875 Commits

Author SHA1 Message Date
Renato Golin
3b1d3b0d84 Revert "Revert "New interface function is added to VectorUtils Value *getSplatValue(Value *Val);""
This reverts commit r246379. It seems that the commit was not the culprit,
and the bot will be investigated for instability.

llvm-svn: 246380
2015-08-30 10:49:04 +00:00
Renato Golin
c7be31736c Revert "New interface function is added to VectorUtils Value *getSplatValue(Value *Val);"
This reverts commit r246371, as it cause a rather obscure bug in AArch64
test-suite paq8p (time outs, seg-faults). I'll investigate it before
reapplying.

llvm-svn: 246379
2015-08-30 10:05:30 +00:00
Elena Demikhovsky
a59fcfa56b New interface function is added to VectorUtils
Value *getSplatValue(Value *Val);

It complements the CreateVectorSplat(), which creates 2 instructions - insertelement and shuffle with all-zero mask.

The new function recognizes the pattern - insertelement+shuffle and returns the splat value (or nullptr).
It also returns a splat value form ConstantDataVector, for completeness.

Differential Revision:	http://reviews.llvm.org/D11124

llvm-svn: 246371
2015-08-30 07:28:18 +00:00
Reid Kleckner
0e2882345d [WinEH] Add some support for code generating catchpad
We can now run 32-bit programs with empty catch bodies.  The next step
is to change PEI so that we get funclet prologues and epilogues.

llvm-svn: 246235
2015-08-27 23:27:47 +00:00
Cong Hou
08cb4fc688 Fixed a bug that edge weights are not assigned correctly when lowering switch statement.
This is a one-line-change patch that moves the update to UnhandledWeights to the correct position: it should be updated for all clusters instead of just range clusters.

Differential Revision: http://reviews.llvm.org/D12391

llvm-svn: 246129
2015-08-27 00:37:40 +00:00
Cong Hou
03127700d5 Assign weights to edges to jump table / bit test header when lowering switch statement.
Currently, when lowering switch statement and a new basic block is built for jump table / bit test header, the edge to this new block is not assigned with a correct weight. This patch collects the edge weight from all its successors and assign this sum of weights to the edge (and also the other fall-through edge). Test cases are adjusted accordingly.

Differential Revision: http://reviews.llvm.org/D12166#fae6eca7

llvm-svn: 246104
2015-08-26 23:15:32 +00:00
Cong Hou
cd59591396 Remove the final bit test during lowering switch statement if all cases in bit test cover a contiguous range.
When lowering switch statement, if bit tests are used then LLVM will always generates a jump to the default statement in the last bit test. However, this is not necessary when all cases in bit tests cover a contiguous range. This is because when generating the bit tests header MBB, there is a range check that guarantees cases in bit tests won't go outside of [low, high], where low and high are minimum and maximum case values in the bit tests. This patch checks if this is the case and then doesn't emit jump to default statement and hence saves a bit test and a branch.

Differential Revision: http://reviews.llvm.org/D12249

llvm-svn: 245976
2015-08-25 21:34:38 +00:00
James Molloy
ef183397b1 Generate FMINNAN/FMINNUM/FMAXNAN/FMAXNUM from SDAGBuilder.
These only get generated if the target supports them. If one of the variants is not legal and the other is, and it is safe to do so, the other variant will be emitted.

For example on AArch32 (V8), we have scalar fminnm but not fmin.

Fix up a couple of tests while we're here - one now produces better code, and the other was just plain wrong to start with.

llvm-svn: 245196
2015-08-17 07:13:10 +00:00
Alex Lorenz
e40c8a2b26 PseudoSourceValue: Replace global manager with a manager in a machine function.
This commit removes the global manager variable which is responsible for
storing and allocating pseudo source values and instead it introduces a new
manager class named 'PseudoSourceValueManager'. Machine functions now own an
instance of the pseudo source value manager class.

