When we vectorize across multiple basic blocks we may vectorize PHINodes that create...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186883 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 350222206942654ea5480a86af51b0159245befa..25f7a78f6671156caf2d39234fde2c5edc628872 100644 (file)
--- a/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -264,12 +264,16 @@ private:
   /// This is the recursive part of buildTree.
   void buildTree_rec(ArrayRef<Value *> Roots, unsigned Depth);
 
-  /// Vectorizer a single entry in the tree.
+  /// Vectorize a single entry in the tree.
   Value *vectorizeTree(TreeEntry *E);
 
-  /// Vectorizer a single entry in the tree, starting in \p VL.
+  /// Vectorize a single entry in the tree, starting in \p VL.
   Value *vectorizeTree(ArrayRef<Value *> VL);
 
+  /// \returns the pointer to the vectorized value if \p VL is already
+  /// vectorized, or NULL. They may happen in cycles.
+  Value *alreadyVectorized(ArrayRef<Value *> VL);
+
   /// \brief Take the pointer operand from the Load/Store instruction.
   /// \returns NULL if this is not a valid Load/Store instruction.
   static Value *getPointerOperand(Value *I);
@@ -1117,6 +1121,16 @@ Value *BoUpSLP::Gather(ArrayRef<Value *> VL, VectorType *Ty) {
   return Vec;
 }
 
+Value *BoUpSLP::alreadyVectorized(ArrayRef<Value *> VL) {
+  if (ScalarToTreeEntry.count(VL[0])) {
+    int Idx = ScalarToTreeEntry[VL[0]];
+    TreeEntry *En = &VectorizableTree[Idx];
+    if (En->isSame(VL) && En->VectorizedValue)
+      return En->VectorizedValue;
+  }
+  return 0;
+}
+
 Value *BoUpSLP::vectorizeTree(ArrayRef<Value *> VL) {
   if (ScalarToTreeEntry.count(VL[0])) {
     int Idx = ScalarToTreeEntry[VL[0]];
@@ -1206,6 +1220,10 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
 
       Builder.SetInsertPoint(getLastInstruction(E->Scalars));
       Value *InVec = vectorizeTree(INVL);
+
+      if (Value *V = alreadyVectorized(E->Scalars))
+        return V;
+
       CastInst *CI = dyn_cast<CastInst>(VL0);
       Value *V = Builder.CreateCast(CI->getOpcode(), InVec, VecTy);
       E->VectorizedValue = V;
@@ -1222,9 +1240,12 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
       Builder.SetInsertPoint(getLastInstruction(E->Scalars));
       Value *L = vectorizeTree(LHSV);
       Value *R = vectorizeTree(RHSV);
-      Value *V;
+
+      if (Value *V = alreadyVectorized(E->Scalars))
+        return V;
 
       CmpInst::Predicate P0 = dyn_cast<CmpInst>(VL0)->getPredicate();
+      Value *V;
       if (Opcode == Instruction::FCmp)
         V = Builder.CreateFCmp(P0, L, R);
       else
@@ -1245,6 +1266,10 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
       Value *Cond = vectorizeTree(CondVec);
       Value *True = vectorizeTree(TrueVec);
       Value *False = vectorizeTree(FalseVec);
+
+      if (Value *V = alreadyVectorized(E->Scalars))
+        return V;
+      
       Value *V = Builder.CreateSelect(Cond, True, False);
       E->VectorizedValue = V;
       return V;
@@ -1281,6 +1306,9 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
         assert((VL0->getOperand(0) == VL0->getOperand(1)) && "Invalid order");
       }
 
+      if (Value *V = alreadyVectorized(E->Scalars))
+        return V;
+
       BinaryOperator *BinOp = cast<BinaryOperator>(VL0);
       Value *V = Builder.CreateBinOp(BinOp->getOpcode(), LHS, RHS);
       E->VectorizedValue = V;

diff --git a/test/Transforms/SLPVectorizer/X86/cycle_dup.ll b/test/Transforms/SLPVectorizer/X86/cycle_dup.ll
new file mode 100644 (file)
index 0000000..501fae1
--- /dev/null
+++ b/test/Transforms/SLPVectorizer/X86/cycle_dup.ll
@@ -0,0 +1,58 @@
+; RUN: opt < %s -basicaa -slp-vectorizer -dce -S -mtriple=x86_64-apple-macosx10.8.0 -mcpu=corei7-avx | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.9.0"
+
+
+; int foo(int *A) {
+;   int r = A[0], g = A[1], b = A[2];
+;   for (int i=0; i < A[13]; i++)
+;     r*=18; g*=19; b*=12;
+;   A[0] = r; A[1] = g; A[2] = b;
+; }
+
+;CHECK-LABEL: @foo
+;CHECK: bitcast i32* %A to <3 x i32>*
+;CHECK-NEXT: load <3 x i32>
+;CHECK: phi <3 x i32>
+;CHECK-NEXT: mul <3 x i32>
+;CHECK-NOT: mul
+;CHECK: phi <3 x i32>
+;CHECK: bitcast i32* %A to <3 x i32>*
+;CHECK-NEXT: store <3 x i32>
+;CHECK-NEXT:ret i32 undef
+define i32 @foo(i32* nocapture %A) {
+entry:
+  %0 = load i32* %A, align 4
+  %arrayidx1 = getelementptr inbounds i32* %A, i64 1
+  %1 = load i32* %arrayidx1, align 4
+  %arrayidx2 = getelementptr inbounds i32* %A, i64 2
+  %2 = load i32* %arrayidx2, align 4
+  %arrayidx3 = getelementptr inbounds i32* %A, i64 13
+  %3 = load i32* %arrayidx3, align 4
+  %cmp18 = icmp sgt i32 %3, 0
+  br i1 %cmp18, label %for.body, label %for.end
+
+for.body:                                         ; preds = %entry, %for.body
+  %i.022 = phi i32 [ %inc, %for.body ], [ 0, %entry ]
+  %b.021 = phi i32 [ %mul5, %for.body ], [ %2, %entry ]
+  %g.020 = phi i32 [ %mul4, %for.body ], [ %1, %entry ]
+  %r.019 = phi i32 [ %mul, %for.body ], [ %0, %entry ]
+  %mul = mul nsw i32 %r.019, 18
+  %mul4 = mul nsw i32 %g.020, 19
+  %mul5 = mul nsw i32 %b.021, 12
+  %inc = add nsw i32 %i.022, 1
+  %cmp = icmp slt i32 %inc, %3
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body, %entry
+  %b.0.lcssa = phi i32 [ %2, %entry ], [ %mul5, %for.body ]
+  %g.0.lcssa = phi i32 [ %1, %entry ], [ %mul4, %for.body ]
+  %r.0.lcssa = phi i32 [ %0, %entry ], [ %mul, %for.body ]
+  store i32 %r.0.lcssa, i32* %A, align 4
+  store i32 %g.0.lcssa, i32* %arrayidx1, align 4
+  store i32 %b.0.lcssa, i32* %arrayidx2, align 4
+  ret i32 undef
+}
+
+