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.)
llvm-svn: 223802
Disallow complex types of function-local metadata. The only valid
function-local metadata is an `MDNode` whose sole argument is a
non-metadata function-local value.
Part of PR21532.
llvm-svn: 223564
When lazy reading a module, the types used in a function will not be visible to
a TypeFinder until the body is read.
This patch fixes that by asking the module for its identified struct types.
If a materializer is present, the module asks it. If not, it uses a TypeFinder.
This fixes pr21374.
I will be the first to say that this is ugly, but it was the best I could find.
Some of the options I looked at:
* Asking the LLVMContext. This could be made to work for gold, but not currently
for ld64. ld64 will load multiple modules into a single context before merging
them. This causes us to see types from future merges. Unfortunately,
MappedTypes is not just a cache when it comes to opaque types. Once the
mapping has been made, we have to remember it for as long as the key may
be used. This would mean moving MappedTypes to the Linker class and having
to drop the Linker::LinkModules static methods, which are visible from C.
* Adding an option to ignore function bodies in the TypeFinder. This would
fix the PR by picking the worst result. It would work, but unfortunately
we are currently quite dependent on the upfront type merging. I will
try to reduce our dependency, but it is not clear that we will be able
to get rid of it for now.
The only clean solution I could think of is making the Module own the types.
This would have other advantages, but it is a much bigger change. I will
propose it, but it is nice to have this fixed while that is discussed.
With the gold plugin, this patch takes the number of types in the LTO clang
binary from 52817 to 49669.
llvm-svn: 223215
Patch by Ben Gamari!
This redefines the `prefix` attribute introduced previously and
introduces a `prologue` attribute. There are a two primary usecases
that these attributes aim to serve,
1. Function prologue sigils
2. Function hot-patching: Enable the user to insert `nop` operations
at the beginning of the function which can later be safely replaced
with a call to some instrumentation facility
3. Runtime metadata: Allow a compiler to insert data for use by the
runtime during execution. GHC is one example of a compiler that
needs this functionality for its tables-next-to-code functionality.
Previously `prefix` served cases (1) and (2) quite well by allowing the user
to introduce arbitrary data at the entrypoint but before the function
body. Case (3), however, was poorly handled by this approach as it
required that prefix data was valid executable code.
Here we redefine the notion of prefix data to instead be data which
occurs immediately before the function entrypoint (i.e. the symbol
address). Since prefix data now occurs before the function entrypoint,
there is no need for the data to be valid code.
The previous notion of prefix data now goes under the name "prologue
data" to emphasize its duality with the function epilogue.
The intention here is to handle cases (1) and (2) with prologue data and
case (3) with prefix data.
References
----------
This idea arose out of discussions[1] with Reid Kleckner in response to a
proposal to introduce the notion of symbol offsets to enable handling of
case (3).
[1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-May/073235.html
Test Plan: testsuite
Differential Revision: http://reviews.llvm.org/D6454
llvm-svn: 223189
Instead, we're going to separate metadata from the Value hierarchy. See
PR21532.
This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.
llvm-svn: 221711
This removes calls to isMaterializable in the following cases:
* It was redundant with a call to isDeclaration now that isDeclaration returns
the correct answer for materializable functions.
* It was followed by a call to Materialize. Just call Materialize and check EC.
llvm-svn: 221050
To do this, change the representation of lazy loaded functions.
The previous representation cannot differentiate between a function whose body
has been removed and one whose body hasn't been read from the .bc file. That
means that in order to drop a function, the entire body had to be read.
llvm-svn: 220580
Enumerate `MDNode`'s operands *before* the node itself, so that the
reader requires less RAUW. Although this will cause different code
paths to be hit in the reader, this should effectively be no
functionality change.
llvm-svn: 220340
1. Use const with autos.
2. Don't bother with explicit const in cast ops because they do it automagically.
Thanks, David B. / Aaron B. / Reid K.
llvm-svn: 219817
The function deleteBody() converts the linkage to external and thus destroys
original linkage type value. Lack of correct linkage type causes wrong
relocations to be emitted later.
Calling dropAllReferences() instead of deleteBody() will fix the issue.
Differential Revision: http://reviews.llvm.org/D5415
llvm-svn: 218302
Summary: This is part of the overall goal of removing static initializers from LLVM.
Reviewers: chandlerc
Reviewed By: chandlerc
Subscribers: chandlerc, llvm-commits
Differential Revision: http://reviews.llvm.org/D5416
llvm-svn: 218149
This doesn't change the interface or gives additional safety but removes
a ton of retain/release boilerplate.
No functionality change.
llvm-svn: 217778
This forces callers to use std::move when calling it. It is somewhat odd to have
code with std::move that doesn't always move, but it is also odd to have code
without std::move that sometimes moves.
llvm-svn: 217049
The attached patch simplifies a few interfaces that don't need to take
ownership of a buffer.
For example, both parseAssembly and parseBitcodeFile will parse the
entire buffer before returning. There is no need to take ownership.
Using a MemoryBufferRef makes it obvious in the type signature that
there is no ownership transfer.
llvm-svn: 216488
Take a StringRef instead of a "const char *".
Take a "std::error_code &" instead of a "std::string &" for error.
A create static method would be even better, but this patch is already a bit too
big.
llvm-svn: 216393
Block address forward-references are implemented by creating a
`BasicBlock` ahead of time that gets inserted in the `Function` when
it's eventually encountered.
However, if the same blockaddress was used in two separate functions
that were parsed *before* the referenced function (and the blockaddress
was never used at global scope), two separate basic blocks would get
created, one of which would be forgotten creating invalid IR.
