Reapply b623df3c, which was reverted while reverting a different patch
with a breaking change. There are no underlying issues with this patch,
so no changes have been made to the original patch.
This reverts commit b11e4c9907.
This patch fixes a crash in LiveDebugVariables for inputs where a
DBG_VALUE_LIST had 64 or more debug operands. This was triggering an
assert, which was added under the assumption that only bad CodeGen would
result in such a limit being hit, but relatively simple source files
that result in these incredibly long debug values have been found, so
this assert has been changed to a condition that drops the debug value
if it is not met.
Differential Revision: https://reviews.llvm.org/D101373
Pseudo probe are currently given a slot index like other regular instructions. This affects register pressure and lifetime weight computation because of enlarged lifetime length with pseudo probe instructions. As a consequence, program could get different code generated w/ and w/o pseudo probes. I'm closing the gap by excluding pseudo probes from stack index and downstream register allocation related passes.
Reviewed By: wmi
Differential Revision: https://reviews.llvm.org/D100334
This patch adds support for DBG_VALUE_LIST in the LiveDebugVariables pass. The
changes are mostly in computeIntervals, extendDef, and addDefsFromCopies; when
extending the def of a DBG_VALUE_LIST the live ranges of every used register
must be considered, and when such a def is killed by more than one of its used
registers being killed at the same time it is necessary to find valid copies of
all of those registers to create a new def with.
The DebugVariableValue class has also been changed to reference multiple
location numbers instead of just one. This has been accomplished by using a
C-style array with a unique_ptr and an array length packed into 6 bits, to
minimize the size of the class (which must be kept low to be used with
IntervalMap). This may not be the most efficient solution possible, and should
be looked at if performance issues arise.
Differential Revision: https://reviews.llvm.org/D83895
iterating the same PHI/LABEL/Debug instructions repeatedly.
We run into a compiling timeout problem when building a target after its
SampleFDO profile is updated. It is because some very large blocks with
a bunch of PHIs at the beginning. LiveDebugVariables::emitDebugValues
called during VirtRegRewriter phase searchs the insertion point for those
large BBs repeatedly in SkipPHIsLabelsAndDebug, and each time
SkipPHIsLabelsAndDebug needs to go through the same set of PHIs before it
can find the first non PHI/Label/Debug instruction. This patch adds a cache
to save the last position for the sequence which has been checked in the
previous call of SkipPHIsLabelsAndDebug.
Differential Revision: https://reviews.llvm.org/D94981
A crash/assertion failure in the greedy register allocator was tracked
down to a debug instr being passed to LiveIntervals::getInstructionIndex.
Normally this should not occur as debug instructions are collected and
removed by LiveDebugVariables before RA, and reinserted afterwards.
However, when a function has no debug info, LiveDebugVariables simply
strips any debug values that are present as they're not needed (this
situation will occur when a function with debug info is inlined into a
nodebug function). The problem is, it only removes DBG_VALUE instructions,
leaving DBG_LABELs (the cause of the crash).
This patch updates the LiveDebugVariables nodebug path to remove all debug
instructions. The test case verifies that DBG_VALUE/DBG_LABEL instructions
are present, and that they are stripped.
When -experimental-debug-variable-locations is enabled, certain variable
locations are represented by DBG_INSTR_REF instead of DBG_VALUE. The test
case verifies that a DBG_INSTR_REF is emitted by the option, and that it
is also stripped.
Differential Revision: https://reviews.llvm.org/D92127
Both FastRegAlloc and LiveDebugVariables/greedy need to cope with
DBG_INSTR_REFs. None of them actually need to take any action, other than
passing DBG_INSTR_REFs through: variable location information doesn't refer
to any registers at this stage.
LiveDebugVariables stashes the instruction information in a tuple, then
re-creates it later. This is only necessary as the register allocator
doesn't expect to see any debug instructions while it's working. No
equivalence classes or interval splitting is required at all!
