Enable GVN by default.

35 files changed, 384 insertions, 529 deletions

diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs
index 3b8adf7e86b..13e5ffea390 100644
--- a/compiler/rustc_mir_transform/src/gvn.rs
+++ b/compiler/rustc_mir_transform/src/gvn.rs
@@ -109,7 +109,7 @@ pub struct GVN;
 
 impl<'tcx> MirPass<'tcx> for GVN {
     fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
-        sess.mir_opt_level() >= 4
+        sess.mir_opt_level() >= 2
     }
 
     #[instrument(level = "trace", skip(self, tcx, body))]
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index 98d4d96d0c7..10ebf469d85 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -588,9 +588,9 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
             // destroy the SSA property. It should still happen before const-propagation, so the
             // latter pass will leverage the created opportunities.
             &separate_const_switch::SeparateConstSwitch,
-            &const_prop::ConstProp,
             &gvn::GVN,
             &simplify::SimplifyLocals::AfterGVN,
+            &const_prop::ConstProp,
             &dataflow_const_prop::DataflowConstProp,
             &const_debuginfo::ConstDebugInfo,
             &o1(simplify_branches::SimplifyConstCondition::AfterConstProp),
diff --git a/tests/codegen/issues/issue-105386-ub-in-debuginfo.rs b/tests/codegen/issues/issue-105386-ub-in-debuginfo.rs
index 54c50f840c5..a9538da1975 100644
--- a/tests/codegen/issues/issue-105386-ub-in-debuginfo.rs
+++ b/tests/codegen/issues/issue-105386-ub-in-debuginfo.rs
@@ -19,5 +19,3 @@ pub fn outer_function(x: S, y: S) -> usize {
 // CHECK-NOT: [[ptr_tmp:%.*]] = getelementptr inbounds %"{closure@{{.*.rs}}:9:23: 9:25}", ptr [[spill]]
 // CHECK-NOT: [[load:%.*]] = load ptr, ptr
 // CHECK: call void @llvm.lifetime.start{{.*}}({{.*}}, ptr [[spill]])
-// CHECK: [[inner:%.*]] = getelementptr inbounds %"{{.*}}", ptr [[spill]]
-// CHECK: call void @llvm.memcpy{{.*}}(ptr {{align .*}} [[inner]], ptr {{align .*}} %x
diff --git a/tests/coverage/async2.cov-map b/tests/coverage/async2.cov-map
index b120e28c464..28f319bfb80 100644
--- a/tests/coverage/async2.cov-map
+++ b/tests/coverage/async2.cov-map
@@ -7,19 +7,17 @@ Number of file 0 mappings: 1
 - Code(Counter(0)) at (prev + 13, 1) to (start + 0, 23)
 
 Function name: async2::async_func::{closure#0}
-Raw bytes (28): 0x[01, 01, 02, 01, 05, 05, 02, 04, 01, 0d, 17, 03, 09, 05, 03, 0a, 02, 06, 02, 02, 06, 00, 07, 07, 01, 01, 00, 02]
+Raw bytes (26): 0x[01, 01, 01, 05, 00, 04, 01, 0d, 17, 03, 09, 05, 03, 0a, 02, 06, 00, 02, 06, 00, 07, 03, 01, 01, 00, 02]
 Number of files: 1
 - file 0 => global file 1
-Number of expressions: 2
-- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
-- expression 1 operands: lhs = Counter(1), rhs = Expression(0, Sub)
+Number of expressions: 1
+- expression 0 operands: lhs = Counter(1), rhs = Zero
 Number of file 0 mappings: 4
 - Code(Counter(0)) at (prev + 13, 23) to (start + 3, 9)
 - Code(Counter(1)) at (prev + 3, 10) to (start + 2, 6)
-- Code(Expression(0, Sub)) at (prev + 2, 6) to (start + 0, 7)
-    = (c0 - c1)
-- Code(Expression(1, Add)) at (prev + 1, 1) to (start + 0, 2)
-    = (c1 + (c0 - c1))
+- Code(Zero) at (prev + 2, 6) to (start + 0, 7)
+- Code(Expression(0, Add)) at (prev + 1, 1) to (start + 0, 2)
+    = (c1 + Zero)
 
 Function name: async2::async_func_just_println
 Raw bytes (9): 0x[01, 01, 00, 01, 01, 15, 01, 00, 24]
diff --git a/tests/coverage/partial_eq.cov-map b/tests/coverage/partial_eq.cov-map
index 3549116db7a..3a803e3c18f 100644
--- a/tests/coverage/partial_eq.cov-map
+++ b/tests/coverage/partial_eq.cov-map
@@ -25,18 +25,18 @@ Number of file 0 mappings: 2
 - Code(Zero) at (prev + 0, 32) to (start + 0, 33)
 
