[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

4 files changed, 1076 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
+}
diff --git a/test/CodeGen/SystemZ/memset-02.ll b/test/CodeGen/SystemZ/memset-02.ll
new file mode 100644
index 0000000000..c2c45fb4ae
--- /dev/null
+++ b/test/CodeGen/SystemZ/memset-02.ll
@@ -0,0 +1,160 @@
+; Test memset in cases where the set value is a constant other than 0 and -1.
+;
+; 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) {
+; CHECK: f1:
+; CHECK-NOT: %r2
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 128, i32 0, i32 1, i1 false)
+  ret void
+}
+
+; No bytes, i64 version.
+define void @f2(i8 *%dest) {
+; CHECK: f2:
+; CHECK-NOT: %r2
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 128, i64 0, i32 1, i1 false)
+  ret void
+}
+
+; 1 byte, i32 version.
+define void @f3(i8 *%dest) {
+; CHECK: f3:
+; CHECK: mvi 0(%r2), 128
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 128, i32 1, i32 1, i1 false)
+  ret void
+}
+
+; 1 byte, i64 version.
+define void @f4(i8 *%dest) {
+; CHECK: f4:
+; CHECK: mvi 0(%r2), 128
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 128, i64 1, i32 1, i1 false)
+  ret void
+}
+
+; 2 bytes, i32 version.
+define void @f5(i8 *%dest) {
+; CHECK: f5:
+; CHECK: mvhhi 0(%r2), -32640
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 128, i32 2, i32 1, i1 false)
+  ret void
+}
+
+; 2 bytes, i64 version.
+define void @f6(i8 *%dest) {
+; CHECK: f6:
+; CHECK: mvhhi 0(%r2), -32640
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 128, i64 2, i32 1, i1 false)
+  ret void
+}
+
+; 3 bytes, i32 version.
+define void @f7(i8 *%dest) {
+; CHECK: f7:
+; CHECK-DAG: mvhhi 0(%r2), -32640
+; CHECK-DAG: mvi 2(%r2), 128
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 128, i32 3, i32 1, i1 false)
+  ret void
+}
+
+; 3 bytes, i64 version.
+define void @f8(i8 *%dest) {
+; CHECK: f8:
+; CHECK-DAG: mvhhi 0(%r2), -32640
+; CHECK-DAG: mvi 2(%r2), 128
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 128, i64 3, i32 1, i1 false)
+  ret void
+}
+
+; 4 bytes, i32 version.
+define void @f9(i8 *%dest) {
+; CHECK: f9:
+; CHECK: iilf [[REG:%r[0-5]]], 2155905152
+; CHECK: st [[REG]], 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 128, i32 4, i32 1, i1 false)
+  ret void
+}
+
+; 4 bytes, i64 version.
+define void @f10(i8 *%dest) {
+; CHECK: f10:
+; CHECK: iilf [[REG:%r[0-5]]], 2155905152
+; CHECK: st [[REG]], 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 128, i64 4, i32 1, i1 false)
+  ret void
+}
+
+; 5 bytes, i32 version.
+define void @f11(i8 *%dest) {
+; CHECK: f11:
+; CHECK: mvi 0(%r2), 128
+; CHECK: mvc 1(4,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 128, i32 5, i32 1, i1 false)
+  ret void
+}
+
+; 5 bytes, i64 version.
+define void @f12(i8 *%dest) {
+; CHECK: f12:
+; CHECK: mvi 0(%r2), 128
+; CHECK: mvc 1(4,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 128, i64 5, i32 1, i1 false)
+  ret void
+}
+
+; 257 bytes, i32 version.
+define void @f13(i8 *%dest) {
+; CHECK: f13:
+; CHECK: mvi 0(%r2), 128
+; CHECK: mvc 1(256,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 128, i32 257, i32 1, i1 false)
+  ret void
+}
+
+; 257 bytes, i64 version.
