This addresses PR26055 LiveDebugValues is very slow.
Contrary to the old LiveDebugVariables pass LiveDebugValues currently
doesn't look at the lexical scopes before inserting a DBG_VALUE
intrinsic. This means that we often propagate DBG_VALUEs much further
down than necessary. This is especially noticeable in large C++
functions with many inlined method calls that all use the same
"this"-pointer.
For example, in the following code it makes no sense to propagate the
inlined variable a from the first inlined call to f() into any of the
subsequent basic blocks, because the variable will always be out of
scope:
void sink(int a);
void __attribute((always_inline)) f(int a) { sink(a); }
void foo(int i) {
f(i);
if (i)
f(i);
f(i);
}
This patch reuses the LexicalScopes infrastructure we have for
LiveDebugVariables to take this into account.
The effect on compile time and memory consumption is quite noticeable:
I tested a benchmark that is a large C++ source with an enormous
amount of inlined "this"-pointers that would previously eat >24GiB
(most of them for DBG_VALUE intrinsics) and whose compile time was
dominated by LiveDebugValues. With this patch applied the memory
consumption is 1GiB and 1.7% of the time is spent in LiveDebugValues.
https://reviews.llvm.org/D24994
Thanks to Daniel Berlin and Keith Walker for reviewing!
llvm-svn: 282611
Variables are sometimes missing their debug location information in
blocks in which the variables should be available. This would occur
when one or more predecessor blocks had not yet been visited by the
routine which propagated the information from predecessor blocks.
This is addressed by only considering predecessor blocks which have
already been visited.
The solution to this problem was suggested by Daniel Berlin on the
LLVM developer mailing list.
Differential Revision: https://reviews.llvm.org/D24927
llvm-svn: 282506
Rename AllVRegsAllocated to NoVRegs. This avoids the connotation of
running after register and simply describes that no vregs are used in
a machine function. With that we can simply compute the property and do
not need to dump/parse it in .mir files.
Differential Revision: http://reviews.llvm.org/D23850
llvm-svn: 279698
This patch builds upon r270776 and speeds up
LiveDebugValues::transferDebugValue() by adding an index that maps each
DebugVariable to its open VarLoc.
The transferDebugValue() function needs to close all open ranges for a
given DebugVariable. Iterating over the set bits of OpenRanges is
prohibitively slow in practice. I experimented with using the sorted map
of VarLocs in the UniqueVector to iterate only over the range of VarLocs
with a given DebugVariable, but the binary search turned out to be even
more expensive than just iterating over the set bits in OpenRanges.
Instead, this patch exploits the fact that there can only be one open
location for each DebugVariable and redundantly stores this location in a
DenseMap.
This patch brings the time spent in the LiveDebugValues pass down to an
almost neglectiable amount.
http://llvm.org/bugs/show_bug.cgi?id=26055http://reviews.llvm.org/D20636
rdar://problem/24091200
llvm-svn: 270923
This patch modifies the LiveDebugValues pass to use more efficient set
data structures as outlined in PR26055. Both VarLocSet and VarLocList are
now SparseBitVectors which allows us to perform much faster bitvector
arithmetic on them.
The speedup can be in the order of minutes especially on ASANified code.
The change is not NFC in the assembler output because the inserted
DBG_VALUEs are now sorted by variable and location.
Many thanks to Daniel Berlin for helping design the improved algorithm and
reviewing the patch.
https://llvm.org/bugs/show_bug.cgi?id=26055http://reviews.llvm.org/D20178
rdar://problem/24091200
llvm-svn: 270776
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
MachineInstr.h and MachineInstrBuilder.h are very popular headers,
widely included across all LLVM backends. It turns out that there only a
handful of TUs that actually care about DI operands on MachineInstrs.
After this change, touching DebugInfoMetadata.h and rebuilding llc only
needs 112 actions instead of 542.
llvm-svn: 266351
MachineFunctionProperties represents a set of properties that a MachineFunction
can have at particular points in time. Existing examples of this idea are
MachineRegisterInfo::isSSA() and MachineRegisterInfo::tracksLiveness() which
will eventually be switched to use this mechanism.
This change introduces the AllVRegsAllocated property; i.e. the property that
all virtual registers have been allocated and there are no VReg operands
left.
With this mechanism, passes can declare that they require a particular property
to be set, or that they set or clear properties by implementing e.g.
MachineFunctionPass::getRequiredProperties(). The MachineFunctionPass base class
verifies that the requirements are met, and handles the setting and clearing
based on the delcarations. Passes can also directly query and update the current
properties of the MF if they want to have conditional behavior.
This change annotates the target-independent post-regalloc passes; future
changes will also annotate target-specific ones.
Reviewers: qcolombet, hfinkel
Differential Revision: http://reviews.llvm.org/D18421
llvm-svn: 264593
Now register parameters that aren't saved to the stack or CSRs are
considered dead after the first call. Previously the debugger would show
whatever was in the register.
Fixes PR26589
Reviewers: aprantl
Differential Revision: http://reviews.llvm.org/D17211
llvm-svn: 264429
Summary:
Use proper dataflow ordering to speed convergence.
This will converge the testcase on bug 26055 in 2 iterations.
(data structures speedups to come to make even that faster)
Reviewers: kcc, samsonov, echristo, dblaikie, tvvikram
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16039
llvm-svn: 257292
Adrian Prantl