No changes are needed for the fast register allocator, as it just ignores
debug instructions. The test added checks that both of them preserve
DBG_INSTR_REFs.
This also expands ScheduleDAGInstrs.cpp to treat DBG_INSTR_REFs the same as
DBG_VALUEs when rescheduling instructions around. The current movement of
DBG_VALUEs around is less than ideal, but it's not a regression to make
DBG_INSTR_REFs subject to the same movement.
Differential Revision: https://reviews.llvm.org/D85757
Also renamed the fields to follow style guidelines.
Accessors help with readability - weight mutation, in particular,
is easier to follow this way.
Differential Revision: https://reviews.llvm.org/D87725
Following on from this RFC[0] from a while back, this is the first patch towards
implementing variadic debug values.
This patch specifically adds a set of functions to MachineInstr for performing
operations specific to debug values, and replacing uses of the more general
functions where appropriate. The most prevalent of these is replacing
getOperand(0) with getDebugOperand(0) for debug-value-specific code, as the
operands corresponding to values will no longer be at index 0, but index 2 and
upwards: getDebugOperand(x) == getOperand(x+2). Similar replacements have been
added for the other operands, along with some helper functions to replace
oft-repeated code and operate on a variable number of value operands.
[0] http://lists.llvm.org/pipermail/llvm-dev/2020-February/139376.html<Paste>
Differential Revision: https://reviews.llvm.org/D81852
When compiling AMDGPUDisassembler.cpp in a stage 1 trunk build with
CMAKE_BUILD_TYPE=RelWithDebInfo LLVM_USE_SANITIZER=Address LiveDebugVariables
accounts for 21.5% wall clock time. This fix reduces that to 1.2% by switching
out a linked list lookup with a map lookup.
Note that the linked list is still used to group UserValues by vreg. The vreg
lookups don't cause any problems in this pathological case.
This is the same idea as D68816, which was reverted, except that it is a less
intrusive fix.
Reviewed By: vsk
Differential Revision: https://reviews.llvm.org/D77226
Fixup the UserValue methods to use FragmentInfo instead of DIExpression because
the DIExpression is only ever used to get the to get the FragmentInfo. The
DIExpression is meaningless in the UserValue class because each definition point
added to a UserValue may have a unique DIExpression.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D74057
Rename the class DbgValueLocation to DbgVariableValue and instances from Loc to
DbgValue. These names better express the new semantics introduced in D74053.
The class previously represented a { Location } only. It now represents a
{ Location, DIExpression } pair which together describe a value.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D74055
LiveDebugVariables uses interval maps to explicitly represent DBG_VALUE
intervals. DBG_VALUEs are filtered into an interval map based on their {
Variable, DIExpression }. The interval map will coalesce adjacent entries that
use the same { Location }. Under this model, DBG_VALUEs which refer to the same
bits of the same variable will be filtered into different interval maps if they
have different DIExpressions which means the original intervals will not be
properly preserved.
This patch fixes the problem by using { Variable, Fragment } to filter the
DBG_VALUEs into maps, and coalesces adjacent entries iff they have the same
{ Location, DIExpression } pair.
The solution is not perfect because we see the similar issues appear when
partially overlapping fragments are encountered, but is far simpler than a
complete solution (i.e. D70121).
Fixes: pr41992, pr43957
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D74053
This reverts commit ed29dbaafa.
I'm backing out D68945, which as the discussion for D73526 shows, doesn't
seem to handle the -O0 path through the codegen backend correctly. I'll
reland the patch when a fix is worked out, apologies for all the churn.
The two parent commits are part of this revert too.
Conflicts:
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/test/DebugInfo/X86/dbg-addr-dse.ll
SelectionDAGBuilder conflict is due to a nearby change in e39e2b4a79
that's technically unrelated. dbg-addr-dse.ll conflicted because
41206b61e3 (legitimately) changes the order of two lines.
