1 files changed, 94 insertions, 0 deletions
diff --git a/test/CodeGen/AArch64/machine-copy-remove.ll b/test/CodeGen/AArch64/machine-copy-remove.ll
new file mode 100644
index 0000000000000..75954f83c19c8
--- /dev/null
+++ b/test/CodeGen/AArch64/machine-copy-remove.ll
@@ -0,0 +1,94 @@
+; RUN: llc -mtriple=aarch64-linux-gnu -mcpu=cortex-a57 -verify-machineinstrs < %s | FileCheck %s
+
+; CHECK-LABEL: f_XX:
+; CHECK: cbz x[[REG:[0-9]+]], [[BB:.LBB.*]]
+; CHECK: [[BB]]:
+; CHECK-NOT: mov x[[REG]], xzr
+define i64 @f_XX(i64 %n, i64* nocapture readonly %P) {
+entry:
+  %tobool = icmp eq i64 %n, 0
+  br i1 %tobool, label %if.end, label %if.then
+
+if.then:                                          ; preds = %entry
+  %0 = load i64, i64* %P
+  br label %if.end
+
+if.end:                                           ; preds = %entry, %if.then
+  %a.0 = phi i64 [ %0, %if.then ], [ 0, %entry ]
+  ret i64 %a.0
+}
+
+; CHECK-LABEL: f_WW:
+; CHECK: cbz w[[REG:[0-9]+]], [[BB:.LBB.*]]
+; CHECK: [[BB]]:
+; CHECK-NOT: mov w[[REG]], wzr
+define i32 @f_WW(i32 %n, i32* nocapture readonly %P) {
+entry:
+  %tobool = icmp eq i32 %n, 0
+  br i1 %tobool, label %if.end, label %if.then
+
+if.then:                                          ; preds = %entry
+  %0 = load i32, i32* %P
+  br label %if.end
+
+if.end:                                           ; preds = %entry, %if.then
+  %a.0 = phi i32 [ %0, %if.then ], [ 0, %entry ]
+  ret i32 %a.0
+}
+
+; CHECK-LABEL: f_XW:
+; CHECK: cbz x[[REG:[0-9]+]], [[BB:.LBB.*]]
+; CHECK: [[BB]]:
+; CHECK-NOT: mov w[[REG]], wzr
+define i32 @f_XW(i64 %n, i32* nocapture readonly %P) {
+entry:
+  %tobool = icmp eq i64 %n, 0
+  br i1 %tobool, label %if.end, label %if.then
+
+if.then:                                          ; preds = %entry
+  %0 = load i32, i32* %P
+  br label %if.end
+
+if.end:                                           ; preds = %entry, %if.then
+  %a.0 = phi i32 [ %0, %if.then ], [ 0, %entry ]
+  ret i32 %a.0
+}
+
+; CHECK-LABEL: f_WX:
+; CHECK: cbz w[[REG:[0-9]+]], [[BB:.LBB.*]]
+; CHECK: [[BB]]:
+; CHECK: mov x[[REG]], xzr
+; Do not remove the mov in this case because we do not know if the upper bits
+; of the X register are zero.
+define i64 @f_WX(i32 %n, i64* nocapture readonly %P) {
+entry:
+  %tobool = icmp eq i32 %n, 0
+  br i1 %tobool, label %if.end, label %if.then
+
+if.then:                                          ; preds = %entry
+  %0 = load i64, i64* %P
+  br label %if.end
+
+if.end:                                           ; preds = %entry, %if.then
+  %a.0 = phi i64 [ %0, %if.then ], [ 0, %entry ]
+  ret i64 %a.0
+}
+
+; CHECK-LABEL: test_superreg:
+; CHECK:     cbz x[[REG:[0-9]+]], [[BB:.LBB.*]]
+; CHECK: [[BB]]:
+; CHECK:     str x[[REG]], [x1]
+; CHECK-NOT: mov w[[REG]], wzr
+; Because we returned w0 but x0 was marked live-in to the block, we didn't
+; remove the <kill> on the str leading to a verification failure.
+define i32 @test_superreg(i64 %in, i64* %dest) {
+  %tst = icmp eq i64 %in, 0
+  br i1 %tst, label %true, label %false
+
+false:
+  ret i32 42
+
+true:
+  store volatile i64 %in, i64* %dest
+  ret i32 0
+}