 Function name: <partial_eq::Version as core::cmp::PartialOrd>::partial_cmp
-Raw bytes (22): 0x[01, 01, 04, 07, 0b, 05, 09, 0f, 15, 0d, 11, 02, 01, 04, 27, 00, 28, 03, 00, 30, 00, 31]
+Raw bytes (22): 0x[01, 01, 04, 07, 0b, 00, 09, 0f, 15, 00, 11, 02, 01, 04, 27, 00, 28, 03, 00, 30, 00, 31]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 4
 - expression 0 operands: lhs = Expression(1, Add), rhs = Expression(2, Add)
-- expression 1 operands: lhs = Counter(1), rhs = Counter(2)
+- expression 1 operands: lhs = Zero, rhs = Counter(2)
 - expression 2 operands: lhs = Expression(3, Add), rhs = Counter(5)
-- expression 3 operands: lhs = Counter(3), rhs = Counter(4)
+- expression 3 operands: lhs = Zero, rhs = Counter(4)
 Number of file 0 mappings: 2
 - Code(Counter(0)) at (prev + 4, 39) to (start + 0, 40)
 - Code(Expression(0, Add)) at (prev + 0, 48) to (start + 0, 49)
-    = ((c1 + c2) + ((c3 + c4) + c5))
+    = ((Zero + c2) + ((Zero + c4) + c5))
 
 Function name: <partial_eq::Version as core::fmt::Debug>::fmt
 Raw bytes (9): 0x[01, 01, 00, 01, 01, 04, 11, 00, 16]
diff --git a/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.panic-abort.diff b/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.panic-abort.diff
index 298a6084899..9d4bfcffcf0 100644
--- a/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.panic-abort.diff
+++ b/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.panic-abort.diff
@@ -9,17 +9,10 @@
       let _4: bool;
       let mut _6: std::option::Option<usize>;
       let mut _7: isize;
-      let mut _9: &mut std::fmt::Formatter<'_>;
-      let mut _10: &T;
-      let mut _11: core::num::flt2dec::Sign;
-      let mut _12: u32;
-      let mut _13: u32;
-      let mut _14: usize;
-      let mut _15: bool;
-      let mut _16: &mut std::fmt::Formatter<'_>;
-      let mut _17: &T;
-      let mut _18: core::num::flt2dec::Sign;
-      let mut _19: bool;
+      let mut _9: core::num::flt2dec::Sign;
+      let mut _10: u32;
+      let mut _11: u32;
+      let mut _12: core::num::flt2dec::Sign;
       scope 1 {
           debug force_sign => _4;
           let _5: core::num::flt2dec::Sign;
@@ -36,32 +29,30 @@
       }
       scope 4 (inlined Formatter::<'_>::sign_plus) {
           debug self => _1;
-          let mut _20: u32;
-          let mut _21: u32;
+          let mut _13: u32;
+          let mut _14: u32;
       }
   
       bb0: {
           StorageLive(_4);
-          StorageLive(_20);
-          StorageLive(_21);
-          _21 = ((*_1).0: u32);
-          _20 = BitAnd(move _21, const 1_u32);
-          StorageDead(_21);
-          _4 = Ne(move _20, const 0_u32);
-          StorageDead(_20);
+          StorageLive(_13);
+          StorageLive(_14);
+          _14 = ((*_1).0: u32);
+          _13 = BitAnd(move _14, const 1_u32);
+          StorageDead(_14);
+          _4 = Ne(move _13, const 0_u32);
+          StorageDead(_13);
           StorageLive(_5);
           switchInt(_4) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
--         _5 = MinusPlus;
-+         _5 = const MinusPlus;
+          _5 = const MinusPlus;
           goto -> bb3;
       }
   
       bb2: {
--         _5 = Minus;
-+         _5 = const Minus;
+          _5 = const Minus;
           goto -> bb3;
       }
   
@@ -74,30 +65,30 @@
   
       bb4: {
           _8 = ((_6 as Some).0: usize);
+          StorageLive(_9);
+          _9 = _5;
+          StorageLive(_10);
           StorageLive(_11);
-          _11 = _5;
-          StorageLive(_12);
-          StorageLive(_13);
-          _13 = _8 as u32 (IntToInt);
-          _12 = Add(move _13, const 1_u32);
-          StorageDead(_13);
-          _0 = float_to_exponential_common_exact::<T>(_1, _2, move _11, move _12, _3) -> [return: bb5, unwind unreachable];
+          _11 = _8 as u32 (IntToInt);
+          _10 = Add(move _11, const 1_u32);
+          StorageDead(_11);
+          _0 = float_to_exponential_common_exact::<T>(_1, _2, move _9, move _10, _3) -> [return: bb5, unwind unreachable];
       }
   
       bb5: {
-          StorageDead(_12);
-          StorageDead(_11);
+          StorageDead(_10);
+          StorageDead(_9);
           goto -> bb8;
       }
   
       bb6: {
-          StorageLive(_18);
-          _18 = _5;
-          _0 = float_to_exponential_common_shortest::<T>(_1, _2, move _18, _3) -> [return: bb7, unwind unreachable];
+          StorageLive(_12);
+          _12 = _5;
+          _0 = float_to_exponential_common_shortest::<T>(_1, _2, move _12, _3) -> [return: bb7, unwind unreachable];
       }
   
       bb7: {
-          StorageDead(_18);
+          StorageDead(_12);
           goto -> bb8;
       }
   
