name change: isPow2DivCheap -> isPow2SDivCheap

isPow2DivCheap

That name doesn't specify signed or unsigned.

Lazy as I am, I eventually read the function and variable comments. It turns out that this is strictly about signed div. But I discovered that the comments are wrong:

   srl/add/sra

is not the general sequence for signed integer division by power-of-2. We need one more 'sra':

   sra/srl/add/sra

That's the sequence produced in DAGCombiner. The first 'sra' may be removed when dividing by exactly '2', but that's a special case.

This patch corrects the comments, changes the name of the flag bit, and changes the name of the accessor methods.

No functional change intended.

Differential Revision: http://reviews.llvm.org/D5010

llvm-svn: 216237
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 3badab6..ebf6910 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -67,7 +67,7 @@
 PPCTargetLowering::PPCTargetLowering(PPCTargetMachine &TM)
     : TargetLowering(TM, createTLOF(Triple(TM.getTargetTriple()))),
       Subtarget(*TM.getSubtargetImpl()) {
-  setPow2DivIsCheap();
+  setPow2SDivIsCheap();
 
   // Use _setjmp/_longjmp instead of setjmp/longjmp.
   setUseUnderscoreSetJmp(true);