Current SCEV expansion will expand SCEV as a sequence of operations
and doesn't utilize the value already existed. This will introduce
redundent computation which may not be cleaned up throughly by
following optimizations.
This patch introduces an ExprValueMap which is a map from SCEV to the
set of equal values with the same SCEV. When a SCEV is expanded, the
set of values is checked and reused whenever possible before generating
a sequence of operations.
The original commit triggered regressions in Polly tests. The regressions
exposed two problems which have been fixed in current version.
1. Polly will generate a new function based on the old one. To generate an
instruction for the new function, it builds SCEV for the old instruction,
applies some tranformation on the SCEV generated, then expands the transformed
SCEV and insert the expanded value into new function. Because SCEV expansion
may reuse value cached in ExprValueMap, the value in old function may be
inserted into new function, which is wrong.
In SCEVExpander::expand, there is a logic to check the cached value to
be used should dominate the insertion point. However, for the above
case, the check always passes. That is because the insertion point is
in a new function, which is unreachable from the old function. However
for unreachable node, DominatorTreeBase::dominates thinks it will be
dominated by any other node.
The fix is to simply add a check that the cached value to be used in
expansion should be in the same function as the insertion point instruction.
2. When the SCEV is of scConstant type, expanding it directly is cheaper than
reusing a normal value cached. Although in the cached value set in ExprValueMap,
there is a Constant type value, but it is not easy to find it out -- the cached
Value set is not sorted according to the potential cost. Existing reuse logic
in SCEVExpander::expand simply chooses the first legal element from the cached
value set.
The fix is that when the SCEV is of scConstant type, don't try the reuse
logic. simply expand it.
Differential Revision: http://reviews.llvm.org/D12090
llvm-svn: 259736
Per review feedback the name was wrong and it can be used outside
Objective-C.
Unfortunately, making the internal struct visible broke some ASTMatchers
tests that assumed that the first record decl would be from user code,
rather than a builtin type. I'm worried that this will also affect
users' code. So this patch adds a typedef to wrap the internal struct
and only makes the typedef visible to namelookup. This is sufficient to
allow the ASTReader to merge the decls we need without making the struct
itself visible.
rdar://problem/24425801
llvm-svn: 259734
D16251)
Summary:
This is a simpler fix to the problem than the dominator approach in
http://reviews.llvm.org/D16251. It adds only values into the gather() while loop
that have been seen before.
The actual endless loop is in the constant compare gather() routine in
Utils/SimplifyCFG.cpp. The same value ret.0.off0.i is pushed back into the
queue:
%.ret.0.off0.i = or i1 %.ret.0.off0.i, %cmp10.i
Here is what happens at the IR level:
for.cond.i: ; preds = %if.end6.i,
%if.end.i54
%ix.0.i = phi i32 [ 0, %if.end.i54 ], [ %inc.i55, %if.end6.i ]
%ret.0.off0.i = phi i1 [false, %if.end.i54], [%.ret.0.off0.i, %if.end6.i] <<<
%cmp2.i = icmp ult i32 %ix.0.i, %11
br i1 %cmp2.i, label %for.body.i, label %LBJ_TmpSimpleNeedExt.exit
if.end6.i: ; preds = %for.body.i
%cmp10.i = icmp ugt i32 %conv.i, %add9.i
%.ret.0.off0.i = or i1 %ret.0.off0.i, %cmp10.i <<<
When if.end.i54 gets eliminated which removes the definition of ret.0.off0.i.
The result is the expression %.ret.0.off0.i = or i1 %.ret.0.off0.i, %cmp10.i
(Note the first ‘or’ operand is now %.ret.0.off0.i, and *NOT* %ret.0.off0.i).
And
now there is use of .ret.0.off0.i before a definition which triggers the
“endless” loop in gather():
while(!DFT.empty()) {
V = DFT.pop_back_val(); // V is .ret.0.off0.i
if (Instruction *I = dyn_cast<Instruction>(V)) {
// If it is a || (or && depending on isEQ), process the operands.
if (I->getOpcode() == (isEQ ? Instruction::Or : Instruction::And)) {
DFT.push_back(I->getOperand(1)); // This is now .ret.0.off0.i also
DFT.push_back(I->getOperand(0));
continue; // “endless loop” for .ret.0.off0.i
}
Reviewers: reames, ahatanak
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16839
llvm-svn: 259730
This option is emitted in the min_version load commands.
Note, there's currently a difference in behaviour compared to ld64 in
that we emit a warning if we generate a min_version load command and
didn't give an sdk_version. We need to decide what the correct behaviour
is here as its possible we want to emit an error and force clients to
provide the option.
llvm-svn: 259729
Original message:
Make CF constant string decl visible to name lookup to fix module errors
The return type of the __builtin___*StringMakeConstantString functions
is a pointer to a struct, so we need that struct to be visible to name
lookup so that we will correctly merge multiple declarations of that
type if they come from different modules.
Incidentally, to make this visible to name lookup we need to rename the
type to __NSConstantString, since the real NSConstantString is an
Objective-C interface type. This shouldn't affect anyone outside the
compiler since users of the constant string builtins cast the result
immediately to CFStringRef.
Since this struct type is otherwise implicitly created by the AST
context and cannot access namelookup, we make this a predefined type
and initialize it in Sema.
