From a0c242cdfde7fd25ab43639e062ad97feb830b05 Mon Sep 17 00:00:00 2001
From: Amaury Sechet <deadalnix@gmail.com>
Date: Tue, 5 Jan 2016 20:17:48 +0000
Subject: Implement load to store => memcpy in MemCpyOpt for aggregates

Summary:
Most of the tool chain is able to optimize scalar and memcpy like operation effisciently while it isn't that good with aggregates. In order to improve the support of aggregate, we try to change aggregate manipulation into either scalar or memcpy like ones whenever possible without loosing informations.

This is one such opportunity.

Reviewers: craig.topper, spatel, dexonsmith, Prazek, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15894

llvm-svn: 256868
---
 llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll | 47 ++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll

(limited to 'llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll')

diff --git a/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll b/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll
new file mode 100644
index 00000000000..61ec7f1d914
--- /dev/null
+++ b/llvm/test/Transforms/MemCpyOpt/fca2memcpy.ll
@@ -0,0 +1,47 @@
+; RUN: opt -memcpyopt -S < %s | FileCheck %s
+
+target datalayout = "e-i64:64-f80:128-n8:16:32:64"
+target triple = "x86_64-unknown-linux-gnu"
+
+%S = type { i8*, i32 }
+
+define void @copy(%S* %src, %S* %dst) {
+; CHECK-LABEL: copy
+; CHECK: call void @llvm.memmove.p0i8.p0i8.i64
+; CHECK-NEXT: ret void
+  %1 = load %S, %S* %src
+  store %S %1, %S* %dst
+  ret void
+}
+
+define void @noaliassrc(%S* noalias %src, %S* %dst) {
+; CHECK-LABEL: noaliassrc
+; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64
+; CHECK-NEXT: ret void
+  %1 = load %S, %S* %src
+  store %S %1, %S* %dst
+  ret void
+}
+
+define void @noaliasdst(%S* %src, %S* noalias %dst) {
+; CHECK-LABEL: noaliasdst
+; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64
+; CHECK-NEXT: ret void
+  %1 = load %S, %S* %src
+  store %S %1, %S* %dst
+  ret void
+}
+
+define void @copyalias(%S* %src, %S* %dst) {
+; CHECK-LABEL: copyalias
+; CHECK-NEXT: [[LOAD:%[a-z0-9\.]+]] = load %S, %S* %src
+; CHECK-NOT: load
+; CHECK: call void @llvm.memmove.p0i8.p0i8.i64
+; CHECK-NEXT: store %S [[LOAD]], %S* %dst
+; CHECK-NEXT: ret void
+  %1 = load %S, %S* %src
+  %2 = load %S, %S* %src
+  store %S %1, %S* %dst
+  store %S %2, %S* %dst
+  ret void
+}
-- 
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