Don't check hasAllowReassoc(); check only hasAllowContract()

Removed folding from foldFMulReassoc() that assumed hasAllowReassoc()
Moved folding back in visitFMul()

Author: amordo

llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp

@@ -947,14 +947,6 @@ Instruction *InstCombinerImpl::foldFMulReassoc(BinaryOperator &I) {
     return BinaryOperator::CreateFMulFMF(XX, Y, &I);
   }
 
-  // tan(X) * cos(X) -> sin(X)
-  if (match(&I,
-            m_c_FMul(m_OneUse(m_Intrinsic<Intrinsic::tan>(m_Value(X))),
-                     m_OneUse(m_Intrinsic<Intrinsic::cos>(m_Deferred(X)))))) {
-    Value *Sin = Builder.CreateUnaryIntrinsic(Intrinsic::sin, X, &I);
-    return replaceInstUsesWith(I, Sin);
-  }
-
   return nullptr;
 }
 
@@ -1081,6 +1073,14 @@ Instruction *InstCombinerImpl::visitFMul(BinaryOperator &I) {
     return Result;
   }
 
+  // tan(X) * cos(X) -> sin(X)
+  if (I.hasAllowContract() && match(&I,
+            m_c_FMul(m_OneUse(m_Intrinsic<Intrinsic::tan>(m_Value(X))),
+                     m_OneUse(m_Intrinsic<Intrinsic::cos>(m_Deferred(X)))))) {
+    Value *Sin = Builder.CreateUnaryIntrinsic(Intrinsic::sin, X, &I);
+    return replaceInstUsesWith(I, Sin);
+  }
+
   return nullptr;
 }