diff --git a/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.panic-unwind.diff b/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.panic-unwind.diff
index 037f4f7cfac..594609fade9 100644
--- a/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.panic-unwind.diff
+++ b/tests/mir-opt/funky_arms.float_to_exponential_common.ConstProp.panic-unwind.diff
@@ -9,17 +9,10 @@
       let _4: bool;
       let mut _6: std::option::Option<usize>;
       let mut _7: isize;
-      let mut _9: &mut std::fmt::Formatter<'_>;
-      let mut _10: &T;
-      let mut _11: core::num::flt2dec::Sign;
-      let mut _12: u32;
-      let mut _13: u32;
-      let mut _14: usize;
-      let mut _15: bool;
-      let mut _16: &mut std::fmt::Formatter<'_>;
-      let mut _17: &T;
-      let mut _18: core::num::flt2dec::Sign;
-      let mut _19: bool;
+      let mut _9: core::num::flt2dec::Sign;
+      let mut _10: u32;
+      let mut _11: u32;
+      let mut _12: core::num::flt2dec::Sign;
       scope 1 {
           debug force_sign => _4;
           let _5: core::num::flt2dec::Sign;
@@ -36,32 +29,30 @@
       }
       scope 4 (inlined Formatter::<'_>::sign_plus) {
           debug self => _1;
-          let mut _20: u32;
-          let mut _21: u32;
+          let mut _13: u32;
+          let mut _14: u32;
       }
   
       bb0: {
           StorageLive(_4);
-          StorageLive(_20);
-          StorageLive(_21);
-          _21 = ((*_1).0: u32);
-          _20 = BitAnd(move _21, const 1_u32);
-          StorageDead(_21);
-          _4 = Ne(move _20, const 0_u32);
-          StorageDead(_20);
+          StorageLive(_13);
+          StorageLive(_14);
+          _14 = ((*_1).0: u32);
+          _13 = BitAnd(move _14, const 1_u32);
+          StorageDead(_14);
+          _4 = Ne(move _13, const 0_u32);
+          StorageDead(_13);
           StorageLive(_5);
           switchInt(_4) -> [0: bb2, otherwise: bb1];
       }
   
       bb1: {
--         _5 = MinusPlus;
-+         _5 = const MinusPlus;
+          _5 = const MinusPlus;
           goto -> bb3;
       }
   
       bb2: {
--         _5 = Minus;
-+         _5 = const Minus;
+          _5 = const Minus;
           goto -> bb3;
       }
   
@@ -74,30 +65,30 @@
   
       bb4: {
           _8 = ((_6 as Some).0: usize);
+          StorageLive(_9);
+          _9 = _5;
+          StorageLive(_10);
           StorageLive(_11);
-          _11 = _5;
-          StorageLive(_12);
-          StorageLive(_13);
-          _13 = _8 as u32 (IntToInt);
-          _12 = Add(move _13, const 1_u32);
-          StorageDead(_13);
-          _0 = float_to_exponential_common_exact::<T>(_1, _2, move _11, move _12, _3) -> [return: bb5, unwind continue];
+          _11 = _8 as u32 (IntToInt);
+          _10 = Add(move _11, const 1_u32);
+          StorageDead(_11);
+          _0 = float_to_exponential_common_exact::<T>(_1, _2, move _9, move _10, _3) -> [return: bb5, unwind continue];
       }
   
       bb5: {
-          StorageDead(_12);
-          StorageDead(_11);
+          StorageDead(_10);
+          StorageDead(_9);
           goto -> bb8;
       }
   
       bb6: {
-          StorageLive(_18);
-          _18 = _5;
-          _0 = float_to_exponential_common_shortest::<T>(_1, _2, move _18, _3) -> [return: bb7, unwind continue];
+          StorageLive(_12);
+          _12 = _5;
+          _0 = float_to_exponential_common_shortest::<T>(_1, _2, move _12, _3) -> [return: bb7, unwind continue];
       }
   
       bb7: {
-          StorageDead(_18);
+          StorageDead(_12);
           goto -> bb8;
       }
   
