Do not unify dereferences in GVN.

compiler/rustc_mir_transform/src/gvn.rs

@@ -638,7 +638,9 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
         let proj = match proj {
             ProjectionElem::Deref => {
                 let ty = place.ty(self.local_decls, self.tcx).ty;
-                if let Some(Mutability::Not) = ty.ref_mutability()
+                // unsound: https://github.com/rust-lang/rust/issues/130853
+                if self.tcx.sess.opts.unstable_opts.unsound_mir_opts
+                    && let Some(Mutability::Not) = ty.ref_mutability()
                     && let Some(pointee_ty) = ty.builtin_deref(true)
                     && pointee_ty.is_freeze(self.tcx, self.typing_env())
                 {

tests/mir-opt/const_prop/read_immutable_static.main.GVN.diff

@@ -14,23 +14,19 @@
   
       bb0: {
           StorageLive(_1);
--         StorageLive(_2);
+          StorageLive(_2);
 -         StorageLive(_3);
-+         nop;
 +         nop;
           _3 = const {ALLOC0: &u8};
--         _2 = copy (*_3);
+          _2 = copy (*_3);
-+         _2 = const 2_u8;
           StorageLive(_4);
           StorageLive(_5);
           _5 = const {ALLOC0: &u8};
 -         _4 = copy (*_5);
--         _1 = Add(move _2, move _4);
++         _4 = copy (*_3);
-+         _4 = const 2_u8;
+          _1 = Add(move _2, move _4);
-+         _1 = const 4_u8;
           StorageDead(_4);
--         StorageDead(_2);
+          StorageDead(_2);
-+         nop;
           StorageDead(_5);
 -         StorageDead(_3);
 +         nop;

tests/mir-opt/const_prop/read_immutable_static.rs

@@ -6,6 +6,6 @@ static FOO: u8 = 2;
 fn main() {
     // CHECK-LABEL: fn main(
     // CHECK: debug x => [[x:_.*]];
-    // CHECK: [[x]] = const 4_u8;
+    // CHECK-NOT: [[x]] = const 4_u8;
     let x = FOO + FOO;
 }

tests/mir-opt/const_prop/ref_deref.main.GVN.diff

@@ -16,8 +16,7 @@
           StorageLive(_2);
           _4 = const main::promoted[0];
           _2 = &(*_4);
--         _1 = copy (*_2);
+          _1 = copy (*_2);
-+         _1 = const 4_i32;
           StorageDead(_2);
           _0 = const ();
           StorageDead(_1);

tests/mir-opt/const_prop/ref_deref_project.main.GVN.diff

@@ -16,8 +16,7 @@
           StorageLive(_2);
           _4 = const main::promoted[0];
           _2 = &((*_4).1: i32);
--         _1 = copy (*_2);
+          _1 = copy (*_2);
-+         _1 = const 5_i32;
           StorageDead(_2);
           _0 = const ();
           StorageDead(_1);

tests/mir-opt/const_prop/ref_deref_project.rs

@@ -5,6 +5,6 @@
 fn main() {
     // CHECK-LABEL: fn main(
     // CHECK: debug a => [[a:_.*]];
-    // CHECK: [[a]] = const 5_i32;
+    // CHECK-NOT: [[a]] = const 5_i32;
     let a = *(&(4, 5).1);
 }

tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-abort.diff

@@ -30,17 +30,16 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
--         _7 = Len((*_2));
+          _7 = Len((*_2));
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind unreachable];
-+         _7 = const 3_usize;
++         _8 = Lt(const 1_usize, copy _7);
-+         _8 = const true;
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind unreachable];
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind unreachable];
       }
   
       bb1: {
 -         _1 = copy (*_2)[_6];
-+         _1 = const 2_u32;
++         _1 = copy (*_2)[1 of 2];
           StorageDead(_6);
           StorageDead(_4);
           StorageDead(_2);

tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-unwind.diff

@@ -30,17 +30,16 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
--         _7 = Len((*_2));
+          _7 = Len((*_2));
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind continue];
-+         _7 = const 3_usize;
++         _8 = Lt(const 1_usize, copy _7);
-+         _8 = const true;
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind continue];
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind continue];
       }
   
       bb1: {
 -         _1 = copy (*_2)[_6];
-+         _1 = const 2_u32;
++         _1 = copy (*_2)[1 of 2];
           StorageDead(_6);
           StorageDead(_4);
           StorageDead(_2);

tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-abort.diff

@@ -30,17 +30,16 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
--         _7 = Len((*_2));
+          _7 = Len((*_2));
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind unreachable];
-+         _7 = const 3_usize;
++         _8 = Lt(const 1_usize, copy _7);
-+         _8 = const true;
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind unreachable];
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind unreachable];
       }
   
       bb1: {
 -         _1 = copy (*_2)[_6];
-+         _1 = const 2_u32;
++         _1 = copy (*_2)[1 of 2];
           StorageDead(_6);
           StorageDead(_4);
           StorageDead(_2);

tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-unwind.diff

@@ -30,17 +30,16 @@
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
--         _7 = Len((*_2));
+          _7 = Len((*_2));
 -         _8 = Lt(copy _6, copy _7);
 -         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, copy _6) -> [success: bb1, unwind continue];
-+         _7 = const 3_usize;
++         _8 = Lt(const 1_usize, copy _7);
-+         _8 = const true;
++         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, const 1_usize) -> [success: bb1, unwind continue];
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 3_usize, const 1_usize) -> [success: bb1, unwind continue];
       }
   
       bb1: {
 -         _1 = copy (*_2)[_6];
-+         _1 = const 2_u32;
++         _1 = copy (*_2)[1 of 2];
           StorageDead(_6);
           StorageDead(_4);
           StorageDead(_2);

tests/mir-opt/const_prop/slice_len.rs

@@ -8,7 +8,7 @@ fn main() {
     // CHECK-LABEL: fn main(
     // CHECK: debug a => [[a:_.*]];
     // CHECK: [[slice:_.*]] = copy {{.*}} as &[u32] (PointerCoercion(Unsize, AsCast));
-    // CHECK: assert(const true,
+    // CHECK-NOT: assert(const true,
-    // CHECK: [[a]] = const 2_u32;
+    // CHECK-NOT: [[a]] = const 2_u32;
     let a = (&[1u32, 2, 3] as &[u32])[1];
 }

tests/mir-opt/gvn.borrowed.GVN.panic-abort.diff

@@ -18,8 +18,7 @@
       }
   
       bb2: {
--         _0 = opaque::<T>(copy (*_3)) -> [return: bb3, unwind unreachable];
+          _0 = opaque::<T>(copy (*_3)) -> [return: bb3, unwind unreachable];
-+         _0 = opaque::<T>(copy _1) -> [return: bb3, unwind unreachable];
       }
   
