Merge branch 'release-3.2' into embtk-support-release-3.2

5 files changed, 58 insertions, 4 deletions

diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index b3d62487fc..a76e5ad1b8 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -2065,8 +2065,25 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
     if (A && C && (A == C || A == D || B == C || B == D) &&
         NoLHSWrapProblem && NoRHSWrapProblem) {
       // Determine Y and Z in the form icmp (X+Y), (X+Z).
-      Value *Y = (A == C || A == D) ? B : A;
-      Value *Z = (C == A || C == B) ? D : C;
+      Value *Y, *Z;
+      if (A == C) {
+        // C + B == C + D  ->  B == D
+        Y = B;
+        Z = D;
+      } else if (A == D) {
+        // D + B == C + D  ->  B == C
+        Y = B;
+        Z = C;
+      } else if (B == C) {
+        // A + C == C + D  ->  A == D
+        Y = A;
+        Z = D;
+      } else {
+        assert(B == D);
+        // A + D == C + D  ->  A == C
+        Y = A;
+        Z = C;
+      }
       if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse-1))
         return V;
     }
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 5416a5c1d7..37d7731aa1 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -7728,7 +7728,18 @@ bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) {
       if (StoreNodes[i].MemNode == EarliestOp)
         continue;
       StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
-      DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain());
+      // ReplaceAllUsesWith will replace all uses that existed when it was
+      // called, but graph optimizations may cause new ones to appear. For
+      // example, the case in pr14333 looks like
+      //
+      //  St's chain -> St -> another store -> X
+      //
+      // And the only difference from St to the other store is the chain.
+      // When we change it's chain to be St's chain they become identical,
+      // get CSEed and the net result is that X is now a use of St.
+      // Since we know that St is redundant, just iterate.
+      while (!St->use_empty())
+        DAG.ReplaceAllUsesWith(SDValue(St, 0), St->getChain());
       removeFromWorkList(St);
       DAG.DeleteNode(St);
     }
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp
index e223a049f0..7c3f8fe15d 100644
--- a/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -2358,15 +2358,20 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
       // Determine Y and Z in the form icmp (X+Y), (X+Z).
       Value *Y, *Z;
       if (A == C) {
+        // C + B == C + D  ->  B == D
         Y = B;
         Z = D;
       } else if (A == D) {
+        // D + B == C + D  ->  B == C
         Y = B;
         Z = C;
       } else if (B == C) {
+        // A + C == C + D  ->  A == D
         Y = A;
         Z = D;
-      } else if (B == D) {
+      } else {
+        assert(B == D);
+        // A + D == C + D  ->  A == C
         Y = A;
         Z = C;
       }
diff --git a/test/CodeGen/X86/pr14333.ll b/test/CodeGen/X86/pr14333.ll
new file mode 100644
index 0000000000..86c12ef6b5
--- /dev/null
+++ b/test/CodeGen/X86/pr14333.ll
@@ -0,0 +1,12 @@
+; RUN: llc -mtriple=x86_64-unknown-unknown < %s
+%foo = type { i64, i64 }
+define void @bar(%foo* %zed) {
+  %tmp = getelementptr inbounds %foo* %zed, i64 0, i32 0
+  store i64 0, i64* %tmp, align 8
+  %tmp2 = getelementptr inbounds %foo* %zed, i64 0, i32 1
+  store i64 0, i64* %tmp2, align 8
+  %tmp3 = bitcast %foo* %zed to i8*
+  call void @llvm.memset.p0i8.i64(i8* %tmp3, i8 0, i64 16, i32 8, i1 false)
+  ret void
+}
+declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind
diff --git a/test/Transforms/InstSimplify/compare.ll b/test/Transforms/InstSimplify/compare.ll
index ced74bd4be..ce2bb799c8 100644
--- a/test/Transforms/InstSimplify/compare.ll
+++ b/test/Transforms/InstSimplify/compare.ll
@@ -266,6 +266,15 @@ define i1 @add5(i32 %x, i32 %y) {
 ; CHECK: ret i1 true
 }
 
+define i1 @add6(i64 %A, i64 %B) {
+; CHECK: @add6
+  %s1 = add i64 %A, %B
+  %s2 = add i64 %B, %A
+  %cmp = icmp eq i64 %s1, %s2
+  ret i1 %cmp
+; CHECK: ret i1 true
+}
+
 define i1 @addpowtwo(i32 %x, i32 %y) {
 ; CHECK: @addpowtwo
   %l = lshr i32 %x, 1