Both MachineLoopInfo and MachineDominatorTree may be null in ScheduleDAGMI
constructor call. It is undefined behavior to take references to these values.
This bug is reported by UBSan.
llvm-svn: 216118
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lookups from
the MachineFunction easily.
Update the MIPS subtarget switching machinery to update this pointer
at the same time it runs.
llvm-svn: 214838
Refactoring; no functional changes intended
Removed PostRAScheduler bits from subtargets (X86, ARM).
Added PostRAScheduler bit to MCSchedModel class.
This bit is set by a CPU's scheduling model (if it exists).
Removed enablePostRAScheduler() function from TargetSubtargetInfo and subclasses.
Fixed the existing enablePostMachineScheduler() method to use the MCSchedModel (was just returning false!).
Added methods to TargetSubtargetInfo to allow overrides for AntiDepBreakMode, CriticalPathRCs, and OptLevel for PostRAScheduling.
Added enablePostRAScheduler() function to PostRAScheduler class which queries the subtarget for the above values.
Preserved existing scheduler behavior for ARM, MIPS, PPC, and X86:
a. ARM overrides the CPU's postRA settings by enabling postRA for any non-Thumb or Thumb2 subtarget.
b. MIPS overrides the CPU's postRA settings by enabling postRA for everything.
c. PPC overrides the CPU's postRA settings by enabling postRA for everything.
d. X86 is the only target that actually has postRA specified via sched model info.
Differential Revision: http://reviews.llvm.org/D4217
llvm-svn: 213101
define below all header includes in the lib/CodeGen/... tree. While the
current modules implementation doesn't check for this kind of ODR
violation yet, it is likely to grow support for it in the future. It
also removes one layer of macro pollution across all the included
headers.
Other sub-trees will follow.
llvm-svn: 206837
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
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.
Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]
llvm-svn: 169131
This adds support for weak DAG edges to the general scheduling
infrastructure in preparation for MachineScheduler support for
heuristics based on weak edges.
llvm-svn: 167738
Alexey Samsonov
Eric Christopher
Sanjay Patel
Chandler Carruth
Craig Topper
Paul Robinson
Nuno Lopes
Benjamin Kramer
Andrew Trick
Hal Finkel
Chad Rosier
Jakob Stoklund Olesen
Manman Ren