From a2446f8d170c97f390d3c8416ba8a5bbac24ff8c Mon Sep 17 00:00:00 2001
From: JF Bastien <jfb@google.com>
Date: Wed, 28 Oct 2015 17:50:23 +0000
Subject: [PATCH] WebAssembly: disable some loop-idiom recognition

memset/memcpy aren't fully supported yet. We should invert this test
once they are supported.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251534 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/TargetLibraryInfo.cpp     |  4 +-
 test/CodeGen/WebAssembly/loop-idiom.ll | 53 ++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGen/WebAssembly/loop-idiom.ll

diff --git a/lib/Analysis/TargetLibraryInfo.cpp b/lib/Analysis/TargetLibraryInfo.cpp
index 635c50ca6e5..39af09e70c2 100644
--- a/lib/Analysis/TargetLibraryInfo.cpp
+++ b/lib/Analysis/TargetLibraryInfo.cpp
@@ -64,7 +64,9 @@ static void initialize(TargetLibraryInfoImpl &TLI, const Triple &T,
   // There are no library implementations of mempcy and memset for AMD gpus and
   // these can be difficult to lower in the backend.
   if (T.getArch() == Triple::r600 ||
-      T.getArch() == Triple::amdgcn) {
+      T.getArch() == Triple::amdgcn ||
+      T.getArch() == Triple::wasm32 ||
+      T.getArch() == Triple::wasm64) {
     TLI.setUnavailable(LibFunc::memcpy);
     TLI.setUnavailable(LibFunc::memset);
     TLI.setUnavailable(LibFunc::memset_pattern16);
diff --git a/test/CodeGen/WebAssembly/loop-idiom.ll b/test/CodeGen/WebAssembly/loop-idiom.ll
new file mode 100644
index 00000000000..2906df20a22
--- /dev/null
+++ b/test/CodeGen/WebAssembly/loop-idiom.ll
@@ -0,0 +1,53 @@
+; RUN: opt -loop-idiom -S < %s -march=wasm32 | FileCheck %s
+
+target datalayout = "e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+
+; Make sure loop-idiom doesn't create memcpy or memset. These aren't well
+; supported in WebAssembly for now.
+;
+; TODO Check the patterns are recognized once memcpy / memset are supported.
+
+; CHECK-LABEL: @cpy(
+; CHECK-NOT: llvm.memcpy
+; CHECK: load
+; CHECK: store
+define void @cpy(i64 %Size) {
+bb.nph:
+  %Base = alloca i8, i32 10000
+  %Dest = alloca i8, i32 10000
+  br label %for.body
+
+for.body:
+  %indvar = phi i64 [ 0, %bb.nph ], [ %indvar.next, %for.body ]
+  %I.0.014 = getelementptr i8, i8* %Base, i64 %indvar
+  %DestI = getelementptr i8, i8* %Dest, i64 %indvar
+  %V = load i8, i8* %I.0.014, align 1
+  store i8 %V, i8* %DestI, align 1
+  %indvar.next = add i64 %indvar, 1
+  %exitcond = icmp eq i64 %indvar.next, %Size
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}
+
+; CHECK-LABEL: @set(
+; CHECK-NOT: llvm.memset
+; CHECK: store
+define void @set(i8* %Base, i64 %Size) {
+bb.nph:
+  br label %for.body
+
+for.body:
+  %indvar = phi i64 [ 0, %bb.nph ], [ %indvar.next, %for.body ]
+  %I.0.014 = getelementptr i8, i8* %Base, i64 %indvar
+  store i8 0, i8* %I.0.014, align 1
+  %indvar.next = add i64 %indvar, 1
+  %exitcond = icmp eq i64 %indvar.next, %Size
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}
-- 
2.34.1