Commit Graph

8533 Commits

Author SHA1 Message Date
Justin Bogner b012699741 SDAG: Rename Select->SelectImpl and repurpose Select as returning void
This is a step towards removing the rampant undefined behaviour in
SelectionDAG, which is a part of llvm.org/PR26808.

We rename SelectionDAGISel::Select to SelectImpl and update targets to
match, and then change Select to return void and consolidate the
sketchy behaviour we're trying to get away from there.

Next, we'll update backends to implement `void Select(...)` instead of
SelectImpl and eventually drop the base Select implementation.

llvm-svn: 268693
2016-05-05 23:19:08 +00:00
Tim Northover df43264cf7 ARM: don't attempt to merge litpools referencing different PC-anchors.
Given something like:

    ldr r0, .LCPI0_0 (== pc-rel var)
    add r0, pc

    ldr r1, .LCPI0_1 (== pc-rel var)
    add r1, pc

we cannot combine the 2 ldr instructions and litpools because they get added to
a different pc to form the correct address. I think the original logic came
from a time when we fused the LDRpci/PICADD instructions into one
pseudo-instruction so the PC was always immediately at-hand. That's no longer
the case.

Should fix general-dynamic TLS access on Linux, and quite possibly other -fPIC
code that relies on litpools (e.g. v6m and -Oz compilations) though trivial
tweaks of the .ll test didn't provoke anything.

llvm-svn: 268662
2016-05-05 18:38:53 +00:00
Justin Bogner 8752be775c ARM: Use a Handle to track SDNodes in case they're CSE'd. NFC
The code here is recursively Select-ing a new Node to avoid issues
where N is CSE'd during replaceDAGValue and stops being valid. We can
accomplish the same goal in a more principled way by using a
HandleSDNode.

This is essentially a less dodgy fix for PR25733 than the original
attempt back in r255120.

llvm-svn: 268590
2016-05-05 01:43:49 +00:00
Vitaly Buka 6b5c89262a Revert r268529 because it caused use-of-uninitialized-value
Summary: This reverts commit d88cc0862bf7da64850b89e9bb5ea9f95e7f1184.

#0 0xfed467 in llvm::ARMFrameLowering::determineCalleeSaves(llvm::MachineFunction&, llvm::BitVector&, llvm::RegScavenger*) const /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/Target/ARM/ARMFrameLowering.cpp:1625:52
#1 0x330d4cc in (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/PrologEpilogInserter.cpp:186:3
#2 0x3193e12 in llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/MachineFunctionPass.cpp:60:13
#3 0x396237d in llvm::FPPassManager::runOnFunction(llvm::Function&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1526:23
#4 0x3962a23 in llvm::FPPassManager::runOnModule(llvm::Module&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1547:16
#5 0x3963d52 in runOnModule /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1603:23
#6 0x3963d52 in llvm::legacy::PassManagerImpl::run(llvm::Module&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1706
#7 0x6bb910 in compileModule(char**, llvm::LLVMContext&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/llc/llc.cpp:412:5
#8 0x6b3c25 in main /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/llc/llc.cpp:218:22
#9 0x7fd4a7d37ec4 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21ec4)
#10 0x625c93 in _start (/mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm_build_msan/bin/llc+0x625c93)

Reviewers:

Subscribers:

llvm-svn: 268536
2016-05-04 19:44:11 +00:00
Weiming Zhao 2373f769ce [ARM] Fix Scavenger assert due to underestimated stack size
Summary:
Currently, when checking if a stack is "BigStack" or not, it doesn't count into spills and arguments. Therefore, LLVM won't reserve spill slot for this actually "BigStack". This may cause scavenger failure.

Reviewers: rengolin

Subscribers: aemerson, rengolin, tberghammer, danalbert, srhines, llvm-commits

Differential Revision: http://reviews.llvm.org/D19896

llvm-svn: 268529
2016-05-04 18:19:33 +00:00
Matthias Braun d1aabb2813 livePhysRegs: Pass MBB by reference in addLive{Ins|Outs}(); NFC
The block must no be nullptr for the addLiveIns()/addLiveOuts()
function.

llvm-svn: 268340
2016-05-03 00:24:32 +00:00
Matthias Braun 24f26e6d91 LivePhysRegs: Automatically determine presence of pristine regs.
Remove the AddPristinesAndCSRs parameters from
addLiveIns()/addLiveOuts().

