member out of line. ftostr is not particularly speedy,
so that method is presumably not perf sensitive.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79885 91177308-0d34-0410-b5e6-96231b3b80d8
forcing them down into various .cpp files.
This change also:
1. Renames TimeValue::toString() and Path::toString() to ::str()
for similarity with the STL.
2. Removes all stream insertion support for sys::Path, forcing
clients to call .str().
3. Removes a use of Config/alloca.h from bugpoint, using smallvector
instead.
4. Weans llvm-db off <iostream>
sys::Path really needs to be gutted, but I don't have the desire to
do it at this point.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79869 91177308-0d34-0410-b5e6-96231b3b80d8
MCAsmStreamer. Based on this, eliminate the current section from AsmPrinter.
While I'm at it, clean up the last of the horrible "switch to null section" stuff
and add an assert. This change is in preparation for completely eliminating
asmprinter::switchtosection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79324 91177308-0d34-0410-b5e6-96231b3b80d8
more properly belong. This allows removing the front-end conditionalized
SJLJ code, and cleans up the generated IR considerably. All of the
infrastructure code (calling _Unwind_SjLj_Register/Unregister, etc) is
added by the SjLjEHPrepare pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79250 91177308-0d34-0410-b5e6-96231b3b80d8
doing it directly. This requires const'izing a bunch of stuff that
took sections, but this seems like the right semantic thing to do:
emitting a label to a section shouldn't mutate the MCSection object
itself, for example.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79227 91177308-0d34-0410-b5e6-96231b3b80d8
the basic block label printing to check whether a block has a name
before printing a comment character and whitespace for it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78830 91177308-0d34-0410-b5e6-96231b3b80d8
"inlineasmstart/end" strings so that the contents of the directive
are separate from the comment character. This lets elf targets
get #APP/#NOAPP for free even if they don't use "#" as the comment
character. This also allows hoisting the darwin stuff up to the
shared TAI class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78737 91177308-0d34-0410-b5e6-96231b3b80d8
and short. Well, it's kinda short. Definitely nasty and brutish.
The front-end generates the register/unregister calls into the SjLj runtime,
call-site indices and landing pad dispatch. The back end fills in the LSDA
with the call-site information provided by the front end. Catch blocks are
not yet implemented.
Built on Darwin and verified no llvm-core "make check" regressions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78625 91177308-0d34-0410-b5e6-96231b3b80d8
This definitely slows down asm output so put it under an -asm-exuberant
flag.
This information is useful when doing static analysis of performance
issues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78567 91177308-0d34-0410-b5e6-96231b3b80d8
2. Move section switch printing to MCSection virtual method which takes a
TAI. This eliminates textual formatting stuff from TLOF.
3. Eliminate SwitchToSectionDirective, getSectionFlagsAsString, and
TLOFELF::AtIsCommentChar.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78510 91177308-0d34-0410-b5e6-96231b3b80d8
A TAI hook is appropriate in this case because this is just an
asm syntax issue, not a semantic difference. TLOF should model
the semantics of the section.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78498 91177308-0d34-0410-b5e6-96231b3b80d8
the masm backend. If anyone cares about masm in the future,
we'll have semantic sections it can hang off of.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78096 91177308-0d34-0410-b5e6-96231b3b80d8
behavior of the LSDA section instead of on some random target hook that
needs to be kept in synch with other points of truth.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77855 91177308-0d34-0410-b5e6-96231b3b80d8
getLSDASection() to be more specific. This makes it pretty obvious
that the ELF LSDA section is being specified wrong in PIC mode. We're
probably getting a lot of startup-time relocations to a readonly page,
which is expensive and bad.
Someone who cares about ELF C++ should investigate this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77847 91177308-0d34-0410-b5e6-96231b3b80d8
compute it based on what it knows. As part of this, rename getSectionForMergeableConstant
to getSectionForConstant because it works for non-mergable constants also.
The only functionality change from this is that Xcore will start dropping
its jump tables into readonly section instead of data section in -static mode.
