Splitting critical edges when one of the source edges is an indirectbr
is hard in general (because it requires changing the memory the indirectbr
reads). But if a block only has a single indirectbr predecessor (which is
the common case), we can simulate splitting that edge by splitting
the destination block, and retargeting the *direct* branches.
This is motivated by the use of computed gotos in python 2.7: PyEval_EvalFrame()
ends up using an indirect branch with ~100 successors, and passing a constant to
each of those. Since MachineSink can't break indirect critical edges on demand
(and doing this in MIR doesn't look feasible), this causes us to emit about ~100
defs of registers containing constants, which we in the predecessor block, where
only one of those constants is used in each successor. So, at each computed goto,
we needlessly spill about a 100 constants to stack. The end result is that a
clang-compiled python interpreter can be about ~2.5x slower on a simple python
reduction loop than a gcc-compiled interpreter.
Differential Revision: https://reviews.llvm.org/D29916
llvm-svn: 296060
We were stopping the translation of the parent block when the
translation of an instruction failed, but we were still trying to
translate the other blocks of the parent function.
Don't do that.
llvm-svn: 296047
Rename ComputedTrellisEdges to ComputedEdges to allow for other methods of
pre-computing edges.
Differential Revision: https://reviews.llvm.org/D30308
llvm-svn: 296018
Having more fine-grained information on the specific construct that
caused us to fallback is valuable for large-scale data collection.
We still have the fallback warning, that's also used for FastISel.
We still need to remove the fallback warning, and teach FastISel to also
emit remarks (it currently has a combination of the warning, stats, and
debug prints: the remarks could unify all three).
The abort-on-fallback path could also be better handled using remarks:
one could imagine a "-Rpass-error", analoguous to "-Werror", which would
promote missed/failed remarks to errors. It's not clear whether that
would be useful for other remarks though, so we're not there yet.
llvm-svn: 296013
If a subreg is used in an instruction it counts as a whole superreg
for the purpose of register pressure calculation. This patch corrects
improper register pressure calculation by examining operand's lane mask.
Differential Revision: https://reviews.llvm.org/D29835
llvm-svn: 296009
Since LoopInfo is not available in machine passes as universally as in IR
passes, using the same approach for OptimizationRemarkEmitter as we did for IR
will run LoopInfo and DominatorTree unnecessarily. (LoopInfo is not used
lazily by ORE.)
To fix this, I am modifying the approach I took in D29836. LazyMachineBFI now
uses its client passes including MachineBFI itself that are available or
otherwise compute them on the fly.
So for example GreedyRegAlloc, since it's already using MBFI, will reuse that
instance. On the other hand, AsmPrinter in Justin's patch will generate DT,
LI and finally BFI on the fly.
(I am of course wondering now if the simplicity of this approach is even
preferable in IR. I will do some experiments.)
Testing is provided by an updated version of D29837 which requires Justin's
patch to bring ORE to the AsmPrinter.
Differential Revision: https://reviews.llvm.org/D30128
llvm-svn: 295996
This just adds the basic skeleton for supporting a new object file format.
All of the actual encoding will be implemented in followup patches.
Differential Revision: https://reviews.llvm.org/D26722
llvm-svn: 295803
Summary:
Rework the code that was sinking/duplicating (icmp and, 0) sequences
into blocks where they were being used by conditional branches to form
more tbz instructions on AArch64. The new code is more general in that
it just looks for 'and's that have all icmp 0's as users, with a target
hook used to select which subset of 'and' instructions to consider.
This change also enables 'and' sinking for X86, where it is more widely
beneficial than on AArch64.
The 'and' sinking/duplicating code is moved into the optimizeInst phase
of CodeGenPrepare, where it can take advantage of the fact the
OptimizeCmpExpression has already sunk/duplicated any icmps into the
blocks where they are used. One minor complication from this change is
that optimizeLoadExt needed to be updated to always mark 'and's it has
determined should be in the same block as their feeding load in the
InsertedInsts set to avoid an infinite loop of hoisting and sinking the
same 'and'.
This change fixes a regression on X86 in the tsan runtime caused by
moving GVNHoist to a later place in the optimization pipeline (see
PR31382).
