Missed some StringRefRefs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122077 91177308-0d34-0410-b5e6-96231b3b80d8

Add bits 31-28 to the Thumb2 encoding of TBB/TBH.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122076 91177308-0d34-0410-b5e6-96231b3b80d8

Handle 2 and 4 byte data blob fixup values for ARM.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122075 91177308-0d34-0410-b5e6-96231b3b80d8

Pass StringRefs by value, for consistency.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122074 91177308-0d34-0410-b5e6-96231b3b80d8

Add MachineLoopRange comparators for sorting loop lists by number and by area.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122073 91177308-0d34-0410-b5e6-96231b3b80d8

Reapply r121905 (automatic synthesis of @llvm.sadd.with.overflow) with a fix for a bug that manifested itself
on the DragonEgg self-host bot.  Unfortunately, the testcase is pretty messy and doesn't reduce well due to
interactions with other parts of InstCombine.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122072 91177308-0d34-0410-b5e6-96231b3b80d8

Store and free the TargetObjectWriter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122070 91177308-0d34-0410-b5e6-96231b3b80d8

Stub out explicit MCELFObjectTargetWriter interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122067 91177308-0d34-0410-b5e6-96231b3b80d8

Cleanup and document .gitignore.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122066 91177308-0d34-0410-b5e6-96231b3b80d8

Support: Rename Path.h to PathV1.h and add a new Path.h that includes both V1 and V2.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122065 91177308-0d34-0410-b5e6-96231b3b80d8

Move createELFObjectWriter to its own header.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122064 91177308-0d34-0410-b5e6-96231b3b80d8

SimplifyCFG: Ranges can be larger than 64 bits. Fixes Release-selfhost build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122054 91177308-0d34-0410-b5e6-96231b3b80d8

Fix mismatched new[]/delete.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122053 91177308-0d34-0410-b5e6-96231b3b80d8

Don't feed 19 bit immediates to ILA.

Patch (slightly modified) by Visa Putkinen.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122052 91177308-0d34-0410-b5e6-96231b3b80d8

Use getFixupKindInfo to implement isFixupKindPCRel, ELF version.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122050 91177308-0d34-0410-b5e6-96231b3b80d8

improve switch formation to handle small range
comparisons formed by comparisons.  For example,
this:

void foo(unsigned x) {
  if (x == 0 || x == 1 || x == 3 || x == 4 || x == 6)
    bar();
}

compiles into:

_foo:                                   ## @foo
## BB#0:                                ## %entry
cmpl $6, %edi
ja LBB0_2
## BB#1:                                ## %entry
movl %edi, %eax
movl $91, %ecx
btq %rax, %rcx
jb LBB0_3

instead of:

_foo:                                   ## @foo
## BB#0:                                ## %entry
cmpl $2, %edi
jb LBB0_4
## BB#1:                                ## %switch.early.test
cmpl $6, %edi
ja LBB0_3
## BB#2:                                ## %switch.early.test
movl %edi, %eax
movl $88, %ecx
btq %rax, %rcx
jb LBB0_4

This catches a bunch of cases in GCC, which look like this:

 %804 = load i32* @which_alternative, align 4, !tbaa !0
 %805 = icmp ult i32 %804, 2
 %806 = icmp eq i32 %804, 3
 %or.cond121 = or i1 %805, %806
 %807 = icmp eq i32 %804, 4
 %or.cond124 = or i1 %or.cond121, %807
 br i1 %or.cond124, label %.thread, label %808

turning this into a range comparison.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122045 91177308-0d34-0410-b5e6-96231b3b80d8

MC/ARM: Use aggressive symbol folding (important for jump tables, for example).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122044 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Expr: Implemnt more aggressive folding during symbol evaluation using
IsSymbolRefDifferenceFullyResolved(). For example, we will now fold away
something like:
--
_a:
...
L0:
...
L1:
...
.long (L1 - L0) / 2
--

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122043 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Mach-O: On second thought, use a custom hook for enabling aggressive
IsSymbolRefDifferenceFullyResolved, it turns out this does change behavior on
enough cases for x86-32 that I would rather wait a bit on it.
 - In practice, we will want to change this eventually because it only means we
   generate less relocations (it also eliminates the need for the horrible
   '.set' hack that Darwin requires in some places).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122042 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Mach-O: Implement IsSymbolRefDifferenceFullyResolved.
 - Unlike for fixups, we always do the "reliable" thing (not just for x86_64).
 - Since Darwin 'as' would typically reject things that using this will allow,
   we don't need to worry about compatibility.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122038 91177308-0d34-0410-b5e6-96231b3b80d8

MC/ObjectWriter: Add a new IsSymbolRefDifferenceFullyResolved target format specific hook.
 - Currently just has stub implementations for Mach-O, ELF, and COFF.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122037 91177308-0d34-0410-b5e6-96231b3b80d8

Provide LiveIntervalUnion::Query::checkLoopInterference.

