12 // positions pass, and a branch pseudo op to machine branch opcode pass.  This
31 #define DEBUG_TYPE "ppc-branch-select"
68     StringRef getPassName() const override { return "PowerPC Branch Selector"; }  in getPassName()
73 INITIALIZE_PASS(PPCBSel, "ppc-branch-select", "PowerPC Branch Selector",
76 /// createPPCBranchSelectionPass - returns an instance of the Branch Selection
155         // but we are in the safe position where if we need a long branch we  in ComputeBlockSizes()
199 /// Determine the offset from the branch in Src block to the Dest block.
200 /// BrOffset is the offset of the branch instruction inside Src block.
209     // If this is a backwards branch, the delta is the offset from the  in computeBranchSize()
210     // start of this block to this branch, plus the sizes of all blocks  in computeBranchSize()
241   // inline assembly. Usually it causes larger computed branch offset.  in computeBranchSize()
242   // But sometimes it may also causes smaller computed branch offset  in computeBranchSize()
243   // than actual branch offset. If the offset is close to the limit of  in computeBranchSize()
261   // ABB between branch and target, assume its alignment is <align>  in computeBranchSize()
267   // padding. It also means the actual branch offset is (2^<align> - 4)  in computeBranchSize()
272   // between the branch block and destination block, the estimated address  in computeBranchSize()
277   // block address. So the actual branch offset is less than or equal to  in computeBranchSize()
278   // computed branch offset.  in computeBranchSize()
299   // If the entire function is smaller than the displacement of a branch field,  in runOnMachineFunction()
307   // For each conditional branch, if the offset to its destination is larger  in runOnMachineFunction()
308   // than the offset field allows, transform it into a long branch sequence  in runOnMachineFunction()
310   //   short branch:  in runOnMachineFunction()
312   //   long branch:  in runOnMachineFunction()
344         // Determine the offset from the current branch to the destination  in runOnMachineFunction()
348         // If this branch is in range, ignore it.  in runOnMachineFunction()
354         // Otherwise, we have to expand it to a long branch.  in runOnMachineFunction()
360           // 0. PPC branch predicate  in runOnMachineFunction()
366           // Jump over the uncond branch inst (i.e. $PC+8) on opposite condition.  in runOnMachineFunction()
384            llvm_unreachable("Unhandled branch type!");  in runOnMachineFunction()
387         // Uncond branch to the real destination.  in runOnMachineFunction()
390         // Remove the old branch from the function.  in runOnMachineFunction()