This commit changes the forward-reference logic to create only one basic
block (and always return the same blockaddress).
llvm-svn: 215805
This is an off-by-one bug I found by inspection, which would only
trigger if the bitcode writer sees more uses of a `Value` than the
reader. Since this is only relevant when an instruction gets upgraded
somehow, there unfortunately isn't a reasonable way to add test
coverage.
llvm-svn: 215804
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)
Changes made by clang-tidy with minor tweaks.
llvm-svn: 215558
`BasicBlockFwdRefs` (and `BlockAddrFwdRefs` before it) was being emptied
in a non-deterministic order. When predicting use-list order I've
worked around this another way, but even when parsing lazily (and we
can't recreate use-list order) use-lists should be deterministic.
Make them so by using a side-queue of functions with forward-referenced
blocks that gets visited in order.
llvm-svn: 214899
`parseBitcodeFile()` uses the generic `getLazyBitcodeFile()` function as
a helper. Since `parseBitcodeFile()` isn't actually lazy -- it calls
`MaterializeAllPermanently()` -- bypass the unnecessary call to
`materializeForwardReferencedFunctions()` by extracting out a common
helper function. This removes the last of the use-list churn caused by
blockaddresses.
This highlights that we can't reproduce use-list order of globals and
constants when parsing lazily -- but that's necessarily out of scope.
When we're parsing lazily, we never have all the functions in memory, so
the use-lists of globals (and constants that reference globals) are
always incomplete.
This is part of PR5680.
llvm-svn: 214581
Now that we can reliably handle forward references to `BlockAddress`
(r214563), change the mechanics to simplify predicting use-list order.
Previously, we created dummy `GlobalVariable`s to represent block
addresses. After every function was materialized, we'd go through any
forward references to its blocks and RAUW them with a proper
`BlockAddress` constant. This causes some (potentially a lot of)
unnecessary use-list churn, since any constant expression that it's a
part of will need to be rematerialized as well.
Instead, pre-construct a `BasicBlock` immediately -- without attaching
it to its (empty) `Function` -- and use that to construct a
`BlockAddress`. This constant will not have to be regenerated. When
the function body is parsed, hook this pre-constructed basic block up
in the right place using `BasicBlock::insertInto()`.
Both before and after this change, the IR is temporarily in an invalid
state that gets resolved when `materializeForwardReferencedFunctions()`
gets called.
This is a prep commit that's part of PR5680, but the only functionality
change is the reduction of churn in the constant pool.
llvm-svn: 214570
`BlockAddress`es are interesting in that they can reference basic blocks
from *outside* the block's function. Since basic blocks are not global
values, this presents particular challenges for lazy parsing.
One corner case was found in PR11677 and fixed in r147425. In that
case, a global variable references a block address. It's necessary to
load the relevant function to resolve the forward reference before doing
anything with the module.
By inspection, I found (and have fixed here) two other cases:
- An instruction from one function references a block address from
another function, and only the first function is lazily loaded.
I fixed this the same way as PR11677: by eagerly loading the
referenced function.
- A function whose block address is taken is dematerialized, leaving
invalid references to it.
I fixed this by refusing to dematerialize functions whose block
addresses are taken (if you have to load it, you can't unload it).
llvm-svn: 214559
Correctly sort self-users (such as PHI nodes). I added a targeted test
in `test/Bitcode/use-list-order.ll` and the final missing RUN line to
tests in `test/Assembly`.
This is part of PR5680.
llvm-svn: 214417
Since initializers of GlobalValues are being assigned IDs before
GlobalValues themselves, explicitly exclude GlobalValues from the
constant pool. Added targeted test in `test/Bitcode/use-list-order.ll`
and added two more RUN lines in `test/Assembly`.
This is part of PR5680.
llvm-svn: 214368
When predicting use-list order, we visit functions in reverse order
followed by `GlobalValue`s and write out use-lists at the first
opportunity. In the reader, this will translate to *after* the last use
has been added.
For this to work, we actually need to descend into `GlobalValue`s.
Added a targeted test in `use-list-order.ll` and `RUN` lines to the
newly passing tests in `test/Bitcode`.
There are two remaining failures in `test/Bitcode`:
- blockaddress.ll: I haven't thought through how to model the way
block addresses change the order of use-lists (or how to work around
it).
- metadata-2.ll: There's an old-style `@llvm.used` global array here
that I suspect the .ll parser isn't upgrading properly. When it
round-trips through bitcode, the .bc reader *does* upgrade it, so
the extra variable (`i8* null`) has an extra use, and the shuffle
vector doesn't match.
I think the fix is to upgrade old-style global arrays (or reject
them?) in the .ll parser.
This is part of PR5680.
llvm-svn: 214321
This commit fixes undefined behaviour that caused the revert in r214249.
The problem was two unsequenced operations on a `DenseMap<>`, giving
different behaviour in GCC and Clang. This:
DenseMap<T*, unsigned> DM;
for (auto &X : ...)
DM[&X] = DM.size() + 1;
should have been:
DenseMap<T*, unsigned> DM;
for (auto &X : ...) {
unsigned Size = DM.size();
DM[&X] = Size + 1;
}
Until r214242, this difference between compilers didn't matter. In
r214242, `OrderMap::LastGlobalValueID` was introduced and compared
against IDs, which in GCC were off-by-one my expectations.
llvm-svn: 214270
To avoid unnecessary forward references, the reader doesn't process
initializers of `GlobalValue`s until after the constant pool has been
processed, and then in reverse order. Model this when predicting
use-list order. This gets two more Bitcode tests passing with
`llvm-uselistorder`.