This commit also modifies the 'get...' methods in the 'MachinePointerInfo'
class to construct pseudo source values using the instance of the pseudo
source value manager object from the machine function.

This commit updates calls to the 'get...' methods from the 'MachinePointerInfo'
class in a lot of different files because those calls now need to pass in a
reference to a machine function to those methods.

This change will make it easier to serialize pseudo source values as it will
enable me to transform the mips specific MipsCallEntry PseudoSourceValue
subclass into two target independent subclasses.

Reviewers: Akira Hatanaka
llvm-svn: 244693
2015-08-11 23:09:45 +00:00
Sanjay Patel
070df89928 fix minsize detection: minsize attribute implies optimizing for size
llvm-svn: 244631
2015-08-11 17:04:31 +00:00
James Molloy
134bec2722 Add support for floating-point minnum and maxnum
The select pattern recognition in ValueTracking (as used by InstCombine
and SelectionDAGBuilder) only knew about integer patterns. This teaches
it about minimum and maximum operations.

matchSelectPattern() has been extended to return a struct containing the
existing Flavor and a new enum defining the pattern's behavior when
given one NaN operand.

C minnum() is defined to return the non-NaN operand in this case, but
the idiomatic C "a < b ? a : b" would return the NaN operand.

ARM and AArch64 at least have different instructions for these different cases.

llvm-svn: 244580
2015-08-11 09:12:57 +00:00
Benjamin Kramer
df005cbe19 Fix some comment typos.
llvm-svn: 244402
2015-08-08 18:27:36 +00:00
Chandler Carruth
50fee93926 [PM/AA] Simplify the AliasAnalysis interface by removing a wrapper
around a DataLayout interface in favor of directly querying DataLayout.

This wrapper specifically helped handle the case where this no
DataLayout, but LLVM now requires it simplifynig all of this. I've
updated callers to directly query DataLayout. This in turn exposed
a bunch of places where we should have DataLayout readily available but
don't which I've fixed. This then in turn exposed that we were passing
DataLayout around in a bunch of arguments rather than making it readily
available so I've also fixed that.

No functionality changed.

llvm-svn: 244189
2015-08-06 02:05:46 +00:00
Sanjay Patel
b6a79f9916 revert r243687: enable fast-math-flag propagation to DAG nodes
We can't propagate FMF partially without breaking DAG-level CSE. We either need to
relax CSE to account for mismatched FMF as a temporary work-around or fully propagate
FMF throughout the DAG.

Surprisingly, there are no existing regression tests for this, but here's an example:

  define float @fmf(float %a, float %b) {
    %mul1 = fmul fast float %a, %b
    %nega = fsub fast float 0.0, %a
    %mul2 = fmul fast float %nega, %b
    %abx2 = fsub fast float %mul1, %mul2
    ret float %abx2
  }


$ llc -o - badflags.ll -march=x86-64 -mattr=fma -enable-unsafe-fp-math -enable-fmf-dag=0
...
    vmulss    %xmm1, %xmm0, %xmm0
    vaddss    %xmm0, %xmm0, %xmm0
    retq

$ llc -o - badflags.ll -march=x86-64 -mattr=fma -enable-unsafe-fp-math -enable-fmf-dag=1
...
    vmulss    %xmm1, %xmm0, %xmm2
    vfmadd213ss    %xmm2, %xmm1, %xmm0  <--- failed to recognize that (a * b) was already calculated
    retq

llvm-svn: 244053
2015-08-05 15:12:03 +00:00
Sanjay Patel
924879ad2c wrap OptSize and MinSize attributes for easier and consistent access (NFCI)
Create wrapper methods in the Function class for the OptimizeForSize and MinSize
attributes. We want to hide the logic of "or'ing" them together when optimizing
just for size (-Os).

Currently, we are not consistent about this and rely on a front-end to always set
OptimizeForSize (-Os) if MinSize (-Oz) is on. Thus, there are 18 FIXME changes here
that should be added as follow-on patches with regression tests.

