1 files changed, 82 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/SystemZ/int-usub-06.ll b/llvm/test/CodeGen/SystemZ/int-usub-06.ll
new file mode 100644
index 00000000000..d7d47889f9e
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/int-usub-06.ll
@@ -0,0 +1,82 @@
+; Test the three-operand form of 32-bit subtraction.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z196 | FileCheck %s
+
+declare i32 @foo(i32, i32, i32)
+
+; Check SLRK.
+define i32 @f1(i32 %dummy, i32 %a, i32 %b, i32 *%flag) {
+; CHECK-LABEL: f1:
+; CHECK: slrk %r2, %r3, %r4
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: afi [[REG]], -536870912
+; CHECK: srl [[REG]], 31
+; CHECK: st [[REG]], 0(%r5)
+; CHECK: br %r14
+  %t = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
+  %val = extractvalue {i32, i1} %t, 0
+  %obit = extractvalue {i32, i1} %t, 1
+  %ext = zext i1 %obit to i32
+  store i32 %ext, i32 *%flag
+  ret i32 %val
+}
+
+; Check using the overflow result for a branch.
+define i32 @f2(i32 %dummy, i32 %a, i32 %b) {
+; CHECK-LABEL: f2:
+; CHECK: slrk %r2, %r3, %r4
+; CHECK-NEXT: bnler %r14
+; CHECK: lhi %r2, 0
+; CHECK: jg foo@PLT
+  %t = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
+  %val = extractvalue {i32, i1} %t, 0
+  %obit = extractvalue {i32, i1} %t, 1
+  br i1 %obit, label %call, label %exit
+
+call:
+  %res = tail call i32 @foo(i32 0, i32 %a, i32 %b)
+  ret i32 %res
+
+exit:
+  ret i32 %val
+}
+
+; ... and the same with the inverted direction.
+define i32 @f3(i32 %dummy, i32 %a, i32 %b) {
+; CHECK-LABEL: f3:
+; CHECK: slrk %r2, %r3, %r4
+; CHECK-NEXT: bler %r14
+; CHECK: lhi %r2, 0
+; CHECK: jg foo@PLT
+  %t = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
+  %val = extractvalue {i32, i1} %t, 0
+  %obit = extractvalue {i32, i1} %t, 1
+  br i1 %obit, label %exit, label %call
+
+call:
+  %res = tail call i32 @foo(i32 0, i32 %a, i32 %b)
+  ret i32 %res
+
+exit:
+  ret i32 %val
+}
+
+; Check that we can still use SLR in obvious cases.
+define i32 @f4(i32 %a, i32 %b, i32 *%flag) {
+; CHECK-LABEL: f4:
+; CHECK: slr %r2, %r3
+; CHECK: ipm [[REG:%r[0-5]]]
+; CHECK: afi [[REG]], -536870912
+; CHECK: srl [[REG]], 31
+; CHECK: st [[REG]], 0(%r4)
+; CHECK: br %r14
+  %t = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
+  %val = extractvalue {i32, i1} %t, 0
+  %obit = extractvalue {i32, i1} %t, 1
+  %ext = zext i1 %obit to i32
+  store i32 %ext, i32 *%flag
+  ret i32 %val
+}
+
+declare {i32, i1} @llvm.usub.with.overflow.i32(i32, i32) nounwind readnone
+