Make the SLP store-merger less paranoid about function calls. We chec…

…k for function calls when we check if it is safe to sink instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179207 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -65,10 +65,6 @@ struct SLPVectorizer : public BasicBlockPass {
   /// if we flush the chain creation every time we run into a memory barrier.
   bool CollectStores(BasicBlock *BB, BoUpSLP &R) {
     for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) {
-      // Can't vectorize instructions with side effects.
-      if (it->mayThrow())
-        return false;
-
       StoreInst *SI = dyn_cast<StoreInst>(it);
       if (!SI)
         continue;

test/Transforms/SLPVectorizer/X86/barriercall.ll

@@ -0,0 +1,40 @@
+; 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-macosx10.8.0"
+
+;CHECK: @foo
+;CHECK: store <4 x i32>
+;CHECK: ret
+define i32 @foo(i32* nocapture %A, i32 %n) #0 {
+entry:
+  %call = tail call i32 (...)* @bar() #2
+  %mul = mul nsw i32 %n, 5
+  %add = add nsw i32 %mul, 9
+  store i32 %add, i32* %A, align 4, !tbaa !0
+  %mul1 = mul nsw i32 %n, 9
+  %add2 = add nsw i32 %mul1, 9
+  %arrayidx3 = getelementptr inbounds i32* %A, i64 1
+  store i32 %add2, i32* %arrayidx3, align 4, !tbaa !0
+  %mul4 = shl i32 %n, 3
+  %add5 = add nsw i32 %mul4, 9
+  %arrayidx6 = getelementptr inbounds i32* %A, i64 2
+  store i32 %add5, i32* %arrayidx6, align 4, !tbaa !0
+  %mul7 = mul nsw i32 %n, 10
+  %add8 = add nsw i32 %mul7, 9
+  %arrayidx9 = getelementptr inbounds i32* %A, i64 3
+  store i32 %add8, i32* %arrayidx9, align 4, !tbaa !0
+  ret i32 undef
+}
+
+  ; We can still vectorize the stores below.
+
+declare i32 @bar(...) #1
+
+attributes #0 = { nounwind ssp uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { nounwind }
+
+!0 = metadata !{metadata !"int", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA"}