This should be fine as the linker resolves the relocations. If this is a
problem, let me know and we'll come up with another solution.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77833 91177308-0d34-0410-b5e6-96231b3b80d8
to:
.quad X
even on a 32-bit system, where X is not 64-bits. There isn't much that
we can do here, so we just print:
.quad ((X) & 4294967295)
instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77818 91177308-0d34-0410-b5e6-96231b3b80d8
should have no state that is specific to particular globals in the
section. In this case, it means the removal of the "isWeak" and
"ExplicitSection" bits. MCSection uses the new form of SectionKind.
To handle isWeak, I introduced a new SectionInfo class, which is
SectionKind + isWeak, and it is used by the part of the code generator
that does classification of a specific global.
The ExplicitSection disappears. It is moved onto MCSection as a new
"IsDirective" bit. Since the Name of a section is either a section
or directive, it makes sense to keep this bit in MCSection. Ultimately
the creator of MCSection should canonicalize (e.g.) .text to whatever
the actual section is.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77803 91177308-0d34-0410-b5e6-96231b3b80d8
padding is disabled, tabs get replaced by spaces except in the case of
the first operand, where the tab is output to line up the operands after
the mnemonics.
Add some better comments and eliminate redundant code.
Fix some testcases to not assume tabs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77740 91177308-0d34-0410-b5e6-96231b3b80d8
thing is #if0'd out anyway. Just simplify the code by reducing the interface.
Not deleting this is essential for Bill's continuing happiness.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77736 91177308-0d34-0410-b5e6-96231b3b80d8
indicate that it is a predicate, not an emitter. This eliminates TAI
dependencies on Mangler and GlobalValue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77726 91177308-0d34-0410-b5e6-96231b3b80d8
correct. But what are you going to do? I'll fix this in the future.
- Move another large loop into its own method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77408 91177308-0d34-0410-b5e6-96231b3b80d8
it is highly specific to the object file that will be generated in the end,
this introduces a new TargetLoweringObjectFile interface that is implemented
for each of ELF/MachO/COFF/Alpha/PIC16 and XCore.
Though still is still a brutal and ugly refactoring, this is a major step
towards goodness.
This patch also:
1. fixes a bunch of dangling pointer problems in the PIC16 backend.
2. disables the TargetLowering copy ctor which PIC16 was accidentally using.
3. gets us closer to xcore having its own crazy target section flags and
pic16 not having to shadow sections with its own objects.
4. fixes wierdness where ELF targets would set CStringSection but not
CStringSection_. Factor the code better.
5. fixes some bugs in string lowering on ELF targets.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77294 91177308-0d34-0410-b5e6-96231b3b80d8
a new getSectionForMergableConstant hook. This removes one dependence
of TAI on Type, and provides the hook with enough info to make the
right decision based on whether the global has relocations etc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76705 91177308-0d34-0410-b5e6-96231b3b80d8
"LinkerPrivatePrefix". It seems to have been used in only one place before I
started this "linker_private" business. I'm thinking that a rename is in
order...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76479 91177308-0d34-0410-b5e6-96231b3b80d8
starting in getCurrentFunctionEHName. Among other problems,
we would try to privative a "foo.eh" label, but end up emitting
the label as _Lfoo.eh instead of L_foo.eh on darwin. This is really
bad, and the linker has always tolerated these labels existing.
For now, just emit them as _foo.eh.
This patch also fixes problems with ".eh" labels on unnamed
functions and eliminates two strangely defined TargetAsmInfo
hooks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76231 91177308-0d34-0410-b5e6-96231b3b80d8
This prefix is used by LLVM to inform the asm printer to not emit usual global symbol prefix before the symbol name.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75875 91177308-0d34-0410-b5e6-96231b3b80d8
additional bug fixes:
1. The bug that everyone hit was a problem in the asmprinter where it
would remove $stub but keep the L prefix on a name when emitting the
indirect symbol. This is easy to fix by keeping the name of the stub
and the name of the symbol in a StringMap instead of just keeping a
StringSet and trying to reconstruct it late.
2. There was a problem printing the personality function. The current
logic to print out the personality function from the DWARF information
is a bit of a cesspool right now that duplicates a bunch of other
logic in the asm printer. The short version of it is that it depends
on emitting both the L and _ prefix for symbols (at least on darwin)
and until I can untangle it, it is best to switch the mangler back to
emitting both prefixes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75646 91177308-0d34-0410-b5e6-96231b3b80d8
This adds location info for all llvm_unreachable calls (which is a macro now) in
!NDEBUG builds.
