2941 Commits

Author SHA1 Message Date
Reid Kleckner
4350881a94 Emit the Itanium LSDA for unknown EH personalities on Win64
This fixes lots of generic CodeGen tests that use __gcc_personality_v0.
This suggests that using ExceptionHandling::MSVC was a mistake, and we
should instead classify each function by personality function. This
would, for example, allow us to LTO a binary containing uses of SEH and
Itanium EH.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226019 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 18:50:10 +00:00
Chandler Carruth
1b279144ec [cleanup] Re-sort all the #include lines in LLVM using
utils/sort_includes.py.

I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225974 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 11:23:27 +00:00
Reid Kleckner
504fa89c8e CodeGen support for x86_64 SEH catch handlers in LLVM
This adds handling for ExceptionHandling::MSVC, used by the
x86_64-pc-windows-msvc triple. It assumes that filter functions have
already been outlined in either the frontend or the backend. Filter
functions are used in place of the landingpad catch clause type info
operands. In catch clause order, the first filter to return true will
catch the exception.

The C specific handler table expects the landing pad to be split into
one block per handler, but LLVM IR uses a single landing pad for all
possible unwind actions. This patch papers over the mismatch by
synthesizing single instruction BBs for every catch clause to fill in
the EH selector that the landing pad block expects.

Missing functionality:
- Accessing data in the parent frame from outlined filters
- Cleanups (from __finally) are unsupported, as they will require
  outlining and parent frame access
- Filter clauses are unsupported, as there's no clear analogue in SEH

In other words, this is the minimal set of changes needed to write IR to
catch arbitrary exceptions and resume normal execution.

Reviewers: majnemer

Differential Revision: http://reviews.llvm.org/D6300

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225904 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 01:05:27 +00:00
Adrian Prantl
f82fc00e4c Debug Info: Implement DwarfCompileUnit::addComplexAddress() using
DIEDwarfExpression (and get rid of a bunch of redundant code).

NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225900 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 01:01:30 +00:00
Adrian Prantl
db48bda4a1 Debug Info: Emitting a register in DwarfExpression may fail. Report the
status in a bool and let the users deal with the error.

NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225899 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 01:01:28 +00:00
Adrian Prantl
e733e5461f Debug Info: Move DIEDwarfExpression into DwarfExpression.h because it
needs to be accessed from both DwarfCompileUnit.cpp and DwarfUnit.cpp.

NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225898 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 01:01:22 +00:00
Adrian Prantl
bb7e1f3687 Debug Info: Don't bother emitting DW_AT_frame_base if the function has
no frame register. "Tested" via an assertion triggered by DwarfExpression.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225858 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 00:15:16 +00:00
Adrian Prantl
4e5d08aad0 Revert "Debug Info: Bail out of AddMachineRegPiece() if MachineReg is not a"
This reverts commit r225852, it was a bad idea.

MachineReg should always be a physical register. If it isn't this DebugLoc
shouldn't have been created in the first place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225857 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 00:15:12 +00:00
Adrian Prantl
bc42415f0f Debug Info: Bail out of AddMachineRegPiece() if MachineReg is not a
physical register. The call to getMinimalPhysRegClass() later on asserts
on this condition.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225852 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 23:39:15 +00:00
Adrian Prantl
57ed5ffc76 Debug Info: Move the complex expression handling (=the remainder) of
emitDebugLocValue() into DwarfExpression.

Ought to be NFC, but it actually uncovered a bug in the debug-loc-asan.ll
testcase. The testcase checks that the address of variable "y" is stored
at [RSP+16], which also lines up with the comment.
It also check(ed) that the *value* of "y" is stored in RDI before that,
but that is actually incorrect, since RDI is the very value that is
stored in [RSP+16]. Here's the assembler output:

	movb	2147450880(%rcx), %r8b
	#DEBUG_VALUE: bar:y <- RDI
	cmpb	$0, %r8b
	movq	%rax, 32(%rsp)          # 8-byte Spill
	movq	%rsi, 24(%rsp)          # 8-byte Spill
	movq	%rdi, 16(%rsp)          # 8-byte Spill
.Ltmp3:
	#DEBUG_VALUE: bar:y <- [RSP+16]

Fixed the comment to spell out the correct register and the check to
expect an address rather than a value.