Part of PR5680.
llvm-svn: 214242
This will let users in other libraries know which error occurred. In particular,
it will be possible to check if the parsing failed or if the file is not
bitcode.
llvm-svn: 214209
Fix the sort of expected order in the reader to correctly return `false`
when comparing a `Use` against itself.
This was caught by test/Bitcode/binaryIntInstructions.3.2.ll, so I'm
adding a `RUN` line using `llvm-uselistorder` for every test in
`test/Bitcode` that passes.
A few tests still fail, so I'll investigate those next.
This is part of PR5680.
llvm-svn: 214157
Since we're storing lots of these, save two-pointers per vector with a
custom type rather than using the relatively heavy `SmallVector`.
Part of PR5680.
llvm-svn: 214135
Predict and serialize use-list order in bitcode. This makes the option
`-preserve-bc-use-list-order` work *most* of the time, but this is still
experimental.
- Builds a full value-table up front in the writer, sets up a list of
use-list orders to write out, and discards the table. This is a
simpler first step than determining the order from the various
overlapping IDs of values on-the-fly.
- The shuffles stored in the use-list order list have an unnecessarily
large memory footprint.
- `blockaddress` expressions cause functions to be materialized
out-of-order. For now I've ignored this problem, so use-list orders
will be wrong for constants used by functions that have block
addresses taken. There are a couple of ways to fix this, but I
don't have a concrete plan yet.
- When materializing functions lazily, the use-lists for constants
will not be correct. This use case is out of scope: what should the
use-list order be, if it's incomplete?
This is part of PR5680.
llvm-svn: 214125
`ValueEnumerator::OptimizeConstants()` creates forward references within
the constant pools, which makes predicting constants' use-list order
difficult. For now, just disable the optimization.
This can be re-enabled in the future in one of two ways:
- Enable a limited version of this optimization that doesn't create
forward references. One idea is to categorize constants by their
"height" and make that the top-level sort.
- Enable it entirely. This requires predicting how may times each
constant will be recreated as its operands' and operands' operands'
(etc.) forward references get resolved.
This is part of PR5680.
llvm-svn: 213953
Add a -verify-use-list-order pass, which shuffles use-list order, writes
to bitcode, reads back, and verifies that the (shuffled) order matches.
- The utility functions live in lib/IR/UseListOrder.cpp.
- Moved (and renamed) the command-line option to enable writing
use-lists, so that this pass can return early if the use-list orders
aren't being serialized.
It's not clear that this pass is the right direction long-term (perhaps
a separate tool instead?), but short-term it's a great way to test the
use-list order prototype. I've added an XFAIL-ed testcase that I'm
hoping to get working pretty quickly.
This is part of PR5680.
llvm-svn: 213945
This attribute indicates that the parameter or return pointer is
dereferenceable. Practically speaking, loads from such a pointer within the
associated byte range are safe to speculatively execute. Such pointer
parameters are common in source languages (C++ references, for example).
llvm-svn: 213385
Currently the only kind of integer IR attributes that we have are alignment
attributes, and so the attribute kind that takes an integer parameter is called
AlignAttr, but that will change (we'll soon be adding a dereferenceable
attribute that also takes an integer value). Accordingly, rename AlignAttribute
to IntAttribute (class names, enums, etc.).
No functionality change intended.
llvm-svn: 213352
This was an oversight in the original support. As it is, I stuffed this
bit into the alignment. The alignment is stored in log2 form, so it
doesn't need more than 5 bits, given that Value::MaximumAlignment is 1
<< 29.
Reviewers: nicholas
Differential Revision: http://reviews.llvm.org/D3943
llvm-svn: 213118
The regular end of the bitcode parsing is in the BitstreamEntry::EndBlock
case.
Should fix the LTO bootstrap on OS X (this function is only used by ld64).
llvm-svn: 212357
This reverts commit r212342.
We can get a StringRef into the current Record, but not one in the bitcode
itself since the string is compressed in it.
llvm-svn: 212356
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.
COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.
This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.
Differential Revision: http://reviews.llvm.org/D4178
llvm-svn: 211920
[LLVM part]
These patches rename the loop unrolling and loop vectorizer metadata
such that they have a common 'llvm.loop.' prefix. Metadata name
changes:
llvm.vectorizer.* => llvm.loop.vectorizer.*
llvm.loopunroll.* => llvm.loop.unroll.*
This was a suggestion from an earlier review
(http://reviews.llvm.org/D4090) which added the loop unrolling
metadata.
Patch by Mark Heffernan.
llvm-svn: 211710
This allows us to just use a std::unique_ptr to store the pointer to the buffer.
The flip side is that they have to support releasing the buffer back to the
caller.
Overall this looks like a more efficient and less brittle api.
llvm-svn: 211542
LLVMGetBitcodeModuleInContext should not take ownership on error. I will
try to localize this odd api requirement, but this should get the bots green.
llvm-svn: 211213
We do have use cases for the bitcode reader owning the buffer or not, but we
always know which one we have when we construct it.
It might be possible to simplify this further, but this is a step in the
right direction.
llvm-svn: 211205
This commit adds a weak variant of the cmpxchg operation, as described
in C++11. A cmpxchg instruction with this modifier is permitted to
fail to store, even if the comparison indicated it should.
As a result, cmpxchg instructions must return a flag indicating
success in addition to their original iN value loaded. Thus, for
uniformity *all* cmpxchg instructions now return "{ iN, i1 }". The
second flag is 1 when the store succeeded.