       bb3: {

tests/mir-opt/gvn.borrowed.GVN.panic-unwind.diff

@@ -18,8 +18,7 @@
       }
   
       bb2: {
--         _0 = opaque::<T>(copy (*_3)) -> [return: bb3, unwind continue];
+          _0 = opaque::<T>(copy (*_3)) -> [return: bb3, unwind continue];
-+         _0 = opaque::<T>(copy _1) -> [return: bb3, unwind continue];
       }
   
       bb3: {

tests/mir-opt/gvn.dereferences.GVN.panic-abort.diff

@@ -107,23 +107,18 @@
           StorageLive(_18);
           _18 = &(*_1);
           StorageLive(_19);
--         StorageLive(_20);
+          StorageLive(_20);
-+         nop;
           _20 = copy (*_18);
--         _19 = opaque::<u32>(move _20) -> [return: bb7, unwind unreachable];
+          _19 = opaque::<u32>(move _20) -> [return: bb7, unwind unreachable];
-+         _19 = opaque::<u32>(copy _20) -> [return: bb7, unwind unreachable];
       }
   
       bb7: {
--         StorageDead(_20);
+          StorageDead(_20);
-+         nop;
           StorageDead(_19);
           StorageLive(_21);
           StorageLive(_22);
--         _22 = copy (*_18);
+          _22 = copy (*_18);
--         _21 = opaque::<u32>(move _22) -> [return: bb8, unwind unreachable];
+          _21 = opaque::<u32>(move _22) -> [return: bb8, unwind unreachable];
-+         _22 = copy _20;
-+         _21 = opaque::<u32>(copy _20) -> [return: bb8, unwind unreachable];
       }
   
       bb8: {
@@ -157,23 +152,18 @@
           StorageDead(_28);
           StorageDead(_27);
           StorageLive(_29);
--         StorageLive(_30);
+          StorageLive(_30);
-+         nop;
           _30 = copy ((*_3).0: u32);
--         _29 = opaque::<u32>(move _30) -> [return: bb12, unwind unreachable];
+          _29 = opaque::<u32>(move _30) -> [return: bb12, unwind unreachable];
-+         _29 = opaque::<u32>(copy _30) -> [return: bb12, unwind unreachable];
       }
   
       bb12: {
--         StorageDead(_30);
+          StorageDead(_30);
-+         nop;
           StorageDead(_29);
           StorageLive(_31);
           StorageLive(_32);
--         _32 = copy ((*_3).0: u32);
+          _32 = copy ((*_3).0: u32);
--         _31 = opaque::<u32>(move _32) -> [return: bb13, unwind unreachable];
+          _31 = opaque::<u32>(move _32) -> [return: bb13, unwind unreachable];
-+         _32 = copy _30;
-+         _31 = opaque::<u32>(copy _30) -> [return: bb13, unwind unreachable];
       }
   
       bb13: {

tests/mir-opt/gvn.dereferences.GVN.panic-unwind.diff

@@ -107,23 +107,18 @@
           StorageLive(_18);
           _18 = &(*_1);
           StorageLive(_19);
--         StorageLive(_20);
+          StorageLive(_20);
-+         nop;
           _20 = copy (*_18);
--         _19 = opaque::<u32>(move _20) -> [return: bb7, unwind continue];
+          _19 = opaque::<u32>(move _20) -> [return: bb7, unwind continue];
-+         _19 = opaque::<u32>(copy _20) -> [return: bb7, unwind continue];
       }
   
       bb7: {
--         StorageDead(_20);
+          StorageDead(_20);
-+         nop;
           StorageDead(_19);
           StorageLive(_21);
           StorageLive(_22);
--         _22 = copy (*_18);
+          _22 = copy (*_18);
--         _21 = opaque::<u32>(move _22) -> [return: bb8, unwind continue];
+          _21 = opaque::<u32>(move _22) -> [return: bb8, unwind continue];
-+         _22 = copy _20;
-+         _21 = opaque::<u32>(copy _20) -> [return: bb8, unwind continue];
       }
   
       bb8: {
@@ -157,23 +152,18 @@
           StorageDead(_28);
           StorageDead(_27);
           StorageLive(_29);
--         StorageLive(_30);
+          StorageLive(_30);
-+         nop;
           _30 = copy ((*_3).0: u32);
--         _29 = opaque::<u32>(move _30) -> [return: bb12, unwind continue];
+          _29 = opaque::<u32>(move _30) -> [return: bb12, unwind continue];
-+         _29 = opaque::<u32>(copy _30) -> [return: bb12, unwind continue];
       }
   
       bb12: {
--         StorageDead(_30);
+          StorageDead(_30);
-+         nop;
           StorageDead(_29);
           StorageLive(_31);
           StorageLive(_32);
--         _32 = copy ((*_3).0: u32);
+          _32 = copy ((*_3).0: u32);
--         _31 = opaque::<u32>(move _32) -> [return: bb13, unwind continue];
+          _31 = opaque::<u32>(move _32) -> [return: bb13, unwind continue];
-+         _32 = copy _30;
-+         _31 = opaque::<u32>(copy _30) -> [return: bb13, unwind continue];
       }
   
       bb13: {

tests/mir-opt/gvn.fn_pointers.GVN.panic-abort.diff

@@ -8,10 +8,10 @@
       let mut _3: fn(u8) -> u8;
       let _5: ();
       let mut _6: fn(u8) -> u8;
-      let mut _9: {closure@$DIR/gvn.rs:614:19: 614:21};
+      let mut _9: {closure@$DIR/gvn.rs:620:19: 620:21};
       let _10: ();
       let mut _11: fn();
-      let mut _13: {closure@$DIR/gvn.rs:614:19: 614:21};
+      let mut _13: {closure@$DIR/gvn.rs:620:19: 620:21};
       let _14: ();
       let mut _15: fn();
       scope 1 {
@@ -19,7 +19,7 @@
           let _4: fn(u8) -> u8;
           scope 2 {
               debug g => _4;
-              let _7: {closure@$DIR/gvn.rs:614:19: 614:21};
+              let _7: {closure@$DIR/gvn.rs:620:19: 620:21};
               scope 3 {
                   debug closure => _7;
                   let _8: fn();
@@ -62,16 +62,16 @@
           StorageDead(_6);
           StorageDead(_5);
 -         StorageLive(_7);
--         _7 = {closure@$DIR/gvn.rs:614:19: 614:21};
+-         _7 = {closure@$DIR/gvn.rs:620:19: 620:21};
 -         StorageLive(_8);
 +         nop;
-+         _7 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21};
++         _7 = const ZeroSized: {closure@$DIR/gvn.rs:620:19: 620:21};
 +         nop;
           StorageLive(_9);
 -         _9 = copy _7;
 -         _8 = move _9 as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
-+         _9 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21};
++         _9 = const ZeroSized: {closure@$DIR/gvn.rs:620:19: 620:21};
-+         _8 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
++         _8 = const ZeroSized: {closure@$DIR/gvn.rs:620:19: 620:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
           StorageDead(_9);
           StorageLive(_10);
           StorageLive(_11);
@@ -88,8 +88,8 @@
           StorageLive(_13);
 -         _13 = copy _7;
 -         _12 = move _13 as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
-+         _13 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21};
++         _13 = const ZeroSized: {closure@$DIR/gvn.rs:620:19: 620:21};
-+         _12 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
++         _12 = const ZeroSized: {closure@$DIR/gvn.rs:620:19: 620:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
           StorageDead(_13);
           StorageLive(_14);
           StorageLive(_15);

