Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 309 insertions, 0 deletions

diff --git a/tests/mir-opt/nll/named_lifetimes_basic.rs b/tests/mir-opt/nll/named_lifetimes_basic.rs
new file mode 100644
index 000000000..843716033
--- /dev/null
+++ b/tests/mir-opt/nll/named_lifetimes_basic.rs
@@ -0,0 +1,15 @@
+// Basic test for named lifetime translation. Check that we
+// instantiate the types that appear in function arguments with
+// suitable variables and that we setup the outlives relationship
+// between R0 and R1 properly.
+
+// compile-flags: -Zverbose
+//                ^^^^^^^^^ force compiler to dump more region information
+
+#![allow(warnings)]
+
+// EMIT_MIR named_lifetimes_basic.use_x.nll.0.mir
+fn use_x<'a, 'b: 'a, 'c>(w: &'a mut i32, x: &'b u32, y: &'a u32, z: &'c u32) -> bool { true }
+
+fn main() {
+}
diff --git a/tests/mir-opt/nll/named_lifetimes_basic.use_x.nll.0.mir b/tests/mir-opt/nll/named_lifetimes_basic.use_x.nll.0.mir
new file mode 100644
index 000000000..6cd6d8b77
--- /dev/null
+++ b/tests/mir-opt/nll/named_lifetimes_basic.use_x.nll.0.mir
@@ -0,0 +1,47 @@
+// MIR for `use_x` 0 nll
+
+| Free Region Mapping
+| '_#0r | Global | ['_#2r, '_#1r, '_#0r, '_#4r, '_#3r]
+| '_#1r | Local | ['_#1r, '_#4r]
+| '_#2r | Local | ['_#2r, '_#1r, '_#4r]
+| '_#3r | Local | ['_#4r, '_#3r]
+| '_#4r | Local | ['_#4r]
+|
+| Inferred Region Values
+| '_#0r | U0 | {bb0[0..=1], '_#0r, '_#1r, '_#2r, '_#3r, '_#4r}
+| '_#1r | U0 | {bb0[0..=1], '_#1r}
+| '_#2r | U0 | {bb0[0..=1], '_#2r}
+| '_#3r | U0 | {bb0[0..=1], '_#3r}
+| '_#4r | U0 | {bb0[0..=1], '_#4r}
+| '_#5r | U0 | {bb0[0..=1], '_#1r}
+| '_#6r | U0 | {bb0[0..=1], '_#2r}
+| '_#7r | U0 | {bb0[0..=1], '_#1r}
+| '_#8r | U0 | {bb0[0..=1], '_#3r}
+|
+| Inference Constraints
+| '_#0r live at {bb0[0..=1]}
+| '_#1r live at {bb0[0..=1]}
+| '_#2r live at {bb0[0..=1]}
+| '_#3r live at {bb0[0..=1]}
+| '_#4r live at {bb0[0..=1]}
+| '_#1r: '_#5r due to BoringNoLocation at All($DIR/named_lifetimes_basic.rs:12:26: 12:27) ($DIR/named_lifetimes_basic.rs:12:26: 12:27 (#0)
+| '_#1r: '_#7r due to BoringNoLocation at All($DIR/named_lifetimes_basic.rs:12:54: 12:55) ($DIR/named_lifetimes_basic.rs:12:54: 12:55 (#0)
+| '_#2r: '_#6r due to BoringNoLocation at All($DIR/named_lifetimes_basic.rs:12:42: 12:43) ($DIR/named_lifetimes_basic.rs:12:42: 12:43 (#0)
+| '_#3r: '_#8r due to BoringNoLocation at All($DIR/named_lifetimes_basic.rs:12:66: 12:67) ($DIR/named_lifetimes_basic.rs:12:66: 12:67 (#0)
+| '_#5r: '_#1r due to BoringNoLocation at All($DIR/named_lifetimes_basic.rs:12:26: 12:27) ($DIR/named_lifetimes_basic.rs:12:26: 12:27 (#0)
+| '_#6r: '_#2r due to BoringNoLocation at All($DIR/named_lifetimes_basic.rs:12:42: 12:43) ($DIR/named_lifetimes_basic.rs:12:42: 12:43 (#0)
+| '_#7r: '_#1r due to BoringNoLocation at All($DIR/named_lifetimes_basic.rs:12:54: 12:55) ($DIR/named_lifetimes_basic.rs:12:54: 12:55 (#0)
+| '_#8r: '_#3r due to BoringNoLocation at All($DIR/named_lifetimes_basic.rs:12:66: 12:67) ($DIR/named_lifetimes_basic.rs:12:66: 12:67 (#0)