At the DAG level, a new ATOMIC_CMP_SWAP_WITH_SUCCESS node has been
added as the natural representation for the new cmpxchg instructions.
It is a strong cmpxchg.
By default this gets Expanded to the existing ATOMIC_CMP_SWAP during
Legalization, so existing backends should see no change in behaviour.
If they wish to deal with the enhanced node instead, they can call
setOperationAction on it. Beware: as a node with 2 results, it cannot
be selected from TableGen.
Currently, no use is made of the extra information provided in this
patch. Test updates are almost entirely adapting the input IR to the
new scheme.
Summary for out of tree users:
------------------------------
+ Legacy Bitcode files are upgraded during read.
+ Legacy assembly IR files will be invalid.
+ Front-ends must adapt to different type for "cmpxchg".
+ Backends should be unaffected by default.
llvm-svn: 210903
Alias with unnamed_addr were in a strange state. It is stored in GlobalValue,
the language reference talks about "unnamed_addr aliases" but the verifier
was rejecting them.
It seems natural to allow unnamed_addr in aliases:
* It is a property of how it is accessed, not of the data itself.
* It is perfectly possible to write code that depends on the address
of an alias.
This patch then makes unname_addr legal for aliases. One side effect is that
the syntax changes for a corner case: In globals, unnamed_addr is now printed
before the address space.
llvm-svn: 210302
It includes a pass that rewrites all indirect calls to jumptable functions to pass through these tables.
This also adds backend support for generating the jump-instruction tables on ARM and X86.
Note that since the jumptable attribute creates a second function pointer for a
function, any function marked with jumptable must also be marked with unnamed_addr.
llvm-svn: 210280
This patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is
up to MC (or the system assembler) to decide if that expression is valid or not.
This reduces our ability to diagnose invalid uses and how early we can spot
them, but it also lets us do things like
@test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32),
i32 ptrtoint (i32* @bar to i32)) to i32*)
An important implication of this patch is that the notion of aliased global
doesn't exist any more. The alias has to encode the information needed to
access it in its metadata (linkage, visibility, type, etc).
Another consequence to notice is that getSection has to return a "const char *".
It could return a NullTerminatedStringRef if there was such a thing, but when
that was proposed the decision was to just uses "const char*" for that.
llvm-svn: 210062
This matches gcc's behavior. It also seems natural given that aliases
contain other properties that govern how it is accessed (linkage,
visibility, dll storage).
Clang still has to be updated to expose this feature to C.
llvm-svn: 209759
This allows us to put dynamic initializers for weak data into the same
comdat group as the data being initialized. This is necessary for MSVC
ABI compatibility. Once we have comdats for guard variables, we can use
the combination to help GlobalOpt fire more often for weak data with
guarded initialization on other platforms.
Reviewers: nlewycky
Differential Revision: http://reviews.llvm.org/D3499
llvm-svn: 209015
This patch changes the design of GlobalAlias so that it doesn't take a
ConstantExpr anymore. It now points directly to a GlobalObject, but its type is
independent of the aliasee type.
To avoid changing all alias related tests in this patches, I kept the common
syntax
@foo = alias i32* @bar
to mean the same as now. The cases that used to use cast now use the more
general syntax
@foo = alias i16, i32* @bar.
Note that GlobalAlias now behaves a bit more like GlobalVariable. We
know that its type is always a pointer, so we omit the '*'.
For the bitcode, a nice surprise is that we were writing both identical types
already, so the format change is minimal. Auto upgrade is handled by looking
through the casts and no new fields are needed for now. New bitcode will
simply have different types for Alias and Aliasee.
One last interesting point in the patch is that replaceAllUsesWith becomes
smart enough to avoid putting a ConstantExpr in the aliasee. This seems better
than checking and updating every caller.
A followup patch will delete getAliasedGlobal now that it is redundant. Another
patch will add support for an explicit offset.
llvm-svn: 209007
Visibilities of `hidden` and `protected` are meaningless for symbols
with local linkage.
- Change the assembler to reject non-default visibility on symbols
with local linkage.
- Change the bitcode reader to auto-upgrade `hidden` and `protected`
to `default` when the linkage is local.
- Update LangRef.
<rdar://problem/16141113>
llvm-svn: 208263
Given the following C code llvm currently generates suboptimal code for
x86-64:
__m128 bss4( const __m128 *ptr, size_t i, size_t j )
{
float f = ptr[i][j];
return (__m128) { f, f, f, f };
}
=================================================
define <4 x float> @_Z4bss4PKDv4_fmm(<4 x float>* nocapture readonly %ptr, i64 %i, i64 %j) #0 {
%a1 = getelementptr inbounds <4 x float>* %ptr, i64 %i
%a2 = load <4 x float>* %a1, align 16, !tbaa !1
%a3 = trunc i64 %j to i32
%a4 = extractelement <4 x float> %a2, i32 %a3
%a5 = insertelement <4 x float> undef, float %a4, i32 0
%a6 = insertelement <4 x float> %a5, float %a4, i32 1
%a7 = insertelement <4 x float> %a6, float %a4, i32 2
%a8 = insertelement <4 x float> %a7, float %a4, i32 3
ret <4 x float> %a8
}
=================================================
shlq $4, %rsi
addq %rdi, %rsi
movslq %edx, %rax
vbroadcastss (%rsi,%rax,4), %xmm0
retq
=================================================
The movslq is uneeded, but is present because of the trunc to i32 and then
sext back to i64 that the backend adds for vbroadcastss.
