Hexagon: Remove implicit ilist iterator conversions, NFC

There are two things out of the ordinary in this commit.  First, I made
a loop obviously "infinite" in HexagonInstrInfo.cpp.  After checking if
an instruction was at the beginning of a basic block (in which case,
`break`), the loop decremented and checked the iterator for `nullptr` as
the loop condition.  This has never been possible (the prev pointers are
always been circular, so even with the weird ilist/iplist
implementation, this isn't been possible), so I removed the condition.

Second, in HexagonAsmPrinter.cpp there was another case of comparing a
`MachineBasicBlock::instr_iterator` against `MachineBasicBlock::end()`
(which returns `MachineBasicBlock::iterator`).  While not incorrect,
it's fragile.  I switched this to `::instr_end()`.

All that said, no functionality change intended here.

llvm-svn: 250778

1 files changed, 4 insertions, 6 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonHardwareLoops.cpp b/llvm/lib/Target/Hexagon/HexagonHardwareLoops.cpp
index e328880c9db..d20a809d6c0 100644
--- a/llvm/lib/Target/Hexagon/HexagonHardwareLoops.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonHardwareLoops.cpp
@@ -1288,14 +1288,14 @@ bool HexagonHardwareLoops::orderBumpCompare(MachineInstr *BumpI,
 
   typedef MachineBasicBlock::instr_iterator instr_iterator;
   // Check if things are in order to begin with.
-  for (instr_iterator I = BumpI, E = BB->instr_end(); I != E; ++I)
+  for (instr_iterator I(BumpI), E = BB->instr_end(); I != E; ++I)
     if (&*I == CmpI)
       return true;
 
   // Out of order.
   unsigned PredR = CmpI->getOperand(0).getReg();
   bool FoundBump = false;
-  instr_iterator CmpIt = CmpI, NextIt = std::next(CmpIt);
+  instr_iterator CmpIt = CmpI->getIterator(), NextIt = std::next(CmpIt);
   for (instr_iterator I = NextIt, E = BB->instr_end(); I != E; ++I) {
     MachineInstr *In = &*I;
     for (unsigned i = 0, n = In->getNumOperands(); i < n; ++i) {
@@ -1307,9 +1307,7 @@ bool HexagonHardwareLoops::orderBumpCompare(MachineInstr *BumpI,
     }
 
     if (In == BumpI) {
-      instr_iterator After = BumpI;
-      instr_iterator From = CmpI;
-      BB->splice(std::next(After), BB, From);
+      BB->splice(++BumpI->getIterator(), BB, CmpI->getIterator());
       FoundBump = true;
       break;
     }
@@ -1850,7 +1848,7 @@ MachineBasicBlock *HexagonHardwareLoops::createPreheaderForLoop(
   }
 
   MachineBasicBlock *NewPH = MF->CreateMachineBasicBlock();
-  MF->insert(Header, NewPH);
+  MF->insert(Header->getIterator(), NewPH);
 
   if (Header->pred_size() > 2) {
     // Ensure that the header has only two predecessors: the preheader and