[SystemZ] Add CodeGen test cases

This adds all CodeGen tests for the SystemZ target.

This version of the patch incorporates feedback from a review by
Sean Silva.  Thanks to all reviewers!

Patch by Richard Sandiford.

llvm-svn: 181204
diff --git a/llvm/test/CodeGen/SystemZ/int-conv-09.ll b/llvm/test/CodeGen/SystemZ/int-conv-09.ll
new file mode 100644
index 0000000..6e93886
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/int-conv-09.ll
@@ -0,0 +1,104 @@
+; Test sign extensions from an i32 to an i64.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+; Test register extension, starting with an i32.
+define i64 @f1(i32 %a) {
+; CHECK: f1:
+; CHECK: lgfr %r2, %r2
+; CHECk: br %r14
+  %ext = sext i32 %a to i64
+  ret i64 %ext
+}
+
+; ...and again with an i64.
+define i64 @f2(i64 %a) {
+; CHECK: f2:
+; CHECK: lgfr %r2, %r2
+; CHECk: br %r14
+  %word = trunc i64 %a to i32
+  %ext = sext i32 %word to i64
+  ret i64 %ext
+}
+
+; Check LGF with no displacement.
+define i64 @f3(i32 *%src) {
+; CHECK: f3:
+; CHECK: lgf %r2, 0(%r2)
+; CHECK: br %r14
+  %word = load i32 *%src
+  %ext = sext i32 %word to i64
+  ret i64 %ext
+}
+
+; Check the high end of the LGF range.
+define i64 @f4(i32 *%src) {
+; CHECK: f4:
+; CHECK: lgf %r2, 524284(%r2)
+; CHECK: br %r14
+  %ptr = getelementptr i32 *%src, i64 131071
+  %word = load i32 *%ptr
+  %ext = sext i32 %word to i64
+  ret i64 %ext
+}
+
+; Check the next word up, which needs separate address logic.
+; Other sequences besides this one would be OK.
+define i64 @f5(i32 *%src) {
+; CHECK: f5:
+; CHECK: agfi %r2, 524288
+; CHECK: lgf %r2, 0(%r2)
+; CHECK: br %r14
+  %ptr = getelementptr i32 *%src, i64 131072
+  %word = load i32 *%ptr
+  %ext = sext i32 %word to i64
+  ret i64 %ext
+}
+
+; Check the high end of the negative LGF range.
+define i64 @f6(i32 *%src) {
+; CHECK: f6:
+; CHECK: lgf %r2, -4(%r2)
+; CHECK: br %r14
+  %ptr = getelementptr i32 *%src, i64 -1
+  %word = load i32 *%ptr
+  %ext = sext i32 %word to i64
+  ret i64 %ext
+}
+
+; Check the low end of the LGF range.
+define i64 @f7(i32 *%src) {
+; CHECK: f7:
+; CHECK: lgf %r2, -524288(%r2)
+; CHECK: br %r14
+  %ptr = getelementptr i32 *%src, i64 -131072
+  %word = load i32 *%ptr
+  %ext = sext i32 %word to i64
+  ret i64 %ext
+}
+
+; Check the next word down, which needs separate address logic.
+; Other sequences besides this one would be OK.
+define i64 @f8(i32 *%src) {
+; CHECK: f8:
+; CHECK: agfi %r2, -524292
+; CHECK: lgf %r2, 0(%r2)
+; CHECK: br %r14
+  %ptr = getelementptr i32 *%src, i64 -131073
+  %word = load i32 *%ptr
+  %ext = sext i32 %word to i64
+  ret i64 %ext
+}
+
+; Check that LGF allows an index.
+define i64 @f9(i64 %src, i64 %index) {
+; CHECK: f9:
+; CHECK: lgf %r2, 524287(%r3,%r2)
+; CHECK: br %r14
+  %add1 = add i64 %src, %index
+  %add2 = add i64 %add1, 524287
+  %ptr = inttoptr i64 %add2 to i32 *
+  %word = load i32 *%ptr
+  %ext = sext i32 %word to i64
+  ret i64 %ext
+}