+define void @f14(i8 *%dest) {
+; CHECK: f14:
+; CHECK: mvi 0(%r2), 128
+; CHECK: mvc 1(256,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 128, 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 @f15(i8 *%dest) {
+; CHECK: f15:
+; CHECK-NOT: mvc
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 128, i32 258, i32 1, i1 false)
+  ret void
+}
+
+; 258 bytes, i64 version, with the same comments as above.
+define void @f16(i8 *%dest) {
+; CHECK: f16:
+; CHECK-NOT: mvc
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 128, i64 258, i32 1, i1 false)
+  ret void
+}
diff --git a/test/CodeGen/SystemZ/memset-03.ll b/test/CodeGen/SystemZ/memset-03.ll
new file mode 100644
index 0000000000..b18cca4ec4
--- /dev/null
+++ b/test/CodeGen/SystemZ/memset-03.ll
@@ -0,0 +1,396 @@
+; Test memsets that clear all bits.
+;
+; 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) {
+; CHECK: f1:
+; CHECK-NOT: %r2
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 0, i32 1, i1 false)
+  ret void
+}
+
+; No bytes, i64 version.
+define void @f2(i8 *%dest) {
+; CHECK: f2:
+; CHECK-NOT: %r2
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 0, i32 1, i1 false)
+  ret void
+}
+
+; 1 byte, i32 version.
+define void @f3(i8 *%dest) {
+; CHECK: f3:
+; CHECK: mvi 0(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 1, i32 1, i1 false)
+  ret void
+}
+
+; 1 byte, i64 version.
+define void @f4(i8 *%dest) {
+; CHECK: f4:
+; CHECK: mvi 0(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 1, i32 1, i1 false)
+  ret void
+}
+
+; 2 bytes, i32 version.
+define void @f5(i8 *%dest) {
+; CHECK: f5:
+; CHECK: mvhhi 0(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 2, i32 1, i1 false)
+  ret void
+}
+
+; 2 bytes, i64 version.
+define void @f6(i8 *%dest) {
+; CHECK: f6:
+; CHECK: mvhhi 0(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 2, i32 1, i1 false)
+  ret void
+}
+
+; 3 bytes, i32 version.
+define void @f7(i8 *%dest) {
+; CHECK: f7:
+; CHECK-DAG: mvhhi 0(%r2), 0
+; CHECK-DAG: mvi 2(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 3, i32 1, i1 false)
+  ret void
+}
+
+; 3 bytes, i64 version.
+define void @f8(i8 *%dest) {
+; CHECK: f8:
+; CHECK-DAG: mvhhi 0(%r2), 0
+; CHECK-DAG: mvi 2(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 3, i32 1, i1 false)
+  ret void
+}
+
+; 4 bytes, i32 version.
+define void @f9(i8 *%dest) {
+; CHECK: f9:
+; CHECK: mvhi 0(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 4, i32 1, i1 false)
+  ret void
+}
+
+; 4 bytes, i64 version.
+define void @f10(i8 *%dest) {
+; CHECK: f10:
+; CHECK: mvhi 0(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 4, i32 1, i1 false)
+  ret void
+}
+
+; 5 bytes, i32 version.
+define void @f11(i8 *%dest) {
+; CHECK: f11:
+; CHECK-DAG: mvhi 0(%r2), 0
+; CHECK-DAG: mvi 4(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 5, i32 1, i1 false)
+  ret void
+}
+
+; 5 bytes, i64 version.
+define void @f12(i8 *%dest) {
+; CHECK: f12:
+; CHECK-DAG: mvhi 0(%r2), 0
+; CHECK-DAG: mvi 4(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 5, i32 1, i1 false)
+  ret void
+}
+
+; 6 bytes, i32 version.
+define void @f13(i8 *%dest) {
+; CHECK: f13:
+; CHECK-DAG: mvhi 0(%r2), 0
+; CHECK-DAG: mvhhi 4(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 6, i32 1, i1 false)
+  ret void
+}
+
+; 6 bytes, i64 version.
