1 files changed, 98 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/SystemZ/int-usub-04.ll b/llvm/test/CodeGen/SystemZ/int-usub-04.ll
new file mode 100644
index 00000000000..d704f62f501
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/int-usub-04.ll
@@ -0,0 +1,98 @@
+; Test 32-bit subtraction in which the second operand is constant.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+declare i32 @foo()
+
+; Check subtraction of 1.
+define zeroext i1 @f1(i32 %dummy, i32 %a, i32 *%res) {
+; CHECK-LABEL: f1:
+; CHECK: slfi %r3, 1
+; CHECK-DAG: st %r3, 0(%r4)
+; CHECK-DAG: ipm [[REG:%r[0-5]]]
+; CHECK-DAG: afi [[REG]], -536870912
+; CHECK-DAG: risbg %r2, [[REG]], 63, 191, 33
+; CHECK: br %r14
+  %t = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 1)
+  %val = extractvalue {i32, i1} %t, 0
+  %obit = extractvalue {i32, i1} %t, 1
+  store i32 %val, i32 *%res
+  ret i1 %obit
+}
+
+; Check the high end of the SLFI range.
+define zeroext i1 @f2(i32 %dummy, i32 %a, i32 *%res) {
+; CHECK-LABEL: f2:
+; CHECK: slfi %r3, 4294967295
+; CHECK-DAG: st %r3, 0(%r4)
+; CHECK-DAG: ipm [[REG:%r[0-5]]]
+; CHECK-DAG: afi [[REG]], -536870912
+; CHECK-DAG: risbg %r2, [[REG]], 63, 191, 33
+; CHECK: br %r14
+  %t = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 4294967295)
+  %val = extractvalue {i32, i1} %t, 0
+  %obit = extractvalue {i32, i1} %t, 1
+  store i32 %val, i32 *%res
+  ret i1 %obit
+}
+
+; Check that negative values are treated as unsigned
+define zeroext i1 @f3(i32 %dummy, i32 %a, i32 *%res) {
+; CHECK-LABEL: f3:
+; CHECK: slfi %r3, 4294967295
+; CHECK-DAG: st %r3, 0(%r4)
+; CHECK-DAG: ipm [[REG:%r[0-5]]]
+; CHECK-DAG: afi [[REG]], -536870912
+; CHECK-DAG: risbg %r2, [[REG]], 63, 191, 33
+; CHECK: br %r14
+  %t = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 -1)
+  %val = extractvalue {i32, i1} %t, 0
+  %obit = extractvalue {i32, i1} %t, 1
+  store i32 %val, i32 *%res
+  ret i1 %obit
+}
+
+; Check using the overflow result for a branch.
+define void @f4(i32 %dummy, i32 %a, i32 *%res) {
+; CHECK-LABEL: f4:
+; CHECK: slfi %r3, 1
+; CHECK: st %r3, 0(%r4)
+; CHECK: jgle foo@PLT
+; CHECK: br %r14
+  %t = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 1)
+  %val = extractvalue {i32, i1} %t, 0
+  %obit = extractvalue {i32, i1} %t, 1
+  store i32 %val, i32 *%res
+  br i1 %obit, label %call, label %exit
+
+call:
+  tail call i32 @foo()
+  br label %exit
+
+exit:
+  ret void
+}
+
+; ... and the same with the inverted direction.
+define void @f5(i32 %dummy, i32 %a, i32 *%res) {
+; CHECK-LABEL: f5:
+; CHECK: slfi %r3, 1
+; CHECK: st %r3, 0(%r4)
+; CHECK: jgnle foo@PLT
+; CHECK: br %r14
+  %t = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 1)
+  %val = extractvalue {i32, i1} %t, 0
+  %obit = extractvalue {i32, i1} %t, 1
+  store i32 %val, i32 *%res
+  br i1 %obit, label %exit, label %call
+
+call:
+  tail call i32 @foo()
+  br label %exit
+
+exit:
+  ret void
+}
+
+declare {i32, i1} @llvm.usub.with.overflow.i32(i32, i32) nounwind readnone
+