We need to respect pristine registers after prologue epilogue insertion,
Seeing that we got this wrong in at least two commits already, we should
rather pay the small price to query MachineFrameInfo for it.

There are three cases that did not set AddPristineAndCSRs to true even
after register allocation:
- ExecutionDepsFix: live-out registers are used as a hint that the
  register is used soon. This is not true for pristine registers so
  use the new addLiveOutsNoPristines() to maintain this behaviour.
- SystemZShortenInst: Not setting AddPristineAndCSRs to true looks like
  a bug, should do the right thing automatically now.
- StackMapLivenessAnalysis: Not adding pristine registers looks like a
  bug to me. Added a FIXME comment but maintain the current behaviour
  as a change may need to get coordinated with GC runtimes.

llvm-svn: 268336
2016-05-03 00:08:46 +00:00
Tim Northover c08db1840c ARM: fix handling of SUB immediates in peephole opt.
We were negating an immediate that was going to be used in a SUBri form
unnecessarily. Since ADD/SUB are very similar we *can* do that, but we have to
change the SUB to an ADD at the same time. This also applies to ADD, and allows
us to handle a slightly larger range of immediates for those two operations.

rdar://25992245

llvm-svn: 268276
2016-05-02 18:30:08 +00:00
Filipe Cabecinhas 0da9937517 Unify XDEBUG and EXPENSIVE_CHECKS (into the latter), and add an option to the cmake build to enable them.
Summary:
Historically, we had a switch in the Makefiles for turning on "expensive
checks". This has never been ported to the cmake build, but the
(dead-ish) code is still around.

This will also make it easier to turn it on in buildbots.

Reviewers: chandlerc

Subscribers: jyknight, mzolotukhin, RKSimon, gberry, llvm-commits

Differential Revision: http://reviews.llvm.org/D19723

llvm-svn: 268050
2016-04-29 15:22:48 +00:00
Craig Topper 33772c5375 [CodeGen] Default CTTZ_ZERO_UNDEF/CTLZ_ZERO_UNDEF to Expand in TargetLoweringBase. This is what the majority of the targets want and removes a bunch of code. Set it to Legal explicitly in the few cases where that's the desired behavior.
llvm-svn: 267853
2016-04-28 03:34:31 +00:00
Ahmed Bougacha 65572afea8 [ARM] Set AddPristinesAndCSRs to expandCMP_SWAP LivePhysRegs.
We run after PEI.
Found via inspection; no obvious testcase.

Follow-up to r266679.

llvm-svn: 267781
2016-04-27 20:33:07 +00:00
Ahmed Bougacha b4af107239 [ARM] Set correct successors in CMPXCHG pseudo expansion.
transferSuccessors() would LoadCmpBB a successor of DoneBB, whereas
it should be a successor of the original MBB.

The testcase changes are caused by Thumb2SizeReduction, which
was previously confused by the broken CFG.

Follow-up to r266679.

Unfortunately, it's tricky to catch this in the verifier.

llvm-svn: 267778
2016-04-27 20:32:54 +00:00
Ahmed Bougacha 128f8732a5 [CodeGen] Add getBuildVector and getSplatBuildVector helpers. NFCI.
Differential Revision: http://reviews.llvm.org/D17176

llvm-svn: 267606
2016-04-26 21:15:30 +00:00
Craig Topper d8d6be4f99 [ARM] Expand vector ctlz_zero_undef so it becomes ctlz.
The default is Legal, which results in 'Cannot select' errors.

llvm-svn: 267521
2016-04-26 05:04:37 +00:00
Craig Topper edb4a6ba98 [ARM] Expand v1i64 and v2i64 ctlz.
The default is legal, which results in 'Cannot select' errors.

llvm-svn: 267520
2016-04-26 05:04:33 +00:00
Andrew Kaylor 1aa3cf7d18 Reverting Thumb2SizeReduction opt bisect change to fix failing buildbots.
llvm-svn: 267506
2016-04-26 00:56:36 +00:00
Junmo Park 3c65acf87e Remove MinLatency in SchedMachineModel. NFC.
Summary:
We don't use MinLatency any more since r184032.

