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path: root/llvm/lib/CodeGen/MachineCombiner.cpp
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2015-07-15[MachineCombiner] Work with itinerariesHal Finkel1-4/+9
MachineCombiner predicated its use of scheduling-based metrics on hasInstrSchedModel(), but useful conclusions can be drawn from pipeline itineraries as well. Almost all of the logic (except for resource tracking in preservesResourceLen) can be used if we have an itinerary, so enable it in that case as well. This will be used by the PowerPC backend in an upcoming commit. llvm-svn: 242277
2015-06-23Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)Alexander Kornienko1-1/+1
Apparently, the style needs to be agreed upon first. llvm-svn: 240390
2015-06-23[x86] generalize reassociation optimization in machine combiner to 2 ↵Sanjay Patel1-18/+31
instructions Currently ( D10321, http://reviews.llvm.org/rL239486 ), we can use the machine combiner pass to reassociate the following sequence to reduce the critical path: A = ? op ? B = A op X C = B op Y --> A = ? op ? B = X op Y C = A op B 'op' is currently limited to x86 AVX scalar FP adds (with fast-math on), but in theory, it could be any associative math/logic op (see TODO in code comment). This patch generalizes the pattern match to ignore the instruction that defines 'A'. So instead of a sequence of 3 adds, we now only need to find 2 dependent adds and decide if it's worth reassociating them. This generalization has a compile-time cost because we can now match more instruction sequences and we rely more heavily on the machine combiner to discard sequences where reassociation doesn't improve the critical path. For example, in the new test case: A = M div N B = A add X C = B add Y We'll match 2 reassociation patterns, but this transform doesn't reduce the critical path: A = M div N B = A add Y C = B add X We need the combiner to reject that pattern but select this: A = M div N B = X add Y C = B add A Differential Revision: http://reviews.llvm.org/D10460 llvm-svn: 240361
2015-06-19name change: hasPattern() -> getMachineCombinerPatterns() ; NFCSanjay Patel1-5/+5
This was suggested as part of D10460, but it's independent of any functional change. llvm-svn: 240192
2015-06-19Fixed/added namespace ending comments using clang-tidy. NFCAlexander Kornienko1-1/+1
The patch is generated using this command: tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \ -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \ llvm/lib/ Thanks to Eugene Kosov for the original patch! llvm-svn: 240137
2015-06-13hoist loop-invariant; NFCISanjay Patel1-3/+2
llvm-svn: 239681
2015-06-13remove unnecessary casts; NFCISanjay Patel1-3/+2
llvm-svn: 239678
2015-06-10punctuation policing; NFCSanjay Patel1-5/+5
llvm-svn: 239484
2015-06-10fix typo in comment; NFCSanjay Patel1-1/+1
llvm-svn: 239478
2015-05-21fix typo in comment; NFCSanjay Patel1-1/+1
llvm-svn: 237962
2015-05-21use range-based for-loops; NFCISanjay Patel1-4/+2
llvm-svn: 237918
2015-02-14CodeGen: Canonicalize access to function attributes, NFCDuncan P. N. Exon Smith1-2/+1
Canonicalize access to function attributes to use the simpler API. getAttributes().getAttribute(AttributeSet::FunctionIndex, Kind) => getFnAttribute(Kind) getAttributes().hasAttribute(AttributeSet::FunctionIndex, Kind) => hasFnAttribute(Kind) Also, add `Function::getFnStackAlignment()`, and canonicalize: getAttributes().getStackAlignment(AttributeSet::FunctionIndex) => getFnStackAlignment() llvm-svn: 229208
2015-01-27remove function names from comments; NFCSanjay Patel1-8/+6
llvm-svn: 227256
2015-01-27fix typos; NFCSanjay Patel1-4/+4
llvm-svn: 227253
2015-01-27The subtarget is cached on the MachineFunction. Access it directly.Eric Christopher1-2/+1
llvm-svn: 227173
2014-09-02Change MCSchedModel to be a struct of statically initialized data.Pete Cooper1-3/+3
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
2014-08-13[MachineCombiner] Removal of dangling DBG_VALUES after combining [20598]Gerolf Hoflehner1-1/+1
This is a cleaner solution to the problem described in r215431. When instructions are combined a dangling DBG_VALUE is removed. This resolves bug 20598. llvm-svn: 215587
2014-08-07MachineCombiner Pass for selecting faster instruction sequence on AArch64Gerolf Hoflehner1-1/+3
Re-commit of r214832,r21469 with a work-around that avoids the previous problem with gcc build compilers The work-around is to use SmallVector instead of ArrayRef of basic blocks in preservesResourceLen()/MachineCombiner.cpp llvm-svn: 215151
2014-08-04Remove the TargetMachine forwards for TargetSubtargetInfo basedEric Christopher1-2/+2
information and update all callers. No functional change. llvm-svn: 214781
2014-08-03CodeGen: silence a warningSaleem Abdulrasool1-2/+1
GCC 4.8.2 objects to the tautological condition in the assert as the unsigned value is guaranteed to be >= 0. Simplify the assertion by dropping the tautological condition. llvm-svn: 214671
2014-08-03MachineCombiner Pass for selecting faster instructionGerolf Hoflehner1-0/+434
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
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