[llvm] r338994 - Revert rL338990 to see if it causes sanitizer failures

Max Kazantsev via llvm-commits llvm-commits at lists.llvm.org
Mon Aug 6 01:10:28 PDT 2018


Author: mkazantsev
Date: Mon Aug  6 01:10:28 2018
New Revision: 338994

URL: http://llvm.org/viewvc/llvm-project?rev=338994&view=rev
Log:
Revert rL338990 to see if it causes sanitizer failures

Multiple failues reported by sanitizer-x86_64-linux, seem to be caused by this
patch. Reverting to see if they sustain without it.

Differential Revision: https://reviews.llvm.org/D50172

Modified:
    llvm/trunk/lib/Analysis/ValueTracking.cpp
    llvm/trunk/test/Transforms/LICM/hoist-deref-load.ll

Modified: llvm/trunk/lib/Analysis/ValueTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ValueTracking.cpp?rev=338994&r1=338993&r2=338994&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ValueTracking.cpp (original)
+++ llvm/trunk/lib/Analysis/ValueTracking.cpp Mon Aug  6 01:10:28 2018
@@ -1861,36 +1861,18 @@ static bool isKnownNonNullFromDominating
       continue;
 
     for (auto *CmpU : U->users()) {
-      SmallVector<const User *, 4> WorkList;
-      SmallPtrSet<const User *, 4> Visited;
-      Visited.insert(CmpU);
-      WorkList.push_back(CmpU);
+      if (const BranchInst *BI = dyn_cast<BranchInst>(CmpU)) {
+        assert(BI->isConditional() && "uses a comparison!");
 
-      while (!WorkList.empty()) {
-        auto *Curr = WorkList.pop_back_val();
-
-        // If a user is an AND, add all its users to the work list.
-        if (auto *BO = dyn_cast<BinaryOperator>(Curr))
-          if (BO->getOpcode() == Instruction::And) {
-            for (auto *BOU : BO->users())
-              if (Visited.insert(BOU).second)
-                WorkList.push_back(BOU);
-            continue;
-          }
-
-        if (const BranchInst *BI = dyn_cast<BranchInst>(Curr)) {
-          assert(BI->isConditional() && "uses a comparison!");
-
-          BasicBlock *NonNullSuccessor =
-              BI->getSuccessor(Pred == ICmpInst::ICMP_EQ ? 1 : 0);
-          BasicBlockEdge Edge(BI->getParent(), NonNullSuccessor);
-          if (Edge.isSingleEdge() && DT->dominates(Edge, CtxI->getParent()))
-            return true;
-        } else if (Pred == ICmpInst::ICMP_NE &&
-                   match(Curr, m_Intrinsic<Intrinsic::experimental_guard>()) &&
-                   DT->dominates(cast<Instruction>(Curr), CtxI)) {
+        BasicBlock *NonNullSuccessor =
+            BI->getSuccessor(Pred == ICmpInst::ICMP_EQ ? 1 : 0);
+        BasicBlockEdge Edge(BI->getParent(), NonNullSuccessor);
+        if (Edge.isSingleEdge() && DT->dominates(Edge, CtxI->getParent()))
           return true;
-        }
+      } else if (Pred == ICmpInst::ICMP_NE &&
+                 match(CmpU, m_Intrinsic<Intrinsic::experimental_guard>()) &&
+                 DT->dominates(cast<Instruction>(CmpU), CtxI)) {
+        return true;
       }
     }
   }

Modified: llvm/trunk/test/Transforms/LICM/hoist-deref-load.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LICM/hoist-deref-load.ll?rev=338994&r1=338993&r2=338994&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LICM/hoist-deref-load.ll (original)
+++ llvm/trunk/test/Transforms/LICM/hoist-deref-load.ll Mon Aug  6 01:10:28 2018
@@ -556,87 +556,5 @@ for.end:
   ret void
 }
 
-; Check that branch by condition "null check AND something" allows to hoist the
-; load.
-define void @test14(i32* noalias %a, i32* %b, i32* dereferenceable_or_null(4) %c, i32 %n, i1 %dummy_cond) #0 {
-
-; CHECK-LABEL: @test14
-; CHECK: load i32, i32* %c, align 4
-; CHECK: for.body:
-
-entry:
-  %not_null = icmp ne i32* %c, null
-  %dummy_and = and i1 %not_null, %dummy_cond
-  br i1 %dummy_and, label %not.null, label %for.end
-
-not.null:
-  %cmp11 = icmp sgt i32 %n, 0
-  br i1 %cmp11, label %for.body, label %for.end
-
-for.body:                                         ; preds = %not.null, %for.inc
-  %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %not.null ]
-  %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv
-  %0 = load i32, i32* %arrayidx, align 4
-  %cmp1 = icmp sgt i32 %0, 0
-  br i1 %cmp1, label %if.then, label %for.inc
-
-if.then:                                          ; preds = %for.body
-  %1 = load i32, i32* %c, align 4
-  %arrayidx3 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv
-  %2 = load i32, i32* %arrayidx3, align 4
-  %mul = mul nsw i32 %2, %1
-  store i32 %mul, i32* %arrayidx, align 4
-  br label %for.inc
-
-for.inc:                                          ; preds = %for.body, %if.then
-  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
-  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
-  %exitcond = icmp eq i32 %lftr.wideiv, %n
-  br i1 %exitcond, label %for.end, label %for.body
-
-for.end:                                          ; preds = %for.inc, %entry, %not.null
-  ret void
-}
-
-; Check that guard by condition "null check AND something" allows to hoist the
-; load.
-define void @test15(i32* noalias %a, i32* %b, i32* dereferenceable_or_null(4) %c, i32 %n, i1 %dummy_cond) #0 {
-
-; CHECK-LABEL: @test15
-; CHECK: load i32, i32* %c, align 4
-; CHECK: for.body:
-
-entry:
-  %not_null = icmp ne i32* %c, null
-  %dummy_and = and i1 %not_null, %dummy_cond
-  call void(i1, ...) @llvm.experimental.guard(i1 %dummy_and) [ "deopt"() ]
-  %cmp11 = icmp sgt i32 %n, 0
-  br i1 %cmp11, label %for.body, label %for.end
-
-for.body:                                         ; preds = %entry, %for.inc
-  %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
-  %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv
-  %0 = load i32, i32* %arrayidx, align 4
-  %cmp1 = icmp sgt i32 %0, 0
-  br i1 %cmp1, label %if.then, label %for.inc
-
-if.then:                                          ; preds = %for.body
-  %1 = load i32, i32* %c, align 4
-  %arrayidx3 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv
-  %2 = load i32, i32* %arrayidx3, align 4
-  %mul = mul nsw i32 %2, %1
-  store i32 %mul, i32* %arrayidx, align 4
-  br label %for.inc
-
-for.inc:                                          ; preds = %for.body, %if.then
-  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
-  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
-  %exitcond = icmp eq i32 %lftr.wideiv, %n
-  br i1 %exitcond, label %for.end, label %for.body
-
-for.end:                                          ; preds = %for.inc, %entry
-  ret void
-}
-
 attributes #0 = { nounwind uwtable }
 !0 = !{i64 4}




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