tests/mir-opt/gvn.fn_pointers.GVN.panic-unwind.diff

@@ -8,10 +8,10 @@
       let mut _3: fn(u8) -> u8;
       let _5: ();
       let mut _6: fn(u8) -> u8;
-      let mut _9: {closure@$DIR/gvn.rs:614:19: 614:21};
+      let mut _9: {closure@$DIR/gvn.rs:620:19: 620:21};
       let _10: ();
       let mut _11: fn();
-      let mut _13: {closure@$DIR/gvn.rs:614:19: 614:21};
+      let mut _13: {closure@$DIR/gvn.rs:620:19: 620:21};
       let _14: ();
       let mut _15: fn();
       scope 1 {
@@ -19,7 +19,7 @@
           let _4: fn(u8) -> u8;
           scope 2 {
               debug g => _4;
-              let _7: {closure@$DIR/gvn.rs:614:19: 614:21};
+              let _7: {closure@$DIR/gvn.rs:620:19: 620:21};
               scope 3 {
                   debug closure => _7;
                   let _8: fn();
@@ -62,16 +62,16 @@
           StorageDead(_6);
           StorageDead(_5);
 -         StorageLive(_7);
--         _7 = {closure@$DIR/gvn.rs:614:19: 614:21};
+-         _7 = {closure@$DIR/gvn.rs:620:19: 620:21};
 -         StorageLive(_8);
 +         nop;
-+         _7 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21};
++         _7 = const ZeroSized: {closure@$DIR/gvn.rs:620:19: 620:21};
 +         nop;
           StorageLive(_9);
 -         _9 = copy _7;
 -         _8 = move _9 as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
-+         _9 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21};
++         _9 = const ZeroSized: {closure@$DIR/gvn.rs:620:19: 620:21};
-+         _8 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
++         _8 = const ZeroSized: {closure@$DIR/gvn.rs:620:19: 620:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
           StorageDead(_9);
           StorageLive(_10);
           StorageLive(_11);
@@ -88,8 +88,8 @@
           StorageLive(_13);
 -         _13 = copy _7;
 -         _12 = move _13 as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
-+         _13 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21};
++         _13 = const ZeroSized: {closure@$DIR/gvn.rs:620:19: 620:21};
-+         _12 = const ZeroSized: {closure@$DIR/gvn.rs:614:19: 614:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
++         _12 = const ZeroSized: {closure@$DIR/gvn.rs:620:19: 620:21} as fn() (PointerCoercion(ClosureFnPointer(Safe), AsCast));
           StorageDead(_13);
           StorageLive(_14);
           StorageLive(_15);

tests/mir-opt/gvn.rs

@@ -99,12 +99,14 @@ fn subexpression_elimination(x: u64, y: u64, mut z: u64) {
     opaque((x * y) - y);
     opaque((x * y) - y);
 
-    // We can substitute through an immutable reference too.
+    // We cannot substitute through an immutable reference.
     // CHECK: [[ref:_.*]] = &_3;
     // CHECK: [[deref:_.*]] = copy (*[[ref]]);
-    // CHECK: [[addref:_.*]] = Add(copy [[deref]], copy _1);
+    // CHECK: [[addref:_.*]] = Add(move [[deref]], copy _1);
-    // CHECK: opaque::<u64>(copy [[addref]])
+    // CHECK: opaque::<u64>(move [[addref]])
-    // CHECK: opaque::<u64>(copy [[addref]])
+    // CHECK: [[deref2:_.*]] = copy (*[[ref]]);
+    // CHECK: [[addref2:_.*]] = Add(move [[deref2]], copy _1);
+    // CHECK: opaque::<u64>(move [[addref2]])
     let a = &z;
     opaque(*a + x);
     opaque(*a + x);
@@ -137,13 +139,15 @@ fn subexpression_elimination(x: u64, y: u64, mut z: u64) {
         opaque(*d + x);
     }
 
-    // We can substitute again, but not with the earlier computations.
+    // We still cannot substitute again, and never with the earlier computations.
     // Important: `e` is not `a`!
     // CHECK: [[ref2:_.*]] = &_3;
     // CHECK: [[deref2:_.*]] = copy (*[[ref2]]);
-    // CHECK: [[addref2:_.*]] = Add(copy [[deref2]], copy _1);
+    // CHECK: [[addref2:_.*]] = Add(move [[deref2]], copy _1);
-    // CHECK: opaque::<u64>(copy [[addref2]])
+    // CHECK: opaque::<u64>(move [[addref2]])
-    // CHECK: opaque::<u64>(copy [[addref2]])
+    // CHECK: [[deref3:_.*]] = copy (*[[ref2]]);
+    // CHECK: [[addref3:_.*]] = Add(move [[deref3]], copy _1);
+    // CHECK: opaque::<u64>(move [[addref3]])
     let e = &z;
     opaque(*e + x);
     opaque(*e + x);
@@ -495,15 +499,16 @@ fn dereferences(t: &mut u32, u: &impl Copy, s: &S<u32>) {
     unsafe { opaque(*z) };
     unsafe { opaque(*z) };
 
-    // We can reuse dereferences of `&Freeze`.
+    // Do not reuse dereferences of `&Freeze`.
     // CHECK: [[ref:_.*]] = &(*_1);
     // CHECK: [[st7:_.*]] = copy (*[[ref]]);
-    // CHECK: opaque::<u32>(copy [[st7]])
+    // CHECK: opaque::<u32>(move [[st7]])
-    // CHECK: opaque::<u32>(copy [[st7]])
+    // CHECK: [[st8:_.*]] = copy (*[[ref]]);
+    // CHECK: opaque::<u32>(move [[st8]])
     let z = &*t;
     opaque(*z);
     opaque(*z);
-    // But not in reborrows.
+    // Not in reborrows either.
     // CHECK: [[reborrow:_.*]] = &(*[[ref]]);
     // CHECK: opaque::<&u32>(move [[reborrow]])
     opaque(&*z);
@@ -516,10 +521,11 @@ fn dereferences(t: &mut u32, u: &impl Copy, s: &S<u32>) {
     opaque(*u);
     opaque(*u);
 