diff --git a/tests/mir-opt/inline/issue_58867_inline_as_ref_as_mut.b.Inline.after.mir b/tests/mir-opt/inline/issue_58867_inline_as_ref_as_mut.b.Inline.after.mir
index 62d7e839f5a..408cc5bb341 100644
--- a/tests/mir-opt/inline/issue_58867_inline_as_ref_as_mut.b.Inline.after.mir
+++ b/tests/mir-opt/inline/issue_58867_inline_as_ref_as_mut.b.Inline.after.mir
@@ -19,7 +19,7 @@ fn b(_1: &mut Box<T>) -> &mut T {
         _4 = &mut (*_1);
         StorageLive(_5);
         StorageLive(_6);
-        _5 = deref_copy (*_4);
+        _5 = (*_4);
         _6 = (((_5.0: std::ptr::Unique<T>).0: std::ptr::NonNull<T>).0: *const T);
         _3 = &mut (*_6);
         StorageDead(_6);
diff --git a/tests/mir-opt/inline/issue_58867_inline_as_ref_as_mut.d.Inline.after.mir b/tests/mir-opt/inline/issue_58867_inline_as_ref_as_mut.d.Inline.after.mir
index bc0aa06a752..4d20f6c4419 100644
--- a/tests/mir-opt/inline/issue_58867_inline_as_ref_as_mut.d.Inline.after.mir
+++ b/tests/mir-opt/inline/issue_58867_inline_as_ref_as_mut.d.Inline.after.mir
@@ -17,7 +17,7 @@ fn d(_1: &Box<T>) -> &T {
         _3 = &(*_1);
         StorageLive(_4);
         StorageLive(_5);
-        _4 = deref_copy (*_3);
+        _4 = (*_3);
         _5 = (((_4.0: std::ptr::Unique<T>).0: std::ptr::NonNull<T>).0: *const T);
         _2 = &(*_5);
         StorageDead(_5);
diff --git a/tests/mir-opt/issue_101973.inner.ConstProp.panic-abort.diff b/tests/mir-opt/issue_101973.inner.ConstProp.panic-abort.diff
index 3748d148380..d082e9d31dc 100644
--- a/tests/mir-opt/issue_101973.inner.ConstProp.panic-abort.diff
+++ b/tests/mir-opt/issue_101973.inner.ConstProp.panic-abort.diff
@@ -10,23 +10,17 @@
       let mut _5: u32;
       let mut _6: u32;
       let mut _7: u32;
-      let mut _8: u32;
-      let mut _9: u32;
-      let mut _10: u32;
-      let mut _11: bool;
-      let mut _12: u32;
-      let mut _13: bool;
       scope 1 (inlined imm8) {
           debug x => _1;
-          let mut _14: u32;
-          let mut _15: u32;
+          let mut _8: u32;
+          let mut _9: u32;
           scope 2 {
               debug out => _4;
           }
       }
       scope 3 (inlined core::num::<impl u32>::rotate_right) {
           debug self => _4;
-          debug n => _6;
+          debug n => _5;
       }
   
       bb0: {
@@ -34,44 +28,34 @@
           StorageLive(_3);
           StorageLive(_4);
           _4 = const 0_u32;
-          StorageLive(_15);
-          StorageLive(_14);
-          _14 = Shr(_1, const 0_i32);
-          _15 = BitAnd(move _14, const 255_u32);
-          StorageDead(_14);
-          _4 = BitOr(const 0_u32, move _15);
-          StorageDead(_15);
+          StorageLive(_9);
+          StorageLive(_8);
+          _8 = Shr(_1, const 0_i32);
+          _9 = BitAnd(move _8, const 255_u32);
+          StorageDead(_8);
+          _4 = BitOr(const 0_u32, move _9);
+          StorageDead(_9);
+          StorageLive(_5);
           StorageLive(_6);
           StorageLive(_7);
-          StorageLive(_8);
--         _10 = const 8_i32 as u32 (IntToInt);
--         _11 = Lt(move _10, const 32_u32);
--         assert(move _11, "attempt to shift right by `{}`, which would overflow", const 8_i32) -> [success: bb1, unwind unreachable];
-+         _10 = const 8_u32;
-+         _11 = const true;
-+         assert(const true, "attempt to shift right by `{}`, which would overflow", const 8_i32) -> [success: bb1, unwind unreachable];
+          assert(const true, "attempt to shift right by `{}`, which would overflow", const 8_i32) -> [success: bb1, unwind unreachable];
       }
   
       bb1: {
-          _8 = Shr(_1, const 8_i32);
-          _7 = BitAnd(move _8, const 15_u32);
-          StorageDead(_8);
--         _12 = const 1_i32 as u32 (IntToInt);
--         _13 = Lt(move _12, const 32_u32);
--         assert(move _13, "attempt to shift left by `{}`, which would overflow", const 1_i32) -> [success: bb2, unwind unreachable];
-+         _12 = const 1_u32;
-+         _13 = const true;
-+         assert(const true, "attempt to shift left by `{}`, which would overflow", const 1_i32) -> [success: bb2, unwind unreachable];
+          _7 = Shr(_1, const 8_i32);
+          _6 = BitAnd(move _7, const 15_u32);
+          StorageDead(_7);
+          assert(const true, "attempt to shift left by `{}`, which would overflow", const 1_i32) -> [success: bb2, unwind unreachable];
       }
   
       bb2: {
-          _6 = Shl(move _7, const 1_i32);
-          StorageDead(_7);
-          _3 = rotate_right::<u32>(move _4, move _6) -> [return: bb3, unwind unreachable];
+          _5 = Shl(move _6, const 1_i32);
+          StorageDead(_6);
+          _3 = rotate_right::<u32>(move _4, move _5) -> [return: bb3, unwind unreachable];
       }
   
       bb3: {
-          StorageDead(_6);
+          StorageDead(_5);
           StorageDead(_4);
           _2 = move _3 as i32 (IntToInt);
           StorageDead(_3);
diff --git a/tests/mir-opt/issue_101973.inner.ConstProp.panic-unwind.diff b/tests/mir-opt/issue_101973.inner.ConstProp.panic-unwind.diff
index 9dab4233c56..0962a449f73 100644
--- a/tests/mir-opt/issue_101973.inner.ConstProp.panic-unwind.diff
+++ b/tests/mir-opt/issue_101973.inner.ConstProp.panic-unwind.diff
@@ -10,23 +10,17 @@
       let mut _5: u32;
       let mut _6: u32;
       let mut _7: u32;
-      let mut _8: u32;
-      let mut _9: u32;
-      let mut _10: u32;
-      let mut _11: bool;
-      let mut _12: u32;
-      let mut _13: bool;
       scope 1 (inlined imm8) {
           debug x => _1;
-          let mut _14: u32;
-          let mut _15: u32;
+          let mut _8: u32;
+          let mut _9: u32;
           scope 2 {
               debug out => _4;
           }
       }
       scope 3 (inlined core::num::<impl u32>::rotate_right) {
           debug self => _4;
-          debug n => _6;
+          debug n => _5;
       }
   
