1 //===- MachineSink.cpp - Sinking for machine instructions -----------------===//
13 // for an LLVM-IR-level sinking pass. It is only designed to sink simple
69            cl::desc("Split critical edges during machine sinking"),
106     cl::desc("The maximum number of instructions considered for cycle sinking."),
286                       "Machine code sinking", false, false)
292                     "Machine code sinking", false, false)  in INITIALIZE_PASS_DEPENDENCY()
516     LLVM_DEBUG(dbgs() << "Sinking copy of"; MI.dump(); dbgs() << "into";  in PerformSinkAndFold()
716   LLVM_DEBUG(dbgs() << "******** Machine Sinking ********\n");  in runOnMachineFunction()
814   // Don't bother sinking code out of unreachable blocks. In addition to being  in ProcessBlock()
832     // sinking.  in ProcessBlock()
867   // recalculate the bb register pressure after sinking one BB.  in ProcessBlock()
897   // sinking multiple "cheap" instructions into the same block.  in isWorthBreakingCriticalEdge()
938     // so sinking their uses won't enable any opportunities.  in isWorthBreakingCriticalEdge()
943     // check if breaking the edge will enable sinking  in isWorthBreakingCriticalEdge()
1050   // register pressure is changed after sinking any instructions into it.  in getBBRegisterPressure()
1139   // If this instruction is inside a Cycle and sinking this instruction can make  in isProfitableToSinkTo()
1158       // This def register's live range is shortened after sinking.  in isProfitableToSinkTo()
1176       // If sinking this operand makes some register pressure set exceed limit,  in isProfitableToSinkTo()
1187   // if no operand sinking make register pressure set exceed limit, it is  in isProfitableToSinkTo()
1204   // Handle cases where sinking can happen but where the sink point isn't a  in GetAllSortedSuccessors()
1422   // Post-regalloc, we may be sinking a DBG_VALUE of a sub or super-register  in attemptDebugCopyProp()
1587     // FIXME: Come up with a proper cost model that estimates whether sinking  in SinkIntoCycle()
1617     LLVM_DEBUG(dbgs() << "CycleSink: Not sinking, can't find sink block.\n");  in SinkIntoCycle()
1622         dbgs() << "CycleSink: Not sinking, sink block is the preheader\n");  in SinkIntoCycle()
1627         dbgs() << "CycleSink: Not Sinking, block too large to analyse.\n");  in SinkIntoCycle()
1631   LLVM_DEBUG(dbgs() << "CycleSink: Sinking instruction!\n");  in SinkIntoCycle()
1670   // FIXME: This should include support for sinking instructions within the  in SinkInstruction()
1674   // be careful not to *increase* register pressure though, e.g. sinking  in SinkInstruction()
1728     // Otherwise we are OK with sinking along a critical edge.  in SinkInstruction()
1730       LLVM_DEBUG(dbgs() << "Sinking along critical edge.\n");  in SinkInstruction()
1762     LLVM_DEBUG(dbgs() << " *** Not sinking: prologue interference\n");  in SinkInstruction()
1790   // After sinking, some debug users may not be dominated any more. If possible,  in SinkInstruction()
2157           dbgs() << " *** Not sinking: prologue interference\n");  in tryToSinkCopy()