[SystemZ] Use "STC;MVC" for memset

Use "STC;MVC" for memsets that are too big for two STCs or MV...Is yet
small enough for a single MVC.  As with memcpy, I'm leaving longer cases
till later.

The number of tests might seem excessive, but f33 & f34 from memset-04.ll
failed the first cut because I'd not added the "?:" on the calculation
of Size1.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185918 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 124 insertions, 0 deletions

diff --git a/test/CodeGen/SystemZ/memset-01.ll b/test/CodeGen/SystemZ/memset-01.ll
new file mode 100644
index 0000000000..1592318b8b
--- /dev/null
+++ b/test/CodeGen/SystemZ/memset-01.ll
@@ -0,0 +1,124 @@
+; Test memset in cases where the set value is variable.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+declare void @llvm.memset.p0i8.i32(i8 *nocapture, i8, i32, i32, i1) nounwind
+declare void @llvm.memset.p0i8.i64(i8 *nocapture, i8, i64, i32, i1) nounwind
+
+; No bytes, i32 version.
+define void @f1(i8 *%dest, i8 %val) {
+; CHECK: f1:
+; CHECK-NOT: %r2
+; CHECK-NOT: %r3
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 %val, i32 0, i32 1, i1 false)
+  ret void
+}
+
+; No bytes, i64 version.
+define void @f2(i8 *%dest, i8 %val) {
+; CHECK: f2:
+; CHECK-NOT: %r2
+; CHECK-NOT: %r3
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 %val, i64 0, i32 1, i1 false)
+  ret void
+}
+
+; 1 byte, i32 version.
+define void @f3(i8 *%dest, i8 %val) {
+; CHECK: f3:
+; CHECK: stc %r3, 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 %val, i32 1, i32 1, i1 false)
+  ret void
+}
+
+; 1 byte, i64 version.
+define void @f4(i8 *%dest, i8 %val) {
+; CHECK: f4:
+; CHECK: stc %r3, 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 %val, i64 1, i32 1, i1 false)
+  ret void
+}
+
+; 2 bytes, i32 version.
+define void @f5(i8 *%dest, i8 %val) {
+; CHECK: f5:
+; CHECK-DAG: stc %r3, 0(%r2)
+; CHECK-DAG: stc %r3, 1(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 %val, i32 2, i32 1, i1 false)
+  ret void
+}
+
+; 2 bytes, i64 version.
+define void @f6(i8 *%dest, i8 %val) {
+; CHECK: f6:
+; CHECK-DAG: stc %r3, 0(%r2)
+; CHECK-DAG: stc %r3, 1(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 %val, i64 2, i32 1, i1 false)
+  ret void
+}
+
+; 3 bytes, i32 version.
+define void @f7(i8 *%dest, i8 %val) {
+; CHECK: f7:
+; CHECK: stc %r3, 0(%r2)
+; CHECK: mvc 1(2,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 %val, i32 3, i32 1, i1 false)
+  ret void
+}
+
+; 3 bytes, i64 version.
+define void @f8(i8 *%dest, i8 %val) {
+; CHECK: f8:
+; CHECK: stc %r3, 0(%r2)
+; CHECK: mvc 1(2,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 %val, i64 3, i32 1, i1 false)
+  ret void
+}
+
+; 257 bytes, i32 version.
+define void @f9(i8 *%dest, i8 %val) {
+; CHECK: f9:
+; CHECK: stc %r3, 0(%r2)
+; CHECK: mvc 1(256,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 %val, i32 257, i32 1, i1 false)
+  ret void
+}
+
+; 257 bytes, i64 version.
+define void @f10(i8 *%dest, i8 %val) {
+; CHECK: f10:
+; CHECK: stc %r3, 0(%r2)
+; CHECK: mvc 1(256,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 %val, i64 257, i32 1, i1 false)
+  ret void
+}
+
+; 258 bytes, i32 version.  258 bytes is too big for a single MVC.
+; For now expect none, so that the test fails and gets updated when
+; large copies are implemented.
+define void @f11(i8 *%dest, i8 %val) {
+; CHECK: f11:
+; CHECK-NOT: mvc
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 %val, i32 258, i32 1, i1 false)
+  ret void
+}
+
+; 258 bytes, i64 version, with the same comments as above.
+define void @f12(i8 *%dest, i8 %val) {
+; CHECK: f12:
+; CHECK-NOT: mvc
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 %val, i64 258, i32 1, i1 false)
+  ret void
+}