       bb0: {
@@ -34,44 +28,34 @@
           StorageLive(_3);
           StorageLive(_4);
           _4 = const 0_u32;
-          StorageLive(_15);
-          StorageLive(_14);
-          _14 = Shr(_1, const 0_i32);
-          _15 = BitAnd(move _14, const 255_u32);
-          StorageDead(_14);
-          _4 = BitOr(const 0_u32, move _15);
-          StorageDead(_15);
+          StorageLive(_9);
+          StorageLive(_8);
+          _8 = Shr(_1, const 0_i32);
+          _9 = BitAnd(move _8, const 255_u32);
+          StorageDead(_8);
+          _4 = BitOr(const 0_u32, move _9);
+          StorageDead(_9);
+          StorageLive(_5);
           StorageLive(_6);
           StorageLive(_7);
-          StorageLive(_8);
--         _10 = const 8_i32 as u32 (IntToInt);
--         _11 = Lt(move _10, const 32_u32);
--         assert(move _11, "attempt to shift right by `{}`, which would overflow", const 8_i32) -> [success: bb1, unwind continue];
-+         _10 = const 8_u32;
-+         _11 = const true;
-+         assert(const true, "attempt to shift right by `{}`, which would overflow", const 8_i32) -> [success: bb1, unwind continue];
+          assert(const true, "attempt to shift right by `{}`, which would overflow", const 8_i32) -> [success: bb1, unwind continue];
       }
   
       bb1: {
-          _8 = Shr(_1, const 8_i32);
-          _7 = BitAnd(move _8, const 15_u32);
-          StorageDead(_8);
--         _12 = const 1_i32 as u32 (IntToInt);
--         _13 = Lt(move _12, const 32_u32);
--         assert(move _13, "attempt to shift left by `{}`, which would overflow", const 1_i32) -> [success: bb2, unwind continue];
-+         _12 = const 1_u32;
-+         _13 = const true;
-+         assert(const true, "attempt to shift left by `{}`, which would overflow", const 1_i32) -> [success: bb2, unwind continue];
+          _7 = Shr(_1, const 8_i32);
+          _6 = BitAnd(move _7, const 15_u32);
+          StorageDead(_7);
+          assert(const true, "attempt to shift left by `{}`, which would overflow", const 1_i32) -> [success: bb2, unwind continue];
       }
   
       bb2: {
-          _6 = Shl(move _7, const 1_i32);
-          StorageDead(_7);
-          _3 = rotate_right::<u32>(move _4, move _6) -> [return: bb3, unwind unreachable];
+          _5 = Shl(move _6, const 1_i32);
+          StorageDead(_6);
+          _3 = rotate_right::<u32>(move _4, move _5) -> [return: bb3, unwind unreachable];
       }
   
       bb3: {
-          StorageDead(_6);
+          StorageDead(_5);
           StorageDead(_4);
           _2 = move _3 as i32 (IntToInt);
           StorageDead(_3);
diff --git a/tests/mir-opt/pre-codegen/checked_ops.checked_shl.PreCodegen.after.mir b/tests/mir-opt/pre-codegen/checked_ops.checked_shl.PreCodegen.after.mir
index 8304cb45b35..9c6c30214aa 100644
--- a/tests/mir-opt/pre-codegen/checked_ops.checked_shl.PreCodegen.after.mir
+++ b/tests/mir-opt/pre-codegen/checked_ops.checked_shl.PreCodegen.after.mir
@@ -55,7 +55,7 @@ fn checked_shl(_1: u32, _2: u32) -> Option<u32> {
     }
 
     bb3: {
-        _0 = Option::<u32>::None;
+        _0 = const Option::<u32>::None;
         goto -> bb4;
     }
 
@@ -66,3 +66,7 @@ fn checked_shl(_1: u32, _2: u32) -> Option<u32> {
         return;
     }
 }
+
+ALLOC0 (size: 8, align: 4) {
+    00 00 00 00 __ __ __ __                         │ ....░░░░
+}
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff
index d5628dc7a6e..5cb528c0d5f 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff
@@ -55,8 +55,10 @@
 -         _2 = Option::<Layout>::None;
 +         _2 = const Option::<Layout>::None;
           StorageLive(_10);
-          _10 = const 0_isize;
-          switchInt(const 0_isize) -> [0: bb1, 1: bb3, otherwise: bb2];
+-         _10 = discriminant(_2);
+-         switchInt(move _10) -> [0: bb1, 1: bb3, otherwise: bb2];
++         _10 = const 0_isize;
++         switchInt(const 0_isize) -> [0: bb1, 1: bb3, otherwise: bb2];
       }
   
