
chained-function construction pattern.  This removes the horrible 15-parameter
constructor for the CallLoweringInfo in favour of setting properties of the call
via chained functions.  No functional change beyond the removal of the old
constructors are intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209082 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-17 21:50:17 +00:00
Rafael Espindola
ad6d7f58c7 Delete getAliasedGlobal.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209040 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 22:37:03 +00:00
Jay Foad
6b543713a2 Rename ComputeMaskedBits to computeKnownBits. "Masked" has been
inappropriate since it lost its Mask parameter in r154011.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208811 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-14 21:14:37 +00:00
Rafael Espindola
2842c051b3 Remove the UseCFI option from createAsmStreamer.
We were already always passing true, this just removes the option.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208205 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-07 13:00:43 +00:00
Craig Topper
d4657fb0c1 [C++11] Add 'override' keywords and remove 'virtual'. Additionally add 'final' and leave 'virtual' on some methods that are marked virtual without overriding anything and have no obvious overrides themselves. XCore edition
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207501 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 07:57:00 +00:00
Eric Christopher
aa475b48cc None of these targets actually define their own CFI_INSTRUCTION
opcode so there's no reason to use the target namespace for it
rather than TargetOpcode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207475 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 00:16:46 +00:00
Eric Christopher
dc1721b004 80-column fixups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207474 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 00:16:42 +00:00
Craig Topper
c34a25d59d [C++] Use 'nullptr'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207394 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-28 04:05:08 +00:00
Craig Topper
a7f892b33b Convert SelectionDAG::getMergeValues to use ArrayRef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207374 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-27 19:20:57 +00:00
Craig Topper
80d8db7a1f Convert SelectionDAG::getNode methods to use ArrayRef<SDValue>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207327 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-26 18:35:24 +00:00
Craig Topper
c848b1bbcf [C++] Use 'nullptr'. Target edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207197 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 05:30:21 +00:00
Chandler Carruth
42e8630239 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, lib/Target/...
edition.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206842 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 02:41:26 +00:00
Chandler Carruth
58f58c97f0 [cleanup] Lift using directives, DEBUG_TYPE definitions, and even some
system headers above the includes of generated '.inc' files that
actually contain code. In a few targets this was already done pretty
consistently, but it wasn't done *really* consistently anywhere. It is
strictly cleaner IMO and necessary in a bunch of places where the
DEBUG_TYPE is referenced from the generated code. Consistency with the
necessary places trumps. Hopefully the build bots are OK with the
movement of intrin.h...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206838 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 02:03:14 +00:00
Chandler Carruth
283b399377 [Modules] Make Support/Debug.h modular. This requires it to not change
behavior based on other files defining DEBUG_TYPE, which means it cannot
define DEBUG_TYPE at all. This is actually better IMO as it forces folks
to define relevant DEBUG_TYPEs for their files. However, it requires all
files that currently use DEBUG(...) to define a DEBUG_TYPE if they don't
already. I've updated all such files in LLVM and will do the same for
other upstream projects.

This still leaves one important change in how LLVM uses the DEBUG_TYPE
macro going forward: we need to only define the macro *after* header
files have been #include-ed. Previously, this wasn't possible because
Debug.h required the macro to be pre-defined. This commit removes that.
By defining DEBUG_TYPE after the includes two things are fixed:

- Header files that need to provide a DEBUG_TYPE for some inline code
  can do so by defining the macro before their inline code and undef-ing
  it afterward so the macro does not escape.

- We no longer have rampant ODR violations due to including headers with
  different DEBUG_TYPE definitions. This may be mostly an academic
  violation today, but with modules these types of violations are easy
  to check for and potentially very relevant.

Where necessary to suppor headers with DEBUG_TYPE, I have moved the
definitions below the includes in this commit. I plan to move the rest
of the DEBUG_TYPE macros in LLVM in subsequent commits; this one is big
enough.

The comments in Debug.h, which were hilariously out of date already,
have been updated to reflect the recommended practice going forward.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206822 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 22:55:11 +00:00
Lang Hames
508bd63046 [MC] Require an MCContext when constructing an MCDisassembler.
This patch re-introduces the MCContext member that was removed from
MCDisassembler in r206063, and requires that an MCContext be passed in at
MCDisassembler construction time. (Previously the MCContext member had been
initialized in an ad-hoc fashion after construction). The MCCContext member
can be used by MCDisassembler sub-classes to construct constant or
target-specific MCExprs.

