11 // (2) fuses compares and branches into COMPARE AND BRANCH instructions
38 STATISTIC(BranchOnCounts, "Number of branch-on-count instructions");
41 STATISTIC(FusedComparisons, "Number of fused compare-and-branch instructions");
181 // of -1 and if CCUsers is a single branch on nonzero, eliminate the addition
182 // and convert the branch to a BRCT(G) or BRCTH.  Return true on success.
203   MachineInstr *Branch = CCUsers[0];  in convertToBRCT()  local
204   if (Branch->getOpcode() != SystemZ::BRC ||  in convertToBRCT()
205       Branch->getOperand(0).getImm() != SystemZ::CCMASK_ICMP ||  in convertToBRCT()
206       Branch->getOperand(1).getImm() != SystemZ::CCMASK_CMP_NE)  in convertToBRCT()
211   // Compare and Branch.  in convertToBRCT()
213   MachineBasicBlock::iterator MBBI = Compare, MBBE = Branch;  in convertToBRCT()
218   // The transformation is OK.  Rebuild Branch as a BRCT(G) or BRCTH.  in convertToBRCT()
219   MachineOperand Target(Branch->getOperand(2));  in convertToBRCT()
220   while (Branch->getNumOperands())  in convertToBRCT()
221     Branch->removeOperand(0);  in convertToBRCT()
222   Branch->setDesc(TII->get(BRCT));  in convertToBRCT()
223   MachineInstrBuilder MIB(*Branch->getParent()->getParent(), Branch);  in convertToBRCT()
226   // branch displacement overflows.  BRCTH has a 32-bit displacement, so  in convertToBRCT()
236 // the load and convert the branch to a load-and-trap.  Return true on success.
247   MachineInstr *Branch = CCUsers[0];  in convertToLoadAndTrap()  local
248   if (Branch->getOpcode() != SystemZ::CondTrap ||  in convertToLoadAndTrap()
249       Branch->getOperand(0).getImm() != SystemZ::CCMASK_ICMP ||  in convertToLoadAndTrap()
250       Branch->getOperand(1).getImm() != SystemZ::CCMASK_CMP_EQ)  in convertToLoadAndTrap()
255   // Compare and Branch.  in convertToLoadAndTrap()
257   MachineBasicBlock::iterator MBBI = Compare, MBBE = Branch;  in convertToLoadAndTrap()
262   // The transformation is OK.  Rebuild Branch as a load-and-trap.  in convertToLoadAndTrap()
263   while (Branch->getNumOperands())  in convertToLoadAndTrap()
264     Branch->removeOperand(0);  in convertToLoadAndTrap()
265   Branch->setDesc(TII->get(LATOpcode));  in convertToLoadAndTrap()
266   MachineInstrBuilder(*Branch->getParent()->getParent(), Branch)  in convertToLoadAndTrap()
518       // Try to remove both MI and Compare by converting a branch to BRCT(G).  in optimizeCompareZero()
576 // Try to fuse comparison instruction Compare into a later branch.
580   // See whether we have a single branch with which to fuse.  in fuseCompareOperations()
583   MachineInstr *Branch = CCUsers[0];  in fuseCompareOperations()  local
585   switch (Branch->getOpcode()) {  in fuseCompareOperations()
608   // Make sure that the operands are available at the branch.  in fuseCompareOperations()
615   MachineBasicBlock::iterator MBBI = Compare, MBBE = Branch;  in fuseCompareOperations()
621   // Read the branch mask, target (if applicable), regmask (if applicable).  in fuseCompareOperations()
636   Branch->removeOperand(CCUse);  in fuseCompareOperations()
639     Branch->removeOperand(3);  in fuseCompareOperations()
640   // Remove target (branch or sibcall).  in fuseCompareOperations()
643     Branch->removeOperand(2);  in fuseCompareOperations()
644   Branch->removeOperand(1);  in fuseCompareOperations()
645   Branch->removeOperand(0);  in fuseCompareOperations()
647   // Rebuild Branch as a fused compare and branch.  in fuseCompareOperations()
653   Branch->setDesc(TII->get(FusedOpcode));  in fuseCompareOperations()
654   MachineInstrBuilder MIB(*Branch->getParent()->getParent(), Branch);  in fuseCompareOperations()
661     // to a non-fused branch because of a long displacement.  Conditional  in fuseCompareOperations()