       bb1: {
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff
index d28059458ae..1e1585f20ae 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff
@@ -40,8 +40,10 @@
 -         _2 = Option::<Layout>::None;
 +         _2 = const Option::<Layout>::None;
           StorageLive(_10);
-          _10 = const 0_isize;
-          switchInt(const 0_isize) -> [0: bb2, 1: bb4, otherwise: bb3];
+-         _10 = discriminant(_2);
+-         switchInt(move _10) -> [0: bb2, 1: bb4, otherwise: bb3];
++         _10 = const 0_isize;
++         switchInt(const 0_isize) -> [0: bb2, 1: bb4, otherwise: bb3];
       }
   
       bb1: {
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff
index d139fc73e21..e655af559a1 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff
@@ -55,8 +55,10 @@
 -         _2 = Option::<Layout>::None;
 +         _2 = const Option::<Layout>::None;
           StorageLive(_10);
-          _10 = const 0_isize;
-          switchInt(const 0_isize) -> [0: bb1, 1: bb3, otherwise: bb2];
+-         _10 = discriminant(_2);
+-         switchInt(move _10) -> [0: bb1, 1: bb3, otherwise: bb2];
++         _10 = const 0_isize;
++         switchInt(const 0_isize) -> [0: bb1, 1: bb3, otherwise: bb2];
       }
   
       bb1: {
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff
index 63db9553b37..a6658713a02 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff
@@ -40,8 +40,10 @@
 -         _2 = Option::<Layout>::None;
 +         _2 = const Option::<Layout>::None;
           StorageLive(_10);
-          _10 = const 0_isize;
-          switchInt(const 0_isize) -> [0: bb2, 1: bb4, otherwise: bb3];
+-         _10 = discriminant(_2);
+-         switchInt(move _10) -> [0: bb2, 1: bb4, otherwise: bb3];
++         _10 = const 0_isize;
++         switchInt(const 0_isize) -> [0: bb2, 1: bb4, otherwise: bb3];
       }
   
       bb1: {
diff --git a/tests/mir-opt/pre-codegen/loops.int_range.PreCodegen.after.mir b/tests/mir-opt/pre-codegen/loops.int_range.PreCodegen.after.mir
index 73a3be7f301..42c7eb3c6aa 100644
--- a/tests/mir-opt/pre-codegen/loops.int_range.PreCodegen.after.mir
+++ b/tests/mir-opt/pre-codegen/loops.int_range.PreCodegen.after.mir
@@ -72,7 +72,7 @@ fn int_range(_1: usize, _2: usize) -> () {
     bb2: {
         StorageDead(_7);
         StorageDead(_6);
-        _11 = Option::<usize>::None;
+        _11 = const Option::<usize>::None;
         goto -> bb5;
     }
 
@@ -118,3 +118,7 @@ fn int_range(_1: usize, _2: usize) -> () {
         unreachable;
     }
 }
+
+ALLOC0 (size: 16, align: 8) {
+    00 00 00 00 00 00 00 00 __ __ __ __ __ __ __ __ │ ........░░░░░░░░
+}
diff --git a/tests/mir-opt/pre-codegen/loops.rs b/tests/mir-opt/pre-codegen/loops.rs
index 7f9c26f4fff..9412c3f234e 100644
--- a/tests/mir-opt/pre-codegen/loops.rs
+++ b/tests/mir-opt/pre-codegen/loops.rs
@@ -1,6 +1,7 @@
 // skip-filecheck
 // compile-flags: -O -Zmir-opt-level=2 -g
 // needs-unwind
+// only-64bit
 
 #![crate_type = "lib"]
 
diff --git a/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.32bit.panic-abort.diff b/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.32bit.panic-abort.diff
index bddd961c933..8c7ed678fe1 100644
--- a/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.32bit.panic-abort.diff
+++ b/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.32bit.panic-abort.diff
@@ -4,60 +4,35 @@
   fn main() -> () {
       let mut _0: ();
       let _1: i32;
-      let mut _2: (i32, bool);
-      let mut _4: [i32; 6];
-      let _5: usize;
-      let mut _6: usize;
-      let mut _7: bool;
-      let mut _9: u32;
+      let mut _3: u32;
       scope 1 {
           debug x => _1;
-          let _3: i32;
+          let _2: i32;
           scope 2 {
-              debug y => _3;
-              let _8: u32;
+              debug y => _2;
               scope 3 {
-                  debug z => _9;
+                  debug z => _3;
               }
           }
       }
   
       bb0: {
           StorageLive(_1);
--         _2 = CheckedAdd(const 2_i32, const 2_i32);
--         assert(!move (_2.1: bool), "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind unreachable];
-+         _2 = const (4_i32, false);
-+         assert(!const false, "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind unreachable];
+          assert(!const false, "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind unreachable];
       }
   
       bb1: {
--         _1 = move (_2.0: i32);
-+         _1 = const 4_i32;
-          StorageLive(_3);
-          StorageLive(_4);
-          _4 = [const 0_i32, const 1_i32, const 2_i32, const 3_i32, const 4_i32, const 5_i32];
-          StorageLive(_5);
-          _5 = const 3_usize;
-          _6 = const 6_usize;
--         _7 = Lt(_5, _6);
--         assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, _5) -> [success: bb2, unwind unreachable];
-+         _7 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 6_usize, const 3_usize) -> [success: bb2, unwind unreachable];
+          _1 = const 4_i32;
+          StorageLive(_2);
+          assert(const true, "index out of bounds: the length is {} but the index is {}", const 6_usize, const 3_usize) -> [success: bb2, unwind unreachable];
       }
   