+define void @f14(i8 *%dest) {
+; CHECK: f14:
+; CHECK-DAG: mvhi 0(%r2), 0
+; CHECK-DAG: mvhhi 4(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 6, i32 1, i1 false)
+  ret void
+}
+
+; 7 bytes, i32 version.
+define void @f15(i8 *%dest) {
+; CHECK: f15:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(6,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 7, i32 1, i1 false)
+  ret void
+}
+
+; 7 bytes, i64 version.
+define void @f16(i8 *%dest) {
+; CHECK: f16:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(6,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 7, i32 1, i1 false)
+  ret void
+}
+
+; 8 bytes, i32 version.
+define void @f17(i8 *%dest) {
+; CHECK: f17:
+; CHECK: mvghi 0(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 8, i32 1, i1 false)
+  ret void
+}
+
+; 8 bytes, i64 version.
+define void @f18(i8 *%dest) {
+; CHECK: f18:
+; CHECK: mvghi 0(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 8, i32 1, i1 false)
+  ret void
+}
+
+; 9 bytes, i32 version.
+define void @f19(i8 *%dest) {
+; CHECK: f19:
+; CHECK-DAG: mvghi 0(%r2), 0
+; CHECK-DAG: mvi 8(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 9, i32 1, i1 false)
+  ret void
+}
+
+; 9 bytes, i64 version.
+define void @f20(i8 *%dest) {
+; CHECK: f20:
+; CHECK-DAG: mvghi 0(%r2), 0
+; CHECK-DAG: mvi 8(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 9, i32 1, i1 false)
+  ret void
+}
+
+; 10 bytes, i32 version.
+define void @f21(i8 *%dest) {
+; CHECK: f21:
+; CHECK-DAG: mvghi 0(%r2), 0
+; CHECK-DAG: mvhhi 8(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 10, i32 1, i1 false)
+  ret void
+}
+
+; 10 bytes, i64 version.
+define void @f22(i8 *%dest) {
+; CHECK: f22:
+; CHECK-DAG: mvghi 0(%r2), 0
+; CHECK-DAG: mvhhi 8(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 10, i32 1, i1 false)
+  ret void
+}
+
+; 11 bytes, i32 version.
+define void @f23(i8 *%dest) {
+; CHECK: f23:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(10,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 11, i32 1, i1 false)
+  ret void
+}
+
+; 11 bytes, i64 version.
+define void @f24(i8 *%dest) {
+; CHECK: f24:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(10,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 11, i32 1, i1 false)
+  ret void
+}
+
+; 12 bytes, i32 version.
+define void @f25(i8 *%dest) {
+; CHECK: f25:
+; CHECK-DAG: mvghi 0(%r2), 0
+; CHECK-DAG: mvhi 8(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 12, i32 1, i1 false)
+  ret void
+}
+
+; 12 bytes, i64 version.
+define void @f26(i8 *%dest) {
+; CHECK: f26:
+; CHECK-DAG: mvghi 0(%r2), 0
+; CHECK-DAG: mvhi 8(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 12, i32 1, i1 false)
+  ret void
+}
+
+; 13 bytes, i32 version.
+define void @f27(i8 *%dest) {
+; CHECK: f27:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(12,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 13, i32 1, i1 false)
+  ret void
+}
+
+; 13 bytes, i64 version.
+define void @f28(i8 *%dest) {
+; CHECK: f28:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(12,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 13, i32 1, i1 false)
+  ret void
+}
+
+; 14 bytes, i32 version.
+define void @f29(i8 *%dest) {
+; CHECK: f29:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(13,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 14, i32 1, i1 false)
+  ret void
+}
+
+; 14 bytes, i64 version.
+define void @f30(i8 *%dest) {
+; CHECK: f30:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(13,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 14, i32 1, i1 false)
+  ret void
+}
+
+; 15 bytes, i32 version.
+define void @f31(i8 *%dest) {
+; CHECK: f31:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(14,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 15, i32 1, i1 false)
+  ret void
+}
+
+; 15 bytes, i64 version.
+define void @f32(i8 *%dest) {
+; CHECK: f32:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(14,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 15, i32 1, i1 false)
+  ret void
+}
+
+; 16 bytes, i32 version.
+define void @f33(i8 *%dest) {
+; CHECK: f33:
+; CHECK-DAG: mvghi 0(%r2), 0
+; CHECK-DAG: mvghi 8(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 16, i32 1, i1 false)
+  ret void
+}
+
+; 16 bytes, i64 version.
+define void @f34(i8 *%dest) {
+; CHECK: f34:
+; CHECK-DAG: mvghi 0(%r2), 0
+; CHECK-DAG: mvghi 8(%r2), 0
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 16, i32 1, i1 false)
+  ret void
+}
+
+; 17 bytes, i32 version.
+define void @f35(i8 *%dest) {
+; CHECK: f35:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(16,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 17, i32 1, i1 false)
+  ret void
+}
+
+; 17 bytes, i64 version.
+define void @f36(i8 *%dest) {
+; CHECK: f36:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(16,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 17, i32 1, i1 false)
+  ret void
+}
+
+; 257 bytes, i32 version.
+define void @f37(i8 *%dest) {
+; CHECK: f37:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(256,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 257, i32 1, i1 false)
+  ret void
+}
+
+; 257 bytes, i64 version.
+define void @f38(i8 *%dest) {
+; CHECK: f38:
+; CHECK: mvi 0(%r2), 0
+; CHECK: mvc 1(256,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, 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 @f39(i8 *%dest) {
+; CHECK: f39:
+; CHECK-NOT: mvc
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 0, i32 258, i32 1, i1 false)
+  ret void
+}
+
+; 258 bytes, i64 version, with the same comments as above.
+define void @f40(i8 *%dest) {
+; CHECK: f40:
+; CHECK-NOT: mvc
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 0, i64 258, i32 1, i1 false)
+  ret void
+}
diff --git a/test/CodeGen/SystemZ/memset-04.ll b/test/CodeGen/SystemZ/memset-04.ll
new file mode 100644
index 0000000000..679e21f8fc
--- /dev/null
+++ b/test/CodeGen/SystemZ/memset-04.ll
@@ -0,0 +1,396 @@
+; Test memsets that set all bits.
+;
+; 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) {
+; CHECK: f1:
+; CHECK-NOT: %r2
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 0, i32 1, i1 false)
+  ret void
+}
+
+; No bytes, i64 version.
+define void @f2(i8 *%dest) {
+; CHECK: f2:
+; CHECK-NOT: %r2
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 0, i32 1, i1 false)
+  ret void
+}
+
+; 1 byte, i32 version.
+define void @f3(i8 *%dest) {
+; CHECK: f3:
+; CHECK: mvi 0(%r2), 255
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 1, i32 1, i1 false)
+  ret void
+}
+
+; 1 byte, i64 version.
+define void @f4(i8 *%dest) {
+; CHECK: f4:
+; CHECK: mvi 0(%r2), 255
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 1, i32 1, i1 false)
+  ret void
+}
+
+; 2 bytes, i32 version.
+define void @f5(i8 *%dest) {
+; CHECK: f5:
+; CHECK: mvhhi 0(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 2, i32 1, i1 false)
+  ret void
+}
+
+; 2 bytes, i64 version.
+define void @f6(i8 *%dest) {
+; CHECK: f6:
+; CHECK: mvhhi 0(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 2, i32 1, i1 false)
+  ret void
+}
+
+; 3 bytes, i32 version.
+define void @f7(i8 *%dest) {
+; CHECK: f7:
+; CHECK-DAG: mvhhi 0(%r2), -1
+; CHECK-DAG: mvi 2(%r2), 255
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 3, i32 1, i1 false)
+  ret void
+}
+
+; 3 bytes, i64 version.