+|
+fn use_x(_1: &'_#5r mut i32, _2: &'_#6r u32, _3: &'_#7r u32, _4: &'_#8r u32) -> bool {
+    debug w => _1;                       // in scope 0 at $DIR/named_lifetimes_basic.rs:+0:26: +0:27
+    debug x => _2;                       // in scope 0 at $DIR/named_lifetimes_basic.rs:+0:42: +0:43
+    debug y => _3;                       // in scope 0 at $DIR/named_lifetimes_basic.rs:+0:54: +0:55
+    debug z => _4;                       // in scope 0 at $DIR/named_lifetimes_basic.rs:+0:66: +0:67
+    let mut _0: bool;                    // return place in scope 0 at $DIR/named_lifetimes_basic.rs:+0:81: +0:85
+
+    bb0: {
+        _0 = const ConstValue(Scalar(0x01): bool); // bb0[0]: scope 0 at $DIR/named_lifetimes_basic.rs:+0:88: +0:92
+        return;                          // bb0[1]: scope 0 at $DIR/named_lifetimes_basic.rs:+0:94: +0:94
+    }
+}
diff --git a/tests/mir-opt/nll/region_subtyping_basic.main.nll.0.32bit.mir b/tests/mir-opt/nll/region_subtyping_basic.main.nll.0.32bit.mir
new file mode 100644
index 000000000..798e45df8
--- /dev/null
+++ b/tests/mir-opt/nll/region_subtyping_basic.main.nll.0.32bit.mir
@@ -0,0 +1,111 @@
+// MIR for `main` 0 nll
+
+| Free Region Mapping
+| '_#0r | Global | ['_#0r, '_#1r]
+| '_#1r | Local | ['_#1r]
+|
+| Inferred Region Values
+| '_#0r | U0 | {bb0[0..=8], bb1[0..=7], bb2[0..=3], bb3[0..=3], bb4[0..=1], bb5[0..=2], bb6[0..=5], bb7[0], '_#0r, '_#1r}
+| '_#1r | U0 | {bb0[0..=8], bb1[0..=7], bb2[0..=3], bb3[0..=3], bb4[0..=1], bb5[0..=2], bb6[0..=5], bb7[0], '_#1r}
+| '_#2r | U0 | {bb1[0..=7], bb2[0..=2]}
+| '_#3r | U0 | {bb1[1..=7], bb2[0..=2]}
+| '_#4r | U0 | {bb1[4..=7], bb2[0..=2]}
+|
+| Inference Constraints
+| '_#0r live at {bb0[0..=8], bb1[0..=7], bb2[0..=3], bb3[0..=3], bb4[0..=1], bb5[0..=2], bb6[0..=5], bb7[0]}
+| '_#1r live at {bb0[0..=8], bb1[0..=7], bb2[0..=3], bb3[0..=3], bb4[0..=1], bb5[0..=2], bb6[0..=5], bb7[0]}
+| '_#2r live at {bb1[0]}
+| '_#3r live at {bb1[1..=3]}
+| '_#4r live at {bb1[4..=7], bb2[0..=2]}
+| '_#2r: '_#3r due to Assignment at Single(bb1[0]) ($DIR/region_subtyping_basic.rs:18:13: 18:18 (#0)
+| '_#3r: '_#4r due to Assignment at Single(bb1[3]) ($DIR/region_subtyping_basic.rs:19:13: 19:14 (#0)
+|
+fn main() -> () {
+    let mut _0: ();                      // return place in scope 0 at $DIR/region_subtyping_basic.rs:+0:11: +0:11
+    let mut _1: [usize; Const(Value(Leaf(0x00000003)): usize)]; // in scope 0 at $DIR/region_subtyping_basic.rs:+1:9: +1:14
+    let _3: usize;                       // in scope 0 at $DIR/region_subtyping_basic.rs:+2:16: +2:17
+    let mut _4: usize;                   // in scope 0 at $DIR/region_subtyping_basic.rs:+2:14: +2:18
+    let mut _5: bool;                    // in scope 0 at $DIR/region_subtyping_basic.rs:+2:14: +2:18
+    let mut _7: bool;                    // in scope 0 at $DIR/region_subtyping_basic.rs:+4:8: +4:12