We can't remove it because it changes the meaning. The IR that clang
generates is already suboptimal. What clang really should emit is:
%a4 = extractelement <4 x float> %a2, i64 %j
This patch makes that legal. A separate patch will teach clang to do it.
Differential Revision: http://reviews.llvm.org/D3519
llvm-svn: 207801
This is similar to the 'tail' marker, except that it guarantees that
tail call optimization will occur. It also comes with convervative IR
verification rules that ensure that tail call optimization is possible.
Reviewers: nicholas
Differential Revision: http://llvm-reviews.chandlerc.com/D3240
llvm-svn: 207143
Since our error_category is based on the std one, we should have the
same visibility for the constructor. This also allows us to avoid
using the _do_message implementation detail in our own categories.
llvm-svn: 203998
These linkages were introduced some time ago, but it was never very
clear what exactly their semantics were or what they should be used
for. Some investigation found these uses:
* utf-16 strings in clang.
* non-unnamed_addr strings produced by the sanitizers.
It turns out they were just working around a more fundamental problem.
For some sections a MachO linker needs a symbol in order to split the
section into atoms, and llvm had no idea that was the case. I fixed
that in r201700 and it is now safe to use the private linkage. When
the object ends up in a section that requires symbols, llvm will use a
'l' prefix instead of a 'L' prefix and things just work.
With that, these linkages were already dead, but there was a potential
future user in the objc metadata information. I am still looking at
CGObjcMac.cpp, but at this point I am convinced that linker_private
and linker_private_weak are not what they need.
The objc uses are currently split in
* Regular symbols (no '\01' prefix). LLVM already directly provides
whatever semantics they need.
* Uses of a private name (start with "\01L" or "\01l") and private
linkage. We can drop the "\01L" and "\01l" prefixes as soon as llvm
agrees with clang on L being ok or not for a given section. I have two
patches in code review for this.
* Uses of private name and weak linkage.
The last case is the one that one could think would fit one of these
linkages. That is not the case. The semantics are
* the linker will merge these symbol by *name*.
* the linker will hide them in the final DSO.
Given that the merging is done by name, any of the private (or
internal) linkages would be a bad match. They allow llvm to rename the
symbols, and that is really not what we want. From the llvm point of
view, these objects should really be (linkonce|weak)(_odr)?.
For now, just keeping the "\01l" prefix is probably the best for these
symbols. If we one day want to have a more direct support in llvm,
IMHO what we should add is not a linkage, it is just a hidden_symbol
attribute. It would be applicable to multiple linkages. For example,
on weak it would produce the current behavior we have for objc
metadata. On internal, it would be equivalent to private (and we
should then remove private).
llvm-svn: 203866
The syntax for "cmpxchg" should now look something like:
cmpxchg i32* %addr, i32 42, i32 3 acquire monotonic
where the second ordering argument gives the required semantics in the case
that no exchange takes place. It should be no stronger than the first ordering
constraint and cannot be either "release" or "acq_rel" (since no store will
have taken place).
rdar://problem/15996804
llvm-svn: 203559
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
detail
2) Change it to actually be a *Use* iterator rather than a *User*
iterator.
3) Add an adaptor which is a User iterator that always looks through the
Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
they wanted a use_iterator (and to explicitly dig out the User when
needed), or a user_iterator which makes the Use itself totally
opaque.
Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.
The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.
However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]
llvm-svn: 203364
This compiles with no changes to clang/lld/lldb with MSVC and includes
overloads to various functions which are used by those projects and llvm
which have OwningPtr's as parameters. This should allow out of tree
projects some time to move. There are also no changes to libs/Target,
which should help out of tree targets have time to move, if necessary.
llvm-svn: 203083
implementation already lived.
After this commit, the only IR-library headers in include/llvm/* are
ones related to the legacy pass infrastructure that I'm planning to
leave there until the new one is farther along.
The only other headers at the top level are linking and initialization
aids that aren't really libraries but just headers.
llvm-svn: 203069
Move the test for this class into the IR unittests as well.
This uncovers that ValueMap too is in the IR library. Ironically, the
unittest for ValueMap is useless in the Support library (honestly, so
was the ValueHandle test) and so it already lives in the IR unittests.
Mmmm, tasty layering.
llvm-svn: 202821
Now that DataLayout is not a pass, store one in Module.
Since the C API expects to be able to get a char* to the datalayout description,
we have to keep a std::string somewhere. This patch keeps it in Module and also
uses it to represent modules without a DataLayout.
Once DataLayout is mandatory, we should probably move the string to DataLayout
itself since it won't be necessary anymore to represent the special case of a
module without a DataLayout.
llvm-svn: 202190
After this I will set the default back to F_None. The advantage is that
before this patch forgetting to set F_Binary would corrupt a file on windows.
Forgetting to set F_Text produces one that cannot be read in notepad, which
is a better failure mode :-)
llvm-svn: 202052
Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.
Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:
define available_externally dllimport void @f() {}
@Var = dllexport global i32 1, align 4
Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.
llvm-svn: 199218
Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.
Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:
define available_externally dllimport void @f() {}
@Var = dllexport global i32 1, align 4
Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.
llvm-svn: 199204
This moves the old pass creation functionality to its own header and
updates the callers of that routine. Then it adds a new PM supporting
bitcode writer to the header file, and wires that up in the opt tool.
A test is added that round-trips code into bitcode and back out using
the new pass manager.
llvm-svn: 199078
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.
Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.
llvm-svn: 198685
The inalloca attribute is designed to support passing C++ objects by
value in the Microsoft C++ ABI. It behaves the same as byval, except
that it always implies that the argument is in memory and that the bytes
are never copied. This attribute allows the caller to take the address
of an outgoing argument's memory and execute arbitrary code to store
into it.