This patch updates disassemblers for in-tree targets, and provides the
MCRegisterInfo instance that some disassemblers were using through the
MCContext (previously those backends were constructing their own
MCRegisterInfo instances).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206241 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 04:40:56 +00:00
Richard Osborne
c9fa660ddd [XCore] Don't create invalid MKMSK instructions inside loadImmediate().
Summary:
Previously loadImmediate() would produce MKMSK instructions with invalid
immediate values such as mkmsk r0, 9. Fix this by checking the mask size
is valid.

Reviewers: robertlytton

Reviewed By: robertlytton

CC: llvm-commits

Differential Revision: http://reviews.llvm.org/D3289

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206163 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-14 12:30:35 +00:00
Craig Topper
84f7f350c3 Make consistent use of MCPhysReg instead of uint16_t throughout the tree.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205610 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-04 05:16:06 +00:00
Rafael Espindola
f165cf7ce8 Prevent alias from pointing to weak aliases.
This adds back r204781.

Original message:

Aliases are just another name for a position in a file. As such, the
regular symbol resolutions are not applied. For example, given

define void @my_func() {
  ret void
}
@my_alias = alias weak void ()* @my_func
@my_alias2 = alias void ()* @my_alias

We produce without this patch:

        .weak   my_alias
my_alias = my_func
        .globl  my_alias2
my_alias2 = my_alias

That is, in the resulting ELF file my_alias, my_func and my_alias are
just 3 names pointing to offset 0 of .text. That is *not* the
semantics of IR linking. For example, linking in a

@my_alias = alias void ()* @other_func

would require the strong my_alias to override the weak one and
my_alias2 would end up pointing to other_func.

There is no way to represent that with aliases being just another
name, so the best solution seems to be to just disallow it, converting
a miscompile into an error.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204934 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 15:26:56 +00:00
Rafael Espindola
72db10a995 Revert "Prevent alias from pointing to weak aliases."
This reverts commit r204781.

I will follow up to with msan folks to see what is what they
were trying to do with aliases to weak aliases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204784 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-26 06:14:40 +00:00
Rafael Espindola
33845aa8c4 Prevent alias from pointing to weak aliases.
Aliases are just another name for a position in a file. As such, the
regular symbol resolutions are not applied. For example, given

define void @my_func() {
  ret void
}
@my_alias = alias weak void ()* @my_func
@my_alias2 = alias void ()* @my_alias

We produce without this patch:

        .weak   my_alias
my_alias = my_func
        .globl  my_alias2
my_alias2 = my_alias

That is, in the resulting ELF file my_alias, my_func and my_alias are
just 3 names pointing to offset 0 of .text. That is *not* the
semantics of IR linking. For example, linking in a

@my_alias = alias void ()* @other_func

would require the strong my_alias to override the weak one and
my_alias2 would end up pointing to other_func.

There is no way to represent that with aliases being just another
name, so the best solution seems to be to just disallow it, converting
a miscompile into an error.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204781 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-26 04:48:47 +00:00
Chandler Carruth
436906ab3c [TTI] There is actually no realistic way to pop TTI implementations off
the stack of the analysis group because they are all immutable passes.
This is made clear by Craig's recent work to use override
systematically -- we weren't overriding anything for 'finalizePass'
because there is no such thing.

This is kind of a lame restriction on the API -- we can no longer push
and pop things, we just set up the stack and run. However, I'm not
invested in building some better solution on top of the existing
(terrifying) immutable pass and legacy pass manager.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203437 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-10 02:45:14 +00:00
Chandler Carruth
36b699f2b1 [C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
   detail
2) Change it to actually be a *Use* iterator rather than a *User*
   iterator.
3) Add an adaptor which is a User iterator that always looks through the
   Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
   they wanted a use_iterator (and to explicitly dig out the User when
   needed), or a user_iterator which makes the Use itself totally
   opaque.

Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.

The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.

However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203364 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-09 03:16:01 +00:00