There are further modifications to dbg-value-func-arg.ll: it landed after
the patch being reverted, and I've converted indirection to be represented
by the isIndirect field rather than DW_OP_deref.
This reverts commit 2d3174c4df.
The overall solution for this problem is reverting D68945, which wasn't
handling the -O0 path through the codegen backend correctly. See:
discussion in D73526.
This patch reverts part of r362750 / D62650, which stopped
LiveDebugVariables from trimming leading variable location ranges down
to only covering those instructions that are in scope. I've observed some
circumstances where the number of DBG_VALUEs in a function can be
amplified in an un-necessary way, to cover more instructions that are
out of scope, leading to very slow compile times. Trimming the range
of instructions that the variables cover solves the slow compile times.
The specific problem that r362750 tries to fix is addressed by the
assignment to RStart that I've added. Any variable location that begins
at the first instruction of a block will now be considered to begin at the
start of the block. While these sound the same, the have different
SlotIndexes, and the register allocator may shoehorn additional
instructions in between the two. The test added in the past
(wrong_debug_loc_after_regalloc.ll) still works with this modification.
live-debug-variables.ll has a range trimmed to not cover the prologue of
the function, while dbg-addr-dse.ll has a DBG_VALUE sink past one
instruction with no DebugLoc, which is expected behaviour.
Differential Revision: https://reviews.llvm.org/D73691
This patch addresses the issue found in https://bugs.llvm.org/show_bug.cgi?id=44585
where a DW_OP_deref was placed at the end of a dwarf expression, resulting in corrupt
symbols when debugging.
This is an attempt to reland with a few fixes for buildbot since I
haven't merged from master in a bit.
Differential Revision: https://reviews.llvm.org/D73526
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.
I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
recompiles touches affected_files header
342380 95 3604 llvm/include/llvm/ADT/STLExtras.h
314730 234 1345 llvm/include/llvm/InitializePasses.h
307036 118 2602 llvm/include/llvm/ADT/APInt.h
213049 59 3611 llvm/include/llvm/Support/MathExtras.h
170422 47 3626 llvm/include/llvm/Support/Compiler.h
162225 45 3605 llvm/include/llvm/ADT/Optional.h
158319 63 2513 llvm/include/llvm/ADT/Triple.h
140322 39 3598 llvm/include/llvm/ADT/StringRef.h
137647 59 2333 llvm/include/llvm/Support/Error.h
131619 73 1803 llvm/include/llvm/Support/FileSystem.h
Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.
Reviewers: bkramer, asbirlea, bollu, jdoerfert
Differential Revision: https://reviews.llvm.org/D70211
Summary:
Make sure RAGreedy informs LiveDebugVariables about new VRegs
that is introduced at spill by InlineSpiller.
Consider this example
LDV: !"var" [48r;128r):0 Loc0=%2
48B %2 = ...
...
128B %7 = ADD %2, ...
If %2 is spilled the InlineSpiller will insert spill/reload
instructions and introduces some new vregs. So we get
48B %4 = ...
56B spill %4
...
120B reload %5
128B %3 = ADD %5, ...
In the past we did not inform LDV about this, and when reintroducing
DBG_VALUE instruction LDV still got information that "var" had the
location of the spilled register %2 for the interval [48r;128r).
The result was bad, since we mapped "var" to the spill slot even
before the spill happened:
%4 = ...
DBG_VALUE %spill.0, !"var"
spill %4 to %spill.0
...
reload %5
%3 = ADD %5, ...
This patch will inform LDV about the interval split introduced
due to spilling. So the location map in LDV will become
!"var" [48r;56r):1 [56r;120r):0 [120r;128r):2 Loc0=%2 Loc1=%4 Loc2=%5
And when inserting DBG_VALUE instructions we get
%4 = ...
DBG_VALUE %4, !"var"
spill %4 to %spill.0
DBG_VALUE %spill.0, !"var"
...
reload %5
DBG_VALUE %5, !"var"
%3 = ADD %5, ...