-    // `*s` is not Copy, but `(*s).0` is, so we can reuse.
+    // `*s` is not Copy, but `(*s).0` is, but we still cannot reuse.
     // CHECK: [[st10:_.*]] = copy ((*_3).0: u32);
-    // CHECK: opaque::<u32>(copy [[st10]])
+    // CHECK: opaque::<u32>(move [[st10]])
-    // CHECK: opaque::<u32>(copy [[st10]])
+    // CHECK: [[st11:_.*]] = copy ((*_3).0: u32);
+    // CHECK: opaque::<u32>(move [[st11]])
     opaque(s.0);
     opaque(s.0);
 }
@@ -736,7 +742,7 @@ fn borrowed<T: Copy + Freeze>(x: T) {
     // CHECK: bb1: {
     // CHECK-NEXT: _0 = opaque::<T>(copy _1)
     // CHECK: bb2: {
-    // CHECK-NEXT: _0 = opaque::<T>(copy _1)
+    // CHECK-NEXT: _0 = opaque::<T>(copy (*_3))
     mir! {
         {
             let a = x;

tests/mir-opt/gvn.slices.GVN.panic-abort.diff

@@ -111,9 +111,8 @@
           StorageLive(_7);
           StorageLive(_8);
 -         StorageLive(_9);
--         StorageLive(_10);
-+         nop;
 +         nop;
+          StorageLive(_10);
           StorageLive(_11);
           _11 = &(*_1);
           _10 = core::str::<impl str>::as_ptr(move _11) -> [return: bb3, unwind unreachable];
@@ -123,9 +122,8 @@
           StorageDead(_11);
           _9 = &_10;
 -         StorageLive(_12);
--         StorageLive(_13);
-+         nop;
 +         nop;
+          StorageLive(_13);
           StorageLive(_14);
 -         _14 = &(*_4);
 +         _14 = &(*_1);
@@ -150,12 +148,11 @@
           StorageLive(_17);
           StorageLive(_18);
 -         _18 = copy (*_15);
-+         _18 = copy _10;
++         _18 = copy (*_9);
           StorageLive(_19);
 -         _19 = copy (*_16);
--         _17 = Eq(move _18, move _19);
++         _19 = copy (*_12);
-+         _19 = copy _13;
+          _17 = Eq(move _18, move _19);
-+         _17 = Eq(copy _10, copy _13);
           switchInt(move _17) -> [0: bb6, otherwise: bb5];
       }
   
@@ -166,10 +163,8 @@
           StorageDead(_17);
           StorageDead(_16);
           StorageDead(_15);
--         StorageDead(_13);
+          StorageDead(_13);
--         StorageDead(_10);
+          StorageDead(_10);
-+         nop;
-+         nop;
           StorageDead(_8);
           StorageDead(_7);
 -         StorageLive(_29);
@@ -218,9 +213,8 @@
           StorageLive(_33);
           StorageLive(_34);
 -         StorageLive(_35);
--         StorageLive(_36);
-+         nop;
 +         nop;
+          StorageLive(_36);
           StorageLive(_37);
           _37 = &(*_1);
           _36 = core::str::<impl str>::as_ptr(move _37) -> [return: bb8, unwind unreachable];
@@ -230,9 +224,8 @@
           StorageDead(_37);
           _35 = &_36;
 -         StorageLive(_38);
--         StorageLive(_39);
-+         nop;
 +         nop;
+          StorageLive(_39);
           StorageLive(_40);
           _40 = &(*_29);
           _39 = core::slice::<impl [u8]>::as_ptr(move _40) -> [return: bb9, unwind unreachable];
@@ -256,12 +249,11 @@
           StorageLive(_43);
           StorageLive(_44);
 -         _44 = copy (*_41);
-+         _44 = copy _36;
++         _44 = copy (*_35);
           StorageLive(_45);
 -         _45 = copy (*_42);
--         _43 = Eq(move _44, move _45);
++         _45 = copy (*_38);
-+         _45 = copy _39;
+          _43 = Eq(move _44, move _45);
-+         _43 = Eq(copy _36, copy _39);
           switchInt(move _43) -> [0: bb11, otherwise: bb10];
       }
   
@@ -272,10 +264,8 @@
           StorageDead(_43);
           StorageDead(_42);
           StorageDead(_41);
--         StorageDead(_39);
+          StorageDead(_39);
--         StorageDead(_36);
+          StorageDead(_36);
-+         nop;
-+         nop;
           StorageDead(_34);
           StorageDead(_33);
           _0 = const ();

tests/mir-opt/gvn.slices.GVN.panic-unwind.diff

@@ -111,9 +111,8 @@
           StorageLive(_7);
           StorageLive(_8);
 -         StorageLive(_9);
--         StorageLive(_10);
-+         nop;
 +         nop;
+          StorageLive(_10);
           StorageLive(_11);
           _11 = &(*_1);
           _10 = core::str::<impl str>::as_ptr(move _11) -> [return: bb3, unwind continue];
@@ -123,9 +122,8 @@
           StorageDead(_11);
           _9 = &_10;
 -         StorageLive(_12);
--         StorageLive(_13);
-+         nop;
 +         nop;
+          StorageLive(_13);
           StorageLive(_14);
 -         _14 = &(*_4);
 +         _14 = &(*_1);
@@ -150,12 +148,11 @@
           StorageLive(_17);
           StorageLive(_18);
 -         _18 = copy (*_15);
-+         _18 = copy _10;
++         _18 = copy (*_9);
           StorageLive(_19);
 -         _19 = copy (*_16);
--         _17 = Eq(move _18, move _19);
++         _19 = copy (*_12);
-+         _19 = copy _13;
+          _17 = Eq(move _18, move _19);
-+         _17 = Eq(copy _10, copy _13);
           switchInt(move _17) -> [0: bb6, otherwise: bb5];
       }
   