       bb2: {
--         _3 = _4[_5];
-+         _3 = const 3_i32;
-          StorageDead(_5);
-          StorageDead(_4);
-          _9 = const 42_u32;
-          StorageDead(_3);
+          _2 = const 3_i32;
+          _3 = const 42_u32;
+          StorageDead(_2);
           StorageDead(_1);
           return;
       }
-+ }
-+ 
-+ ALLOC0 (size: 8, align: 4) {
-+     04 00 00 00 00 __ __ __                         │ .....░░░
   }
   
diff --git a/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.32bit.panic-unwind.diff b/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.32bit.panic-unwind.diff
index 297ebd79fad..5ba417a5b0f 100644
--- a/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.32bit.panic-unwind.diff
+++ b/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.32bit.panic-unwind.diff
@@ -4,60 +4,35 @@
   fn main() -> () {
       let mut _0: ();
       let _1: i32;
-      let mut _2: (i32, bool);
-      let mut _4: [i32; 6];
-      let _5: usize;
-      let mut _6: usize;
-      let mut _7: bool;
-      let mut _9: u32;
+      let mut _3: u32;
       scope 1 {
           debug x => _1;
-          let _3: i32;
+          let _2: i32;
           scope 2 {
-              debug y => _3;
-              let _8: u32;
+              debug y => _2;
               scope 3 {
-                  debug z => _9;
+                  debug z => _3;
               }
           }
       }
   
       bb0: {
           StorageLive(_1);
--         _2 = CheckedAdd(const 2_i32, const 2_i32);
--         assert(!move (_2.1: bool), "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind continue];
-+         _2 = const (4_i32, false);
-+         assert(!const false, "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind continue];
+          assert(!const false, "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind continue];
       }
   
       bb1: {
--         _1 = move (_2.0: i32);
-+         _1 = const 4_i32;
-          StorageLive(_3);
-          StorageLive(_4);
-          _4 = [const 0_i32, const 1_i32, const 2_i32, const 3_i32, const 4_i32, const 5_i32];
-          StorageLive(_5);
-          _5 = const 3_usize;
-          _6 = const 6_usize;
--         _7 = Lt(_5, _6);
--         assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, _5) -> [success: bb2, unwind continue];
-+         _7 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 6_usize, const 3_usize) -> [success: bb2, unwind continue];
+          _1 = const 4_i32;
+          StorageLive(_2);
+          assert(const true, "index out of bounds: the length is {} but the index is {}", const 6_usize, const 3_usize) -> [success: bb2, unwind continue];
       }
   
       bb2: {
--         _3 = _4[_5];
-+         _3 = const 3_i32;
-          StorageDead(_5);
-          StorageDead(_4);
-          _9 = const 42_u32;
-          StorageDead(_3);
+          _2 = const 3_i32;
+          _3 = const 42_u32;
+          StorageDead(_2);
           StorageDead(_1);
           return;
       }
-+ }
-+ 
-+ ALLOC0 (size: 8, align: 4) {
-+     04 00 00 00 00 __ __ __                         │ .....░░░
   }
   
diff --git a/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.64bit.panic-abort.diff b/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.64bit.panic-abort.diff
index bddd961c933..8c7ed678fe1 100644
--- a/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.64bit.panic-abort.diff
+++ b/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.64bit.panic-abort.diff
@@ -4,60 +4,35 @@
   fn main() -> () {
       let mut _0: ();
       let _1: i32;
-      let mut _2: (i32, bool);
-      let mut _4: [i32; 6];
-      let _5: usize;
-      let mut _6: usize;
-      let mut _7: bool;
-      let mut _9: u32;
+      let mut _3: u32;
       scope 1 {
           debug x => _1;
-          let _3: i32;
+          let _2: i32;
           scope 2 {
-              debug y => _3;
-              let _8: u32;
+              debug y => _2;
               scope 3 {
-                  debug z => _9;
+                  debug z => _3;
               }
           }
       }
   
       bb0: {
           StorageLive(_1);
--         _2 = CheckedAdd(const 2_i32, const 2_i32);
--         assert(!move (_2.1: bool), "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind unreachable];
-+         _2 = const (4_i32, false);
-+         assert(!const false, "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind unreachable];
+          assert(!const false, "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind unreachable];
       }
   
       bb1: {
--         _1 = move (_2.0: i32);
-+         _1 = const 4_i32;
-          StorageLive(_3);
-          StorageLive(_4);
-          _4 = [const 0_i32, const 1_i32, const 2_i32, const 3_i32, const 4_i32, const 5_i32];
-          StorageLive(_5);
-          _5 = const 3_usize;
-          _6 = const 6_usize;
--         _7 = Lt(_5, _6);
--         assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, _5) -> [success: bb2, unwind unreachable];
-+         _7 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 6_usize, const 3_usize) -> [success: bb2, unwind unreachable];
+          _1 = const 4_i32;
+          StorageLive(_2);
+          assert(const true, "index out of bounds: the length is {} but the index is {}", const 6_usize, const 3_usize) -> [success: bb2, unwind unreachable];
       }
   