Fixes: https://bugs.llvm.org/show_bug.cgi?id=38899
Reviewers: jmorse, vsk, aprantl
Reviewed By: jmorse
Subscribers: dstenb, wuzish, MatzeB, qcolombet, nemanjai, hiraditya, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69584
In LiveDebugVariables.cpp:
Prior to this patch, UserValues were grouped into linked list chains. Each
chain was the union of two sets: { A: Matching Source variable } or
{ B: Matching virtual register }. A ptr to the heads (or 'leaders')
of each of these chains were kept in a map with the { Source variable } used
as the key (set A predicate) and another with { Virtual register } as key
(set B predicate).
There was a search through the chains in the function getUserValue looking for
UserValues with matching { Source variable, Complex expression, Inlined-at
location }. Essentially searching for a subset of A through two interleaved
linked lists of set A and B. Importantly, by design, the subset will only
contain one or zero elements here. That is to say a UserValue can be uniquely
identified by the tuple { Source variable, Complex expression, Inlined-at
location } if it exists.
This patch removes the linked list and instead uses a DenseMap to map
the tuple { Source variable, Complex expression, Inlined-at location }
to UserValue ptrs so that the getUserValue search predicate is this map key.
The virtual register map now maps a vreg to a SmallVector<UserVal *> so that
set B is still available for quick searches.
Reviewers: aprantl, probinson, vsk, dblaikie
Reviewed By: aprantl
Subscribers: russell.gallop, gbedwell, bjope, hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D68816
llvm-svn: 374979
This patch kills off a significant user of the "IsIndirect" field of
DBG_VALUE machine insts. Brought up in in PR41675, IsIndirect is
techncally redundant as it can be expressed by the DIExpression of a
DBG_VALUE inst, and it isn't helpful to have two ways of expressing
things.
Rather than setting IsIndirect, have DBG_VALUE creators add an extra deref
to the insts DIExpression. There should now be no appearences of
IsIndirect=True from isel down to LiveDebugVariables / VirtRegRewriter,
which is ensured by an assertion in LDVImpl::handleDebugValue. This means
we also get to delete the IsIndirect handling in LiveDebugVariables. Tests
can be upgraded by for example swapping the following IsIndirect=True
DBG_VALUE:
DBG_VALUE $somereg, 0, !123, !DIExpression(DW_OP_foo)
With one where the indirection is in the DIExpression, by _appending_
a deref:
DBG_VALUE $somereg, $noreg, !123, !DIExpression(DW_OP_foo, DW_OP_deref)
Which both mean the same thing.
Most of the test changes in this patch are updates of that form; also some
changes in how the textual assembly printer handles these insts.
Differential Revision: https://reviews.llvm.org/D68945
llvm-svn: 374877
Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).
Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor
Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&
Depends on D65919
Reviewers: arsenm, bogner, craig.topper, RKSimon
Reviewed By: arsenm
Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65962
llvm-svn: 369041
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
llvm-svn: 369013
Incorrect Debug Variable Range was calculated while "COMPUTING LIVE DEBUG VARIABLES" stage.
Range for Debug Variable("i") computed according to current state of instructions
inside of basic block. But Register Allocator creates new instructions which were not taken
into account when Live Debug Variables computed. In the result DBG_VALUE instruction for
the "i" variable was put after these newly inserted instructions. This is incorrect.
Debug Value for the loop counter should be inserted before any loop instruction.
Differential Revision: https://reviews.llvm.org/D62650
llvm-svn: 362750
Refactor DIExpression::With* into a flag enum in order to be less
error-prone to use (as discussed on D60866).
Patch by Djordje Todorovic.
