This optional register liveness analysis pass can be enabled with either
-enable-stackmap-liveness, -enable-patchpoint-liveness, or both. The pass
traverses each basic block in a machine function. For each basic block the
instructions are processed in reversed order and if a patchpoint or stackmap
instruction is encountered the current live-out register set is encoded as a
register mask and attached to the instruction.
Later on during stackmap generation the live-out register mask is processed and
also emitted as part of the stackmap.
This information is optional and intended for optimization purposes only. This
will enable a client of the stackmap to reason about the registers it can use
and which registers need to be preserved.
Reviewed by Andy
llvm-svn: 197317
IMHO At some point BasicBlock should be refactored along the lines of
MachineBasicBlock so that successors/weights are actually embedded within the
block. Now is not that time though.
llvm-svn: 197303
This is slightly more interesting than the previous batch of changes.
Specifically:
1. We refactor getSpillWeight to take a MachineBlockFrequencyInfo (MBFI)
object. This enables us to completely encapsulate the actual manner we
use the MachineBlockFrequencyInfo to get our spill weights. This yields
cleaner code since one does not need to fetch the actual block frequency
before getting the spill weight if all one wants it the spill weight. It
also gives us access to entry frequency which we need for our
computation.
2. Instead of having getSpillWeight take a MachineBasicBlock (as one
might think) to look up the block frequency via the MBFI object, we
instead take in a MachineInstr object. The reason for this is that the
method is supposed to return the spill weight for an instruction
according to the comments around the function.
llvm-svn: 197296
BlockFrequencies can only be printed relative to their entry frequency. Thus
since the entry frequency is no longer necessarily a static constant on the
BlockFrequency class and is instead a potentially dynamic value taken from
BlockFrequencyImpl, we must necessarily print it via a method on
BlockFrequencyImpl.
llvm-svn: 197285
This is a property associated with a function, not with BlockFrequency data.
Additionally it loosens the artifical requirement that the entry frequency
arbitrarily be the same for every function.
There is a series of patches forthcoming updating various code that uses the old
way of getting a block frequency to the new location.
llvm-svn: 197284
This commit does not complete the type units feature - there are issues
around fission support (skeletal type units, pubtypes/pubnames) and
hashing of some types including those containing references to types in
other type units.
Originally committed as r197073 and reverted in r197079.
Recommitted as r197197 to reproduce the failure and reverted as r197199
Turns out there was unstable ordering in the type unit dumping code.
Fixed by using MapVector in DWARFContext to store the debug_types
comdat sections.
Recommitted as r197210 with a fix to dumping and reverted as r197211
because I was a bit gun shy and thought I saw a failure that turned out
to be unrelated.
So here we go - once more with feeling! \o/
llvm-svn: 197275
This reverts commit r197254.
This was an accidental merge of Juergen's patch. It will be checked in
shortly, but wasn't meant to go in quite yet.
Conflicts:
include/llvm/CodeGen/StackMaps.h
lib/CodeGen/StackMaps.cpp
test/CodeGen/X86/stackmap-liveness.ll
llvm-svn: 197260
The cpp backend is not a reasonable fallback for a missing target. It is a
very special backend, so it is reasonable to use it only if explicitly
requested.
While at it, simplify the interface a bit.
llvm-svn: 197241
This commit does not complete the type units feature - there are issues
around fission support (skeletal type units, pubtypes/pubnames) and
hashing of some types including those containing references to types in
other type units.
Originally committed as r197073 and reverted in r197079.
Recommitted as r197197 to reproduce the failure and reverted as r197199
Turns out there was unstable ordering in the type unit dumping code.
Fixed by using MapVector in DWARFContext to store the debug_types
comdat sections.
llvm-svn: 197210
This option tells llvm-cov to print out branch probabilities when
a basic block contains multiple branches. It also prints out some
function summary info including the number of times the function enters,
the percent of time it returns, and how many blocks were executed.
Also updated tests.
llvm-svn: 197198
This commit does not complete the type units feature - there are issues
around fission support (skeletal type units, pubtypes/pubnames) and
hashing of some types including those containing references to types in
other type units.
Originally committed as r197073 and reverted in r197079.
This commit originally got jumbled up with another build-breaking commit
and I can't find the failures I thought this caused anymore.
Recommitting to hopefully get some clean buildbot results to work from.
I have a sneaking suspicion there's unstable output in the comdat group
output of MCStreamer...
llvm-svn: 197197
SDep had is* functions for the other kinds of order dependencies (isMustAlias,
isWeak, isArtificial, etc.), but not for barrier. Upcoming commits in the
PowerPC backend will make use of this function.
llvm-svn: 197098
This adds two additional functions to the hazard recognizer interface. These
are optional (in the sense that the default implementations preserve the
current behavior), and used by the post-RA scheduler. Upcoming commits will use
this functionality in order to improve dispatch-group formation on the POWER7
and related cores. Dispatch groups are an odd construct: sometimes we need to
insert nops to force a new one to start (for performance reasons), and some
instructions need to appear in certain positions within a group, but the groups
are not fundamentally cycle based (they can contain instructions with data
dependencies with non-trivial latencies).
Motivation:
unsigned PreEmitNoops(SUnit *) - Used to force the post-RA scheduler to insert
nops to force a new dispatch group to begin. We already have a NoopHazard, and
this is also still needed. However, NoopHazard only causes a nop to be inserted
if there are no other available instructions, and so is not always sufficient.
The number of nops to insert depends on state that only the hazard recognizer
has, so a general callback is necessary.
bool ShouldPreferAnother(SUnit *) - Used to avoid scheduling instructions that
would start a new dispatch group when others are available that could be part
of the current dispatch group. In this case, we don't want to issue nops,
because the non-preferred instruction will implicitly start a new dispatch
group regardless.
Although the motivation for these functions is driven by the PowerPC backend,
they are completely general.
llvm-svn: 197084
The linkers on these systems don't have anything special to do with these
symbols. Since the intent is for them to be absent from the final object,
just treat them as private.
llvm-svn: 197080
This reverts commit r197073.
The test seems to be failing on some buildbots for unknown reasons.
Reverting until I can figure that out. If anyone's got a reproduction
(.s and .o together would be great) - I'd really appreciate it.
llvm-svn: 197079
This commit does not complete the type units feature - there are issues
around fission support (skeletal type units, pubtypes/pubnames) and
hashing of some types including those containing references to types in
other type units.
llvm-svn: 197073
point reciprocal exponent, and floating-point reciprocal square root estimate
LLVM AArch64 intrinsics to use f32/f64 types, rather than their vector
equivalents.
llvm-svn: 197066
This hook reverses the order of assignment for local live ranges. This
will generally allocate shorter local live ranges first. For targets with
many registers, this could reduce regalloc compile time by a large
factor. It should still achieve optimal coloring; however, it can change
register eviction decisions. It is disabled by default for two reasons:
(1) Top-down allocation is simpler and easier to debug for targets that
don't benefit from reversing the order.
(2) Bottom-up allocation could result in poor evicition decisions on some
targets affecting the performance of compiled code.
llvm-svn: 197001
