Commit Graph

31 Commits

Author SHA1 Message Date
MinSeong Kim 4a9a4e198f [MISched] Explanatory error message when machine model is not complete. NFC
When not all instructions have a scheduling class,
the error message now provides a possible solution.

Differential Revision: http://reviews.llvm.org/D15854

llvm-svn: 256839
2016-01-05 14:50:15 +00:00
Matthias Braun 244a6773c7 Use llvm_unreachable() instead of report_fatal_error() if the machine model is incomplete
This error is for developers only so it makes sense to abort and get a
backtrace.

llvm-svn: 242551
2015-07-17 17:50:11 +00:00
Matthias Braun 7a247f709b Turn effective assert(0) into llvm_unreachable
llvm-svn: 237379
2015-05-14 18:33:29 +00:00
Matthias Braun 42e1e66e55 TargetSchedule: factor out common code; NFC
llvm-svn: 237376
2015-05-14 18:01:13 +00:00
Eric Christopher 307c2cb26f Remove unnecessary TargetMachine.h includes.
llvm-svn: 219672
2014-10-14 07:22:08 +00:00
Pete Cooper 1175945710 Change MCSchedModel to be a struct of statically initialized data.
This removes static initializers from the backends which generate this data, and also makes this struct match the other Tablegen generated structs in behaviour

Reviewed by Andy Trick and Chandler C

llvm-svn: 216919
2014-09-02 17:43:54 +00:00
Eric Christopher fc6de428c8 Have MachineFunction cache a pointer to the subtarget to make lookups
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
2014-08-05 02:39:49 +00:00
Eric Christopher d913448b38 Remove the TargetMachine forwards for TargetSubtargetInfo based
information and update all callers. No functional change.

llvm-svn: 214781
2014-08-04 21:25:23 +00:00
Gerolf Hoflehner 5e1207e54c MachineCombiner Pass for selecting faster instruction
sequence -  target independent framework

 When the DAGcombiner selects instruction sequences
 it could increase the critical path or resource len.

 For example, on arm64 there are multiply-accumulate instructions (madd,
 msub). If e.g. the equivalent  multiply-add sequence is not on the
 crictial path it makes sense to select it instead of  the combined,
 single accumulate instruction (madd/msub). The reason is that the
 conversion from add+mul to the madd could lengthen the critical path
 by the latency of the multiply.

 But the DAGCombiner would always combine and select the madd/msub
 instruction.

 This patch uses machine trace metrics to estimate critical path length
 and resource length of an original instruction sequence vs a combined
 instruction sequence and picks the faster code based on its estimates.

 This patch only commits the target independent framework that evaluates
 and selects code sequences. The machine instruction combiner is turned
 off for all targets and expected to evolve over time by gradually
 handling DAGCombiner pattern in the target specific code.

 This framework lays the groundwork for fixing
 rdar://16319955

llvm-svn: 214666
2014-08-03 21:35:39 +00:00
Alp Toker e69170a110 Revert "Introduce a string_ostream string builder facilty"
Temporarily back out commits r211749, r211752 and r211754.

llvm-svn: 211814
2014-06-26 22:52:05 +00:00
Alp Toker 614717388c Introduce a string_ostream string builder facilty
string_ostream is a safe and efficient string builder that combines opaque
stack storage with a built-in ostream interface.

small_string_ostream<bytes> additionally permits an explicit stack storage size
other than the default 128 bytes to be provided. Beyond that, storage is
transferred to the heap.

This convenient class can be used in most places an
std::string+raw_string_ostream pair or SmallString<>+raw_svector_ostream pair
would previously have been used, in order to guarantee consistent access
without byte truncation.

The patch also converts much of LLVM to use the new facility. These changes
include several probable bug fixes for truncated output, a programming error
that's no longer possible with the new interface.

llvm-svn: 211749
2014-06-26 00:00:48 +00:00
Arnold Schwaighofer d2f96b91ca IfConverter: Use TargetSchedule for instruction latencies
For targets that have instruction itineraries this means no change. Targets
that move over to the new schedule model will use be able the new schedule
module for instruction latencies in the if-converter (the logic is such that if
there is no itineary we will use the new sched model for the latencies).

Before, we queried "TTI->getInstructionLatency()" for the instruction latency
and the extra prediction cost. Now, we query the TargetSchedule abstraction for
the instruction latency and TargetInstrInfo for the extra predictation cost. The
TargetSchedule abstraction will internally call "TTI->getInstructionLatency" if
an itinerary exists, otherwise it will use the new schedule model.

ATTENTION: Out of tree targets!

(I will also send out an email later to LLVMDev)

This means, if your target implements

 unsigned getInstrLatency(const InstrItineraryData *ItinData,
                          const MachineInstr *MI,
                          unsigned *PredCost);

and returns a value for "PredCost", you now also need to implement

 unsigned getPredictationCost(const MachineInstr *MI);

(if your target uses the IfConversion.cpp pass)

radar://15077010

llvm-svn: 191671
2013-09-30 15:28:56 +00:00
Andrew Trick b6854d80e3 Mark the x86 machine model as incomplete. PR17367.
Ideally, the machinel model is added at the time the instructions are
defined. But many instructions in X86InstrSSE.td still need a model.

Without this workaround the scheduler asserts because x86 already has
itinerary classes for these instructions, indicating they should be
modeled by the scheduler. Since we use the new machine model for other
instructions, it expects a new machine model for these too.

llvm-svn: 191391
2013-09-25 18:14:12 +00:00
Andrew Trick 5d4861867a MI-Sched: handle ReadAdvance latencies as used by Swift.
llvm-svn: 184135
2013-06-17 21:45:18 +00:00
Andrew Trick de2109eb4c Machine Model: Add MicroOpBufferSize and resource BufferSize.
Replace the ill-defined MinLatency and ILPWindow properties with
with straightforward buffer sizes:
MCSchedMode::MicroOpBufferSize
MCProcResourceDesc::BufferSize

These can be used to more precisely model instruction execution if desired.

Disabled some misched tests temporarily. They'll be reenabled in a few commits.

llvm-svn: 184032
2013-06-15 04:49:57 +00:00
Andrew Trick be2bccbce9 MI-Sched cleanup. If an instruction has no valid sched class, do not attempt to check for a variant.
llvm-svn: 179451
2013-04-13 06:07:45 +00:00
Andrew Trick 6057017c68 Change the default latency for implicit defs.
Implicit defs are not currently positional and not modeled by the
per-operand machine model. Unfortunately, we treat defs that are part
of the architectural instruction description, like flags, the same as
other implicit defs. Really, they should have a fixed MachineInstr
layout and probably shouldn't be "implicit" at all.

For now, we'll change the default latency to be the max operand
latency. That will give flag setting operands full latency for x86
folded loads. Other kinds of "fake" implicit defs don't occur prior to
regalloc anyway, and we would like them to go away postRegAlloc as
well.

llvm-svn: 177227
2013-03-16 18:58:57 +00:00
Chandler Carruth ed0881b2a6 Use the new script to sort the includes of every file under lib.
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
2012-12-03 16:50:05 +00:00
Andrew Trick e96390ea96 misched: TargetSchedule interface for machine resources.
Expose the processor resources defined by the machine model to the
scheduler and other clients through the TargetSchedule interface.

Normalize each resource count with respect to other kinds of
resources. This allows scheduling heuristics to balance resources
against other kinds of resources and latency.

llvm-svn: 167444
2012-11-06 07:10:38 +00:00
Andrew Trick 0b1d8d04b9 misched: Better handling of invalid latencies in the machine model
llvm-svn: 166107
2012-10-17 17:27:10 +00:00
Andrew Trick 5f35afb0f1 misched: Handle "transient" non-instructions.
llvm-svn: 165701
2012-10-11 05:37:06 +00:00
Andrew Trick c334bd4577 misched: fall-back to a target hook for instr bundles.
llvm-svn: 165606
2012-10-10 05:43:18 +00:00
Andrew Trick dd79f0fcea misched: Use the TargetSchedModel interface wherever possible.
Allows the new machine model to be used for NumMicroOps and OutputLatency.

Allows the HazardRecognizer to be disabled along with itineraries.

llvm-svn: 165603
2012-10-10 05:43:09 +00:00
Andrew Trick 780fae8cd6 misched: Add computeInstrLatency to TargetSchedModel.
llvm-svn: 165566
2012-10-09 23:44:32 +00:00
Andrew Trick cfcf5202a1 misched: Allow flags to disable hasInstrSchedModel/hasInstrItineraries for external users of TargetSchedule.
llvm-svn: 165564
2012-10-09 23:44:26 +00:00
Andrew Trick 8abcf4df68 Enable -schedmodel, but prefer itineraries until we have more benchmark data.
llvm-svn: 165188
2012-10-04 00:24:34 +00:00
Andrew Trick f2b70d9f3a TargetSchedule: cleanup computeOperandLatency logic & diagnostics.
llvm-svn: 164154
2012-09-18 18:20:02 +00:00
Andrew Trick 6e6d597b1c TargetSchedModel API. Implement latency lookup, disabled.
llvm-svn: 164098
2012-09-18 04:03:34 +00:00
Andrew Trick 8e7f202e32 Revert r164061-r164067. Most of the new subtarget emitter.
I have to work out the Target/CodeGen header dependencies
before putting this back.

llvm-svn: 164072
2012-09-17 23:00:42 +00:00
Andrew Trick f403ee7937 TargetSchedModel API. Implement latency lookup, disabled.
llvm-svn: 164065
2012-09-17 22:19:08 +00:00
Andrew Trick d2a19da1b8 TargetSchedModel interface. To be implemented...
llvm-svn: 163934
2012-09-14 20:26:46 +00:00