Note that the range that is emitted for the RDI location was and is still
wrong, it claims to begin at the function prologue, but really it should
start where RDI is first assigned.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225851 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 23:39:11 +00:00
Adrian Prantl
9fb34c5169 cleanup.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225848 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 23:11:51 +00:00
Adrian Prantl
82df5a6981 Document, cleanup, and clang-format DwarfExpression.h
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225847 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 23:11:07 +00:00
Adrian Prantl
78415546e9 Debug Info: Turn DIExpression::getFrameRegister() into an isFrameRegister()
function.

NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225846 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 23:10:43 +00:00
Reid Kleckner
221a7075cf Add the llvm.frameallocate and llvm.recoverframeallocation intrinsics
These intrinsics allow multiple functions to share a single stack
allocation from one function's call frame. The function with the
allocation may only perform one allocation, and it must be in the entry
block.

Functions accessing the allocation call llvm.recoverframeallocation with
the function whose frame they are accessing and a frame pointer from an
active call frame of that function.

These intrinsics are very difficult to inline correctly, so the
intention is that they be introduced rarely, or at least very late
during EH preparation.

Reviewers: echristo, andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D6493

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225746 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 00:48:10 +00:00
Adrian Prantl
75212344d1 Debug Info: Move support for constants into DwarfExpression.
Move the declaration of DebugLocDwarfExpression into DwarfExpression.h
because it needs to be accessed from AsmPrinterDwarf.cpp and DwarfDebug.cpp

NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225734 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 00:04:06 +00:00
Adrian Prantl
df545e8d6c Make DwarfExpression store the AsmPrinter instead of the TargetMachine.
NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225731 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 23:36:56 +00:00
Adrian Prantl
0ec7e836f9 remove extra semicolon
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225730 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 23:36:50 +00:00
Adrian Prantl
2f95648566 Run clang-format on the parts of AsmPrinterDwarf where it improves the
readability.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225726 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 23:03:23 +00:00
Adrian Prantl
34ae4e7151 Debug Info: Add a virtual destructor to DwarfExpression.
Thanks Chandler for noticing!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225724 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 22:59:28 +00:00
Adrian Prantl
3d6fed1a57 Untwine this expression. Thanks to David for noticing!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225720 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 22:39:14 +00:00
Adrian Prantl
8afb6d0e2f Debug Info: Implement DwarfUnit::addRegisterOpPiece() using DwarfExpression.
NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225717 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 22:37:16 +00:00
Adrian Prantl
93eb099f24 Debug Info: Implement DwarfUnit::addRegisterOffset using DwarfExpression.
No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225707 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 22:19:26 +00:00
Adrian Prantl
f89325d832 Debug info: Factor out the creation of DWARF expressions from AsmPrinter
into a new class DwarfExpression that can be shared between AsmPrinter
and DwarfUnit.

This is the first step towards unifying the two entirely redundant
implementations of dwarf expression emission in DwarfUnit and AsmPrinter.

Almost no functional change — Testcases were updated because asm comments
that used to be on two lines now appear on the same line, which is
actually preferable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225706 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 22:19:22 +00:00
Adrian Prantl
31208c1591 Update a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225399 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 21:35:13 +00:00
Adrian Prantl
7950596b55 Debug info: Allow aggregate types to be described by constants.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225378 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 20:48:58 +00:00
Philip Reames
28fa9e1e9f Introduce an example statepoint GC strategy
This change includes the most basic possible GCStrategy for a GC which is using the statepoint lowering code. At the moment, this GCStrategy doesn't really do much - aside from actually generate correct stackmaps that is - but I went ahead and added a few extra correctness checks as proof of concept. It's mostly here to provide documentation on how to do one, and to provide a point for various optimization legality hooks I'd like to add going forward. (For context, see the TODOs in InstCombine around gc.relocate.)

Most of the validation logic added here as proof of concept will soon move in to the Verifier.  That move is dependent on http://reviews.llvm.org/D6811

There was discussion in the review thread about addrspace(1) being reserved for something.  I'm going to follow up on a seperate llvmdev thread.  If needed, I'll update all the code at once.

Note that I am deliberately not making a GCStrategy required to use gc.statepoints with this change. I want to give folks out of tree - including myself - a chance to migrate. In a week or two, I'll make having a GCStrategy be required for gc.statepoints. To this end, I added the gc tag to one of the test cases but not others.