This is a three-way interval list intersection between a virtual register, a
live interval union, and a loop. It will be used to identify interference-free
loops for live range splitting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122034 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Assembler: Strip out object writer arguments, now that it is always available
-- and remove FIXME asking for the same!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122032 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Assembler: Make the MCObjectWriter available through the lifetime of the
assembler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122031 91177308-0d34-0410-b5e6-96231b3b80d8

Trailing whitespace and 80 column fixups.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122026 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Target: Remove HasScatteredSymbols target hook variable, which has been
superceded and was effectively dead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122024 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Expr: Simplify.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122023 91177308-0d34-0410-b5e6-96231b3b80d8

Complete tests for IntervalMapOverlaps.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122019 91177308-0d34-0410-b5e6-96231b3b80d8

Fix crash compiling a QQQQ REG_SEQUENCE for a Neon vld3_lane operation.
Radar 8776599

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122018 91177308-0d34-0410-b5e6-96231b3b80d8

Use PairDRegs to implement ConcatVectors.  No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122017 91177308-0d34-0410-b5e6-96231b3b80d8

Fix a comment typo.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122016 91177308-0d34-0410-b5e6-96231b3b80d8

Neon intrinsic tests need to be compiled for Cortex-A9 for f16 support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122015 91177308-0d34-0410-b5e6-96231b3b80d8

Revert r64460. strtol and friends cannot be marked readonly, even with
a null endptr argument, because they may write to errno.

This fixes a seflhost miscompile observed on Linux targets when TBAA
was enabled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122014 91177308-0d34-0410-b5e6-96231b3b80d8

MC: Remove another dead MCAssembler argument, and update clients.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122013 91177308-0d34-0410-b5e6-96231b3b80d8

MC: Remove dead MCAssembler argument -- Rafael, can you check the FIXME I added
here?

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122012 91177308-0d34-0410-b5e6-96231b3b80d8

MC: Simplify (remove unnecessary MCAssembler argument, obsoleted by containment
in MCAsmLayout).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122011 91177308-0d34-0410-b5e6-96231b3b80d8

Fix 80-col viola.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122010 91177308-0d34-0410-b5e6-96231b3b80d8

Write => in a more normal form.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122009 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Expr: Simplify (and add a FIXME).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122008 91177308-0d34-0410-b5e6-96231b3b80d8

"Fix" FDE alignment to match what gas does.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122006 91177308-0d34-0410-b5e6-96231b3b80d8

Make pushq produce signed relocations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122005 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-dis: Fix memory leak. ParseBitcodeFile should be taking ownership of
the MemoryBuffer*, however, it doesn't seem to delete it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122004 91177308-0d34-0410-b5e6-96231b3b80d8

Add basic test exposing many bugs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121995 91177308-0d34-0410-b5e6-96231b3b80d8

Fix MBlaze backend call instructions so that arguments passed through registers
are correctly marked as used. This removes a hack where the call instructions
marked all possible argument registers as used in the tablegen description.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121994 91177308-0d34-0410-b5e6-96231b3b80d8

Pseudo-ize the Thumb1 tBfar pattern. rdar://8777974

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121990 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Expr: Add a doxyment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121988 91177308-0d34-0410-b5e6-96231b3b80d8

Oops, didn't mean to ignore .gitignore.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121985 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Mach-O: Lift some MachObjectWriter arguments into the target specific

interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121981 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-dis: Simplify MemoryBuffer usage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121975 91177308-0d34-0410-b5e6-96231b3b80d8

Fix whitespace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121974 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Mach-O: Stub out explicit MCMachObjectTargetWriter interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121973 91177308-0d34-0410-b5e6-96231b3b80d8

