Summary:
Re-enable lifetime-start-on-first-use for stack coloring,
but explicitly disable it for slots with more than one start
or end lifetime marker.
Bug: 27903
Reviewers: wmi, tejohnson, qcolombet, gbiv
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20739
llvm-svn: 271412
Summary:
Turn off lifetime-start-on-first-use enhancement for the moment
pending a fix for bug 27903.
Bug: 27903
Reviewers: tejohnson, wmi, qcolombet, gbiv
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20731
llvm-svn: 271003
Replace bidirectional flow analysis to compute liveness with forward
analysis pass. Treat lifetimes as starting when there is a first
reference to the stack slot, as opposed to starting at the point of the
lifetime.start intrinsic, so as to increase the number of stack
variables we can overlap.
Reviewers: gbiv, qcolumbet, wmi
Differential Revision: http://reviews.llvm.org/D18827
Bug: 25776
llvm-svn: 270559
Summary:
Refactor debugging routines to reduce code duplication. Remove a couple
of #include's that were not needed. Don't require MachineDominator as a
prereq for this pass (not needed).
These changes split off from http://reviews.llvm.org/D18827.
Reviewers: wmi, gbiv, qcolombet
Subscribers: llvm-commits, davidxl, jevinskie
Differential Revision: http://reviews.llvm.org/D18992
llvm-svn: 267766
The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).
Differential Revision: http://reviews.llvm.org/D19172
llvm-svn: 267231
This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations.
The bisection is enabled using a new command line option (-opt-bisect-limit). Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit. A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used.
The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check. Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute. A new function call has been added for module and SCC passes that behaves in a similar way.
Differential Revision: http://reviews.llvm.org/D19172
llvm-svn: 267022
Removed some unused headers, replaced some headers with forward class declarations.
Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'
Patch by Eugene Kosov <claprix@yandex.ru>
Differential Revision: http://reviews.llvm.org/D19219
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
Catch objects with a displacement of zero do not initialize a catch
object. The displacement is relative to %rsp at the end of the
function's prologue for x86_64 targets.
If we place an object at the top-of-stack, we will end up wit a
displacement of zero resulting in our catch object remaining
uninitialized.
Address this by creating our catch objects as fixed objects. We will
ensure that the UnwindHelp object is created after the catch objects so
that no catch object will have a displacement of zero.
Differential Revision: http://reviews.llvm.org/D17823
llvm-svn: 262546
Take MachineInstr by reference instead of by pointer in SlotIndexes and
the SlotIndex wrappers in LiveIntervals. The MachineInstrs here are
never null, so this cleans up the API a bit. It also incidentally
removes a few implicit conversions from MachineInstrBundleIterator to
MachineInstr* (see PR26753).
At a couple of call sites it was convenient to convert to a range-based
for loop over MachineBasicBlock::instr_begin/instr_end, so I added
MachineBasicBlock::instrs.
llvm-svn: 262115
I originally reapplied this in 257550, but had to revert again due to bot
breakage. The only change in this version is to allow either the TypeSize
or the TypeAllocSize of the variable to be the one represented in debug info
(hopefully in the future we can figure out how to encode the difference).
Additionally, several bot failures following r257550, were due to
optimizer bugs now fixed in r257787 and r257795.
r257550 commit message was:
```
The follow extra changes were made to test cases:
Manually making the variable be the actual type instead of a pointer
to avoid pointer-size differences in generic code:
LLVM :: DebugInfo/Generic/2010-03-24-MemberFn.ll
LLVM :: DebugInfo/Generic/2010-04-06-NestedFnDbgInfo.ll
LLVM :: DebugInfo/Generic/2010-05-03-DisableFramePtr.ll
LLVM :: DebugInfo/Generic/varargs.ll
Delete sizing information from debug info for the same reason
(but the presence of the pointer was important to the test case):
LLVM :: DebugInfo/Generic/restrict.ll
LLVM :: DebugInfo/Generic/tu-composite.ll
LLVM :: Linker/type-unique-type-array-a.ll
LLVM :: Linker/type-unique-simple2.ll
Fixing an incorrect DW_OP_deref
LLVM :: DebugInfo/Generic/2010-05-03-OriginDIE.ll
Fixing a missing DW_OP_deref
LLVM :: DebugInfo/Generic/incorrect-variable-debugloc.ll
Additionally, clang should no longer complain during bootstrap should no
longer happen after r257534.
The original commit message was:
``
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.
One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.
Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
variable as that would depend on the target, even though this test is
supposed to be generic
- I had to manually declared size/align for reference type. See also the
discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref
``
```
llvm-svn: 257850
The follow extra changes were made to test cases:
Manually making the variable be the actual type instead of a pointer
to avoid pointer-size differences in generic code:
LLVM :: DebugInfo/Generic/2010-03-24-MemberFn.ll
LLVM :: DebugInfo/Generic/2010-04-06-NestedFnDbgInfo.ll
LLVM :: DebugInfo/Generic/2010-05-03-DisableFramePtr.ll
LLVM :: DebugInfo/Generic/varargs.ll
Delete sizing information from debug info for the same reason
(but the presence of the pointer was important to the test case):
LLVM :: DebugInfo/Generic/restrict.ll
LLVM :: DebugInfo/Generic/tu-composite.ll
LLVM :: Linker/type-unique-type-array-a.ll
LLVM :: Linker/type-unique-simple2.ll
Fixing an incorrect DW_OP_deref
LLVM :: DebugInfo/Generic/2010-05-03-OriginDIE.ll
Fixing a missing DW_OP_deref
LLVM :: DebugInfo/Generic/incorrect-variable-debugloc.ll
Additionally, clang should no longer complain during bootstrap should no
longer happen after r257534.
The original commit message was:
```
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.
One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.
Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
variable as that would depend on the target, even though this test is
supposed to be generic
- I had to manually declared size/align for reference type. See also the
discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref
```
llvm-svn: 257550
StackColoring rewrites the frame indicies of operations involving
allocas if it can find that the life time of two objects do not overlap.
MSVC EH needs to be kept aware of this if happens in the event that a
catch object has moved around. However, we represent the non-existance
of a catch object with a sentinel frame index (INT_MAX). This sentinel
also happens to be the EmptyKey of the SlotRemap DenseMap. Testing for
whether or not we need to translate the frame index fails in this case
because we call the count method on the DenseMap with the EmptyKey,
leading to assertions. Instead, check if it is our sentinel value
before trying to look into the DenseMap.
This fixes PR26073.
llvm-svn: 257182
Windows EH keeping track of which frame index corresponds to a catchpad
in order to inform the runtime where the catch parameter should be
initialized. LLVM's optimizations are able to prove that the memory
used by the catch parameter can be reused with another memory
optimization, changing it's frame index.
We need to keep WinEHFuncInfo up to date with respect to this or we will
miscompile/assert.
This fixes PR26069.
llvm-svn: 257158
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.
One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.
Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
variable as that would depend on the target, even though this test is
supposed to be generic
- I had to manually declared size/align for reference type. See also the
discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref
Reviewers: aprantl
Differential Revision: http://reviews.llvm.org/D14276
llvm-svn: 257105
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`. The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.
Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one. It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs. YMMV of
course.
Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py. I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three. It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).
Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.
llvm-svn: 236120
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
define below all header includes in the lib/CodeGen/... tree. While the
current modules implementation doesn't check for this kind of ODR
violation yet, it is likely to grow support for it in the future. It
also removes one layer of macro pollution across all the included
headers.
Other sub-trees will follow.
llvm-svn: 206837
Also updated as many loops as I could find using df_begin/idf_begin -
strangely I found no uses of idf_begin. Is that just used out of tree?
Also a few places couldn't use df_begin because either they used the
member functions of the depth first iterators or had specific ordering
constraints (I added a comment in the latter case).
Based on a patch by Jim Grosbach. (Jim - you just had iterator_range<T>
where you needed iterator_range<idf_iterator<T>>)
llvm-svn: 206016
There are currently two issues, of which I currently know, that prevent TBAA
from being correctly usable in CodeGen:
1. Stack coloring does not update TBAA when merging allocas. This is easy
enough to fix, but is not the largest problem.
2. CGP inserts ptrtoint/inttoptr pairs when sinking address computations.
Because BasicAA does not handle inttoptr, we'll often miss basic type punning
idioms that we need to catch so we don't miscompile real-world code (like LLVM).
I don't yet have a small test case for this, but this fixes self hosting a
non-asserts build of LLVM on PPC64 when using -enable-aa-sched-mi and -misched=shuffle.
llvm-svn: 200093
StackProtector keeps a ValueMap of alloca instructions to layout kind tags for
use by PEI and other later passes. When stack coloring replaces one alloca with
a bitcast to another one, the key replacement in this map does not work.
Instead, provide an interface to manage this updating directly. This seems like
an improvement over the old behavior, where the layout map would not get
updated at all when the stack slots were merged. In practice, however, there is
likely no observable difference because PEI only did anything special with
'large array' kinds, and if one large array is merged with another, than the
replacement should already have been a large array.