Differential Revision: http://reviews.llvm.org/D6808



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225365 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 19:07:50 +00:00
Frederic Riss
0c36e97b78 Make DIE.h a public CodeGen header.
dsymutil would like to use all the AsmPrinter/MCStreamer infrastructure
to stream out the DWARF. In order to do so, it will reuse the DIE object
and so this header needs to be public.

The interface exposed here has some corners that cannot be used without a
DwarfDebug object, but clients that want to stream Dwarf can just avoid
these.

Differential Revision: http://reviews.llvm.org/D6695

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225208 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-05 21:29:41 +00:00
David Blaikie
1d68fc5021 DebugInfo: Omit is_stmt from line table entries on the same line.
GCC does this for non-zero discriminators and since GCC doesn't produce
column info, that was the only place it comes up there. For LLVM, since
we can emit discriminators and/or column info, it makes more sense to
invert the condition and just test for changes in line number.

This should resolve at least some of the GDB 7.5 test suite failures
created by recent Clang changes that increase the location fidelity
(which, since Clang defaults to including column info on Linux by
default created a bunch of cases that confused GDB).

In theory we could do this better/differently by grouping actual source
statements together in a similar manner to the way lexical scopes are
handled but given that GDB isn't really in a position to consume that (&
users are probably somewhat used to different lines being different
'statements') this seems the safest and cheapest change. (I'm concerned
that doing this 'right' would bloat the debugloc data even further -
something Duncan's working hard to address)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225011 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-30 22:47:13 +00:00
Peter Collingbourne
d8ae3e1fee x86_64: Fix calls to __morestack under the large code model.
Under the large code model, we cannot assume that __morestack lives within
2^31 bytes of the call site, so we cannot use pc-relative addressing. We
cannot perform the call via a temporary register, as the rax register may
be used to store the static chain, and all other suitable registers may be
either callee-save or used for parameter passing. We cannot use the stack
at this point either because __morestack manipulates the stack directly.

To avoid these issues, perform an indirect call via a read-only memory
location containing the address.

This solution is not perfect, as it assumes that the .rodata section
is laid out within 2^31 bytes of each function body, but this seems to
be sufficient for JIT.

Differential Revision: http://reviews.llvm.org/D6787

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225003 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-30 20:05:19 +00:00
Timur Iskhodzhanov
f4076dc995 Band-aid fix for PR22032: don't emit DWARF debug info if AddressSanitizer is enabled on Windows
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224860 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-26 17:00:51 +00:00
David Majnemer
e277a13a71 CodeGen: Error on redefinitions instead of asserting
It's possible to have a prior definition of a symbol in module asm.
Raise an error instead of crashing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224828 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-24 23:06:55 +00:00
David Majnemer
d36cad9914 CodeGen: Allow aliases to be overridden by variables
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224827 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-24 22:44:29 +00:00
David Majnemer
e54eacce75 MC: Label definitions are permitted after .set directives
.set directives may be overridden by other .set directives as well as
label definitions.

This fixes PR22019.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224811 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-24 10:27:50 +00:00
Adrian Prantl
34f81e8bec Debug Info: In symmetry to DW_TAG_pointer_type, do not emit the byte size
of a DW_TAG_ptr_to_member_type.
This restores the behavior from before r224780-r224781.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224799 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-24 01:17:51 +00:00
Reid Kleckner
b60b7360f5 EH: Sink computation of local PadMap variable into function that uses it
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224635 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 22:30:08 +00:00
Reid Kleckner
0f85d54670 Add the ExceptionHandling::MSVC enumeration
It is intended to be used for a family of personality functions that
have similar IR preparation requirements. Typically when interoperating
with MSVC personality functions, bits of functionality need to be
outlined from the main function into helper functions. There is also
usually more than one landing pad per invoke, which does not match the
LLVM IR landingpad representation.

None of this is implemented yet. This change just adds a new enum that
is active for *-windows-msvc and delegates to the EH removal preparation
pass.  No functionality change for other targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224625 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 22:19:48 +00:00
Adrian Prantl
7a6f0084e2 Explain why LLVM is emitting a DW_AT_containing_type inside of a class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224555 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 00:01:20 +00:00
Toma Tabacu
3fea427a63 [mips] Set GCC-compatible MIPS asssembler options before inline asm blocks.
Summary:
When generating MIPS assembly, LLVM always overrides the default assembler options by emitting the '.set noreorder', '.set nomacro' and '.set noat' directives,
while GCC uses the default options if an assembly-level function contains inline assembly code.

