Implement multiple with overflow by 2 with an add instruction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63090 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/smul-with-overflow-2.ll b/test/CodeGen/X86/smul-with-overflow-2.ll
new file mode 100644
index 0000000..c3dbfd7
--- /dev/null
+++ b/test/CodeGen/X86/smul-with-overflow-2.ll
@@ -0,0 +1,20 @@
+; RUN: llvm-as < %s | llc -march=x86 | grep mul | count 1
+; RUN: llvm-as < %s | llc -march=x86 | grep add | count 3
+
+define i32 @t1(i32 %a, i32 %b) nounwind readnone {
+entry:
+        %tmp0 = add i32 %b, %a
+	%tmp1 = call { i32, i1 } @llvm.smul.with.overflow.i32(i32 %tmp0, i32 2)
+	%tmp2 = extractvalue { i32, i1 } %tmp1, 0
+	ret i32 %tmp2
+}
+
+define i32 @t2(i32 %a, i32 %b) nounwind readnone {
+entry:
+        %tmp0 = add i32 %b, %a
+	%tmp1 = call { i32, i1 } @llvm.smul.with.overflow.i32(i32 %tmp0, i32 4)
+	%tmp2 = extractvalue { i32, i1 } %tmp1, 0
+	ret i32 %tmp2
+}
+
+declare { i32, i1 } @llvm.smul.with.overflow.i32(i32, i32) nounwind