+    let _8: bool;                        // in scope 0 at $DIR/region_subtyping_basic.rs:+5:9: +5:18
+    let mut _9: usize;                   // in scope 0 at $DIR/region_subtyping_basic.rs:+5:15: +5:17
+    let _10: bool;                       // in scope 0 at $DIR/region_subtyping_basic.rs:+7:9: +7:18
+    scope 1 {
+        debug v => _1;                   // in scope 1 at $DIR/region_subtyping_basic.rs:+1:9: +1:14
+        let _2: &'_#3r usize;            // in scope 1 at $DIR/region_subtyping_basic.rs:+2:9: +2:10
+        scope 2 {
+            debug p => _2;               // in scope 2 at $DIR/region_subtyping_basic.rs:+2:9: +2:10
+            let _6: &'_#4r usize;        // in scope 2 at $DIR/region_subtyping_basic.rs:+3:9: +3:10
+            scope 3 {
+                debug q => _6;           // in scope 3 at $DIR/region_subtyping_basic.rs:+3:9: +3:10
+            }
+        }
+    }
+
+    bb0: {
+        StorageLive(_1);                 // bb0[0]: scope 0 at $DIR/region_subtyping_basic.rs:+1:9: +1:14
+        _1 = [const ConstValue(Scalar(0x00000001): usize), const ConstValue(Scalar(0x00000002): usize), const ConstValue(Scalar(0x00000003): usize)]; // bb0[1]: scope 0 at $DIR/region_subtyping_basic.rs:+1:17: +1:26
+        FakeRead(ForLet(None), _1);      // bb0[2]: scope 0 at $DIR/region_subtyping_basic.rs:+1:9: +1:14
+        StorageLive(_2);                 // bb0[3]: scope 1 at $DIR/region_subtyping_basic.rs:+2:9: +2:10
+        StorageLive(_3);                 // bb0[4]: scope 1 at $DIR/region_subtyping_basic.rs:+2:16: +2:17
+        _3 = const ConstValue(Scalar(0x00000000): usize); // bb0[5]: scope 1 at $DIR/region_subtyping_basic.rs:+2:16: +2:17
+        _4 = Len(_1);                    // bb0[6]: scope 1 at $DIR/region_subtyping_basic.rs:+2:14: +2:18
+        _5 = Lt(_3, _4);                 // bb0[7]: scope 1 at $DIR/region_subtyping_basic.rs:+2:14: +2:18
+        assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind: bb7]; // bb0[8]: scope 1 at $DIR/region_subtyping_basic.rs:+2:14: +2:18
+    }
+
+    bb1: {
+        _2 = &'_#2r _1[_3];              // bb1[0]: scope 1 at $DIR/region_subtyping_basic.rs:+2:13: +2:18
+        FakeRead(ForLet(None), _2);      // bb1[1]: scope 1 at $DIR/region_subtyping_basic.rs:+2:9: +2:10
+        StorageLive(_6);                 // bb1[2]: scope 2 at $DIR/region_subtyping_basic.rs:+3:9: +3:10
+        _6 = _2;                         // bb1[3]: scope 2 at $DIR/region_subtyping_basic.rs:+3:13: +3:14
+        FakeRead(ForLet(None), _6);      // bb1[4]: scope 2 at $DIR/region_subtyping_basic.rs:+3:9: +3:10
+        StorageLive(_7);                 // bb1[5]: scope 3 at $DIR/region_subtyping_basic.rs:+4:8: +4:12
+        _7 = const ConstValue(Scalar(0x01): bool); // bb1[6]: scope 3 at $DIR/region_subtyping_basic.rs:+4:8: +4:12
+        switchInt(move _7) -> [0: bb4, otherwise: bb2]; // bb1[7]: scope 3 at $DIR/region_subtyping_basic.rs:+4:8: +4:12
+    }
+
+    bb2: {
