[llvm-commits] [llvm] r54545 - /llvm/trunk/lib/Analysis/ScalarEvolution.cpp

[Dan Gohman]

Author: djg
Date: Fri Aug  8 13:33:12 2008
New Revision: 54545

URL: http://llvm.org/viewvc/llvm-project?rev=54545&view=rev
Log:
Canonicalize nested AddRecs in by nesting them in order of loop depth.

Modified:
    llvm/trunk/lib/Analysis/ScalarEvolution.cpp

Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=54545&r1=54544&r2=54545&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Fri Aug  8 13:33:12 2008
@@ -1158,6 +1158,19 @@
     return getAddRecExpr(Operands, L);             // { X,+,0 }  -->  X
   }
 
+  // Canonicalize nested AddRecs in by nesting them in order of loop depth.
+  if (SCEVAddRecExpr *NestedAR = dyn_cast<SCEVAddRecExpr>(Operands[0])) {
+    const Loop* NestedLoop = NestedAR->getLoop();
+    if (L->getLoopDepth() < NestedLoop->getLoopDepth()) {
+      std::vector<SCEVHandle> NestedOperands(NestedAR->op_begin(),
+                                             NestedAR->op_end());
+      SCEVHandle NestedARHandle(NestedAR);
+      Operands[0] = NestedAR->getStart();
+      NestedOperands[0] = getAddRecExpr(Operands, L);
+      return getAddRecExpr(NestedOperands, NestedLoop);
+    }
+  }
+
   SCEVAddRecExpr *&Result =
     (*SCEVAddRecExprs)[std::make_pair(L, std::vector<SCEV*>(Operands.begin(),
                                                             Operands.end()))];