Note: this issue of builtins that refer to types not visible to name
lookup technically also affects other builtins (e.g. objc_msgSendSuper),
but in all other cases the builtin is a library builtin and the issue
goes away if you include the library that defines the types it uses,
unlike for these constant string builtins.
rdar://problem/24425801
llvm-svn: 259721
If the command line contains something like -macosx_version_min and we
don't explicitly disable generation with -no_version_load_command then
we generate the LC_VERSION_MIN command in the output file.
There's a couple of FIXME's in here. These will be handled soon with
more tests but I didn't want to grow this patch any more than it already was.
rdar://problem/24472630
llvm-svn: 259718
Avoid crashing when printing diagnostics for vtable-related CFI
errors. In diagnostic mode, the frontend does an additional check of
the vtable pointer against the set of all known vtable addresses and
lets the runtime handler know if it is safe to inspect the vtable.
http://reviews.llvm.org/D16824
llvm-svn: 259717
Avoid crashing when printing diagnostics for vtable-related CFI
errors. In diagnostic mode, the frontend does an additional check of
the vtable pointer against the set of all known vtable addresses and
lets the runtime handler know if it is safe to inspect the vtable.
http://reviews.llvm.org/D16823
llvm-svn: 259716
Unfortunately, ProgramInfo::ProcessId is signed on Unix and unsigned on
Windows, breaking the standard fix of using '0U' in the gtest
expectation.
llvm-svn: 259704
Summary:
Fixed pointers to go on the right hand side following coding guidelines. NFC.
Patch by Mandeep Singh Grang.
Reviewers: majnemer, arsenm, sanjoy
Differential Revision: http://reviews.llvm.org/D16866
llvm-svn: 259703
Bail out if we have a PHI on an EHPad that gets a value from a
CatchSwitchInst. Because the CatchSwitchInst cannot be split, there is
no good place to stick any instructions.
This fixes PR26373.
llvm-svn: 259702
This is mostly about having shorter lines and standardizing on one
interface, but it also avoids some needless indirection.
No functional change.
llvm-svn: 259697
Summary:
In r257979, I added code to ensure that we wouldn't merge DebugLocEntries if
the pieces they describe overlap. Unfortunately, I failed to cover the case,
where there may have multiple active Expressions in the entry, in which case we
need to make sure that no two values overlap before we can perform the merge.
This fixed PR26148.
Reviewers: aprantl
Differential Revision: http://reviews.llvm.org/D16742
llvm-svn: 259696
The IR/Value class had a linkage issue present when LLVM was built
as a library, and the LLVM library build time had different settings
for NDEBUG than the client of the LLVM library. Clients could get
into a state where the LLVM lib expected
Value::assertModuleIsMaterialized() to be inline-defined in the header
but clients expected that method to be defined in the LLVM library.
See this llvm-commits thread for more details:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160201/329667.html
llvm-svn: 259695
This patch consists of two parts: a performance fix in DAGCombiner.cpp
and a correctness fix in SelectionDAG.cpp.
The test case tests the bug that's uncovered by the performance fix, and
fixed by the correctness fix.
The performance fix keeps the containers required by the
hasPredecessorHelper (which is a lazy DFS) and reuse them. Since
hasPredecessorHelper is called in a loop, the overall efficiency reduced
from O(n^2) to O(n), where n is the number of SDNodes.
The correctness fix keeps iterating the neighbor list even if it's time
to early return. It will return after finishing adding all neighbors to
Worklist, so that no neighbors are discarded due to the original early
return.
llvm-svn: 259691
reason to None when we stop due to a trace, then noticed that
we were on a breakpoint that was not valid for the current thread.
That should actually have set it back to trace.
This was pr26441 (<rdar://problem/24470203>)
llvm-svn: 259684
Summary:
This patch adds a reserve call to an expensive function
(`llvm::LoadIntrinsics`), and may fix a few other low hanging
performance fruit (I've put them in comments for now, so we can
discuss).
**Motivation:**
As I'm sure other developers do, when I build LLVM, I build the entire
project with the same config (`Debug`, `MinSizeRel`, `Release`, or
`RelWithDebInfo`). However, the `Debug` config also builds llvm-tblgen
in `Debug` mode. Later build steps that run llvm-tblgen then can
actually be the slowest steps in the entire build. Nobody likes slow
builds.
Reviewers: rnk, dblaikie
Differential Revision: http://reviews.llvm.org/D16832
Patch by Alexander G. Riccio
llvm-svn: 259683
Rather than crashing in match_results::format() when a reference to a
marked subexpression is out of range, format the subexpression as empty
(i.e., replace it with an empty string). Note that
match_results::operator[]() has a range-check and returns a null match
in this case, so this just re-uses that logic.
llvm-svn: 259682
When performing a cast from an __unknown_anytype function call to a
non-void type, we need to make sure that type is complete. Fixes
rdar://problem/23959960.
llvm-svn: 259681
My eventual goal is to move all of the test decorators to their
own module such as `decorators.py`. But some of the decorators
use existing functions in `lldbtest.py` and conceptually the
functions are probably more appropriately placed in lldbplatformutil.
Moreover, lldbtest.py is a huge file with a ton of random utility
functions scattered around, so this patch also workds toward the
goal of reducing the footprint of this one module to a more
reasonable size.
So this patch moves some of them over to lldbplatformutil with the
eventual goal of moving decorators over to their own module.
Reviewed By: Tamas Berghammer, Pavel Labath
Differential Revision: http://reviews.llvm.org/D16830
llvm-svn: 259680
Wei Mi