Reviewers: atrick, hfinkel, mcrosier

Differential Revision: http://reviews.llvm.org/D19474

llvm-svn: 267502
2016-04-26 00:37:46 +00:00
Andrew Kaylor 736efc894d Fix build warning
llvm-svn: 267487
2016-04-25 22:27:30 +00:00
Andrew Kaylor a2b9111ef7 Add optimization bisect opt-in calls for ARM passes
Differential Revision: http://reviews.llvm.org/D19449

llvm-svn: 267480
2016-04-25 22:01:04 +00:00
Tim Northover 5c3140f745 ARM: put extern __thread stubs in a special section.
The linker needs to know that the symbols are thread-local to do its job
properly.

llvm-svn: 267473
2016-04-25 21:12:04 +00:00
Silviu Baranga 82d04260b7 [ARM] Add support for the X asm constraint
Summary:
This patch adds support for the X asm constraint.

To do this, we lower the constraint to either a "w" or "r" constraint
depending on the operand type (both constraints are supported on ARM).

Fixes PR26493

Reviewers: t.p.northover, echristo, rengolin

Subscribers: joker.eph, jgreenhalgh, aemerson, rengolin, llvm-commits

Differential Revision: http://reviews.llvm.org/D19061

llvm-svn: 267411
2016-04-25 14:29:18 +00:00
Saleem Abdulrasool 9611518646 ARM: fix __chkstk Frame Setup on WoA
This corrects the MI annotations for the stack adjustment following the __chkstk
invocation.  We were marking the original SP usage as a Def rather than Kill.
The (new) assigned value is the definition, the original reference is killed.

Adjust the ISelLowering to mark Kills and FrameSetup as well.

This partially resolves PR27480.

llvm-svn: 267361
2016-04-24 20:12:48 +00:00
Peter Collingbourne 265ebd7d70 CodeGen: Use PLT relocations for relative references to unnamed_addr functions.
The relative vtable ABI (PR26723) needs PLT relocations to refer to virtual
functions defined in other DSOs. The unnamed_addr attribute means that the
function's address is not significant, so we're allowed to substitute it
with the address of a PLT entry.

Also includes a bonus feature: addends for COFF image-relative references.

Differential Revision: http://reviews.llvm.org/D17938

llvm-svn: 267211
2016-04-22 20:40:10 +00:00
David Majnemer 68318e0414 Fix some spelling mistakes
llvm-svn: 267112
2016-04-22 06:37:48 +00:00
Saleem Abdulrasool a028853540 ARM: restrict register class for WIN__DBZCHK
WIN__DBZCHK will insert a CBZ instruction into the stream.  This instruction
reserves 3 bits for the condition register (rn).  As such, we must ensure that
we restrict the register to a low register.  Use the tGPR class instead of GPR
to ensure that this is properly constrained.  In debug builds, we would attempt
to use lr as a condition register which would silently get truncated with no
hint that the register selection was incorrect.

llvm-svn: 267080
2016-04-21 23:53:19 +00:00
Tim Northover c52c74efdf MachO: enable .data_region directives everywhere
We'd disabled them on x86 because back in the early days some host tools
couldn't handle the new load commands. This no longer holds: anyone capable of
deploying Clang should be able to deploy its copies of ar/ranlib/etc.

rdar://25254790

llvm-svn: 267075
2016-04-21 23:00:17 +00:00
Tim Northover 1ee27c74cb ARM: fix assertion failure on -O0 cmpxchg.
Because lowering of CMP_SWAP_64 occurs during type legalization, there can be
i64 types produced by more than just a BUILD_PAIR or similar. My initial tests
used just incoming function args.

llvm-svn: 266828
2016-04-19 22:25:02 +00:00
Marcin Koscielnicki 3fdc257d6a [AArch64] [ARM] Make a target-independent llvm.thread.pointer intrinsic.
Both AArch64 and ARM support llvm.<arch>.thread.pointer intrinsics that
just return the thread pointer.  I have a pending patch that does the same
for SystemZ (D19054), and there are many more targets that could benefit
from one.

