[llvm-commits] [llvm] r111031 - /llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpressions.h

[Dan Gohman]

Author: djg
Date: Fri Aug 13 15:03:15 2010
New Revision: 111031

URL: http://llvm.org/viewvc/llvm-project?rev=111031&view=rev
Log:
Implement hasComputableLoopEvolution for Add, Mul, and Trunc operators,
since they can support trivial implementations. This avoids potentially
expensive traversals of the operands.

Modified:
    llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpressions.h

Modified: llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpressions.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpressions.h?rev=111031&r1=111030&r2=111031&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpressions.h (original)
+++ llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpressions.h Fri Aug 13 15:03:15 2010
@@ -126,6 +126,12 @@
   public:
     virtual void print(raw_ostream &OS) const;
 
+    virtual bool hasComputableLoopEvolution(const Loop *QL) const {
+      // Not computable. A truncate of an addrec is always folded into
+      // the addrec.
+      return false;
+    }
+
     /// Methods for support type inquiry through isa, cast, and dyn_cast:
     static inline bool classof(const SCEVTruncateExpr *S) { return true; }
     static inline bool classof(const SCEV *S) {
@@ -294,6 +300,12 @@
     }
 
   public:
+    virtual bool hasComputableLoopEvolution(const Loop *QL) const {
+      // Not computable. An add of an addrec is always folded into the addrec
+      // if the other operands are loop-variant or loop-computable.
+      return false;
+    }
+
     virtual const char *getOperationStr() const { return " + "; }
 
     virtual const Type *getType() const {
@@ -322,6 +334,12 @@
     }
 
   public:
+    virtual bool hasComputableLoopEvolution(const Loop *QL) const {
+      // Not computable. A mul of an addrec is always folded into the addrec
+      // if the other operands are loop-variant or loop-computable.
+      return false;
+    }
+
     virtual const char *getOperationStr() const { return " * "; }
 
     /// Methods for support type inquiry through isa, cast, and dyn_cast: