--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/CodeGen/SystemZ/memcmp-01.ll	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,221 @@
+; Test memcmp using CLC, with i32 results.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+declare signext i32 @memcmp(i8 *%src1, i8 *%src2, i64 %size)
+
+; Zero-length comparisons should be optimized away.
+define i32 @f1(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f1:
+; CHECK: lhi %r2, 0
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 0)
+  ret i32 %res
+}
+
+; Check a case where the result is used as an integer.
+define i32 @f2(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f2:
+; CHECK: clc 0(2,%r2), 0(%r3)
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: srl [[REG]], 28
+; CHECK: rll %r2, [[REG]], 31
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 2)
+  ret i32 %res
+}
+
+; Check a case where the result is tested for equality.
+define void @f3(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f3:
+; CHECK: clc 0(3,%r2), 0(%r3)
+; CHECK-NEXT: je {{\..*}}
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 3)
+  %cmp = icmp eq i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Check a case where the result is tested for inequality.
+define void @f4(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f4:
+; CHECK: clc 0(4,%r2), 0(%r3)
+; CHECK-NEXT: jlh {{\..*}}
+; CHECK: br %r14
+entry:
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 4)
+  %cmp = icmp ne i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Check a case where the result is tested via slt.
+define void @f5(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f5:
+; CHECK: clc 0(5,%r2), 0(%r3)
+; CHECK-NEXT: jl {{\..*}}
+; CHECK: br %r14
+entry:
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 5)
+  %cmp = icmp slt i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Check a case where the result is tested for sgt.
+define void @f6(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f6:
+; CHECK: clc 0(6,%r2), 0(%r3)
+; CHECK-NEXT: jh {{\..*}}
+; CHECK: br %r14
+entry:
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 6)
+  %cmp = icmp sgt i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Check the upper end of the CLC range.  Here the result is used both as
+; an integer and for branching.
+define i32 @f7(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f7:
+; CHECK: clc 0(256,%r2), 0(%r3)
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: srl [[REG]], 28
+; CHECK: rll %r2, [[REG]], 31
+; CHECK: jl {{.L*}}
+; CHECK: br %r14
+entry:
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 256)
+  %cmp = icmp slt i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret i32 %res
+}
+
+; 257 bytes needs two CLCs.
+define i32 @f8(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f8:
+; CHECK: clc 0(256,%r2), 0(%r3)
+; CHECK: jlh [[LABEL:\..*]]
+; CHECK: clc 256(1,%r2), 256(%r3)
+; CHECK: [[LABEL]]:
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 257)
+  ret i32 %res
+}
+
+; Test a comparison of 258 bytes in which the CC result can be used directly.
+define void @f9(i8 *%src1, i8 *%src2, i32 *%dest) {
+; CHECK-LABEL: f9:
+; CHECK: clc 0(256,%r2), 0(%r3)
+; CHECK: jlh [[LABEL:\..*]]
+; CHECK: clc 256(1,%r2), 256(%r3)
+; CHECK: [[LABEL]]:
+; CHECK-NEXT: jl .L
+; CHECK: br %r14
+entry:
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 257)
+  %cmp = icmp slt i32 %res, 0
+  br i1 %cmp, label %exit, label %store
+
+store:
+  store i32 0, i32 *%dest
+  br label %exit
+
+exit:
+  ret void
+}
+
+; Test the largest size that can use two CLCs.
+define i32 @f10(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f10:
+; CHECK: clc 0(256,%r2), 0(%r3)
+; CHECK: jlh [[LABEL:\..*]]
+; CHECK: clc 256(256,%r2), 256(%r3)
+; CHECK: [[LABEL]]:
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 512)
+  ret i32 %res
+}
+
+; Test the smallest size that needs 3 CLCs.
+define i32 @f11(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f11:
+; CHECK: clc 0(256,%r2), 0(%r3)
+; CHECK: jlh [[LABEL:\..*]]
+; CHECK: clc 256(256,%r2), 256(%r3)
+; CHECK: jlh [[LABEL]]
+; CHECK: clc 512(1,%r2), 512(%r3)
+; CHECK: [[LABEL]]:
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 513)
+  ret i32 %res
+}
+
+; Test the largest size than can use 3 CLCs.
+define i32 @f12(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f12:
+; CHECK: clc 0(256,%r2), 0(%r3)
+; CHECK: jlh [[LABEL:\..*]]
+; CHECK: clc 256(256,%r2), 256(%r3)
+; CHECK: jlh [[LABEL]]
+; CHECK: clc 512(256,%r2), 512(%r3)
+; CHECK: [[LABEL]]:
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 768)
+  ret i32 %res
+}
+
+; The next size up uses a loop instead.  We leave the more complicated
+; loop tests to memcpy-01.ll, which shares the same form.
+define i32 @f13(i8 *%src1, i8 *%src2) {
+; CHECK-LABEL: f13:
+; CHECK: lghi [[COUNT:%r[0-5]]], 3
+; CHECK: [[LOOP:.L[^:]*]]:
+; CHECK: clc 0(256,%r2), 0(%r3)
+; CHECK: jlh [[LABEL:\..*]]
+; CHECK-DAG: la %r2, 256(%r2)
+; CHECK-DAG: la %r3, 256(%r3)
+; CHECK: brctg [[COUNT]], [[LOOP]]
+; CHECK: clc 0(1,%r2), 0(%r3)
+; CHECK: [[LABEL]]:
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: br %r14
+  %res = call i32 @memcmp(i8 *%src1, i8 *%src2, i64 769)
+  ret i32 %res
+}