In NDEBUG builds location info and the message is off (it only prints
"UREACHABLE executed").
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75640 91177308-0d34-0410-b5e6-96231b3b80d8
--- Reverse-merging r75619 into '.':
U lib/Target/DarwinTargetAsmInfo.cpp
U lib/CodeGen/AsmPrinter/AsmPrinter.cpp
--- Reverse-merging r75618 into '.':
U lib/CodeGen/ELFWriter.cpp
U lib/CodeGen/MachOCodeEmitter.cpp
U lib/CodeGen/MachOWriter.cpp
--- Reverse-merging r75617 into '.':
U lib/Target/CBackend/CBackend.cpp
--- Reverse-merging r75616 into '.':
U tools/bugpoint/Miscompilation.cpp
U tools/lto/LTOCodeGenerator.cpp
U tools/lto/LTOModule.cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75638 91177308-0d34-0410-b5e6-96231b3b80d8
indicates whether the label is private or not, instead of taking
prefix stuff. One effect of this is that symbols will be generated
with *just* the private prefix, instead of both the private prefix
*and* the user-label-prefix, but this doesn't matter as long as it
is consistent. For example we'll now get "Lfoo" instead of "L_foo".
These are just assembler temporary labels anyway, so they never even
make it into the .o file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75607 91177308-0d34-0410-b5e6-96231b3b80d8
We'll eventually use this to print comments in asm files and do other
fun things.
This adds interfaces to the AsmPrinter and changes TableGen to invoke
the postInstructionAction when appropriate. It also add parameters to
TargetAsmInfo to control comment layout.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75490 91177308-0d34-0410-b5e6-96231b3b80d8
Make llvm_unreachable take an optional string, thus moving the cerr<< out of
line.
LLVM_UNREACHABLE is now a simple wrapper that makes the message go away for
NDEBUG builds.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75379 91177308-0d34-0410-b5e6-96231b3b80d8
- This more or less amounts to a revert of r65379. I'm curious to know what
happened that caused this variable to become unused.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74579 91177308-0d34-0410-b5e6-96231b3b80d8
a bunch of code from all the targets, and eliminates nondeterministic
ordering of directives being emitted in the output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74096 91177308-0d34-0410-b5e6-96231b3b80d8
the 'constract function dbg thingy'. Rename some methods to make them consistent
with the rest of the methods. Move the 'Emit' methods to the end of the file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72192 91177308-0d34-0410-b5e6-96231b3b80d8
function, this could be many, many times. We don't want to re-add variables to
that DIE for each time. We just want to add them once. Check to make sure that
we haven't added them already.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72047 91177308-0d34-0410-b5e6-96231b3b80d8
logical/sane approach to organizing all of the stuff that goes into writing out
DWARF information. Honestly? even this is too complex for what it's supposed to
be doing.
Trivia: It *looks* like there would be functionality changes, however there aren't!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71821 91177308-0d34-0410-b5e6-96231b3b80d8
Basically, there was a situation where it was getting an empty vector and doing
a .back() on that. Which isn't cool.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71746 91177308-0d34-0410-b5e6-96231b3b80d8
belonged. The variable declaration stuff wasn't happy with it where it
was. Sorry that the testcase is so big. Bugpoint wasn't able to reduce it
successfully.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71714 91177308-0d34-0410-b5e6-96231b3b80d8
The DwarfWriter expects DbgScopes and DIEs to behave themselves according to
DwarfWriter's rules. However, inlined functions violate these rules. There are
two different types of DIEs associated with an inlined function: an abstract
instance, which has information about the original source code for the function
being inlined; and concrete instances, which are created for each place the
function was inlined and point back to the abstract instance.
This patch tries to stay true to this schema. It bypasses how regular DbgScopes
and DIEs are created and used when necessary. It provides special handling for
DIEs of abstract and concrete instances.
This doesn't take care of all of the problems with debug info for inlined
functions, but it's a step in the right direction. For one thing, llvm-gcc
generates wrong IR (it's missing some llvm.dbg intrinsics at the point where the
function's inlined) for this example:
#include <stdio.h>
static __inline__ __attribute__((always_inline)) int bar(int x) { return 4; }
void foo() {
long long b = 1;
int Y = bar(4);
printf("%d\n", Y);
}
while clang generates correct IR.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71410 91177308-0d34-0410-b5e6-96231b3b80d8
concrete instance of an inlined function, we can get the actual address of the
abstract instance inside of the compile unit.