+        StorageLive(_8);                 // bb2[0]: scope 3 at $DIR/region_subtyping_basic.rs:+5:9: +5:18
+        StorageLive(_9);                 // bb2[1]: scope 3 at $DIR/region_subtyping_basic.rs:+5:15: +5:17
+        _9 = (*_6);                      // bb2[2]: scope 3 at $DIR/region_subtyping_basic.rs:+5:15: +5:17
+        _8 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(move _9) -> [return: bb3, unwind: bb7]; // bb2[3]: scope 3 at $DIR/region_subtyping_basic.rs:+5:9: +5:18
+                                         // mir::Constant
+                                         // + span: $DIR/region_subtyping_basic.rs:21:9: 21:14
+                                         // + literal: Const { ty: fn(usize) -> bool {use_x}, val: Value(<ZST>) }
+    }
+
+    bb3: {
+        StorageDead(_9);                 // bb3[0]: scope 3 at $DIR/region_subtyping_basic.rs:+5:17: +5:18
+        StorageDead(_8);                 // bb3[1]: scope 3 at $DIR/region_subtyping_basic.rs:+5:18: +5:19
+        _0 = const ConstValue(ZeroSized: ()); // bb3[2]: scope 3 at $DIR/region_subtyping_basic.rs:+4:13: +6:6
+        goto -> bb6;                     // bb3[3]: scope 3 at $DIR/region_subtyping_basic.rs:+4:5: +8:6
+    }
+
+    bb4: {
+        StorageLive(_10);                // bb4[0]: scope 3 at $DIR/region_subtyping_basic.rs:+7:9: +7:18
+        _10 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(const ConstValue(Scalar(0x00000016): usize)) -> [return: bb5, unwind: bb7]; // bb4[1]: scope 3 at $DIR/region_subtyping_basic.rs:+7:9: +7:18
+                                         // mir::Constant
+                                         // + span: $DIR/region_subtyping_basic.rs:23:9: 23:14
+                                         // + literal: Const { ty: fn(usize) -> bool {use_x}, val: Value(<ZST>) }
+    }
+
+    bb5: {
+        StorageDead(_10);                // bb5[0]: scope 3 at $DIR/region_subtyping_basic.rs:+7:18: +7:19
+        _0 = const ConstValue(ZeroSized: ()); // bb5[1]: scope 3 at $DIR/region_subtyping_basic.rs:+6:12: +8:6
+        goto -> bb6;                     // bb5[2]: scope 3 at $DIR/region_subtyping_basic.rs:+4:5: +8:6
+    }
+
+    bb6: {
+        StorageDead(_7);                 // bb6[0]: scope 3 at $DIR/region_subtyping_basic.rs:+8:5: +8:6
+        StorageDead(_6);                 // bb6[1]: scope 2 at $DIR/region_subtyping_basic.rs:+9:1: +9:2
+        StorageDead(_3);                 // bb6[2]: scope 1 at $DIR/region_subtyping_basic.rs:+9:1: +9:2
+        StorageDead(_2);                 // bb6[3]: scope 1 at $DIR/region_subtyping_basic.rs:+9:1: +9:2
+        StorageDead(_1);                 // bb6[4]: scope 0 at $DIR/region_subtyping_basic.rs:+9:1: +9:2
+        return;                          // bb6[5]: scope 0 at $DIR/region_subtyping_basic.rs:+9:2: +9:2
+    }
+
+    bb7 (cleanup): {
+        resume;                          // bb7[0]: scope 0 at $DIR/region_subtyping_basic.rs:+0:1: +9:2