This becomes a problem when the code generated by LLVM is interleaved with inline assembly which assumes GCC-like assembler options (from Linux, for example).

This patch fixes these conflicts by setting the appropriate assembler options at the beginning of an inline asm block and popping them at the end.

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6637

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224425 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-17 10:56:16 +00:00
David Blaikie
7c3af9120c PR21875: codegen for non-type template parameters of nullptr_t type
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224399 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-17 00:43:22 +00:00
Matt Arsenault
8b5b0f5ee5 Move lowerConstant to AsmPrinter
This was a static function before, and NVPTX duplicated it
because it wasn't exposed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224354 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 19:16:14 +00:00
Aaron Ballman
51c2bdca72 Fixing -Wsign-compare warnings; NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224337 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 14:04:11 +00:00
Adrian Prantl
6f059afde6 ARM/AArch64: Attach the FrameSetup MIFlag to CFI instructions.
Debug info marks the first instruction without the FrameSetup flag
as being the end of the function prologue. Any CFI instructions in the
middle of the function prologue would cause debug info to end the prologue
too early and worse, attach the line number of the CFI instruction, which
incidentally is often 0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224294 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 00:20:49 +00:00
Michael Ilseman
9ecdca9115 Silence more static analyzer warnings.
Add in definedness checks for shift operators, null checks when
pointers are assumed by the code to be non-null, and explicit
unreachables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224255 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 18:48:43 +00:00
Ekaterina Romanova
e0b0363e44 A fix for PR21176.
DW_OP_const <const> doesn't describe a constant value, but a value at a constant address. 
The proper way to describe a constant value is DW_OP_constu <const>, DW_OP_stack_value. 
Added DW_OP_stack_value to the stack. 

Marked incorrect-variable-debugloc1.ll to xfail for PowerPC64, while the the failure (PR21881) 
is being investigated. 



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224098 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-12 05:11:47 +00:00
Ekaterina Romanova
e9afc33de5 Reverting commit 223981, because the test that I added (incorrect-variable-debugloc1.ll) failed for llvm-ppc64.
The test is failing for llvm-ppc64 because for this platform the location list is not being generated at all (most likely because of the bug in PPC code optimization or generation). I will file a bug agains PPC compiler, but meanwhile, until PPC bug is fixed, I will have to revert my change.  



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224000 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 06:22:35 +00:00
Philip Reames
5e62b8471d GCStrategy should not own GCFunctionInfo
This change moves the ownership and access of GCFunctionInfo (the object which describes the safepoints associated with a safepoint under GCRoot) to GCModuleInfo. Previously, this was owned by GCStrategy which was in turned owned by GCModuleInfo. This made GCStrategy module specific which is 'surprising' given it's name and other purposes.

There's a few more changes needed, but we're getting towards the point we can reuse GCStrategy for gc.statepoint as well.

p.s. The style of this code ends up being a mess. I was trying to move code around without otherwise changing much. Once I get the ownership structure rearranged, I will go through and fixup spacing, naming, comments etc.

Differential Revision: http://reviews.llvm.org/D6587



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223994 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 01:47:23 +00:00
Ekaterina Romanova
de68a563bc A fix for PR21176.
DW_OP_const <const> doesn't describe a constant value, but a value at a constant address.
The proper way to describe a constant value is DW_OP_constu <const>, DW_OP_stack_value.

Added DW_OP_stack_value to the stack.

-This line, and those below, will be ignored--

M    lib/CodeGen/AsmPrinter/DwarfDebug.cpp
A    test/DebugInfo/incorrect-variable-debugloc1.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223981 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 23:19:56 +00:00
Philip Reames
3490d23337 Remove the Module pointer from GCStrategy and GCMetadataPrinter
In the current implementation, GCStrategy is a part of the ownership structure for the gc metadata which describes a Module. It also contains a reference to the module in question. As a result, GCStrategy instances are essentially Module specific.

I plan to transition away from this design. Instead, a GCStrategy will be owned by the LLVMContext. It will be a lightweight policy object which contains no information about the Modules or Functions involved, but can be easily reached given a Function.

The first step in this transition is to remove the direct Module reference from GCStrategy. This also requires removing the single user of this reference, the GCMetadataPrinter hierarchy. In theory, this will allow the lifetime of the printers to be scoped to the LLVMContext as well, but in practice, I'm not actually changing that. (Yet?)