Reviewers: t.p.northover, qcolombet, MatzeB
Subscribers: aemerson, mcrosier, sebpop, llvm-commits
Differential Revision: https://reviews.llvm.org/D28813
llvm-svn: 295746
- Fix doxygen comments (do not repeat documented name, remove definition
comment if there is already one at the declaration, add \p, ...)
- Add some const modifiers
- Use range based for
llvm-svn: 295688
Summary:
Currently, BranchFolder drops DebugLoc for branch instructions in some places. For example, for the test code attached, the branch instruction of 'entry' block has a DILocation of
```
!12 = !DILocation(line: 6, column: 3, scope: !11)
```
, but this information is gone when then block is lowered because BranchFolder misses it. This patch is a fix for this issue.
Reviewers: qcolombet, aprantl, craig.topper, MatzeB
Reviewed By: aprantl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29902
llvm-svn: 295684
- Adapt MachineBasicBlock::getName() to have the same behavior as the IR
BasicBlock (Value::getName()).
- Add it to lib/CodeGen/CodeGen.cpp::initializeCodeGen so that it is linked in
the CodeGen library.
- MachineRegionInfoPass's name conflicts with RegionInfoPass's name ("region").
- MachineRegionInfo should depend on MachineDominatorTree,
MachinePostDominatorTree and MachineDominanceFrontier instead of their
respective IR versions.
- Since there were no tests for this, add a X86 MIR test.
Patch by Francis Visoiu Mistrih<fvisoiumistrih@apple.com>
llvm-svn: 295518
This fixes PR31381, which caused an assertion and/or invalid debug info.
This affects debug variables that have multiple fragments in the MMI
side (i.e.: in the stack frame) table.
rdar://problem/30571676
llvm-svn: 295486
During legalization we are often creating shuffles (via a build_vector scalarization stage) that are "any_extend_vector_inreg" style masks, and also other masks that are the equivalent of "truncate_vector_inreg" (if we had such a thing).
This patch is an attempt to match these cases to help undo the effects of just leaving shuffle lowering to handle it - which typically means we lose track of the undefined elements of the shuffles resulting in an unnecessary extension+truncation stage for widened illegal types.
The 2011-10-21-widen-cmp.ll regression will be fixed by making SIGN_EXTEND_VECTOR_IN_REG legal in SSE instead of lowering them to X86ISD::VSEXT (PR31712).
Differential Revision: https://reviews.llvm.org/D29454
llvm-svn: 295451
Summary:
This is an issue both with regular and Thin LTO. When we link together
a DICompileUnit that is marked NoDebug (e.g when compiling with -g0
but applying an AutoFDO profile, which requires location tracking
in the compiler) and a DICompileUnit with debug emission enabled,
we can have failures during dwarf debug generation. Specifically,
when we have inlined from the NoDebug compile unit into the debug
compile unit, we can fail during construction of the abstract and
inlined scope DIEs. This is because the SPMap does not include NoDebug
CUs (they are skipped in the debug_compile_units_iterator).
This patch fixes the failures by skipping locations from NoDebug CUs
when extracting lexical scopes.
Reviewers: dblaikie, aprantl
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D29765
llvm-svn: 295384
Resubmit -r295314 with PowerPC and AMDGPU tests updated.
Support {a|s}ext, {a|z|s}ext load nodes as a part of load combine patters.
Reviewed By: filcab
Differential Revision: https://reviews.llvm.org/D29591
llvm-svn: 295336
Support {a|s}ext, {a|z|s}ext load nodes as a part of load combine patters.
Reviewed By: filcab
Differential Revision: https://reviews.llvm.org/D29591
llvm-svn: 295314
For the hard float calling convention, we just use the D registers.
For the soft-fp calling convention, we use the R registers and move values
to/from the D registers by means of G_SEQUENCE/G_EXTRACT. While doing so, we
make sure to honor the endianness of the target, since the CCAssignFn doesn't do
that for us.
For pure soft float targets, we still bail out because we don't support the
libcalls yet.
llvm-svn: 295295
This reverts r294348, which removed support for conditional tail calls
due to the PR above. It fixes the PR by marking live registers as
implicitly used and defined by the now predicated tailcall. This is
similar to how IfConversion predicates instructions.
Differential Revision: https://reviews.llvm.org/D29856
llvm-svn: 295262
Uses a Custom implementation because the slot sizes being a multiple of the
pointer size isn't really universal, even for the architectures that do have a
simple "void *" va_list.
llvm-svn: 295255