This patch adds basic IR support, docs, and verification. It does not
attempt to implement any lowering or fix any possibly broken transforms.
When this patch lands, a complete description of this feature should
appear at http://llvm.org/docs/InAlloca.html .
Differential Revision: http://llvm-reviews.chandlerc.com/D2173
llvm-svn: 197645
Add a helper function getDebugInfoVersionFromModule to return the debug info
version number for a module.
"Verifier/module-flags-1.ll" checks for verification errors.
It will seg fault when calling getDebugInfoVersionFromModule because of the
incorrect format for module flags in the testing case. We make
getModuleFlagsMetadata more robust by checking for error conditions.
PR17982
llvm-svn: 196158
In order to create an ObjectFile implementation that uses bitcode files, we
need to propagate the bitcode errors to the ObjectFile interface, so we need
to convert it to use the same error handling as ObjectFile: error_code.
llvm-svn: 193996
linkonce_odr_auto_hide was in incomplete attempt to implement a way
for the linker to hide symbols that are known to be available in every
TU and whose addresses are not relevant for a particular DSO.
It was redundant in that it all its uses are equivalent to
linkonce_odr+unnamed_addr. Unlike those, it has never been connected
to clang or llvm's optimizers, so it was effectively dead.
Given that nothing produces it, this patch just nukes it
(other than the llvm-c enum value).
llvm-svn: 193865
Major steps include:
1). introduces a not-addr-taken bit-field in GlobalVariable
2). GlobalOpt pass sets "not-address-taken" if it proves a global varirable
dosen't have its address taken.
3). AA use this info for disambiguation.
llvm-svn: 193251
Reviewed by Joe Abbey and Tobias Grosser
Here is a patch that fixes decoding of CE_SELECT in BitcodeReader,
along with a simple test case. The problem in the current code is that
it generates but doesn't accept bitcode that uses vectors for the
first element of a select in this context.
llvm-svn: 190634
The work on this project was left in an unfinished and inconsistent state.
Hopefully someone will eventually get a chance to implement this feature, but
in the meantime, it is better to put things back the way the were. I have
left support in the bitcode reader to handle the case-range bitcode format,
so that we do not lose bitcode compatibility with the llvm 3.3 release.
This reverts the following commits: 155464, 156374, 156377, 156613, 156704,
156757, 156804 156808, 156985, 157046, 157112, 157183, 157315, 157384, 157575,
157576, 157586, 157612, 157810, 157814, 157815, 157880, 157881, 157882, 157884,
157887, 157901, 158979, 157987, 157989, 158986, 158997, 159076, 159101, 159100,
159200, 159201, 159207, 159527, 159532, 159540, 159583, 159618, 159658, 159659,
159660, 159661, 159703, 159704, 160076, 167356, 172025, 186736
llvm-svn: 190328
This function attribute indicates that the function is not optimized
by any optimization or code generator passes with the
exception of interprocedural optimization passes.
llvm-svn: 189101
The bitcode representation attribute kinds are encoded into / decoded from
should be independent of the current set of LLVM attributes and their position
in the AttrKind enum. This patch explicitly encodes attributes to fixed bitcode
values.
With this patch applied, LLVM does not silently misread attributes written by
LLVM 3.3. We also enhance the decoding slightly such that an error message is
printed if an unknown AttrKind encoding was dected.
Bonus: Dropping bitcode attributes from AttrKind is now easy, as old AttrKinds
do not need to be kept to support the Bitcode reader.
llvm-svn: 187186
There was exactly one caller using this API right, the others were relying on
specific behavior of the default implementation. Since it's too hard to use it
right just remove it and standardize on the default behavior.
Defines away PR16132.
llvm-svn: 182636
Previously, BitstreamCursor read an abbreviated record by splatting the
whole thing into a data vector, then extracting and removing the /first/
element. Now, it reads the first element--the record code--separately from
the actual field values.
No (intended) functionality change.
llvm-svn: 181639
the things, and renames it to CBindingWrapping.h. I also moved
CBindingWrapping.h into Support/.
This new file just contains the macros for defining different wrap/unwrap
methods.
The calls to those macros, as well as any custom wrap/unwrap definitions
(like for array of Values for example), are put into corresponding C++
headers.
Doing this required some #include surgery, since some .cpp files relied
on the fact that including Wrap.h implicitly caused the inclusion of a
bunch of other things.
This also now means that the C++ headers will include their corresponding
C API headers; for example Value.h must include llvm-c/Core.h. I think
this is harmless, since the C API headers contain just external function
declarations and some C types, so I don't believe there should be any
nasty dependency issues here.
llvm-svn: 180881
The bitcode writer emits a reference to the attribute group that the object at
the given index refers to. The bitcode reader is modified to read this in and
map it back to the attribute group.
llvm-svn: 174952
I have some uncommitted changes to the cast code that catch this sort of thing
at compile-time but I still need to do some other cleanup before I can enable
it.
llvm-svn: 174853
This reads the attribute groups. It currently doesn't do anything with them.
NOTE: In the commit to the bitcode writer, the format *may* change in the near
future. Which means that this code would also change.
llvm-svn: 174849
This is some initial code for emitting the attribute groups into the bitcode.
NOTE: This format *may* change! Do not rely upon the attribute groups' bitcode
not changing.
llvm-svn: 174845
bitcode writer would generate abbrev records saying that the abbrev should be
filled with fixed zero-bit bitfields (this happens in the .bc writer when
the number of types used in a module is exactly one, since log2(1) == 0).