@@ -166,10 +163,8 @@
           StorageDead(_17);
           StorageDead(_16);
           StorageDead(_15);
--         StorageDead(_13);
+          StorageDead(_13);
--         StorageDead(_10);
+          StorageDead(_10);
-+         nop;
-+         nop;
           StorageDead(_8);
           StorageDead(_7);
 -         StorageLive(_29);
@@ -218,9 +213,8 @@
           StorageLive(_33);
           StorageLive(_34);
 -         StorageLive(_35);
--         StorageLive(_36);
-+         nop;
 +         nop;
+          StorageLive(_36);
           StorageLive(_37);
           _37 = &(*_1);
           _36 = core::str::<impl str>::as_ptr(move _37) -> [return: bb8, unwind continue];
@@ -230,9 +224,8 @@
           StorageDead(_37);
           _35 = &_36;
 -         StorageLive(_38);
--         StorageLive(_39);
-+         nop;
 +         nop;
+          StorageLive(_39);
           StorageLive(_40);
           _40 = &(*_29);
           _39 = core::slice::<impl [u8]>::as_ptr(move _40) -> [return: bb9, unwind continue];
@@ -256,12 +249,11 @@
           StorageLive(_43);
           StorageLive(_44);
 -         _44 = copy (*_41);
-+         _44 = copy _36;
++         _44 = copy (*_35);
           StorageLive(_45);
 -         _45 = copy (*_42);
--         _43 = Eq(move _44, move _45);
++         _45 = copy (*_38);
-+         _45 = copy _39;
+          _43 = Eq(move _44, move _45);
-+         _43 = Eq(copy _36, copy _39);
           switchInt(move _43) -> [0: bb11, otherwise: bb10];
       }
   
@@ -272,10 +264,8 @@
           StorageDead(_43);
           StorageDead(_42);
           StorageDead(_41);
--         StorageDead(_39);
+          StorageDead(_39);
--         StorageDead(_36);
+          StorageDead(_36);
-+         nop;
-+         nop;
           StorageDead(_34);
           StorageDead(_33);
           _0 = const ();

tests/mir-opt/gvn.subexpression_elimination.GVN.panic-abort.diff

@@ -758,39 +758,32 @@
           StorageLive(_126);
           _126 = &_3;
           StorageLive(_127);
--         StorageLive(_128);
+          StorageLive(_128);
--         StorageLive(_129);
+          StorageLive(_129);
-+         nop;
-+         nop;
           _129 = copy (*_126);
           StorageLive(_130);
           _130 = copy _1;
 -         _128 = Add(move _129, move _130);
-+         _128 = Add(copy _129, copy _1);
++         _128 = Add(move _129, copy _1);
           StorageDead(_130);
--         StorageDead(_129);
+          StorageDead(_129);
--         _127 = opaque::<u64>(move _128) -> [return: bb35, unwind unreachable];
+          _127 = opaque::<u64>(move _128) -> [return: bb35, unwind unreachable];
-+         nop;
-+         _127 = opaque::<u64>(copy _128) -> [return: bb35, unwind unreachable];
       }
   
       bb35: {
--         StorageDead(_128);
+          StorageDead(_128);
-+         nop;
           StorageDead(_127);
           StorageLive(_131);
           StorageLive(_132);
           StorageLive(_133);
--         _133 = copy (*_126);
+          _133 = copy (*_126);
-+         _133 = copy _129;
           StorageLive(_134);
           _134 = copy _1;
 -         _132 = Add(move _133, move _134);
-+         _132 = copy _128;
++         _132 = Add(move _133, copy _1);
           StorageDead(_134);
           StorageDead(_133);
--         _131 = opaque::<u64>(move _132) -> [return: bb36, unwind unreachable];
+          _131 = opaque::<u64>(move _132) -> [return: bb36, unwind unreachable];
-+         _131 = opaque::<u64>(copy _128) -> [return: bb36, unwind unreachable];
       }
   
       bb36: {
@@ -906,39 +899,32 @@
           StorageLive(_163);
           _163 = &_3;
           StorageLive(_164);
--         StorageLive(_165);
+          StorageLive(_165);
--         StorageLive(_166);
+          StorageLive(_166);
-+         nop;
-+         nop;
           _166 = copy (*_163);
           StorageLive(_167);
           _167 = copy _1;
 -         _165 = Add(move _166, move _167);
-+         _165 = Add(copy _166, copy _1);
++         _165 = Add(move _166, copy _1);
           StorageDead(_167);
--         StorageDead(_166);
+          StorageDead(_166);
--         _164 = opaque::<u64>(move _165) -> [return: bb43, unwind unreachable];
+          _164 = opaque::<u64>(move _165) -> [return: bb43, unwind unreachable];
-+         nop;
-+         _164 = opaque::<u64>(copy _165) -> [return: bb43, unwind unreachable];
       }
   
       bb43: {
--         StorageDead(_165);
+          StorageDead(_165);
-+         nop;
           StorageDead(_164);
           StorageLive(_168);
           StorageLive(_169);
           StorageLive(_170);
--         _170 = copy (*_163);
+          _170 = copy (*_163);
-+         _170 = copy _166;
           StorageLive(_171);
           _171 = copy _1;
 -         _169 = Add(move _170, move _171);
-+         _169 = copy _165;
++         _169 = Add(move _170, copy _1);
           StorageDead(_171);
           StorageDead(_170);
--         _168 = opaque::<u64>(move _169) -> [return: bb44, unwind unreachable];
+          _168 = opaque::<u64>(move _169) -> [return: bb44, unwind unreachable];
-+         _168 = opaque::<u64>(copy _165) -> [return: bb44, unwind unreachable];
       }
   
       bb44: {

tests/mir-opt/gvn.subexpression_elimination.GVN.panic-unwind.diff

@@ -758,39 +758,32 @@
           StorageLive(_126);
           _126 = &_3;
           StorageLive(_127);
--         StorageLive(_128);
+          StorageLive(_128);
--         StorageLive(_129);
+          StorageLive(_129);
-+         nop;
-+         nop;
           _129 = copy (*_126);
           StorageLive(_130);
           _130 = copy _1;
 -         _128 = Add(move _129, move _130);
-+         _128 = Add(copy _129, copy _1);
++         _128 = Add(move _129, copy _1);
           StorageDead(_130);
--         StorageDead(_129);
+          StorageDead(_129);
--         _127 = opaque::<u64>(move _128) -> [return: bb35, unwind continue];
+          _127 = opaque::<u64>(move _128) -> [return: bb35, unwind continue];
-+         nop;
-+         _127 = opaque::<u64>(copy _128) -> [return: bb35, unwind continue];
       }
   
       bb35: {
--         StorageDead(_128);
+          StorageDead(_128);
-+         nop;
           StorageDead(_127);
           StorageLive(_131);
           StorageLive(_132);
           StorageLive(_133);
--         _133 = copy (*_126);
+          _133 = copy (*_126);
-+         _133 = copy _129;
           StorageLive(_134);
           _134 = copy _1;
 -         _132 = Add(move _133, move _134);
-+         _132 = copy _128;
++         _132 = Add(move _133, copy _1);
           StorageDead(_134);
           StorageDead(_133);
--         _131 = opaque::<u64>(move _132) -> [return: bb36, unwind continue];
+          _131 = opaque::<u64>(move _132) -> [return: bb36, unwind continue];
-+         _131 = opaque::<u64>(copy _128) -> [return: bb36, unwind continue];
       }
   
