commit afd6db99322ca8a6556b1e93699b4b4c9ebf5080
author Dan Gohman <gohman@apple.com> Wed Nov 17 21:23:15 2010 +0000
committer Dan Gohman <gohman@apple.com> Wed Nov 17 21:23:15 2010 +0000
tree 0fa53a12b2a9c96bd60e4ff42ae36e22cf80b36d
parent 5ba1459c4c65c56358a8fdd26c731398c4326e64

Move SCEV::isLoopInvariant and hasComputableLoopEvolution to be member
functions of ScalarEvolution, in preparation for memoization and
other optimizations.

llvm-svn: 119562

llvm/lib/Transforms/Scalar/IndVarSimplify.cpp

diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index 0fad048..a439e02 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -200,7 +200,7 @@
   }
 
   // Expand the code for the iteration count.
-  assert(RHS->isLoopInvariant(L) &&
+  assert(SE->isLoopInvariant(RHS, L) &&
          "Computed iteration count is not loop invariant!");
   Value *ExitCnt = Rewriter.expandCodeFor(RHS, IndVar->getType(), BI);
 
@@ -302,7 +302,7 @@
         // and varies predictably *inside* the loop.  Evaluate the value it
         // contains when the loop exits, if possible.
         const SCEV *ExitValue = SE->getSCEVAtScope(Inst, L->getParentLoop());
-        if (!ExitValue->isLoopInvariant(L))
+        if (!SE->isLoopInvariant(ExitValue, L))
           continue;
 
         Changed = true;
@@ -617,9 +617,9 @@
 // currently can only reduce affine polynomials.  For now just disable
 // indvar subst on anything more complex than an affine addrec, unless
 // it can be expanded to a trivial value.
-static bool isSafe(const SCEV *S, const Loop *L) {
+static bool isSafe(const SCEV *S, const Loop *L, ScalarEvolution *SE) {
   // Loop-invariant values are safe.
-  if (S->isLoopInvariant(L)) return true;
+  if (SE->isLoopInvariant(S, L)) return true;
 
   // Affine addrecs are safe. Non-affine are not, because LSR doesn't know how
   // to transform them into efficient code.
@@ -630,18 +630,18 @@
   if (const SCEVCommutativeExpr *Commutative = dyn_cast<SCEVCommutativeExpr>(S)) {
     for (SCEVCommutativeExpr::op_iterator I = Commutative->op_begin(),
          E = Commutative->op_end(); I != E; ++I)
-      if (!isSafe(*I, L)) return false;
+      if (!isSafe(*I, L, SE)) return false;
     return true;
   }
   
   // A cast is safe if its operand is.
   if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(S))
-    return isSafe(C->getOperand(), L);
+    return isSafe(C->getOperand(), L, SE);
 
   // A udiv is safe if its operands are.
   if (const SCEVUDivExpr *UD = dyn_cast<SCEVUDivExpr>(S))
-    return isSafe(UD->getLHS(), L) &&
-           isSafe(UD->getRHS(), L);
+    return isSafe(UD->getLHS(), L, SE) &&
+           isSafe(UD->getRHS(), L, SE);
 
   // SCEVUnknown is always safe.
   if (isa<SCEVUnknown>(S))
@@ -672,7 +672,7 @@
     // Evaluate the expression out of the loop, if possible.
     if (!L->contains(UI->getUser())) {
       const SCEV *ExitVal = SE->getSCEVAtScope(AR, L->getParentLoop());
-      if (ExitVal->isLoopInvariant(L))
+      if (SE->isLoopInvariant(ExitVal, L))
         AR = ExitVal;
     }
 
@@ -682,7 +682,7 @@
     // currently can only reduce affine polynomials.  For now just disable
     // indvar subst on anything more complex than an affine addrec, unless
     // it can be expanded to a trivial value.
-    if (!isSafe(AR, L))
+    if (!isSafe(AR, L, SE))
       continue;
 
     // Determine the insertion point for this user. By default, insert