fold memcpy/set/move_chk to llvm.memcpy/set/move when the sizes

are trivial.  This exposes opportunities earlier, and allows fastisel
to do good things with these at -O0.

This addresses rdar://9289468 - clang doesn't fold memset_chk at -O0


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@129651 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 28 insertions, 1 deletions

diff --git a/test/CodeGen/builtin-memfns.c b/test/CodeGen/builtin-memfns.c
index e8c407fd6f..2ea6793654 100644
--- a/test/CodeGen/builtin-memfns.c
+++ b/test/CodeGen/builtin-memfns.c
@@ -1,12 +1,13 @@
 // RUN: %clang_cc1 -triple i386-pc-linux-gnu -emit-llvm < %s| FileCheck %s
 
+// CHECK: @test1
 // CHECK: call void @llvm.memset.p0i8.i32
 // CHECK: call void @llvm.memset.p0i8.i32
 // CHECK: call void @llvm.memcpy.p0i8.p0i8.i32
 // CHECK: call void @llvm.memmove.p0i8.p0i8.i32
 // CHECK-NOT: __builtin
 // CHECK: ret
-int main(int argc, char **argv) {
+int test1(int argc, char **argv) {
   unsigned char a = 0x11223344;
   unsigned char b = 0x11223344;
   __builtin_bzero(&a, sizeof(a));
@@ -15,3 +16,29 @@ int main(int argc, char **argv) {
   __builtin_memmove(&a, &b, sizeof(a));
   return 0;
 }
+
+// rdar://9289468
+
+// CHECK: @test2
+// CHECK: call void @llvm.memcpy.p0i8.p0i8.i32
+char* test2(char* a, char* b) {
+  return __builtin_memcpy(a, b, 4);
+}
+
+// CHECK: @test3
+// CHECK: call void @llvm.memset
+void test3(char *P) {
+  __builtin___memset_chk(P, 42, 128, 128);
+}
+
+// CHECK: @test4
+// CHECK: call void @llvm.memcpy
+void test4(char *P, char *Q) {
+  __builtin___memcpy_chk(P, Q, 128, 128);
+}
+
+// CHECK: @test5
+// CHECK: call void @llvm.memmove
+void test5(char *P, char *Q) {
+  __builtin___memmove_chk(P, Q, 128, 128);
+}