       bb36: {
@@ -906,39 +899,32 @@
           StorageLive(_163);
           _163 = &_3;
           StorageLive(_164);
--         StorageLive(_165);
+          StorageLive(_165);
--         StorageLive(_166);
+          StorageLive(_166);
-+         nop;
-+         nop;
           _166 = copy (*_163);
           StorageLive(_167);
           _167 = copy _1;
 -         _165 = Add(move _166, move _167);
-+         _165 = Add(copy _166, copy _1);
++         _165 = Add(move _166, copy _1);
           StorageDead(_167);
--         StorageDead(_166);
+          StorageDead(_166);
--         _164 = opaque::<u64>(move _165) -> [return: bb43, unwind continue];
+          _164 = opaque::<u64>(move _165) -> [return: bb43, unwind continue];
-+         nop;
-+         _164 = opaque::<u64>(copy _165) -> [return: bb43, unwind continue];
       }
   
       bb43: {
--         StorageDead(_165);
+          StorageDead(_165);
-+         nop;
           StorageDead(_164);
           StorageLive(_168);
           StorageLive(_169);
           StorageLive(_170);
--         _170 = copy (*_163);
+          _170 = copy (*_163);
-+         _170 = copy _166;
           StorageLive(_171);
           _171 = copy _1;
 -         _169 = Add(move _170, move _171);
-+         _169 = copy _165;
++         _169 = Add(move _170, copy _1);
           StorageDead(_171);
           StorageDead(_170);
--         _168 = opaque::<u64>(move _169) -> [return: bb44, unwind continue];
+          _168 = opaque::<u64>(move _169) -> [return: bb44, unwind continue];
-+         _168 = opaque::<u64>(copy _165) -> [return: bb44, unwind continue];
       }
   
       bb44: {

tests/mir-opt/gvn_uninhabited.f.GVN.panic-abort.diff

@@ -17,16 +17,15 @@
           StorageLive(_3);
           _5 = const f::promoted[0];
           _3 = &(*_5);
--         _2 = copy ((*_3).1: E);
+          _2 = copy ((*_3).1: E);
-+         _2 = copy ((*_5).1: E);
+-         StorageLive(_1);
-          StorageLive(_1);
++         nop;
--         _1 = copy ((_2 as A).1: u32);
+          _1 = copy ((_2 as A).1: u32);
-+         _1 = const 0_u32;
           StorageDead(_3);
           StorageDead(_2);
--         _0 = copy _1;
+          _0 = copy _1;
-+         _0 = const 0_u32;
+-         StorageDead(_1);
-          StorageDead(_1);
++         nop;
           return;
       }
   }

tests/mir-opt/gvn_uninhabited.f.GVN.panic-unwind.diff

@@ -17,16 +17,15 @@
           StorageLive(_3);
           _5 = const f::promoted[0];
           _3 = &(*_5);
--         _2 = copy ((*_3).1: E);
+          _2 = copy ((*_3).1: E);
-+         _2 = copy ((*_5).1: E);
+-         StorageLive(_1);
-          StorageLive(_1);
++         nop;
--         _1 = copy ((_2 as A).1: u32);
+          _1 = copy ((_2 as A).1: u32);
-+         _1 = const 0_u32;
           StorageDead(_3);
           StorageDead(_2);
--         _0 = copy _1;
+          _0 = copy _1;
-+         _0 = const 0_u32;
+-         StorageDead(_1);
-          StorageDead(_1);
++         nop;
           return;
       }
   }

tests/mir-opt/pre-codegen/deref_nested_borrows.rs

@@ -2,7 +2,9 @@
 
 fn src(x: &&u8) -> bool {
     // CHECK-LABEL: fn src(
-    // CHECK: _0 = const true;
+    // CHECK-NOT: _0 = const true;
+    // CHECK: _0 = Eq({{.*}}, {{.*}});
+    // CHECK-NOT: _0 = const true;
     let y = **x;
     unsafe { unknown() };
     **x == y

tests/mir-opt/pre-codegen/deref_nested_borrows.src.GVN.panic-abort.diff

@@ -26,13 +26,12 @@
       bb1: {
           StorageLive(_4);
 -         _7 = deref_copy (*_1);
--         _4 = copy (*_7);
++         _7 = copy (*_1);
-+         _7 = copy _6;
+          _4 = copy (*_7);
-+         _4 = copy _2;
           StorageLive(_5);
           _5 = copy _2;
 -         _0 = Eq(move _4, move _5);
-+         _0 = const true;
++         _0 = Eq(move _4, copy _2);
           StorageDead(_5);
           StorageDead(_4);
 -         StorageDead(_2);

tests/mir-opt/pre-codegen/deref_nested_borrows.src.GVN.panic-unwind.diff

@@ -26,13 +26,12 @@
       bb1: {
           StorageLive(_4);
 -         _7 = deref_copy (*_1);
--         _4 = copy (*_7);
++         _7 = copy (*_1);
-+         _7 = copy _6;
+          _4 = copy (*_7);
-+         _4 = copy _2;
           StorageLive(_5);
           _5 = copy _2;
 -         _0 = Eq(move _4, move _5);
-+         _0 = const true;
++         _0 = Eq(move _4, copy _2);
           StorageDead(_5);
           StorageDead(_4);
 -         StorageDead(_2);

tests/mir-opt/pre-codegen/deref_nested_borrows.src.PreCodegen.after.panic-abort.mir

@@ -6,6 +6,8 @@ fn src(_1: &&u8) -> bool {
     let mut _2: &u8;
     let _3: u8;
     let _4: ();
+    let mut _5: &u8;
+    let mut _6: u8;
     scope 1 {
         debug y => _3;
     }
@@ -17,7 +19,11 @@ fn src(_1: &&u8) -> bool {
     }
 
     bb1: {
-        _0 = const true;
+        StorageLive(_6);
+        _5 = copy (*_1);
+        _6 = copy (*_5);
+        _0 = Eq(move _6, copy _3);
+        StorageDead(_6);
         return;
     }
 }

tests/mir-opt/pre-codegen/deref_nested_borrows.src.PreCodegen.after.panic-unwind.mir

@@ -6,6 +6,8 @@ fn src(_1: &&u8) -> bool {
     let mut _2: &u8;
     let _3: u8;
     let _4: ();
+    let mut _5: &u8;
+    let mut _6: u8;
     scope 1 {
         debug y => _3;
     }
@@ -17,7 +19,11 @@ fn src(_1: &&u8) -> bool {
     }
 
     bb1: {
-        _0 = const true;
+        StorageLive(_6);
+        _5 = copy (*_1);
+        _6 = copy (*_5);
+        _0 = Eq(move _6, copy _3);
+        StorageDead(_6);
         return;
     }
 }

tests/mir-opt/pre-codegen/slice_filter.variant_a-{closure#0}.PreCodegen.after.mir