This patch merges the ARM and AArch64 intrinsics into a single target
independent one that will also be used by subsequent targets.

Differential Revision: http://reviews.llvm.org/D19098

llvm-svn: 266818
2016-04-19 20:51:05 +00:00
Tim Northover b629c77692 ARM: use a pseudo-instruction for cmpxchg at -O0.
The fast register-allocator cannot cope with inter-block dependencies without
spilling. This is fine for ldrex/strex loops coming from atomicrmw instructions
where any value produced within a block is dead by the end, but not for
cmpxchg. So we lower a cmpxchg at -O0 via a pseudo-inst that gets expanded
after regalloc.

Fortunately this is at -O0 so we don't have to care about performance. This
simplifies the various axes of expansion considerably: we assume a strong
seq_cst operation and ensure ordering via the always-present DMB instructions
rather than v8 acquire/release instructions.

Should fix the 32-bit part of PR25526.

llvm-svn: 266679
2016-04-18 21:48:55 +00:00
Renato Golin 4b18a510a2 [ARM] AArch32 v8 NEON is still not IEEE-754 compliant
llvm-svn: 266603
2016-04-18 12:06:47 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Tim Northover 903f81ba18 ARM: don't try to hoist constant RHS out of a division.
Divisions by a constant can be converted into multiplies which are usually
cheaper, but this isn't possible if the constant gets separated (particularly
in loops). Fix this by telling ConstantHoisting that the immediate in a DIV is
cheap.

I considered making the check generic, but neither AArch64 (strangely) nor x86
showed any benefit on the tests I had.

llvm-svn: 266464
2016-04-15 18:17:18 +00:00
Renato Golin 5cb666add7 [ARM] Adding IEEE-754 SIMD detection to loop vectorizer
Some SIMD implementations are not IEEE-754 compliant, for example ARM's NEON.

This patch teaches the loop vectorizer to only allow transformations of loops
that either contain no floating-point operations or have enough allowance
flags supporting lack of precision (ex. -ffast-math, Darwin).

For that, the target description now has a method which tells us if the
vectorizer is allowed to handle FP math without falling into unsafe
representations, plus a check on every FP instruction in the candidate loop
to check for the safety flags.

This commit makes LLVM behave like GCC with respect to ARM NEON support, but
it stops short of fixing the underlying problem: sub-normals. Neither GCC
nor LLVM have a flag for allowing sub-normal operations. Before this patch,
GCC only allows it using unsafe-math flags and LLVM allows it by default with
no way to turn it off (short of not using NEON at all).

As a first step, we push this change to make it safe and in sync with GCC.
The second step is to discuss a new sub-normal's flag on both communitues
and come up with a common solution. The third step is to improve the FastMath
flags in LLVM to encode sub-normals and use those flags to restrict NEON FP.

Fixes PR16275.

llvm-svn: 266363
2016-04-14 20:42:18 +00:00
Matthias Braun 46b0f03e12 TargetLowering: Factor out common code for tail call eligibility checking; NFC
llvm-svn: 266270
2016-04-14 01:10:42 +00:00
Tim Northover 5c02f9ad28 ARM: override cost function to re-enable ConstantHoisting (& fix it).
At some point, ARM stopped getting any benefit from ConstantHoisting because
the pass called a different variant of getIntImmCost. Reimplementing the
correct variant revealed some problems, however:

  + ConstantHoisting was modifying switch statements. This is simply invalid,
    the cases must remain integer constants no matter the notional cost.
  + ConstantHoisting was mangling alloca instructions in the entry block. These
    should be handled by FrameLowering, so constants actually have a cost of 0.
    Worse, the resulting bitcasts meant they became dynamic allocas.

rdar://25707382

llvm-svn: 266260
2016-04-13 23:08:27 +00:00
Matthias Braun 707e02c273 ARM: Use a callee save register for the swiftself parameter.
It is very likely that the swiftself parameter is alive throughout most
functions function so putting it into a callee save register should
avoid spills for the callers with only a minimum amount of extra spills
in the callees.