This patch is NFC-intended: it just replaces existing direct accesses of the attributes
by the equivalent wrapper call.

Differential Revision: http://reviews.llvm.org/D11734

llvm-svn: 243994
2015-08-04 15:49:57 +00:00
Duncan P. N. Exon Smith
ed013cd221 DI: Remove DW_TAG_arg_variable and DW_TAG_auto_variable
Remove the fake `DW_TAG_auto_variable` and `DW_TAG_arg_variable` tags,
using `DW_TAG_variable` in their place Stop exposing the `tag:` field at
all in the assembly format for `DILocalVariable`.

Most of the testcase updates were generated by the following sed script:

    find test/ -name "*.ll" -o -name "*.mir" |
    xargs grep -l 'DILocalVariable' |
    xargs sed -i '' \
      -e 's/tag: DW_TAG_arg_variable, //' \
      -e 's/tag: DW_TAG_auto_variable, //'

There were only a handful of tests in `test/Assembly` that I needed to
update by hand.

(Note: a follow-up could change `DILocalVariable::DILocalVariable()` to
set the tag to `DW_TAG_formal_parameter` instead of `DW_TAG_variable`
(as appropriate), instead of having that logic magically in the backend
in `DbgVariable`.  I've added a FIXME to that effect.)

llvm-svn: 243774
2015-07-31 18:58:39 +00:00
David Majnemer
654e130b6e New EH representation for MSVC compatibility
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support.  Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.

Differential Revision: http://reviews.llvm.org/D11097

llvm-svn: 243766
2015-07-31 17:58:14 +00:00
Sanjay Patel
a93cf60a77 enable fast-math-flag propagation to DAG nodes
This uncovered latent bugs previously:
http://reviews.llvm.org/D10403

...but it's time to try again because internal tests aren't finding more.

If time passes and no other bugs are reported, we can remove this cl::opt.

llvm-svn: 243687
2015-07-30 21:06:55 +00:00
Matthias Braun
3cd00c1739 Fix __builtin_setjmp in combination with sjlj exception handling.
llvm.eh.sjlj.setjmp was used as part of the SjLj exception handling
style but is also used in clang to implement __builtin_setjmp.  The ARM
backend needs to output additional dispatch tables for the SjLj
exception handling style, these tables however can't be emitted if
llvm.eh.sjlj.setjmp is simply used for __builtin_setjmp and no actual
landing pad blocks exist.

To solve this issue a new llvm.eh.sjlj.setup_dispatch intrinsic is
introduced which is used instead of llvm.eh.sjlj.setjmp in the SjLj
exception handling lowering, so we can differentiate between the case
where we actually need to setup a dispatch table and the case where we
just need the __builtin_setjmp semantic.

Differential Revision: http://reviews.llvm.org/D9313

llvm-svn: 242481
2015-07-16 22:34:16 +00:00
James Molloy
7395a8182c [Codegen] Add intrinsics 'absdiff' and corresponding SDNodes for absolute difference operation
This adds new intrinsics "*absdiff" for absolute difference ops to facilitate efficient code generation for "sum of absolute differences" operation.
The patch also contains the introduction of corresponding SDNodes and basic legalization support.Sanity of the generated code is tested on X86.

This is 1st of the three patches.

Patch by Shahid Asghar-ahmad!

llvm-svn: 242409
2015-07-16 15:22:46 +00:00
Mehdi Amini
bd7287ebe5 Move most user of TargetMachine::getDataLayout to the Module one
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

This patch is quite boring overall, except for some uglyness in
ASMPrinter which has a getDataLayout function but has some clients
that use it without a Module (llmv-dsymutil, llvm-dwarfdump), so
some methods are taking a DataLayout as parameter.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11090

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 242386
2015-07-16 06:11:10 +00:00
Pete Cooper
6923461a16 Use enum instead of unsigned. NFC.
The unsigned opcode argument here was the result of BinaryOperator->getOpcode().
That returns a BinaryOps enum which is more accurate than passing around an
unsigned.

