[llvm-commits] [llvm] r141873 - in /llvm/trunk: lib/Analysis/ScalarEvolutionExpander.cpp test/Transforms/LoopStrengthReduce/2011-10-13-SCEVChain.ll

[Andrew Trick]

Author: atrick
Date: Thu Oct 13 12:58:24 2011
New Revision: 141873

URL: http://llvm.org/viewvc/llvm-project?rev=141873&view=rev
Log:
Revert r141870. The test case crashes on linux with data corruption. A deeper issue was exposed.

Removed:
    llvm/trunk/test/Transforms/LoopStrengthReduce/2011-10-13-SCEVChain.ll
Modified:
    llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp

Modified: llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp?rev=141873&r1=141872&r2=141873&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp Thu Oct 13 12:58:24 2011
@@ -1120,14 +1120,6 @@
     BasicBlock *LatchBlock = L->getLoopLatch();
     assert(LatchBlock && "PostInc mode requires a unique loop latch!");
     Result = PN->getIncomingValueForBlock(LatchBlock);
-
-    // For an expansion to use the postinc form, the client must call
-    // expandCodeFor with an InsertPoint that is either outside the PostIncLoop
-    // or dominated by IVIncInsertPos.
-    assert((!isa<Instruction>(Result) ||
-            SE.DT->dominates(cast<Instruction>(Result),
-                             Builder.GetInsertPoint())) &&
-           "postinc expansion does not dominate use");
   }
 
   // Re-apply any non-loop-dominating scale.
@@ -1418,12 +1410,8 @@
   Value *V = visit(S);
 
   // Remember the expanded value for this SCEV at this location.
-  //
-  // This is independent of PostIncLoops. The mapped value simply materializes
-  // the expression at this insertion point. If the mapped value happened to be
-  // a postinc expansion, it could be reused by a non postinc user, but only if
-  // its insertion point was already at the head of the loop.
-  InsertedExpressions[std::make_pair(S, InsertPt)] = V;
+  if (PostIncLoops.empty())
+    InsertedExpressions[std::make_pair(S, InsertPt)] = V;
 
   restoreInsertPoint(SaveInsertBB, SaveInsertPt);
   return V;

Removed: llvm/trunk/test/Transforms/LoopStrengthReduce/2011-10-13-SCEVChain.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopStrengthReduce/2011-10-13-SCEVChain.ll?rev=141872&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopStrengthReduce/2011-10-13-SCEVChain.ll (original)
+++ llvm/trunk/test/Transforms/LoopStrengthReduce/2011-10-13-SCEVChain.ll (removed)
@@ -1,111 +0,0 @@
-; RUN: opt -loop-reduce -S < %s | FileCheck %s
-;
-; Test TransformForPostIncUse and LSR's expansion of expressions in
-; post-inc form to ensure the implementation can handle expressions
-; DAGs, not just trees.
-
-target triple = "x86_64-apple-darwin"
-
-; Verify that -loop-reduce runs without "hanging" and reuses post-inc
-; expansions.
-; CHECK: @test
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK: icmp
-; CHECK-NOT: icmp
-define void @test(i8* %base, i32 %a0) nounwind {
-entry:
-  br label %bb1
-bb1:
-  %n0 = sub i32 0, %a0
-  %t0 = icmp ugt i32 %n0, -4
-  %m0 = select i1 %t0, i32 %n0, i32 -4
-  %a1 = add i32 %m0, %a0
-  %n1 = sub i32 0, %a1
-  %t1 = icmp ugt i32 %n1, -4
-  %m1 = select i1 %t1, i32 %n1, i32 -4
-  %a2 = add i32 %m1, %a1
-  %n2 = sub i32 0, %a2
-  %t2 = icmp ugt i32 %n2, -4
-  %m2 = select i1 %t2, i32 %n2, i32 -4
-  %a3 = add i32 %m2, %a2
-  %n3 = sub i32 0, %a3
-  %t3 = icmp ugt i32 %n3, -4
-  %m3 = select i1 %t3, i32 %n3, i32 -4
-  %a4 = add i32 %m3, %a3
-  %n4 = sub i32 0, %a4
-  %t4 = icmp ugt i32 %n4, -4
-  %m4 = select i1 %t4, i32 %n4, i32 -4
-  %a5 = add i32 %m4, %a4
-  %n5 = sub i32 0, %a5
-  %t5 = icmp ugt i32 %n5, -4
-  %m5 = select i1 %t5, i32 %n5, i32 -4
-  %a6 = add i32 %m5, %a5
-  %n6 = sub i32 0, %a6
-  %t6 = icmp ugt i32 %n6, -4
-  %m6 = select i1 %t6, i32 %n6, i32 -4
-  %a7 = add i32 %m6, %a6
-  %n7 = sub i32 0, %a7
-  %t7 = icmp ugt i32 %n7, -4
-  %m7 = select i1 %t7, i32 %n7, i32 -4
-  %a8 = add i32 %m7, %a7
-  %n8 = sub i32 0, %a8
-  %t8 = icmp ugt i32 %n8, -4
-  %m8 = select i1 %t8, i32 %n8, i32 -4
-  %a9 = add i32 %m8, %a8
-  %n9 = sub i32 0, %a9
-  %t9 = icmp ugt i32 %n9, -4
-  %m9 = select i1 %t9, i32 %n9, i32 -4
-  %a10 = add i32 %m9, %a9
-  %n10 = sub i32 0, %a10
-  %t10 = icmp ugt i32 %n10, -4
-  %m10 = select i1 %t10, i32 %n10, i32 -4
-  %a11 = add i32 %m10, %a10
-  %n11 = sub i32 0, %a11
-  %t11 = icmp ugt i32 %n11, -4
-  %m11 = select i1 %t11, i32 %n11, i32 -4
-  %a12 = add i32 %m11, %a11
-  %n12 = sub i32 0, %a12
-  %t12 = icmp ugt i32 %n12, -4
-  %m12 = select i1 %t12, i32 %n12, i32 -4
-  %a13 = add i32 %m12, %a12
-  %n13 = sub i32 0, %a13
-  %t13 = icmp ugt i32 %n13, -4
-  %m13 = select i1 %t13, i32 %n13, i32 -4
-  %a14 = add i32 %m13, %a13
-  %n14 = sub i32 0, %a14
-  %t14 = icmp ugt i32 %n14, -4
-  %m14 = select i1 %t14, i32 %n14, i32 -4
-  %a15 = add i32 %m14, %a14
-  %n15 = sub i32 0, %a15
-  %t15 = icmp ugt i32 %n15, -4
-  %m15 = select i1 %t15, i32 %n15, i32 -4
-  %a16 = add i32 %m15, %a15
-  %gep = getelementptr i8* %base, i32 %a16
-  %ofs = add i32 %a16, 4
-  %limit = getelementptr i8* %base, i32 %ofs
-  br label %loop
-
-loop:
-  %iv = phi i8* [ %gep, %bb1 ], [ %inc, %loop ]
-  %inc = getelementptr inbounds i8* %iv, i64 1
-  %exitcond = icmp eq i8* %inc, %limit
-  br i1 %exitcond, label %loop, label %exit
-
-exit:
-  ret void
-}