Currently the generated code is correct but unnecessarily spills and
reloads arguments passed in callee save registers, I will address this
in upcoming patches.

This also adds a missing check that for tail calls the preserved value
of the caller must be the same as the callees parameter.

Differential Revision: http://reviews.llvm.org/D18901

llvm-svn: 266253
2016-04-13 21:43:25 +00:00
Tim Northover a6dea06fe3 ARM: use r7 as the frame-pointer on all MachO targets.
This is better for a few reasons:
  + It matches the other tooling for iOS.
  + It matches EABI in more cases (i.e. Thumb-mode, and in practice we don't
    use ARM mode).
  + It leads to infinitesimally smaller code (0.2%, yay!).

rdar://25369506

llvm-svn: 266003
2016-04-11 22:27:40 +00:00
Manman Ren 5751814eda Swift Calling Convention: swifterror target support.
Differential Revision: http://reviews.llvm.org/D18716

llvm-svn: 265997
2016-04-11 21:08:06 +00:00
Oliver Stannard c869e9158d [ARM] Avoid switching ARM/Thumb mode on .arch/.cpu directive
When we see a .arch or .cpu directive, we should try to avoid switching
ARM/Thumb mode if possible.

If we do have to switch modes, we also need to emit the correct mapping
symbol for the new ISA. We did not do this previously, so could emit
ARM code with Thumb mapping symbols (or vice-versa).

The GAS behaviour is to always stay in the same mode, and to emit an
error on any instructions seen when the current mode is not available on
the current target. We can't represent that situation easily (we assume
that Thumb mode is available if ModeThumb is set), so we differ from the
GAS behaviour when switching to a target that can't support the old
mode. I've added a warning for when this implicit mode-switch occurs.

Differential Revision: http://reviews.llvm.org/D18955

llvm-svn: 265936
2016-04-11 13:06:28 +00:00
Sam Parker 2d5126cdf5 [ARM] Enable SMLAW[B|T] and SMLUW[B|T] instruction selection
Added ISelDAGToDAG functions to enable selection of the smlawb, smlawt,
smulwb and smulwt instructions for the ARM backend. Also updated the smul
CodeGen test and removed the smulw one.

Differential Revision: http://reviews.llvm.org/D18892

llvm-svn: 265793
2016-04-08 16:02:53 +00:00
JF Bastien 800f87a871 NFC: make AtomicOrdering an enum class
Summary:
In the context of http://wg21.link/lwg2445 C++ uses the concept of
'stronger' ordering but doesn't define it properly. This should be fixed
in C++17 barring a small question that's still open.

The code currently plays fast and loose with the AtomicOrdering
enum. Using an enum class is one step towards tightening things. I later
also want to tighten related enums, such as clang's
AtomicOrderingKind (which should be shared with LLVM as a 'C++ ABI'
enum).

This change touches a few lines of code which can be improved later, I'd
like to keep it as NFC for now as it's already quite complex. I have
related changes for clang.

As a follow-up I'll add:
  bool operator<(AtomicOrdering, AtomicOrdering) = delete;
  bool operator>(AtomicOrdering, AtomicOrdering) = delete;
  bool operator<=(AtomicOrdering, AtomicOrdering) = delete;
  bool operator>=(AtomicOrdering, AtomicOrdering) = delete;
This is separate so that clang and LLVM changes don't need to be in sync.

Reviewers: jyknight, reames

Subscribers: jyknight, llvm-commits

Differential Revision: http://reviews.llvm.org/D18775

llvm-svn: 265602
2016-04-06 21:19:33 +00:00
Manman Ren 802cd6f9d7 Swift Calling Convention: swiftcc for ARM.
Differential Revision: http://reviews.llvm.org/D18769

llvm-svn: 265482
2016-04-05 22:44:44 +00:00
Sam Parker 0d3a3a537c [ARM] Cleanup of smul and smla instruction descriptions
Removed the SDNode argument passed to the AI_smul and AI_smla multiclass
definitions as they are always mul.