Fix indentation (per style guide).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121972 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Mach-O: Move createMachObjectWriter into MCMachObjectWriter.h.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121971 91177308-0d34-0410-b5e6-96231b3b80d8

MC/Mach-O: Use fixup info instead of hard coded list.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121970 91177308-0d34-0410-b5e6-96231b3b80d8

build: Fix ONLY_TOOLS to not build lto etc. unless specified.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121969 91177308-0d34-0410-b5e6-96231b3b80d8

Add some more .gitignore entries.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121968 91177308-0d34-0410-b5e6-96231b3b80d8

Fix a bug in the loop in JumpThreading::ProcessThreadableEdges() where it could falsely produce a MultipleDestSentinel value if the first predecessor ended with an 'indirectbr'. If that happened, it caused an unnecessary FindMostPopularDest() call.
This wasn't a correctness problem, but it broke the fast path for single-predecessor blocks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121966 91177308-0d34-0410-b5e6-96231b3b80d8

Speculatively revert commit 121905 since it looks like it might have broken the
dragonegg self-host buildbot.  Original commit message:

Add an InstCombine transform to recognize instances of manual overflow-safe addition
(performing the addition in a wider type and explicitly checking for overflow), and
fold them down to intrinsics.  This currently only supports signed-addition, but could
be generalized if someone works out the magic constant formulas for other operations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121965 91177308-0d34-0410-b5e6-96231b3b80d8

Fix some compiler warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121959 91177308-0d34-0410-b5e6-96231b3b80d8

MemoryBuffer now return an error_code and returns a OwningPtr<MemoryBuffer> via an out parm.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121958 91177308-0d34-0410-b5e6-96231b3b80d8

Add .gitignore. I chose not to dump the svn ignore list into this because most
of the entries there are useless for out of source builds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121955 91177308-0d34-0410-b5e6-96231b3b80d8

MC: Move target specific fixup info descriptors to TargetAsmBackend instead of
the MCCodeEmitter, which seems like a better organization.
 - Also, cleaned up some magic constants while in the area.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121953 91177308-0d34-0410-b5e6-96231b3b80d8

1. ARM/MC/ELF: A few more ELF relocs for .o
2. Fixed EmitLocalCommonSymbol for ELF (Yes, they exist. :)
   Test added.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121951 91177308-0d34-0410-b5e6-96231b3b80d8

MC: Make TargetAsmBackend available to the AsmStreamer.
 - Treaty talks on the non-proliferation of MC objects broke down.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121949 91177308-0d34-0410-b5e6-96231b3b80d8

MC: Split MCFixupKindInfo out into its own header.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121948 91177308-0d34-0410-b5e6-96231b3b80d8

MC: Remove a FIXME I no longer agree with.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121947 91177308-0d34-0410-b5e6-96231b3b80d8

Update a comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121946 91177308-0d34-0410-b5e6-96231b3b80d8

-enable-tbaa is on by default now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121945 91177308-0d34-0410-b5e6-96231b3b80d8

Make memcpyopt TBAA-aware.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121944 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/regexec.c: Let Regex LLP64-aware.

On LLP64 Win64, 'states1' (for small version) was expanded to 'char *' for large version. Thus small version would be mischosen when nstates > 32 regardless of sizeof(long) on Win64.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121942 91177308-0d34-0410-b5e6-96231b3b80d8

Delete an extra "Imm5 = ", caught by GCC's -Wsequence-point but not by Clang
(see PR4579).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121939 91177308-0d34-0410-b5e6-96231b3b80d8

Add IntervalMapOverlaps - An iterator for overlapping intervals in two
IntervalMaps.

The IntervalMaps can have different template parameters, but the KeyT and Traits
types must be the same.

Tests are forthcoming.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121935 91177308-0d34-0410-b5e6-96231b3b80d8

Remove fixup_arm_thumb_ldst. The code was never calling the "fixup" stuff for
it. I.e., it was always an immediate value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121932 91177308-0d34-0410-b5e6-96231b3b80d8

Add tSpill and tRestore to the opcodes to replace with tSTRi and tLDRi
respectively.