In this case, just handle it as a literal zero. We can't "just fix" the writer
without breaking compatibility with existing bc files, so have the abbrev reader
do the substitution.
Strengthen the assert in read to reject reads of zero bits so we catch such
crimes in the future, and remove the special case designed to handle this.
llvm-svn: 174801
Rename the PARAMATTR_CODE_ENTRY to PARAMATTR_CODE_ENTRY_OLD. It will be replaced
by another encoding. Keep around the current LLVM attribute encoder/decoder
code, but move it to the bitcode directories so that no one's tempted to use
them.
llvm-svn: 174335
We no longer accept an encoded integer as representing all of the
attributes. Convert this via the AttrBuilder class into an AttributeSet with the
correct representation (an AttributeSetImpl that holds a list of Attribute
objects).
llvm-svn: 173750
The 'getSlot' function and its ilk allow introspection into the AttributeSet
class. However, that class should be opaque. Allow access through accessor
methods instead.
llvm-svn: 173522
Previously we tried to infer it from the bit width size, with an added
IsIEEE argument for the PPC/IEEE 128-bit case, which had a default
value. This default value allowed bugs to creep in, where it was
inappropriate.
llvm-svn: 173138
BLOB (i.e., large, performance intensive data) in a bitcode file was switched to
invoking one virtual method call per byte read. Now we do one virtual call per
BLOB.
llvm-svn: 173065
through a BitstreamCursor that produce it: advance() and
advanceSkippingSubblocks(), representing the two most common ways clients
want to walk through bitcode.
llvm-svn: 172919
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.
There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.
The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.
I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).
I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.
llvm-svn: 171366
missed in the first pass because the script didn't yet handle include
guards.
Note that the script is now able to handle all of these headers without
manual edits. =]
llvm-svn: 169224
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.
Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]
llvm-svn: 169131
Added in bitcode enum for the serializing of fast-math flags. Added in the reading/writing of fast-math flags from the OptimizationFlags record for BinaryOps.
llvm-svn: 168646
- Widespread trailing space removal
- A dash of OCD spacing to block align enums
- joined a line that probably needed 80 cols a while back
llvm-svn: 168566
When code deletes the context, the AttributeImpls that the AttrListPtr points to
are now invalid. Therefore, instead of keeping a separate managed static for the
AttrListPtrs that's reference counted, move it into the LLVMContext and delete
it when deleting the AttributeImpls.
llvm-svn: 168354
Previously in a vector of pointers, the pointer couldn't be any pointer type,
it had to be a pointer to an integer or floating point type. This is a hassle
for dragonegg because the GCC vectorizer happily produces vectors of pointers
where the pointer is a pointer to a struct or whatever. Vector getelementptr
was restricted to just one index, but now that vectors of pointers can have
any pointer type it is more natural to allow arbitrary vector getelementptrs.
There is however the issue of struct GEPs, where if each lane chose different
struct fields then from that point on each lane will be working down into
unrelated types. This seems like too much pain for too little gain, so when
you have a vector struct index all the elements are required to be the same.
llvm-svn: 167828
Convert the internal representation of the Attributes class into a pointer to an
opaque object that's uniqued by and stored in the LLVMContext object. The
Attributes class then becomes a thin wrapper around this opaque
object. Eventually, the internal representation will be expanded to include
attributes that represent code generation options, etc.
llvm-svn: 165917
to the instruction position. The old encoding would give an absolute
ID which counts up within a function, and only resets at the next function.
I.e., Instead of having:
... = icmp eq i32 n-1, n-2
br i1 ..., label %bb1, label %bb2
it will now be roughly:
... = icmp eq i32 1, 2
br i1 1, label %bb1, label %bb2
This makes it so that ids remain relatively small and can be encoded
in fewer bits.
With this encoding, forward reference operands will be given
negative-valued IDs. Use signed VBRs for the most common case
of forward references, which is phi instructions.
To retain backward compatibility we bump the bitcode version
from 0 to 1 to distinguish between the different encodings.
llvm-svn: 165739
We inserted a placeholder that was never replaced because the function was
already visited. Assert that all placeholders have been resolved when tearing
down the bitcode reader.
Fixes PR13895.
llvm-svn: 164369
make it more consistent with its intended semantics.
The `linker_private_weak_def_auto' linkage type was meant to automatically hide
globals which never had their addresses taken. It has nothing to do with the
`linker_private' linkage type, which outputs the symbols with a `l' (ell) prefix
among other things.
The intended semantic is more like the `linkonce_odr' linkage type.
Change the name of the linkage type to `linkonce_odr_auto_hide'. And therefore
changing the semantics so that it produces the correct output for the linker.
Note: The old linkage name `linker_private_weak_def_auto' will still parse but
is not a synonym for `linkonce_odr_auto_hide'. This should be removed in 4.0.
<rdar://problem/11754934>
llvm-svn: 162114
This allows the user/front-end to specify a model that is better
than what LLVM would choose by default. For example, a variable
might be declared as
@x = thread_local(initialexec) global i32 42
if it will not be used in a shared library that is dlopen'ed.
If the specified model isn't supported by the target, or if LLVM can
make a better choice, a different model may be used.
llvm-svn: 159077
Attribute bits above 1<<30 are now encoded correctly. Additionally,
the encoding/decoding functionality has been hoisted to helper functions
in Attributes.h in an effort to help the encoding/decoding to stay in
sync with the Attribute bitcode definitions.
llvm-svn: 157581
Implemented IntItem - the wrapper around APInt. Why not to use APInt item directly right now?
