1 files changed, 76 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/SystemZ/frame-21.ll b/llvm/test/CodeGen/SystemZ/frame-21.ll
new file mode 100644
index 00000000000..360740028a9
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/frame-21.ll
@@ -0,0 +1,76 @@
+; Test the allocation of emergency spill slots.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+; For frames of size less than 4096 - 2*160, no emercengy spill slot
+; is required.  Check the maximum such case.
+define void @f1(i64 %x) {
+; CHECK-LABEL: f1:
+; CHECK: stg %r2, 160(%r15)
+; CHECK: br %r14
+  %y = alloca [471 x i64], align 8
+  %ptr = getelementptr inbounds [471 x i64], [471 x i64]* %y, i64 0, i64 0
+  store volatile i64 %x, i64* %ptr
+  ret void
+}
+
+; If the frame size is at least 4096 - 2*160, we do need the emergency
+; spill slots.  Check the minimum such case.
+define void @f2(i64 %x) {
+; CHECK-LABEL: f2:
+; CHECK: stg %r2, 176(%r15)
+; CHECK: br %r14
+  %y = alloca [472 x i64], align 8
+  %ptr = getelementptr inbounds [472 x i64], [472 x i64]* %y, i64 0, i64 0
+  store volatile i64 %x, i64* %ptr
+  ret void
+}
+
+; However, if there are incoming stack arguments, those also need to be
+; in reach, so the maximum frame size without emergency spill slots is
+; 4096 - 2*160 - <size of incoming stack arguments>.  Check the maximum
+; case where we still need no emergency spill slots ...
+define void @f3(i64 %x, i64 %r3, i64 %r4, i64 %r5, i64 %r6, i64 %stack) {
+; CHECK-LABEL: f3:
+; CHECK: stg %r2, 160(%r15)
+; CHECK: br %r14
+  %y = alloca [470 x i64], align 8
+  %ptr = getelementptr inbounds [470 x i64], [470 x i64]* %y, i64 0, i64 0
+  store volatile i64 %x, i64* %ptr
+  ret void
+}
+
+; ... and the minimum case where we do.
+define void @f4(i64 %x, i64 %r3, i64 %r4, i64 %r5, i64 %r6, i64 %stack) {
+; CHECK-LABEL: f4:
+; CHECK: stg %r2, 176(%r15)
+; CHECK: br %r14
+  %y = alloca [471 x i64], align 8
+  %ptr = getelementptr inbounds [471 x i64], [471 x i64]* %y, i64 0, i64 0
+  store volatile i64 %x, i64* %ptr
+  ret void
+}
+
+; Try again for the case of two stack arguments.
+; Check the maximum case where we still need no emergency spill slots ...
+define void @f5(i64 %x, i64 %r3, i64 %r4, i64 %r5, i64 %r6, i64 %stack1, i64 %stack2) {
+; CHECK-LABEL: f5:
+; CHECK: stg %r2, 160(%r15)
+; CHECK: br %r14
+  %y = alloca [469 x i64], align 8
+  %ptr = getelementptr inbounds [469 x i64], [469 x i64]* %y, i64 0, i64 0
+  store volatile i64 %x, i64* %ptr
+  ret void
+}
+
+; ... and the minimum case where we do.
+define void @f6(i64 %x, i64 %r3, i64 %r4, i64 %r5, i64 %r6, i64 %stack1, i64 %stack2) {
+; CHECK-LABEL: f6:
+; CHECK: stg %r2, 176(%r15)
+; CHECK: br %r14
+  %y = alloca [470 x i64], align 8
+  %ptr = getelementptr inbounds [470 x i64], [470 x i64]* %y, i64 0, i64 0
+  store volatile i64 %x, i64* %ptr
+  ret void
+}
+