This isn't currently used, but will be by a future check-in.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71263 91177308-0d34-0410-b5e6-96231b3b80d8
checking for bcopy... no
checking for getc_unlocked... Assertion failed: (0 && "Unknown SCEV kind!"), function operator(), file /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmCore.roots/llvmCore~obj/src/lib/Analysis/ScalarEvolution.cpp, line 511.
/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmgcc42.roots/llvmgcc42~obj/src/libdecnumber/decUtility.c:360: internal compiler error: Abort trap
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://developer.apple.com/bugreporter> for instructions.
make[4]: *** [decUtility.o] Error 1
make[4]: *** Waiting for unfinished jobs....
Assertion failed: (0 && "Unknown SCEV kind!"), function operator(), file /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmCore.roots/llvmCore~obj/src/lib/Analysis/ScalarEvolution.cpp, line 511.
/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmgcc42.roots/llvmgcc42~obj/src/libdecnumber/decNumber.c:5591: internal compiler error: Abort trap
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://developer.apple.com/bugreporter> for instructions.
make[4]: *** [decNumber.o] Error 1
make[3]: *** [all-stage2-libdecnumber] Error 2
make[3]: *** Waiting for unfinished jobs....
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71165 91177308-0d34-0410-b5e6-96231b3b80d8
Massive check in. This changes the "-fast" flag to "-O#" in llc. If you want to
use the old behavior, the flag is -O0. This change allows for finer-grained
control over which optimizations are run at different -O levels.
Most of this work was pretty mechanical. The majority of the fixes came from
verifying that a "fast" variable wasn't used anymore. The JIT still uses a
"Fast" flag. I'll change the JIT with a follow-up patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70343 91177308-0d34-0410-b5e6-96231b3b80d8
use the old behavior, the flag is -O0. This change allows for finer-grained
control over which optimizations are run at different -O levels.
Most of this work was pretty mechanical. The majority of the fixes came from
verifying that a "fast" variable wasn't used anymore. The JIT still uses a
"Fast" flag. I'm not 100% sure if it's necessary to change it there...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70270 91177308-0d34-0410-b5e6-96231b3b80d8
Now debug_inlined section is covered by TAI->doesDwarfUsesInlineInfoSection(), which is false by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68964 91177308-0d34-0410-b5e6-96231b3b80d8
to support C99 inline, GNU extern inline, etc. Related bugzilla's
include PR3517, PR3100, & PR2933. Nothing uses this yet, but it
appears to work.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68940 91177308-0d34-0410-b5e6-96231b3b80d8
Create debug_inlined dwarf section using these information. This info is used by gdb, at least on Darwin, to enable better experience debugging inlined functions. See DwarfWriter.cpp for more information on structure of debug_inlined section.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68847 91177308-0d34-0410-b5e6-96231b3b80d8
the key. This will cause it to create a new std::string, which isn't
wanted. Instead, pass back the "const char*". Modify the EmitString() method to
take a "const char*".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68741 91177308-0d34-0410-b5e6-96231b3b80d8
avoiding sign extension for the top octet. For "negative" chars, we'd print
stuff like:
.asciz "\702...
now we print:
.asciz "\302...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68577 91177308-0d34-0410-b5e6-96231b3b80d8
same as a normal i80 {low64, high16} rather
than its own {high64, low16}. A depressing number
of places know about this; I think I got them all.
Bitcode readers and writers convert back to the old
form to avoid breaking compatibility.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67562 91177308-0d34-0410-b5e6-96231b3b80d8
1. ConstantPoolSDNode alignment field is log2 value of the alignment requirement. This is not consistent with other SDNode variants.
2. MachineConstantPool alignment field is also a log2 value.
3. However, some places are creating ConstantPoolSDNode with alignment value rather than log2 values. This creates entries with artificially large alignments, e.g. 256 for SSE vector values.
4. Constant pool entry offsets are computed when they are created. However, asm printer group them by sections. That means the offsets are no longer valid. However, asm printer uses them to determine size of padding between entries.