+    }
+}
diff --git a/tests/mir-opt/nll/region_subtyping_basic.main.nll.0.64bit.mir b/tests/mir-opt/nll/region_subtyping_basic.main.nll.0.64bit.mir
new file mode 100644
index 000000000..4767bfc76
--- /dev/null
+++ b/tests/mir-opt/nll/region_subtyping_basic.main.nll.0.64bit.mir
@@ -0,0 +1,111 @@
+// MIR for `main` 0 nll
+
+| Free Region Mapping
+| '_#0r | Global | ['_#0r, '_#1r]
+| '_#1r | Local | ['_#1r]
+|
+| Inferred Region Values
+| '_#0r | U0 | {bb0[0..=8], bb1[0..=7], bb2[0..=3], bb3[0..=3], bb4[0..=1], bb5[0..=2], bb6[0..=5], bb7[0], '_#0r, '_#1r}
+| '_#1r | U0 | {bb0[0..=8], bb1[0..=7], bb2[0..=3], bb3[0..=3], bb4[0..=1], bb5[0..=2], bb6[0..=5], bb7[0], '_#1r}
+| '_#2r | U0 | {bb1[0..=7], bb2[0..=2]}
+| '_#3r | U0 | {bb1[1..=7], bb2[0..=2]}
+| '_#4r | U0 | {bb1[4..=7], bb2[0..=2]}
+|
+| Inference Constraints
+| '_#0r live at {bb0[0..=8], bb1[0..=7], bb2[0..=3], bb3[0..=3], bb4[0..=1], bb5[0..=2], bb6[0..=5], bb7[0]}
+| '_#1r live at {bb0[0..=8], bb1[0..=7], bb2[0..=3], bb3[0..=3], bb4[0..=1], bb5[0..=2], bb6[0..=5], bb7[0]}
+| '_#2r live at {bb1[0]}
+| '_#3r live at {bb1[1..=3]}
+| '_#4r live at {bb1[4..=7], bb2[0..=2]}
+| '_#2r: '_#3r due to Assignment at Single(bb1[0]) ($DIR/region_subtyping_basic.rs:18:13: 18:18 (#0)
+| '_#3r: '_#4r due to Assignment at Single(bb1[3]) ($DIR/region_subtyping_basic.rs:19:13: 19:14 (#0)
+|
+fn main() -> () {
+    let mut _0: ();                      // return place in scope 0 at $DIR/region_subtyping_basic.rs:+0:11: +0:11
+    let mut _1: [usize; Const(Value(Leaf(0x0000000000000003)): usize)]; // in scope 0 at $DIR/region_subtyping_basic.rs:+1:9: +1:14
+    let _3: usize;                       // in scope 0 at $DIR/region_subtyping_basic.rs:+2:16: +2:17
+    let mut _4: usize;                   // in scope 0 at $DIR/region_subtyping_basic.rs:+2:14: +2:18
+    let mut _5: bool;                    // in scope 0 at $DIR/region_subtyping_basic.rs:+2:14: +2:18
+    let mut _7: bool;                    // in scope 0 at $DIR/region_subtyping_basic.rs:+4:8: +4:12
+    let _8: bool;                        // in scope 0 at $DIR/region_subtyping_basic.rs:+5:9: +5:18
+    let mut _9: usize;                   // in scope 0 at $DIR/region_subtyping_basic.rs:+5:15: +5:17
+    let _10: bool;                       // in scope 0 at $DIR/region_subtyping_basic.rs:+7:9: +7:18
+    scope 1 {
+        debug v => _1;                   // in scope 1 at $DIR/region_subtyping_basic.rs:+1:9: +1:14
+        let _2: &'_#3r usize;            // in scope 1 at $DIR/region_subtyping_basic.rs:+2:9: +2:10
+        scope 2 {
+            debug p => _2;               // in scope 2 at $DIR/region_subtyping_basic.rs:+2:9: +2:10
+            let _6: &'_#4r usize;        // in scope 2 at $DIR/region_subtyping_basic.rs:+3:9: +3:10
+            scope 3 {
+                debug q => _6;           // in scope 3 at $DIR/region_subtyping_basic.rs:+3:9: +3:10
+            }
+        }
+    }
+
+    bb0: {