@@ -4,65 +4,70 @@ fn variant_a::{closure#0}(_1: &mut {closure@$DIR/slice_filter.rs:7:25: 7:39}, _2
     let mut _0: bool;
     let mut _3: &(usize, usize, usize, usize);
     let _4: &usize;
-    let _5: &usize;
+    let mut _5: &(usize, usize, usize, usize);
     let _6: &usize;
-    let _7: &usize;
+    let mut _7: &(usize, usize, usize, usize);
-    let mut _8: &&usize;
+    let _8: &usize;
-    let _9: &usize;
+    let mut _9: &(usize, usize, usize, usize);
-    let mut _10: &&usize;
+    let _10: &usize;
-    let mut _13: bool;
+    let mut _11: &&usize;
-    let mut _14: &&usize;
+    let _12: &usize;
-    let _15: &usize;
+    let mut _13: &&usize;
-    let mut _16: &&usize;
+    let mut _16: bool;
-    let mut _19: bool;
+    let mut _17: &&usize;
-    let mut _20: &&usize;
+    let _18: &usize;
-    let _21: &usize;
+    let mut _19: &&usize;
-    let mut _22: &&usize;
+    let mut _22: bool;
-    let mut _23: bool;
+    let mut _23: &&usize;
-    let mut _24: &&usize;
+    let _24: &usize;
-    let _25: &usize;
+    let mut _25: &&usize;
-    let mut _26: &&usize;
+    let mut _28: bool;
+    let mut _29: &&usize;
+    let _30: &usize;
+    let mut _31: &&usize;
     scope 1 {
         debug a => _4;
-        debug b => _5;
+        debug b => _6;
-        debug c => _6;
+        debug c => _8;
-        debug d => _7;
+        debug d => _10;
         scope 2 (inlined std::cmp::impls::<impl PartialOrd for &usize>::le) {
-            debug self => _8;
+            debug self => _11;
-            debug other => _10;
+            debug other => _13;
             scope 3 (inlined std::cmp::impls::<impl PartialOrd for usize>::le) {
                 debug self => _4;
-                debug other => _6;
+                debug other => _8;
-                let mut _11: usize;
+                let mut _14: usize;
-                let mut _12: usize;
+                let mut _15: usize;
             }
         }
         scope 4 (inlined std::cmp::impls::<impl PartialOrd for &usize>::le) {
-            debug self => _14;
+            debug self => _17;
-            debug other => _16;
+            debug other => _19;
             scope 5 (inlined std::cmp::impls::<impl PartialOrd for usize>::le) {
-                debug self => _7;
+                debug self => _10;
-                debug other => _5;
+                debug other => _6;
-                let mut _17: usize;
+                let mut _20: usize;
-                let mut _18: usize;
+                let mut _21: usize;
             }
         }
         scope 6 (inlined std::cmp::impls::<impl PartialOrd for &usize>::le) {
-            debug self => _20;
+            debug self => _23;
-            debug other => _22;
+            debug other => _25;
             scope 7 (inlined std::cmp::impls::<impl PartialOrd for usize>::le) {
-                debug self => _6;
+                debug self => _8;
                 debug other => _4;
+                let mut _26: usize;
+                let mut _27: usize;
             }
         }
         scope 8 (inlined std::cmp::impls::<impl PartialOrd for &usize>::le) {
-            debug self => _24;
+            debug self => _29;
-            debug other => _26;
+            debug other => _31;
             scope 9 (inlined std::cmp::impls::<impl PartialOrd for usize>::le) {
-                debug self => _5;
+                debug self => _6;
-                debug other => _7;
+                debug other => _10;
-                let mut _27: usize;
+                let mut _32: usize;
-                let mut _28: usize;
+                let mut _33: usize;
             }
         }
     }
@@ -70,116 +75,129 @@ fn variant_a::{closure#0}(_1: &mut {closure@$DIR/slice_filter.rs:7:25: 7:39}, _2
     bb0: {
         _3 = copy (*_2);
         _4 = &((*_3).0: usize);
-        _5 = &((*_3).1: usize);
+        _5 = copy (*_2);
-        _6 = &((*_3).2: usize);
+        _6 = &((*_5).1: usize);
-        _7 = &((*_3).3: usize);
+        _7 = copy (*_2);
+        _8 = &((*_7).2: usize);
+        _9 = copy (*_2);
+        _10 = &((*_9).3: usize);
+        StorageLive(_16);
+        StorageLive(_11);
+        _11 = &_4;
         StorageLive(_13);
-        StorageLive(_8);
+        StorageLive(_12);
-        _8 = &_4;
+        _12 = copy _8;
-        StorageLive(_10);
+        _13 = &_12;
-        StorageLive(_9);
+        StorageLive(_14);
-        _9 = copy _6;
+        _14 = copy ((*_3).0: usize);
-        _10 = &_9;
+        StorageLive(_15);
-        _11 = copy ((*_3).0: usize);
+        _15 = copy ((*_7).2: usize);
-        _12 = copy ((*_3).2: usize);
+        _16 = Le(move _14, move _15);
-        _13 = Le(copy _11, copy _12);
+        StorageDead(_15);
-        switchInt(move _13) -> [0: bb1, otherwise: bb2];
+        StorageDead(_14);
+        switchInt(move _16) -> [0: bb1, otherwise: bb2];
     }
 
     bb1: {
-        StorageDead(_9);
+        StorageDead(_12);
-        StorageDead(_10);
+        StorageDead(_13);
-        StorageDead(_8);
+        StorageDead(_11);
         goto -> bb4;
     }
 
     bb2: {
-        StorageDead(_9);
+        StorageDead(_12);
-        StorageDead(_10);
+        StorageDead(_13);
-        StorageDead(_8);
+        StorageDead(_11);
-        StorageLive(_19);
+        StorageLive(_22);
-        StorageLive(_14);
-        _14 = &_7;
-        StorageLive(_16);
-        StorageLive(_15);
-        _15 = copy _5;
-        _16 = &_15;
         StorageLive(_17);
-        _17 = copy ((*_3).3: usize);
+        _17 = &_10;
+        StorageLive(_19);
         StorageLive(_18);
-        _18 = copy ((*_3).1: usize);
+        _18 = copy _6;
-        _19 = Le(move _17, move _18);
+        _19 = &_18;
-        StorageDead(_18);
+        StorageLive(_20);
-        StorageDead(_17);
+        _20 = copy ((*_9).3: usize);
-        switchInt(move _19) -> [0: bb3, otherwise: bb8];
+        StorageLive(_21);
+        _21 = copy ((*_5).1: usize);
+        _22 = Le(move _20, move _21);
+        StorageDead(_21);
+        StorageDead(_20);
+        switchInt(move _22) -> [0: bb3, otherwise: bb8];
     }
 
