1 files changed, 116 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/SystemZ/int-usub-05.ll b/llvm/test/CodeGen/SystemZ/int-usub-05.ll
new file mode 100644
index 00000000000..ffa1e90c843
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/int-usub-05.ll
@@ -0,0 +1,116 @@
+; Test 64-bit subtraction in which the second operand is constant.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+
+declare i64 @foo()
+
+; Check addition of 1.
+define zeroext i1 @f1(i64 %dummy, i64 %a, i64 *%res) {
+; CHECK-LABEL: f1:
+; CHECK: slgfi %r3, 1
+; CHECK-DAG: stg %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 {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 1)
+  %val = extractvalue {i64, i1} %t, 0
+  %obit = extractvalue {i64, i1} %t, 1
+  store i64 %val, i64 *%res
+  ret i1 %obit
+}
+
+; Check the high end of the SLGFI range.
+define zeroext i1 @f2(i64 %dummy, i64 %a, i64 *%res) {
+; CHECK-LABEL: f2:
+; CHECK: slgfi %r3, 4294967295
+; CHECK-DAG: stg %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 {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 4294967295)
+  %val = extractvalue {i64, i1} %t, 0
+  %obit = extractvalue {i64, i1} %t, 1
+  store i64 %val, i64 *%res
+  ret i1 %obit
+}
+
+; Check the next value up, which must be loaded into a register first.
+define zeroext i1 @f3(i64 %dummy, i64 %a, i64 *%res) {
+; CHECK-LABEL: f3:
+; CHECK: llihl [[REG1:%r[0-9]+]], 1
+; CHECK: slgr %r3, [[REG1]]
+; CHECK-DAG: stg %r3, 0(%r4)
+; CHECK-DAG: ipm [[REG2:%r[0-5]]]
+; CHECK-DAG: afi [[REG]], -536870912
+; CHECK-DAG: risbg %r2, [[REG2]], 63, 191, 33
+; CHECK: br %r14
+  %t = call {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 4294967296)
+  %val = extractvalue {i64, i1} %t, 0
+  %obit = extractvalue {i64, i1} %t, 1
+  store i64 %val, i64 *%res
+  ret i1 %obit
+}
+
+; Likewise for negative values.
+define zeroext i1 @f4(i64 %dummy, i64 %a, i64 *%res) {
+; CHECK-LABEL: f4:
+; CHECK: lghi [[REG1:%r[0-9]+]], -1
+; CHECK: slgr %r3, [[REG1]]
+; CHECK-DAG: stg %r3, 0(%r4)
+; CHECK-DAG: ipm [[REG2:%r[0-5]]]
+; CHECK-DAG: afi [[REG]], -536870912
+; CHECK-DAG: risbg %r2, [[REG2]], 63, 191, 33
+; CHECK: br %r14
+  %t = call {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 -1)
+  %val = extractvalue {i64, i1} %t, 0
+  %obit = extractvalue {i64, i1} %t, 1
+  store i64 %val, i64 *%res
+  ret i1 %obit
+}
+
+; Check using the overflow result for a branch.
+define void @f5(i64 %dummy, i64 %a, i64 *%res) {
+; CHECK-LABEL: f5:
+; CHECK: slgfi %r3, 1
+; CHECK: stg %r3, 0(%r4)
+; CHECK: jgle foo@PLT
+; CHECK: br %r14
+  %t = call {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 1)
+  %val = extractvalue {i64, i1} %t, 0
+  %obit = extractvalue {i64, i1} %t, 1
+  store i64 %val, i64 *%res
+  br i1 %obit, label %call, label %exit
+
+call:
+  tail call i64 @foo()
+  br label %exit
+
+exit:
+  ret void
+}
+
+; ... and the same with the inverted direction.
+define void @f6(i64 %dummy, i64 %a, i64 *%res) {
+; CHECK-LABEL: f6:
+; CHECK: slgfi %r3, 1
+; CHECK: stg %r3, 0(%r4)
+; CHECK: jgnle foo@PLT
+; CHECK: br %r14
+  %t = call {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 1)
+  %val = extractvalue {i64, i1} %t, 0
+  %obit = extractvalue {i64, i1} %t, 1
+  store i64 %val, i64 *%res
+  br i1 %obit, label %exit, label %call
+
+call:
+  tail call i64 @foo()
+  br label %exit
+
+exit:
+  ret void
+}
+
+declare {i64, i1} @llvm.usub.with.overflow.i64(i64, i64) nounwind readnone
+