+        StorageLive(_1);                 // bb0[0]: scope 0 at $DIR/region_subtyping_basic.rs:+1:9: +1:14
+        _1 = [const ConstValue(Scalar(0x0000000000000001): usize), const ConstValue(Scalar(0x0000000000000002): usize), const ConstValue(Scalar(0x0000000000000003): usize)]; // bb0[1]: scope 0 at $DIR/region_subtyping_basic.rs:+1:17: +1:26
+        FakeRead(ForLet(None), _1);      // bb0[2]: scope 0 at $DIR/region_subtyping_basic.rs:+1:9: +1:14
+        StorageLive(_2);                 // bb0[3]: scope 1 at $DIR/region_subtyping_basic.rs:+2:9: +2:10
+        StorageLive(_3);                 // bb0[4]: scope 1 at $DIR/region_subtyping_basic.rs:+2:16: +2:17
+        _3 = const ConstValue(Scalar(0x0000000000000000): usize); // bb0[5]: scope 1 at $DIR/region_subtyping_basic.rs:+2:16: +2:17
+        _4 = Len(_1);                    // bb0[6]: scope 1 at $DIR/region_subtyping_basic.rs:+2:14: +2:18
+        _5 = Lt(_3, _4);                 // bb0[7]: scope 1 at $DIR/region_subtyping_basic.rs:+2:14: +2:18
+        assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind: bb7]; // bb0[8]: scope 1 at $DIR/region_subtyping_basic.rs:+2:14: +2:18
+    }
+
+    bb1: {
+        _2 = &'_#2r _1[_3];              // bb1[0]: scope 1 at $DIR/region_subtyping_basic.rs:+2:13: +2:18
+        FakeRead(ForLet(None), _2);      // bb1[1]: scope 1 at $DIR/region_subtyping_basic.rs:+2:9: +2:10
+        StorageLive(_6);                 // bb1[2]: scope 2 at $DIR/region_subtyping_basic.rs:+3:9: +3:10
+        _6 = _2;                         // bb1[3]: scope 2 at $DIR/region_subtyping_basic.rs:+3:13: +3:14
+        FakeRead(ForLet(None), _6);      // bb1[4]: scope 2 at $DIR/region_subtyping_basic.rs:+3:9: +3:10
+        StorageLive(_7);                 // bb1[5]: scope 3 at $DIR/region_subtyping_basic.rs:+4:8: +4:12
+        _7 = const ConstValue(Scalar(0x01): bool); // bb1[6]: scope 3 at $DIR/region_subtyping_basic.rs:+4:8: +4:12
+        switchInt(move _7) -> [0: bb4, otherwise: bb2]; // bb1[7]: scope 3 at $DIR/region_subtyping_basic.rs:+4:8: +4:12
+    }
+
+    bb2: {
+        StorageLive(_8);                 // bb2[0]: scope 3 at $DIR/region_subtyping_basic.rs:+5:9: +5:18
+        StorageLive(_9);                 // bb2[1]: scope 3 at $DIR/region_subtyping_basic.rs:+5:15: +5:17
+        _9 = (*_6);                      // bb2[2]: scope 3 at $DIR/region_subtyping_basic.rs:+5:15: +5:17
+        _8 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(move _9) -> [return: bb3, unwind: bb7]; // bb2[3]: scope 3 at $DIR/region_subtyping_basic.rs:+5:9: +5:18
+                                         // mir::Constant
+                                         // + span: $DIR/region_subtyping_basic.rs:21:9: 21:14
+                                         // + literal: Const { ty: fn(usize) -> bool {use_x}, val: Value(<ZST>) }
+    }
+
+    bb3: {
+        StorageDead(_9);                 // bb3[0]: scope 3 at $DIR/region_subtyping_basic.rs:+5:17: +5:18
