[llvm] r249758 - PowerPC: Don't use getNextNode() for insertion point

[Duncan P. N. Exon Smith via llvm-commits]

Author: dexonsmith
Date: Thu Oct  8 17:20:37 2015
New Revision: 249758

URL: http://llvm.org/viewvc/llvm-project?rev=249758&view=rev
Log:
PowerPC: Don't use getNextNode() for insertion point

Stop using `getNextNode()` to create an insertion point for machine
instructions (at least, in this one place).  Instead, use an iterator.
As a drive-by, clean up dump statements to use iterator logic.

The `getNextNode()` interface isn't actually supposed to work for
insertion points; it's supposed to return `nullptr` if this is the last
node.  It's currently broken and will "happen" to work, but if we ever
fix the function, we'll get some strange failures.

Modified:
    llvm/trunk/lib/Target/PowerPC/PPCVSXSwapRemoval.cpp

Modified: llvm/trunk/lib/Target/PowerPC/PPCVSXSwapRemoval.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCVSXSwapRemoval.cpp?rev=249758&r1=249757&r2=249758&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCVSXSwapRemoval.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCVSXSwapRemoval.cpp Thu Oct  8 17:20:37 2015
@@ -862,7 +862,7 @@ void PPCVSXSwapRemoval::handleSpecialSwa
     DEBUG(dbgs() << "  Into: ");
     DEBUG(MI->dump());
 
-    MachineBasicBlock::iterator InsertPoint = MI->getNextNode();
+    auto InsertPoint = ++MachineBasicBlock::iterator(MI);
 
     // Note that an XXPERMDI requires a VSRC, so if the SUBREG_TO_REG
     // is copying to a VRRC, we need to be careful to avoid a register
@@ -876,19 +876,19 @@ void PPCVSXSwapRemoval::handleSpecialSwa
       BuildMI(*MI->getParent(), InsertPoint, MI->getDebugLoc(),
               TII->get(PPC::COPY), VSRCTmp1)
         .addReg(NewVReg);
-      DEBUG(MI->getNextNode()->dump());
+      DEBUG(std::prev(InsertPoint)->dump());
 
       insertSwap(MI, InsertPoint, VSRCTmp2, VSRCTmp1);
-      DEBUG(MI->getNextNode()->getNextNode()->dump());
+      DEBUG(std::prev(InsertPoint)->dump());
 
       BuildMI(*MI->getParent(), InsertPoint, MI->getDebugLoc(),
               TII->get(PPC::COPY), DstReg)
         .addReg(VSRCTmp2);
-      DEBUG(MI->getNextNode()->getNextNode()->getNextNode()->dump());
+      DEBUG(std::prev(InsertPoint)->dump());
 
     } else {
       insertSwap(MI, InsertPoint, DstReg, NewVReg);
-      DEBUG(MI->getNextNode()->dump());
+      DEBUG(std::prev(InsertPoint)->dump());
     }
     break;
   }