[llvm-commits] [llvm] r153132 - in /llvm/trunk: lib/Analysis/IVUsers.cpp test/Transforms/LoopStrengthReduce/2012-03-15-nopreheader.ll

[Andrew Trick]

Author: atrick
Date: Tue Mar 20 16:24:44 2012
New Revision: 153132

URL: http://llvm.org/viewvc/llvm-project?rev=153132&view=rev
Log:
LSR: teach isSimplifiedLoopNest to handle PHI IVUsers.

Modified:
    llvm/trunk/lib/Analysis/IVUsers.cpp
    llvm/trunk/test/Transforms/LoopStrengthReduce/2012-03-15-nopreheader.ll

Modified: llvm/trunk/lib/Analysis/IVUsers.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/IVUsers.cpp?rev=153132&r1=153131&r2=153132&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/IVUsers.cpp (original)
+++ llvm/trunk/lib/Analysis/IVUsers.cpp Tue Mar 20 16:24:44 2012
@@ -148,7 +148,14 @@
 
     // Only consider IVUsers that are dominated by simplified loop
     // headers. Otherwise, SCEVExpander will crash.
-    if (!isSimplifiedLoopNest(User->getParent(), DT, LI, SimpleLoopNests))
+    BasicBlock *UseBB = User->getParent();
+    // A phi's use is live out of its predecessor block.
+    if (PHINode *PHI = dyn_cast<PHINode>(User)) {
+      unsigned OperandNo = UI.getOperandNo();
+      unsigned ValNo = PHINode::getIncomingValueNumForOperand(OperandNo);
+      UseBB = PHI->getIncomingBlock(ValNo);
+    }
+    if (!isSimplifiedLoopNest(UseBB, DT, LI, SimpleLoopNests))
       return false;
 
     // Descend recursively, but not into PHI nodes outside the current loop.

Modified: llvm/trunk/test/Transforms/LoopStrengthReduce/2012-03-15-nopreheader.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopStrengthReduce/2012-03-15-nopreheader.ll?rev=153132&r1=153131&r2=153132&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopStrengthReduce/2012-03-15-nopreheader.ll (original)
+++ llvm/trunk/test/Transforms/LoopStrengthReduce/2012-03-15-nopreheader.ll Tue Mar 20 16:24:44 2012
@@ -49,6 +49,8 @@
   ret void
 }
 
+; Another case with a dominating loop that does not contain the IV
+; User. Just make sure it doesn't assert.
 define void @nopreheader2() nounwind ssp {
 entry:
   indirectbr i8* undef, [label %while.cond, label %return]
@@ -121,3 +123,33 @@
 return:                                           ; preds = %if.end216, %land.lhs.true183, %land.lhs.true, %while.end52, %lor.lhs.false, %while.end, %entry
   ret void
 }
+
+; Test a phi operand IV User dominated by a no-preheader loop.
+define void @nopreheader3() nounwind uwtable ssp align 2 {
+entry:
+  indirectbr i8* blockaddress(@nopreheader3, %if.end10), [label %if.end22, label %if.end10]
+
+if.end10:                                         ; preds = %entry
+  indirectbr i8* blockaddress(@nopreheader3, %if.end6.i), [label %if.end22, label %if.end6.i]
+
+if.end6.i:                                        ; preds = %if.end10
+  indirectbr i8* blockaddress(@nopreheader3, %while.cond2.preheader.i.i), [label %if.then12, label %while.cond2.preheader.i.i]
+
+while.cond2.preheader.i.i:                        ; preds = %while.end.i18.i, %if.end6.i
+  indirectbr i8* blockaddress(@nopreheader3, %while.cond2.i.i), [label %while.cond2.i.i]
+
+while.cond2.i.i:                                  ; preds = %while.cond2.i.i, %while.cond2.preheader.i.i
+  %i1.1.i14.i = phi i32 [ %add.i15.i, %while.cond2.i.i ], [ undef, %while.cond2.preheader.i.i ]
+  %add.i15.i = add nsw i32 %i1.1.i14.i, undef
+  indirectbr i8* blockaddress(@nopreheader3, %while.end.i18.i), [label %while.cond2.i.i, label %while.end.i18.i]
+
+while.end.i18.i:                                  ; preds = %while.cond2.i.i
+  indirectbr i8* blockaddress(@nopreheader3, %while.cond2.preheader.i.i), [label %if.then12, label %while.cond2.preheader.i.i]
+
+if.then12:                                        ; preds = %while.end.i18.i, %if.end6.i
+  %i1.0.lcssa.i.i = phi i32 [ undef, %if.end6.i ], [ %i1.1.i14.i, %while.end.i18.i ]
+  indirectbr i8* blockaddress(@nopreheader3, %if.end22), [label %if.end22]
+
+if.end22:                                         ; preds = %if.then12, %if.end10, %entry
+  ret void
+}