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path: root/llvm/lib/CodeGen/MachineCombiner.cpp
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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