Differential Revision: http://reviews.llvm.org/D18791

llvm-svn: 265409
2016-04-05 16:01:25 +00:00
Matthias Braun 870c34f0cf ARM, AArch64, X86: Check preserved registers for tail calls.
We can only perform a tail call to a callee that preserves all the
registers that the caller needs to preserve.

This situation happens with calling conventions like preserver_mostcc or
cxx_fast_tls. It was explicitely handled for fast_tls and failing for
preserve_most. This patch generalizes the check to any calling
convention.

Related to rdar://24207743

Differential Revision: http://reviews.llvm.org/D18680

llvm-svn: 265329
2016-04-04 18:56:13 +00:00
Derek Schuff 1dbf7a571f Add MachineFunctionProperty checks for AllVRegsAllocated for target passes
Summary:
This adds the same checks that were added in r264593 to all
target-specific passes that run after register allocation.

Reviewers: qcolombet

Subscribers: jyknight, dsanders, llvm-commits

Differential Revision: http://reviews.llvm.org/D18525

llvm-svn: 265313
2016-04-04 17:09:25 +00:00
James Y Knight e6a4646372 Remove useless check for ThreadModel==Single in ARMISelLowering. NFC.
ThreadModel::Single is already handled already by ARMPassConfig adding
LowerAtomicPass to the pass list, which lowers all atomics to non-atomic
ops and deletes fences.

So by the time we get to ISel, there's no atomic fences left, so they
don't need special handling.

llvm-svn: 265178
2016-04-01 19:33:19 +00:00
James Molloy b876c72bcc Fix for pr24346: arm asm label calculation error in sub
Some ARM instructions encode 32-bit immediates as a 8-bit integer (0-255)
and a 4-bit rotation (0-30, even) in its least significant 12 bits. The
original fixup, FK_Data_4, patches the instruction by the value bit-to-bit,
regardless of the encoding. For example, assuming the label L1 and L2 are
0x0 and 0x104 respectively, the following instruction:

  add r0, r0, #(L2 - L1) ; expects 0x104, i.e., 260

would be assembled to the following, which adds 1 to r0, instead of 260:

  e2800104 add r0, r0, #4, 2 ; equivalently 1

The new fixup kind fixup_arm_mod_imm takes care of the encoding:

  e2800f41 add r0, r0, #260

Patch by Ting-Yuan Huang!

llvm-svn: 265122
2016-04-01 09:40:47 +00:00
Benjamin Kramer 569efd2cfd [ARM] Expand v1i64 and v2i64 ctpop.
The default is legal, which results in 'Cannot select' errors. This is
triggered during selfhost due to a recent cost model change.

llvm-svn: 265040
2016-03-31 19:42:04 +00:00
Hans Wennborg e1a2e90ffa Change eliminateCallFramePseudoInstr() to return an iterator
This will become necessary in a subsequent change to make this method
merge adjacent stack adjustments, i.e. it might erase the previous
and/or next instruction.

It also greatly simplifies the calls to this function from Prolog-
EpilogInserter. Previously, that had a bunch of logic to resume iteration
after the call; now it just continues with the returned iterator.

Note that this changes the behaviour of PEI a little. Previously,
it attempted to re-visit the new instruction created by
eliminateCallFramePseudoInstr(). That code was added in r36625,
but I can't see any reason for it: the new instructions will obviously
not be pseudo instructions, they will not have FrameIndex operands,
and we have already accounted for the stack adjustment.

Differential Revision: http://reviews.llvm.org/D18627

llvm-svn: 265036
2016-03-31 18:33:38 +00:00
Matthias Braun 8d41436004 CodeGen: Factor out code for tail call result compatibility check; NFC
llvm-svn: 264959
2016-03-30 22:46:04 +00:00