llvm-svn: 242265
2015-07-15 01:31:26 +00:00
Pete Cooper
a8127d8c92 Use cast<> instead of dyn_cast to remove llvm_unreachable. NFC.
This code was checking if we are an ICmpInst or FCmpInst then throwing
unreachable if we are neither.  We must be one or the other, so use a
cast on the FCmpInst case to ensure that we are that case.  Then we can
avoid having an unreachable but still catch an error if we ever had another
subclass of CmpInst.

llvm-svn: 242264
2015-07-15 01:31:23 +00:00
Pete Cooper
20dc71b1f1 Use another foreach loop. NFC
llvm-svn: 242263
2015-07-15 01:31:20 +00:00
Pete Cooper
6a96c61659 Use getAnyExtOrTrunc helper instead of manually doing ext/trunc check. NFC.
The code here was doing exactly what is already in getAnyExtOrTrunc().
Just use that method instead.

llvm-svn: 242261
2015-07-15 00:43:57 +00:00
David Majnemer
db82d2f338 Revert the new EH instructions
This reverts commits r241888-r241891, I didn't mean to commit them.

llvm-svn: 241893
2015-07-10 07:15:17 +00:00
David Majnemer
ae2ffc8a8c New EH representation for MSVC compatibility
Summary:
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support.  Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.

Reviewers: rnk, JosephTremoulet, reames, nlewycky, rjmccall

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11041

llvm-svn: 241888
2015-07-10 07:00:44 +00:00
Reid Kleckner
0f7f8d41f7 Remove dead code from old 64-bit SEH lowering
llvm-svn: 241829
2015-07-09 17:46:39 +00:00
Elena Demikhovsky
37a4da825f Extended syntax of vector version of getelementptr instruction.
The justification of this change is here: http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-March/082989.html

According to the current GEP syntax, vector GEP requires that each index must be a vector with the same number of elements.

%A = getelementptr i8, <4 x i8*> %ptrs, <4 x i64> %offsets

In this implementation I let each index be or vector or scalar. All vector indices must have the same number of elements. The scalar value will mean the splat vector value.

(1) %A = getelementptr i8, i8* %ptr, <4 x i64> %offsets
or
(2) %A = getelementptr i8, <4 x i8*> %ptrs, i64 %offset

In all cases the %A type is <4 x i8*>

In the case (2) we add the same offset to all pointers.

The case (1) covers C[B[i]] case, when we have the same base C and different offsets B[i].

The documentation is updated.

http://reviews.llvm.org/D10496

llvm-svn: 241788
2015-07-09 07:42:48 +00:00
Mehdi Amini
5c183d5239 Make getByValTypeAlignment() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11038

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241777
2015-07-09 02:09:28 +00:00
Mehdi Amini
9639d650bb Make TargetLowering::getShiftAmountTy() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, llvm-commits, rafael, yaron.keren

Differential Revision: http://reviews.llvm.org/D11037

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241776
2015-07-09 02:09:20 +00:00
Mehdi Amini
44ede33a69 Make TargetLowering::getPointerTy() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, ted, yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11028

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241775
2015-07-09 02:09:04 +00:00
Mehdi Amini
56228dabfa Redirect DataLayout from TargetMachine to Module in ComputeValueVTs()
Summary:
Avoid using the TargetMachine owned DataLayout and use the Module owned
one instead. This requires passing the DataLayout up the stack to
ComputeValueVTs().