It may be a bug that these opcodes are getting this far into machine code
generation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121931 91177308-0d34-0410-b5e6-96231b3b80d8

Add encodings for Thumb1 Spill and Restore pseudos.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121929 91177308-0d34-0410-b5e6-96231b3b80d8

Fix elf-dump --dump-section-data for .bss section

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121927 91177308-0d34-0410-b5e6-96231b3b80d8

Enable TBAA by default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121923 91177308-0d34-0410-b5e6-96231b3b80d8

Preserve TBAA tags when doing load PRE.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121921 91177308-0d34-0410-b5e6-96231b3b80d8

Thumb1 had two patterns for the same load-from-constant-pool instruction.
Canonicalize on tLDRpci and remove tLDRcp.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121920 91177308-0d34-0410-b5e6-96231b3b80d8

Don't handle -arm-long-calls in fast isel for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121919 91177308-0d34-0410-b5e6-96231b3b80d8

Start using SplitKit and MachineLoopRanges in RegAllocGreedy in preparation of
live range splitting around loops guided by register pressure.

So far, trySplit() simply prints a lot of debug output.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121918 91177308-0d34-0410-b5e6-96231b3b80d8

Add MachineLoopRanges analysis.

A MachineLoopRange contains the intervals of slot indexes covered by the blocks
in a loop. This representation of the loop blocks is more efficient to compare
against interfering registers during register coalescing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121917 91177308-0d34-0410-b5e6-96231b3b80d8

If we're changing the frame register to a physical register other than SP, we
need to use tLDRi and tSTRi instead of tLDRspi and tSTRspi respectively.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121915 91177308-0d34-0410-b5e6-96231b3b80d8

Whitespace cleanups.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121914 91177308-0d34-0410-b5e6-96231b3b80d8

Teach the Neon intrinsic generator to widen half-precision float types.
This isn't currently used for anything but I ran into it when experimenting
with some changes, and it might be useful in the future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121911 91177308-0d34-0410-b5e6-96231b3b80d8

Better fix for opt build

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121910 91177308-0d34-0410-b5e6-96231b3b80d8

Fix a typo that Bill spotted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121909 91177308-0d34-0410-b5e6-96231b3b80d8

Only rr forms of ADD*_DB are commutable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121908 91177308-0d34-0410-b5e6-96231b3b80d8

Typo.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121906 91177308-0d34-0410-b5e6-96231b3b80d8

Add an InstCombine transform to recognize instances of manual overflow-safe addition
(performing the addition in a wider type and explicitly checking for overflow), and
fold them down to intrinsics.  This currently only supports signed-addition, but could
be generalized if someone works out the magic constant formulas for other operations.

Fixes <rdar://problem/8558713>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121905 91177308-0d34-0410-b5e6-96231b3b80d8

Fix opt -Werror build

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121904 91177308-0d34-0410-b5e6-96231b3b80d8

Teach machine cse to commute instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121903 91177308-0d34-0410-b5e6-96231b3b80d8

Add Neon VCVT instructions for f32 <-> f16 conversions.
Clang is now providing intrinsics for these and so we need to support them
in the backend.  Radar 8068427.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121902 91177308-0d34-0410-b5e6-96231b3b80d8

Fix misspelled target triples in MC/ARM test commands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121901 91177308-0d34-0410-b5e6-96231b3b80d8

Reapply r121886, and also update DecomposeGEPExpression to keep
it in sync.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121895 91177308-0d34-0410-b5e6-96231b3b80d8

Add SlotIndexes::getMBBRange() to get the range of a basic block in a single
lookup.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121893 91177308-0d34-0410-b5e6-96231b3b80d8

Revert r121886. DecomposeGEPExpression needs to be kept
in sync.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121892 91177308-0d34-0410-b5e6-96231b3b80d8

Lower the MBlaze target specific calling conventions for "interrupt_handler"
and "save_volatiles" correctly. This completes the custom calling convention
functionality changes for the MBlaze backend that were started in 121888.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121891 91177308-0d34-0410-b5e6-96231b3b80d8

Adding target specific calling conventions to support the MBlaze GCC function
attributes "interrupt_handle" and "save_volatiles". Support for lowering these
correctly will be in an upcoming commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121888 91177308-0d34-0410-b5e6-96231b3b80d8

Strengthen GetUnderlyingObject using InstructionSimplify.

While LLVM's main design is that analysis code shouldn't
go out of its way to understand code which hasn't been
InstCombined, analysis utility routines like this can
find themselves being called in the middle of transform
passes when instcombine hasn't had a chance to run.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121886 91177308-0d34-0410-b5e6-96231b3b80d8