5. Asm printer uses expensive data structure multimap to track constant pool entries by sections.
6. Asm printer iterate over SmallPtrSet when it's emitting constant pool entries. This is non-deterministic.
Solutions:
1. ConstantPoolSDNode alignment field is changed to keep non-log2 value.
2. MachineConstantPool alignment field is also changed to keep non-log2 value.
3. Functions that create ConstantPool nodes are passing in non-log2 alignments.
4. MachineConstantPoolEntry no longer keeps an offset field. It's replaced with an alignment field. Offsets are not computed when constant pool entries are created. They are computed on the fly in asm printer and JIT.
5. Asm printer uses cheaper data structure to group constant pool entries.
6. Asm printer compute entry offsets after grouping is done.
7. Change JIT code to compute entry offsets on the fly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66875 91177308-0d34-0410-b5e6-96231b3b80d8
the untimed version of getOrCreateSourceID. getOrCreateSourceID calls
GetOrCreateSourceID, of course.
- Move some methods into the "private" section. Constify at least one method.
- General clean-ups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66582 91177308-0d34-0410-b5e6-96231b3b80d8
whether a global is dead or not. This should fix PR3749 - linker adds
spurious use to appending globals. I can't reasonably add a testcase
for this, because the bc writer/reader strip dead constant users.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66404 91177308-0d34-0410-b5e6-96231b3b80d8
and extern_weak_odr. These are the same as the non-odr versions,
except that they indicate that the global will only be overridden
by an *equivalent* global. In C, a function with weak linkage can
be overridden by a function which behaves completely differently.
This means that IP passes have to skip weak functions, since any
deductions made from the function definition might be wrong, since
the definition could be replaced by something completely different
at link time. This is not allowed in C++, thanks to the ODR
(One-Definition-Rule): if a function is replaced by another at
link-time, then the new function must be the same as the original
function. If a language knows that a function or other global can
only be overridden by an equivalent global, it can give it the
weak_odr linkage type, and the optimizers will understand that it
is alright to make deductions based on the function body. The
code generators on the other hand map weak and weak_odr linkage
to the same thing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66339 91177308-0d34-0410-b5e6-96231b3b80d8
them are generic changes.
- Use the "fast" flag that's already being passed into the asm printers instead
of shoving it into the DwarfWriter.
- Instead of calling "MI->getParent()->getParent()" for every MI, set the
machine function when calling "runOnMachineFunction" in the asm printers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65379 91177308-0d34-0410-b5e6-96231b3b80d8
Now we're using one gross, but quite robust hack :) (previous ones
did not work, for example, when ext_weak symbol was used deep inside
constant expression in the initializer).
The proper fix of this problem will require some quite huge asmprinter
changes and that's why was postponed. This fixes PR3629 by the way :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65230 91177308-0d34-0410-b5e6-96231b3b80d8
information output. However, many target specific tool chains prefer to encode
only one compile unit in an object file. In this situation, the LLVM code
generator will include debugging information entities in the compile unit
that is marked as main compile unit. The code generator accepts maximum one main
compile unit per module. If a module does not contain any main compile unit
then the code generator will emit multiple compile units in the output object
file.
[Part 1]
Update DebugInfo APIs to accept optional boolean value while creating DICompileUnit to mark the unit as "main" unit. By defaults all units are considered non-main. Update SourceLevelDebugging.html to document "main" compile unit.
Update DebugInfo APIs to not accept and encode separate source file/directory entries while creating various llvm.dbg.* entities. There was a recent, yet to be documented, change to include this additional information so no documentation changes are required here.
Update DwarfDebug to handle "main" compile unit. If "main" compile unit is seen then all DIEs are inserted into "main" compile unit. All other compile units are used to find source location for llvm.dbg.* values. If there is not any "main" compile unit then create unique compile unit DIEs for each llvm.dbg.compile_unit.
[Part 2]
Create separate llvm.dbg.compile_unit for each input file. Mark compile unit create for main_input_filename as "main" compile unit. Use appropriate compile unit, based on source location information collected from the tree node, while creating llvm.dbg.* values using DebugInfo APIs.
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This is Part 1.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63400 91177308-0d34-0410-b5e6-96231b3b80d8