Differential Revision: https://reviews.llvm.org/D61943
llvm-svn: 361137
Klocwork static check:
Pointer from call to function `DebugLoc::operator DILocation *() const `
may be NULL and will be dereference in function `printExtendedName```
Patch by Shengchen Kan (skan)
Differential Revision: https://reviews.llvm.org/D61715
llvm-svn: 360317
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
Extend LDV so that stack slot offsets for spilled sub-registers
are added to the emitted debug locations. This is accomplished
by querying InstrInfo::getStackSlotRange().
With this change, LDV will add a DW_OP_plus_uconst operation to
the expression if a sub-register is spilled. Later on, PEI will
add an offset operation for the stack slot, meaning that we will
get expressions of the forms:
* {DW_OP_constu #fp-offset, DW_OP_minus,
DW_OP_plus_uconst #subreg-offset}
* {DW_OP_plus_const #fp-offset,
DW_OP_minus, DW_OP_plus_uconst #subreg-offset}
The two offset operations should ideally be merged.
Reviewers: rnk, aprantl, stoklund
Reviewed By: aprantl
Subscribers: dblaikie, bjope, nemanjai, JDevlieghere, llvm-commits
Tags: #debug-info
Differential Revision: https://reviews.llvm.org/D51612
llvm-svn: 341659
In lib/CodeGen/LiveDebugVariables.cpp, it uses std::prev(MBBI) to
get DebugValue's SlotIndex. However, the previous instruction may be
also a debug instruction. It could not use a debug instruction to query
SlotIndex in mi2iMap.
Scan all debug instructions and use the first debug instruction to query
SlotIndex for following debug instructions. Only handle DBG_VALUE in
handleDebugValue().
Differential Revision: https://reviews.llvm.org/D50621
llvm-svn: 341446
In lib/CodeGen/LiveDebugVariables.cpp, it uses std::prev(MBBI) to
get DebugValue's SlotIndex. However, the previous instruction may be
also a debug instruction. It could not use a debug instruction to query
SlotIndex in mi2iMap.
Scan all debug instructions and use the first debug instruction to query
SlotIndex for following debug instructions. Only handle DBG_VALUE in
handleDebugValue().
Differential Revision: https://reviews.llvm.org/D50621
llvm-svn: 341289
Summary:
When computeIntervals is looking through COPY instruction to
extend the location mapping for a debug variable it did not
handle subregisters correctly.
For example
DBG_VALUE debug-use %0.sub_8bit_hi, ...
%1:gr16 = COPY %0
was transformed into
DBG_VALUE debug-use %0.sub_8bit_hi, ...
%1:gr16 = COPY %0
DBG_VALUE debug-use %1, ...
So the subregister index was missing in the added DBG_VALUE.
As long as the subreg refered to the least significant bits
of the superreg, then I guess we could get the correct
result in a debugger even when referring to the superreg.
But as in the example above when the subreg refers to other
parts of the superreg, then debuginfo would be incorrect.
I'm not sure exactly how to fix this properly, so this patch
just avoids looking through the COPY when there is a subreg
involved (for more info, see the FIXME added in the code).
Reviewers: rnk, aprantl
Reviewed By: aprantl
Subscribers: JDevlieghere, llvm-commits
Tags: #debug-info
Differential Revision: https://reviews.llvm.org/D50788
llvm-svn: 340679
This patch's test case relies on debug prints which isn't generally an
OK way to test stuff in LLVM and fails whenever asserts aren't enabled.
I've send a heads-up to the commit and detailed comments on the review.
llvm-svn: 340513
In lib/CodeGen/LiveDebugVariables.cpp, it uses std::prev(MBBI) to
get DebugValue's SlotIndex. However, the previous instruction may be
also a debug instruction. It could not use a debug instruction to query
SlotIndex in mi2iMap.
Scan all debug instructions and use the first debug instruction to query
SlotIndex for following debug instructions. Only handle DBG_VALUE in
handleDebugValue().
Differential Revision: https://reviews.llvm.org/D50621
llvm-svn: 340508
Stephen Tozer