+        StorageDead(_8);                 // bb3[1]: scope 3 at $DIR/region_subtyping_basic.rs:+5:18: +5:19
+        _0 = const ConstValue(ZeroSized: ()); // bb3[2]: scope 3 at $DIR/region_subtyping_basic.rs:+4:13: +6:6
+        goto -> bb6;                     // bb3[3]: scope 3 at $DIR/region_subtyping_basic.rs:+4:5: +8:6
+    }
+
+    bb4: {
+        StorageLive(_10);                // bb4[0]: scope 3 at $DIR/region_subtyping_basic.rs:+7:9: +7:18
+        _10 = ConstValue(ZeroSized: fn(usize) -> bool {use_x})(const ConstValue(Scalar(0x0000000000000016): usize)) -> [return: bb5, unwind: bb7]; // bb4[1]: scope 3 at $DIR/region_subtyping_basic.rs:+7:9: +7:18
+                                         // mir::Constant
+                                         // + span: $DIR/region_subtyping_basic.rs:23:9: 23:14
+                                         // + literal: Const { ty: fn(usize) -> bool {use_x}, val: Value(<ZST>) }
+    }
+
+    bb5: {
+        StorageDead(_10);                // bb5[0]: scope 3 at $DIR/region_subtyping_basic.rs:+7:18: +7:19
+        _0 = const ConstValue(ZeroSized: ()); // bb5[1]: scope 3 at $DIR/region_subtyping_basic.rs:+6:12: +8:6
+        goto -> bb6;                     // bb5[2]: scope 3 at $DIR/region_subtyping_basic.rs:+4:5: +8:6
+    }
+
+    bb6: {
+        StorageDead(_7);                 // bb6[0]: scope 3 at $DIR/region_subtyping_basic.rs:+8:5: +8:6
+        StorageDead(_6);                 // bb6[1]: scope 2 at $DIR/region_subtyping_basic.rs:+9:1: +9:2
+        StorageDead(_3);                 // bb6[2]: scope 1 at $DIR/region_subtyping_basic.rs:+9:1: +9:2
+        StorageDead(_2);                 // bb6[3]: scope 1 at $DIR/region_subtyping_basic.rs:+9:1: +9:2
+        StorageDead(_1);                 // bb6[4]: scope 0 at $DIR/region_subtyping_basic.rs:+9:1: +9:2
+        return;                          // bb6[5]: scope 0 at $DIR/region_subtyping_basic.rs:+9:2: +9:2
+    }
+
+    bb7 (cleanup): {
+        resume;                          // bb7[0]: scope 0 at $DIR/region_subtyping_basic.rs:+0:1: +9:2
+    }
+}
diff --git a/tests/mir-opt/nll/region_subtyping_basic.rs b/tests/mir-opt/nll/region_subtyping_basic.rs
new file mode 100644
index 000000000..64332f302
--- /dev/null
+++ b/tests/mir-opt/nll/region_subtyping_basic.rs
@@ -0,0 +1,25 @@
+// Basic test for liveness constraints: the region (`R1`) that appears
+// in the type of `p` includes the points after `&v[0]` up to (but not
+// including) the call to `use_x`. The `else` branch is not included.
+
+// compile-flags:-Zverbose
+//               ^^^^^^^^^ force compiler to dump more region information
+
+#![allow(warnings)]
+
+fn use_x(_: usize) -> bool {
+    true
+}
+
+// EMIT_MIR_FOR_EACH_BIT_WIDTH
+// EMIT_MIR region_subtyping_basic.main.nll.0.mir
+fn main() {
+    let mut v = [1, 2, 3];
+    let p = &v[0];
+    let q = p;
+    if true {
+        use_x(*q);
+    } else {
+        use_x(22);
+    }
+}