This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11019

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241773
2015-07-09 01:57:34 +00:00
Mehdi Amini
ffc1402fad Remove IsLittleEndian from TargetLowering and redirect to DataLayout
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: llvm-commits, rafael, yaron.keren

Differential Revision: http://reviews.llvm.org/D11017

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241655
2015-07-08 01:00:38 +00:00
Reid Kleckner
e69bdb8619 [WinEH] Make llvm.x86.seh.restoreframe work for stack realignment prologues
The incoming EBP value points to the end of a local stack allocation, so
we can use that to restore ESI, the base pointer. Once we do that, we
can use local stack allocations. If we know we need stack realignment,
spill the original frame pointer in the prologue and reload it after
restoring ESI.

llvm-svn: 241648
2015-07-07 23:45:58 +00:00
Reid Kleckner
60381791b5 Rename llvm.frameescape and llvm.framerecover to localescape and localrecover
Summary:
Initially, these intrinsics seemed like part of a family of "frame"
related intrinsics, but now I think that's more confusing than helpful.
Initially, the LangRef specified that this would create a new kind of
allocation that would be allocated at a fixed offset from the frame
pointer (EBP/RBP). We ended up dropping that design, and leaving the
stack frame layout alone.

These intrinsics are really about sharing local stack allocations, not
frame pointers. I intend to go further and add an `llvm.localaddress()`
intrinsic that returns whatever register (EBP, ESI, ESP, RBX) is being
used to address locals, which should not be confused with the frame
pointer.

Naming suggestions at this point are welcome, I'm happy to re-run sed.

Reviewers: majnemer, nicholas

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11011

llvm-svn: 241633
2015-07-07 22:25:32 +00:00
Mehdi Amini
8ac7a9d57a Redirect DataLayout from TargetMachine to Module in SelectionDAG
Summary:
SelectionDAG itself is not invoking directly the DataLayout in the
TargetMachine, but the "TargetLowering" class is still using it. I'll
address it in a following commit.

This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11000

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241618
2015-07-07 19:07:19 +00:00
Nadav Rotem
754eb7c563 Fix an overly aggressive assertion in getCopyFromPartsVector.
The assertion in getCopyFromPartsVector assumed that the vector 'part' must
match the type of argument (arguments are potentially split into multiple
parts). However, in some cases the targets return a 'part' of the right size
but with a different type. We already handle this case correctly later on
and generate a bitcast. This commit just makes sure that we are actually
checking the property that we care about.

llvm-svn: 241312
2015-07-02 23:23:52 +00:00
Akira Hatanaka
56c70441dc Use function attribute "trap-func-name" and remove TargetOptions::TrapFuncName.
This commit changes normal isel and fast isel to read the user-defined trap
function name from function attribute "trap-func-name" attached to llvm.trap or
llvm.debugtrap instead of from TargetOptions::TrapFuncName. This is needed to
use clang's command line option "-ftrap-function" for LTO and enable changing
the trap function name on a per-call-site basis.

Out-of-tree projects currently using TargetOptions::TrapFuncName to specify the
trap function name should attach attribute "trap-func-name" to the call sites
of llvm.trap and llvm.debugtrap instead.

rdar://problem/21225723

Differential Revision: http://reviews.llvm.org/D10832

llvm-svn: 241305
2015-07-02 22:13:27 +00:00
Benjamin Kramer
5b455f0b62 [SDAG] Now that we have a way to communicate the exact bit on sdiv use it to simplify sdiv by a constant.
We had a hack in SDAGBuilder in place to work around this but now we
can avoid that. Call BuildExactSDIV from BuildSDIV so DAGCombiner can
perform this trick automatically.

The added check in DAGCombiner is necessary to prevent exact sdiv by pow2
from regressing as the target-specific pow2 lowering is not aware of
exact bits yet.

This is mostly covered by existing tests. One side effect is that we
get the better lowering for exact vector sdivs now too :)

llvm-svn: 240891
2015-06-27 20:33:26 +00:00
Sanjay Patel
e4aedb55d6 fix typos; NFC
llvm-svn: 240699
2015-06-25 21:11:08 +00:00
Rafael Espindola
36b718fc74 Avoid a Symbol -> Name -> Symbol conversion.
Before this we were producing a TargetExternalSymbol from a MCSymbol.
That meant extracting the symbol name and fetching the symbol again
down the pipeline.

This patch adds a DAG.getMCSymbol that lets the MCSymbol pass unchanged on the
DAG.