+define void @f8(i8 *%dest) {
+; CHECK: f8:
+; CHECK-DAG: mvhhi 0(%r2), -1
+; CHECK-DAG: mvi 2(%r2), 255
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 3, i32 1, i1 false)
+  ret void
+}
+
+; 4 bytes, i32 version.
+define void @f9(i8 *%dest) {
+; CHECK: f9:
+; CHECK: mvhi 0(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 4, i32 1, i1 false)
+  ret void
+}
+
+; 4 bytes, i64 version.
+define void @f10(i8 *%dest) {
+; CHECK: f10:
+; CHECK: mvhi 0(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 4, i32 1, i1 false)
+  ret void
+}
+
+; 5 bytes, i32 version.
+define void @f11(i8 *%dest) {
+; CHECK: f11:
+; CHECK-DAG: mvhi 0(%r2), -1
+; CHECK-DAG: mvi 4(%r2), 255
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 5, i32 1, i1 false)
+  ret void
+}
+
+; 5 bytes, i64 version.
+define void @f12(i8 *%dest) {
+; CHECK: f12:
+; CHECK-DAG: mvhi 0(%r2), -1
+; CHECK-DAG: mvi 4(%r2), 255
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 5, i32 1, i1 false)
+  ret void
+}
+
+; 6 bytes, i32 version.
+define void @f13(i8 *%dest) {
+; CHECK: f13:
+; CHECK-DAG: mvhi 0(%r2), -1
+; CHECK-DAG: mvhhi 4(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 6, i32 1, i1 false)
+  ret void
+}
+
+; 6 bytes, i64 version.
+define void @f14(i8 *%dest) {
+; CHECK: f14:
+; CHECK-DAG: mvhi 0(%r2), -1
+; CHECK-DAG: mvhhi 4(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 6, i32 1, i1 false)
+  ret void
+}
+
+; 7 bytes, i32 version.
+define void @f15(i8 *%dest) {
+; CHECK: f15:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(6,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 7, i32 1, i1 false)
+  ret void
+}
+
+; 7 bytes, i64 version.
+define void @f16(i8 *%dest) {
+; CHECK: f16:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(6,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 7, i32 1, i1 false)
+  ret void
+}
+
+; 8 bytes, i32 version.
+define void @f17(i8 *%dest) {
+; CHECK: f17:
+; CHECK: mvghi 0(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 8, i32 1, i1 false)
+  ret void
+}
+
+; 8 bytes, i64 version.
+define void @f18(i8 *%dest) {
+; CHECK: f18:
+; CHECK: mvghi 0(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 8, i32 1, i1 false)
+  ret void
+}
+
+; 9 bytes, i32 version.
+define void @f19(i8 *%dest) {
+; CHECK: f19:
+; CHECK-DAG: mvghi 0(%r2), -1
+; CHECK-DAG: mvi 8(%r2), 255
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 9, i32 1, i1 false)
+  ret void
+}
+
+; 9 bytes, i64 version.
+define void @f20(i8 *%dest) {
+; CHECK: f20:
+; CHECK-DAG: mvghi 0(%r2), -1
+; CHECK-DAG: mvi 8(%r2), 255
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 9, i32 1, i1 false)
+  ret void
+}
+
+; 10 bytes, i32 version.
+define void @f21(i8 *%dest) {
+; CHECK: f21:
+; CHECK-DAG: mvghi 0(%r2), -1
+; CHECK-DAG: mvhhi 8(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 10, i32 1, i1 false)
+  ret void
+}
+
+; 10 bytes, i64 version.
+define void @f22(i8 *%dest) {
+; CHECK: f22:
+; CHECK-DAG: mvghi 0(%r2), -1
+; CHECK-DAG: mvhhi 8(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 10, i32 1, i1 false)
+  ret void
+}
+
+; 11 bytes, i32 version.