An alternate design would have been to move the direct Module reference into the GCMetadataPrinter and change the keying of the owning maps to explicitly key off both GCStrategy and Module. I'm open to doing it that way instead, but didn't see much value in preserving the per Module association for GCMetadataPrinters.

The next change in this sequence will be to start unwinding the intertwined ownership between GCStrategy, GCModuleInfo, and GCFunctionInfo.

Differential Revision: http://reviews.llvm.org/D6566



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223859 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 23:57:54 +00:00
Duncan P. N. Exon Smith
dad20b2ae2 IR: Split Metadata from Value
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532.  Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.

I have a follow-up patch prepared for `clang`.  If this breaks other
sub-projects, I apologize in advance :(.  Help me compile it on Darwin
I'll try to fix it.  FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.

This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.

Here's a quick guide for updating your code:

  - `Metadata` is the root of a class hierarchy with three main classes:
    `MDNode`, `MDString`, and `ValueAsMetadata`.  It is distinct from
    the `Value` class hierarchy.  It is typeless -- i.e., instances do
    *not* have a `Type`.

  - `MDNode`'s operands are all `Metadata *` (instead of `Value *`).

  - `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
    replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.

    If you're referring solely to resolved `MDNode`s -- post graph
    construction -- just use `MDNode*`.

  - `MDNode` (and the rest of `Metadata`) have only limited support for
    `replaceAllUsesWith()`.

    As long as an `MDNode` is pointing at a forward declaration -- the
    result of `MDNode::getTemporary()` -- it maintains a side map of its
    uses and can RAUW itself.  Once the forward declarations are fully
    resolved RAUW support is dropped on the ground.  This means that
    uniquing collisions on changing operands cause nodes to become
    "distinct".  (This already happened fairly commonly, whenever an
    operand went to null.)

    If you're constructing complex (non self-reference) `MDNode` cycles,
    you need to call `MDNode::resolveCycles()` on each node (or on a
    top-level node that somehow references all of the nodes).  Also,
    don't do that.  Metadata cycles (and the RAUW machinery needed to
    construct them) are expensive.

  - An `MDNode` can only refer to a `Constant` through a bridge called
    `ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).

    As a side effect, accessing an operand of an `MDNode` that is known
    to be, e.g., `ConstantInt`, takes three steps: first, cast from
    `Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
    third, cast down to `ConstantInt`.

    The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
    metadata schema owners transition away from using `Constant`s when
    the type isn't important (and they don't care about referring to
    `GlobalValue`s).

    In the meantime, I've added transitional API to the `mdconst`
    namespace that matches semantics with the old code, in order to
    avoid adding the error-prone three-step equivalent to every call
    site.  If your old code was:

        MDNode *N = foo();
        bar(isa             <ConstantInt>(N->getOperand(0)));
        baz(cast            <ConstantInt>(N->getOperand(1)));
        bak(cast_or_null    <ConstantInt>(N->getOperand(2)));
        bat(dyn_cast        <ConstantInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));

    you can trivially match its semantics with:

        MDNode *N = foo();
        bar(mdconst::hasa               <ConstantInt>(N->getOperand(0)));
        baz(mdconst::extract            <ConstantInt>(N->getOperand(1)));
        bak(mdconst::extract_or_null    <ConstantInt>(N->getOperand(2)));
        bat(mdconst::dyn_extract        <ConstantInt>(N->getOperand(3)));
        bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));

    and when you transition your metadata schema to `MDInt`:

        MDNode *N = foo();
        bar(isa             <MDInt>(N->getOperand(0)));
        baz(cast            <MDInt>(N->getOperand(1)));
        bak(cast_or_null    <MDInt>(N->getOperand(2)));
        bat(dyn_cast        <MDInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));

  - A `CallInst` -- specifically, intrinsic instructions -- can refer to
    metadata through a bridge called `MetadataAsValue`.  This is a
    subclass of `Value` where `getType()->isMetadataTy()`.

    `MetadataAsValue` is the *only* class that can legally refer to a
    `LocalAsMetadata`, which is a bridged form of non-`Constant` values
    like `Argument` and `Instruction`.  It can also refer to any other
    `Metadata` subclass.

(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223802 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 18:38:53 +00:00
Eric Christopher
7a76d76e0c These two calls were grabbing the same register info. Unify them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223502 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-05 19:23:55 +00:00