1. It will very difficult to implement case ranges as series of small patches. We got several large and heavy patches. Each patch will about 90-120 kb. If you replace ConstantInt with APInt in SwitchInst you will need to changes at the same time all Readers,Writers and absolutely all passes that uses SwitchInst.
2. We can implement APInt pool inside and save memory space. E.g. we use several switches that works with 256 bit items (switch on signatures, or strings). We can avoid value duplicates in this case.
3. IntItem can be easyly easily replaced with APInt.
4. Currenly we can interpret IntItem both as ConstantInt and as APInt. It allows to provide SwitchInst methods that works with ConstantInt for non-updated passes.
Why I need it right now? Currently I need to update SimplifyCFG pass (EqualityComparisons). I need to work with APInts directly a lot, so peaces of code
ConstantInt *V = ...;
if (V->getValue().ugt(AnotherV->getValue()) {
...
}
will look awful. Much more better this way:
IntItem V = ConstantIntVal->getValue();
if (AnotherV < V) {
}
Of course any reviews are welcome.
P.S.: I'm also going to rename ConstantRangesSet to IntegersSubset, and CRSBuilder to IntegersSubsetMapping (allows to map individual subsets of integers to the BasicBlocks).
Since in future these classes will founded on APInt, it will possible to use them in more generic ways.
llvm-svn: 157576
Ordinary patch for PR1255.
Added new case-ranges orientated methods for adding/removing cases in SwitchInst. After this patch cases will internally representated as ConstantArray-s instead of ConstantInt, externally cases wrapped within the ConstantRangesSet object.
Old methods of SwitchInst are also works well, but marked as deprecated. So on this stage we have no side effects except that I added support for case ranges in BitcodeReader/Writer, of course test for Bitcode is also added. Old "switch" format is also supported.
llvm-svn: 156704
Added new case-ranges orientated methods for adding/removing cases in SwitchInst. After this patch cases will internally representated as ConstantArray-s instead of ConstantInt, externally cases wrapped within the ConstantRangesSet object.
Old methods of SwitchInst are also works well, but marked as deprecated. So on this stage we have no side effects except that I added support for case ranges in BitcodeReader/Writer, of course test for Bitcode is also added. Old "switch" format is also supported.
llvm-svn: 156374
Renamed methods caseBegin, caseEnd and caseDefault with case_begin, case_end, and case_default.
Added some notes relative to case iterators.
llvm-svn: 152532
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120130/136146.html
Implemented CaseIterator and it solves almost all described issues: we don't need to mix operand/case/successor indexing anymore. Base iterator class is implemented as a template since it may be initialized either from "const SwitchInst*" or from "SwitchInst*".
ConstCaseIt is just a read-only iterator.
CaseIt is read-write iterator; it allows to change case successor and case value.
Usage of iterator allows totally remove resolveXXXX methods. All indexing convertions done automatically inside the iterator's getters.
Main way of iterator usage looks like this:
SwitchInst *SI = ... // intialize it somehow
for (SwitchInst::CaseIt i = SI->caseBegin(), e = SI->caseEnd(); i != e; ++i) {
BasicBlock *BB = i.getCaseSuccessor();
ConstantInt *V = i.getCaseValue();
// Do something.
}
If you want to convert case number to TerminatorInst successor index, just use getSuccessorIndex iterator's method.
If you want initialize iterator from TerminatorInst successor index, use CaseIt::fromSuccessorIndex(...) method.
There are also related changes in llvm-clients: klee and clang.
llvm-svn: 152297
std::vector.
- Good for 1-2% speedup on writing PCH for Cocoa.h.
- Clang side API match to follow shortly, there wasn't an easy way to make this
non-breaking.
llvm-svn: 151750
This CL delays reading of function bodies from initial parse until
materialization, allowing overlap of compilation with bitcode download.
llvm-svn: 149918
but with a critical fix to the SelectionDAG code that optimizes copies
from strings into immediate stores: the previous code was stopping reading
string data at the first nul. Address this by adding a new argument to
llvm::getConstantStringInfo, preserving the behavior before the patch.
llvm-svn: 149800
The purpose of refactoring is to hide operand roles from SwitchInst user (programmer). If you want to play with operands directly, probably you will need lower level methods than SwitchInst ones (TerminatorInst or may be User). After this patch we can reorganize SwitchInst operands and successors as we want.
What was done:
1. Changed semantics of index inside the getCaseValue method:
getCaseValue(0) means "get first case", not a condition. Use getCondition() if you want to resolve the condition. I propose don't mix SwitchInst case indexing with low level indexing (TI successors indexing, User's operands indexing), since it may be dangerous.
2. By the same reason findCaseValue(ConstantInt*) returns actual number of case value. 0 means first case, not default. If there is no case with given value, ErrorIndex will returned.
3. Added getCaseSuccessor method. I propose to avoid usage of TerminatorInst::getSuccessor if you want to resolve case successor BB. Use getCaseSuccessor instead, since internal SwitchInst organization of operands/successors is hidden and may be changed in any moment.
4. Added resolveSuccessorIndex and resolveCaseIndex. The main purpose of these methods is to see how case successors are really mapped in TerminatorInst.
4.1 "resolveSuccessorIndex" was created if you need to level down from SwitchInst to TerminatorInst. It returns TerminatorInst's successor index for given case successor.
4.2 "resolveCaseIndex" converts low level successors index to case index that curresponds to the given successor.
Note: There are also related compatability fix patches for dragonegg, klee, llvm-gcc-4.0, llvm-gcc-4.2, safecode, clang.
llvm-svn: 149481
Duncan P. N. Exon Smith