Generalize MemCpyOpt's handling of call slot forwarding to function properly when the call slot

forwarding is implemented with a load/store pair rather than a memcpy.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116637 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/MemCpyOpt/loadstore-sret.ll

@@ -0,0 +1,25 @@
+; RUN: opt -S < %s -memcpyopt | FileCheck %s
+; <rdar://problem/8536696>
+
+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"
+target triple = "x86_64-apple-darwin10.0.0"
+
+%"class.std::auto_ptr" = type { i32* }
+
+; CHECK: @_Z3foov
+define void @_Z3foov(%"class.std::auto_ptr"* noalias nocapture sret %agg.result) ssp {
+_ZNSt8auto_ptrIiED1Ev.exit:
+  %temp.lvalue = alloca %"class.std::auto_ptr", align 8
+; CHECK: call void @_Z3barv(%"class.std::auto_ptr"* sret %agg.result)
+  call void @_Z3barv(%"class.std::auto_ptr"* sret %temp.lvalue)
+  %tmp.i.i = getelementptr inbounds %"class.std::auto_ptr"* %temp.lvalue, i64 0, i32 0
+; CHECK-NOT: load
+  %tmp2.i.i = load i32** %tmp.i.i, align 8
+  %tmp.i.i4 = getelementptr inbounds %"class.std::auto_ptr"* %agg.result, i64 0, i32 0
+; CHECK-NOT: store
+  store i32* %tmp2.i.i, i32** %tmp.i.i4, align 8
+; CHECK: ret void
+  ret void
+}
+
+declare void @_Z3barv(%"class.std::auto_ptr"* sret)