+define void @f23(i8 *%dest) {
+; CHECK: f23:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(10,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 11, i32 1, i1 false)
+  ret void
+}
+
+; 11 bytes, i64 version.
+define void @f24(i8 *%dest) {
+; CHECK: f24:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(10,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 11, i32 1, i1 false)
+  ret void
+}
+
+; 12 bytes, i32 version.
+define void @f25(i8 *%dest) {
+; CHECK: f25:
+; CHECK-DAG: mvghi 0(%r2), -1
+; CHECK-DAG: mvhi 8(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 12, i32 1, i1 false)
+  ret void
+}
+
+; 12 bytes, i64 version.
+define void @f26(i8 *%dest) {
+; CHECK: f26:
+; CHECK-DAG: mvghi 0(%r2), -1
+; CHECK-DAG: mvhi 8(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 12, i32 1, i1 false)
+  ret void
+}
+
+; 13 bytes, i32 version.
+define void @f27(i8 *%dest) {
+; CHECK: f27:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(12,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 13, i32 1, i1 false)
+  ret void
+}
+
+; 13 bytes, i64 version.
+define void @f28(i8 *%dest) {
+; CHECK: f28:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(12,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 13, i32 1, i1 false)
+  ret void
+}
+
+; 14 bytes, i32 version.
+define void @f29(i8 *%dest) {
+; CHECK: f29:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(13,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 14, i32 1, i1 false)
+  ret void
+}
+
+; 14 bytes, i64 version.
+define void @f30(i8 *%dest) {
+; CHECK: f30:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(13,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 14, i32 1, i1 false)
+  ret void
+}
+
+; 15 bytes, i32 version.
+define void @f31(i8 *%dest) {
+; CHECK: f31:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(14,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 15, i32 1, i1 false)
+  ret void
+}
+
+; 15 bytes, i64 version.
+define void @f32(i8 *%dest) {
+; CHECK: f32:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(14,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 15, i32 1, i1 false)
+  ret void
+}
+
+; 16 bytes, i32 version.
+define void @f33(i8 *%dest) {
+; CHECK: f33:
+; CHECK-DAG: mvghi 0(%r2), -1
+; CHECK-DAG: mvghi 8(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 16, i32 1, i1 false)
+  ret void
+}
+
+; 16 bytes, i64 version.
+define void @f34(i8 *%dest) {
+; CHECK: f34:
+; CHECK-DAG: mvghi 0(%r2), -1
+; CHECK-DAG: mvghi 8(%r2), -1
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 16, i32 1, i1 false)
+  ret void
+}
+
+; 17 bytes, i32 version.
+define void @f35(i8 *%dest) {
+; CHECK: f35:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(16,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 17, i32 1, i1 false)
+  ret void
+}
+
+; 17 bytes, i64 version.
+define void @f36(i8 *%dest) {
+; CHECK: f36:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(16,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 17, i32 1, i1 false)
+  ret void
+}
+
+; 257 bytes, i32 version.
+define void @f37(i8 *%dest) {
+; CHECK: f37:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(256,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 257, i32 1, i1 false)
+  ret void
+}
+
+; 257 bytes, i64 version.
+define void @f38(i8 *%dest) {
+; CHECK: f38:
+; CHECK: mvi 0(%r2), 255
+; CHECK: mvc 1(256,%r2), 0(%r2)
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, 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 @f39(i8 *%dest) {
+; CHECK: f39:
+; CHECK-NOT: mvc
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i32(i8 *%dest, i8 -1, i32 258, i32 1, i1 false)
+  ret void
+}
+
+; 258 bytes, i64 version, with the same comments as above.
+define void @f40(i8 *%dest) {
+; CHECK: f40:
+; CHECK-NOT: mvc
+; CHECK: br %r14
+  call void @llvm.memset.p0i8.i64(i8 *%dest, i8 -1, i64 258, i32 1, i1 false)
+  ret void
+}