This is an attempt to unbreak the clang-x86_64-darwin11-RA builder.
llvm-svn: 199684
The way that stack coloring updated MMOs when merging stack slots, while
correct, is suboptimal, and is incompatible with the use of AA during
instruction scheduling. The solution, which involves the use of const_cast (and
more importantly, updating the IR from within an MI-level pass), obviously
requires some explanation:
When the stack coloring pass was originally committed, the code in
ScheduleDAGInstrs::buildSchedGraph tracked possible alias sets by using
GetUnderlyingObject, and all load/store and store/store memory control
dependencies where added between SUs at the object level (where only one
object, that returned by GetUnderlyingObject, was used to identify the object
associated with each MMO). When stack coloring merged stack slots, it would
replace MMOs derived from the remapped alloca with the alloca with which the
remapped alloca was being replaced. Because ScheduleDAGInstrs only used single
objects, and tracked alias sets at the object level, this was a fine solution.
In r169744, (Andy and) I updated the code in ScheduleDAGInstrs to use
GetUnderlyingObjects, and track alias sets using, potentially, multiple
underlying objects for each MMO. This was done, primarily, to provide the
ability to look through PHIs, and provide better scheduling for
induction-variable-dependent loads and stores inside loops. At this point, the
MMO-updating code in stack coloring became suboptimal, because it would clear
the MMOs for (i.e. completely pessimize) all instructions for which r169744
might help in scheduling. Updating the IR directly is the simplest fix for this
(and the one with, by far, the least compile-time impact), but others are
possible (we could give each MMO a small vector of potential values, or make
use of a remapping table, constructed from MFI, inside ScheduleDAGInstrs).
Unfortunately, replacing all MMO values derived from the remapped alloca with
the base replacement alloca fundamentally breaks our ability to use AA during
instruction scheduling (which is critical to performance on some targets). The
reason is that the original MMO might have had an offset (either constant or
dynamic) from the base remapped alloca, and that offset is not present in the
updated MMO. One possible way around this would be to use
GetPointerBaseWithConstantOffset, and update not only the MMO's value, but also
its offset based on the original offset. Unfortunately, this solution would
only handle constant offsets, and for safety (because AA is not completely
restricted to deducing relationships with constant offsets), we would need to
clear all MMOs without constant offsets over the entire function. This would be
an even worse pessimization than the current single-object restriction. Any
other solution would involve passing around a vector of remapped allocas, and
teaching AA to use it, introducing additional complexity and overhead into AA.
Instead, when remapping an alloca, we replace all IR uses of that alloca as
well (optionally inserting a bitcast as necessary). This is even more efficient
that the old MMO-updating code in the stack coloring pass (because it removes
the need to call GetUnderlyingObject on all MMO values), removes the
single-object pessimization in the default configuration, and enables the
correct use of AA during instruction scheduling (all without any additional
overhead).
LLVM now no longer miscompiles itself on x86_64 when using -enable-misched
-enable-aa-sched-mi -misched-bottomup=0 -misched-topdown=0 -misched=shuffle!
Fixed PR18497.
Because the alloca replacement is now done at the IR level, unless the MMO
directly refers to the remapped alloca, the change cannot be seen at the MI
level. As a result, there is no good way to fix test/CodeGen/X86/pr14090.ll.
llvm-svn: 199658
directory. These passes are already defined in the IR library, and it
doesn't make any sense to have the headers in Analysis.
Long term, I think there is going to be a much better way to divide
these matters. The dominators code should be fully separated into the
abstract graph algorithm and have that put in Support where it becomes
obvious that evn Clang's CFGBlock's can use it. Then the verifier can
manually construct dominance information from the Support-driven
interface while the Analysis library can provide a pass which both
caches, reconstructs, and supports a nice update API.
But those are very long term, and so I don't want to leave the really
confusing structure until that day arrives.
llvm-svn: 199082
The Segment struct contains a single interval; multiple instances of this struct
are used to construct a live range, but the struct is not a live range by
itself.
llvm-svn: 192392
IR optimisation passes can result in a basic block that contains:
llvm.lifetime.start(%buf)
...
llvm.lifetime.end(%buf)
...
llvm.lifetime.start(%buf)
Before this change, calculateLiveIntervals() was ignoring the second
lifetime.start() and was regarding %buf as being dead from the
lifetime.end() through to the end of the basic block. This can cause
StackColoring to incorrectly merge %buf with another stack slot.
Fix by removing the incorrect Starts[pos].isValid() and
Finishes[pos].isValid() checks.
Just doing:
Starts[pos] = Indexes->getMBBStartIdx(MBB);
Finishes[pos] = Indexes->getMBBEndIdx(MBB);
unconditionally would be enough to fix the bug, but it causes some
test failures due to stack slots not being merged when they were
before. So, in order to keep the existing tests passing, treat LiveIn
and LiveOut separately rather than approximating the live ranges by
merging LiveIn and LiveOut.
This fixes PR15707.
Patch by Mark Seaborn.
llvm-svn: 181922