Doing so removes the need for MO_NOPREFIX and fixes the root cause of pr23900,
allowing r240130 to be committed again.

llvm-svn: 240300
2015-06-22 17:46:53 +00:00
Hans Wennborg
6ed81cbcdb Switch lowering: add heuristic for filling leaf nodes in the weight-balanced binary search tree
Sparse switches with profile info are lowered as weight-balanced BSTs. For
example, if the node weights are {1,1,1,1,1,1000}, the right-most node would
end up in a tree by itself, bringing it closer to the top.

However, a leaf in this BST can contain up to 3 cases, and having a single
case in a leaf node as in the example means the tree might become
unnecessarily high.

This patch adds a heauristic to the pivot selection algorithm that moves more
cases into leaf nodes unless that would lower their rank. It still doesn't
yield the optimal tree in every case, but I believe it's conservatibely correct.

llvm-svn: 240224
2015-06-20 17:14:07 +00:00
Hans Wennborg
67d492a544 Switch lowering: enable whole-switch jump tables at -O0.
To same compile time, the analysis to find dense case-clusters in switches is
not done at -O0. However, when the whole switch is dense enough, it is easy to
turn it into a jump table, resulting in much faster code with no extra effort.

llvm-svn: 240071
2015-06-18 22:22:30 +00:00
Sanjay Patel
a3f423b4fc remove unnecessary casts; NFC
llvm-svn: 239942
2015-06-17 20:54:46 +00:00
Sanjay Patel
dcaa53791c fix typos in comments; NFC
llvm-svn: 239916
2015-06-17 16:34:48 +00:00
Chandler Carruth
ac80dc7532 [PM/AA] Remove the Location typedef from the AliasAnalysis class now
that it is its own entity in the form of MemoryLocation, and update all
the callers.

This is an entirely mechanical change. References to "Location" within
AA subclases become "MemoryLocation", and elsewhere
"AliasAnalysis::Location" becomes "MemoryLocation". Hope that helps
out-of-tree folks update.

llvm-svn: 239885
2015-06-17 07:18:54 +00:00
Sanjay Patel
f134048b1d propagate IR-level fast-math-flags to DAG nodes, disabled by default
This is an updated version of the patch that was checked in at:
http://reviews.llvm.org/rL237046

but subsequently reverted because it exposed a bug in the DAG Combiner:
http://reviews.llvm.org/D9893

This time, there's an enablement flag ("EnableFMFInDAG") around the code in
SelectionDAGBuilder where we copy the set of FP optimization flags from IR
instructions to DAG nodes. So, in theory, there should be no functional change
from this patch as-is, but it will allow testing with the added functionality
to proceed via "-enable-fmf-dag" passed to llc.

This patch adds the minimum plumbing necessary to use IR-level
fast-math-flags (FMF) in the backend without actually using
them for anything yet. This is a follow-on to:
http://reviews.llvm.org/rL235997

Differential Revision: http://reviews.llvm.org/D10403

llvm-svn: 239828
2015-06-16 16:25:43 +00:00
Reid Kleckner
f12c030f48 [WinEH] Add 32-bit SEH state table emission prototype
This gets all the handler info through to the asm printer and we can
look at the .xdata tables now. I've convinced one small catch-all test
case to work, but other than that, it would be a stretch to say this is
functional.

The state numbering algorithm avoids doing any scope reconstruction as
we do for C++ to simplify the implementation.

llvm-svn: 239433
2015-06-09 21:42:19 +00:00
Benjamin Kramer
ff0fb6936b [SDAG switch lowering] Fix switch case -> or merging for 0 and INT_MIN
The big/small ordering here is based on signed values so SmallValue will
be INT_MIN and BigValue 0. This shouldn't be a problem but the code
assumed that BigValue always had more bits set than SmallValue.

We used to just miss the transformation, but a recent refactoring of
mine turned this into an assertion failure.

llvm-svn: 239105
2015-06-04 22:05:51 +00:00