     bb3: {
-        StorageDead(_15);
+        StorageDead(_18);
-        StorageDead(_16);
+        StorageDead(_19);
-        StorageDead(_14);
+        StorageDead(_17);
         goto -> bb4;
     }
 
     bb4: {
+        StorageLive(_28);
         StorageLive(_23);
-        StorageLive(_20);
+        _23 = &_8;
-        _20 = &_6;
+        StorageLive(_25);
-        StorageLive(_22);
+        StorageLive(_24);
-        StorageLive(_21);
+        _24 = copy _4;
-        _21 = copy _4;
+        _25 = &_24;
-        _22 = &_21;
+        StorageLive(_26);
-        _23 = Le(copy _12, copy _11);
+        _26 = copy ((*_7).2: usize);
-        switchInt(move _23) -> [0: bb5, otherwise: bb6];
+        StorageLive(_27);
+        _27 = copy ((*_3).0: usize);
+        _28 = Le(move _26, move _27);
+        StorageDead(_27);
+        StorageDead(_26);
+        switchInt(move _28) -> [0: bb5, otherwise: bb6];
     }
 
     bb5: {
-        StorageDead(_21);
+        StorageDead(_24);
-        StorageDead(_22);
+        StorageDead(_25);
-        StorageDead(_20);
+        StorageDead(_23);
         _0 = const false;
         goto -> bb7;
     }
 
     bb6: {
-        StorageDead(_21);
-        StorageDead(_22);
-        StorageDead(_20);
-        StorageLive(_24);
-        _24 = &_5;
-        StorageLive(_26);
-        StorageLive(_25);
-        _25 = copy _7;
-        _26 = &_25;
-        StorageLive(_27);
-        _27 = copy ((*_3).1: usize);
-        StorageLive(_28);
-        _28 = copy ((*_3).3: usize);
-        _0 = Le(move _27, move _28);
-        StorageDead(_28);
-        StorageDead(_27);
-        StorageDead(_25);
-        StorageDead(_26);
         StorageDead(_24);
+        StorageDead(_25);
+        StorageDead(_23);
+        StorageLive(_29);
+        _29 = &_6;
+        StorageLive(_31);
+        StorageLive(_30);
+        _30 = copy _10;
+        _31 = &_30;
+        StorageLive(_32);
+        _32 = copy ((*_5).1: usize);
+        StorageLive(_33);
+        _33 = copy ((*_9).3: usize);
+        _0 = Le(move _32, move _33);
+        StorageDead(_33);
+        StorageDead(_32);
+        StorageDead(_30);
+        StorageDead(_31);
+        StorageDead(_29);
         goto -> bb7;
     }
 
     bb7: {
-        StorageDead(_23);
+        StorageDead(_28);
         goto -> bb9;
     }
 
     bb8: {
-        StorageDead(_15);
+        StorageDead(_18);
-        StorageDead(_16);
+        StorageDead(_19);
-        StorageDead(_14);
+        StorageDead(_17);
         _0 = const true;
         goto -> bb9;
     }
 
     bb9: {
-        StorageDead(_19);
+        StorageDead(_22);
-        StorageDead(_13);
+        StorageDead(_16);
         return;
     }
 }

tests/mir-opt/pre-codegen/slice_filter.variant_b-{closure#0}.PreCodegen.after.mir

@@ -4,40 +4,46 @@ fn variant_b::{closure#0}(_1: &mut {closure@$DIR/slice_filter.rs:11:25: 11:41},
     let mut _0: bool;
     let mut _3: &(usize, usize, usize, usize);
     let _4: usize;
-    let _5: usize;
+    let mut _5: &(usize, usize, usize, usize);
     let _6: usize;
-    let _7: usize;
+    let mut _7: &(usize, usize, usize, usize);
-    let mut _8: bool;
+    let _8: usize;
-    let mut _9: bool;
+    let mut _9: &(usize, usize, usize, usize);
-    let mut _10: bool;
+    let _10: usize;
+    let mut _11: bool;
+    let mut _12: bool;
+    let mut _13: bool;
     scope 1 {
         debug a => _4;
-        debug b => _5;
+        debug b => _6;
-        debug c => _6;
+        debug c => _8;
-        debug d => _7;
+        debug d => _10;
     }
 
     bb0: {
         _3 = copy (*_2);
         _4 = copy ((*_3).0: usize);
-        _5 = copy ((*_3).1: usize);
+        _5 = copy (*_2);
-        _6 = copy ((*_3).2: usize);
+        _6 = copy ((*_5).1: usize);
-        _7 = copy ((*_3).3: usize);
+        _7 = copy (*_2);
-        StorageLive(_8);
+        _8 = copy ((*_7).2: usize);
-        _8 = Le(copy _4, copy _6);
+        _9 = copy (*_2);
-        switchInt(move _8) -> [0: bb2, otherwise: bb1];
+        _10 = copy ((*_9).3: usize);
+        StorageLive(_11);
+        _11 = Le(copy _4, copy _8);
+        switchInt(move _11) -> [0: bb2, otherwise: bb1];
     }
 
     bb1: {
-        StorageLive(_9);
+        StorageLive(_12);
-        _9 = Le(copy _7, copy _5);
+        _12 = Le(copy _10, copy _6);
-        switchInt(move _9) -> [0: bb2, otherwise: bb6];
+        switchInt(move _12) -> [0: bb2, otherwise: bb6];
     }
 
     bb2: {
-        StorageLive(_10);
+        StorageLive(_13);
-        _10 = Le(copy _6, copy _4);
+        _13 = Le(copy _8, copy _4);
-        switchInt(move _10) -> [0: bb3, otherwise: bb4];
+        switchInt(move _13) -> [0: bb3, otherwise: bb4];
     }
 
     bb3: {
@@ -46,12 +52,12 @@ fn variant_b::{closure#0}(_1: &mut {closure@$DIR/slice_filter.rs:11:25: 11:41},
     }
 
     bb4: {
-        _0 = Le(copy _5, copy _7);
+        _0 = Le(copy _6, copy _10);
         goto -> bb5;
     }
 
     bb5: {
-        StorageDead(_10);
+        StorageDead(_13);
         goto -> bb7;
     }
 
@@ -61,8 +67,8 @@ fn variant_b::{closure#0}(_1: &mut {closure@$DIR/slice_filter.rs:11:25: 11:41},
     }
 
     bb7: {
-        StorageDead(_9);
+        StorageDead(_12);
-        StorageDead(_8);
+        StorageDead(_11);
         return;
     }
 }