       bb2: {
--         _3 = _4[_5];
-+         _3 = const 3_i32;
-          StorageDead(_5);
-          StorageDead(_4);
-          _9 = const 42_u32;
-          StorageDead(_3);
+          _2 = const 3_i32;
+          _3 = const 42_u32;
+          StorageDead(_2);
           StorageDead(_1);
           return;
       }
-+ }
-+ 
-+ ALLOC0 (size: 8, align: 4) {
-+     04 00 00 00 00 __ __ __                         │ .....░░░
   }
   
diff --git a/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.64bit.panic-unwind.diff b/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.64bit.panic-unwind.diff
index 297ebd79fad..5ba417a5b0f 100644
--- a/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.64bit.panic-unwind.diff
+++ b/tests/mir-opt/pre-codegen/optimizes_into_variable.main.ConstProp.64bit.panic-unwind.diff
@@ -4,60 +4,35 @@
   fn main() -> () {
       let mut _0: ();
       let _1: i32;
-      let mut _2: (i32, bool);
-      let mut _4: [i32; 6];
-      let _5: usize;
-      let mut _6: usize;
-      let mut _7: bool;
-      let mut _9: u32;
+      let mut _3: u32;
       scope 1 {
           debug x => _1;
-          let _3: i32;
+          let _2: i32;
           scope 2 {
-              debug y => _3;
-              let _8: u32;
+              debug y => _2;
               scope 3 {
-                  debug z => _9;
+                  debug z => _3;
               }
           }
       }
   
       bb0: {
           StorageLive(_1);
--         _2 = CheckedAdd(const 2_i32, const 2_i32);
--         assert(!move (_2.1: bool), "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind continue];
-+         _2 = const (4_i32, false);
-+         assert(!const false, "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind continue];
+          assert(!const false, "attempt to compute `{} + {}`, which would overflow", const 2_i32, const 2_i32) -> [success: bb1, unwind continue];
       }
   
       bb1: {
--         _1 = move (_2.0: i32);
-+         _1 = const 4_i32;
-          StorageLive(_3);
-          StorageLive(_4);
-          _4 = [const 0_i32, const 1_i32, const 2_i32, const 3_i32, const 4_i32, const 5_i32];
-          StorageLive(_5);
-          _5 = const 3_usize;
-          _6 = const 6_usize;
--         _7 = Lt(_5, _6);
--         assert(move _7, "index out of bounds: the length is {} but the index is {}", move _6, _5) -> [success: bb2, unwind continue];
-+         _7 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", const 6_usize, const 3_usize) -> [success: bb2, unwind continue];
+          _1 = const 4_i32;
+          StorageLive(_2);
+          assert(const true, "index out of bounds: the length is {} but the index is {}", const 6_usize, const 3_usize) -> [success: bb2, unwind continue];
       }
   
       bb2: {
--         _3 = _4[_5];
-+         _3 = const 3_i32;
-          StorageDead(_5);
-          StorageDead(_4);
-          _9 = const 42_u32;
-          StorageDead(_3);
+          _2 = const 3_i32;
+          _3 = const 42_u32;
+          StorageDead(_2);
           StorageDead(_1);
           return;
       }
-+ }
-+ 
-+ ALLOC0 (size: 8, align: 4) {
-+     04 00 00 00 00 __ __ __                         │ .....░░░
   }
   
diff --git a/tests/mir-opt/pre-codegen/range_iter.forward_loop.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/range_iter.forward_loop.PreCodegen.after.panic-abort.mir
index cd734b10fea..e5940bd8201 100644
--- a/tests/mir-opt/pre-codegen/range_iter.forward_loop.PreCodegen.after.panic-abort.mir
+++ b/tests/mir-opt/pre-codegen/range_iter.forward_loop.PreCodegen.after.panic-abort.mir
@@ -75,7 +75,7 @@ fn forward_loop(_1: u32, _2: u32, _3: impl Fn(u32)) -> () {
     bb2: {
         StorageDead(_8);
         StorageDead(_7);
-        _12 = Option::<u32>::None;
+        _12 = const Option::<u32>::None;
         goto -> bb5;
     }
 
@@ -131,3 +131,7 @@ fn forward_loop(_1: u32, _2: u32, _3: impl Fn(u32)) -> () {
         unreachable;
     }
 }
+
+ALLOC0 (size: 8, align: 4) {
+    00 00 00 00 __ __ __ __                         │ ....░░░░
+}
diff --git a/tests/mir-opt/pre-codegen/range_iter.forward_loop.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/range_iter.forward_loop.PreCodegen.after.panic-unwind.mir
index 3342da545ae..87e7485cb36 100644
--- a/tests/mir-opt/pre-codegen/range_iter.forward_loop.PreCodegen.after.panic-unwind.mir
+++ b/tests/mir-opt/pre-codegen/range_iter.forward_loop.PreCodegen.after.panic-unwind.mir
@@ -75,7 +75,7 @@ fn forward_loop(_1: u32, _2: u32, _3: impl Fn(u32)) -> () {
     bb2: {
         StorageDead(_8);
         StorageDead(_7);
-        _12 = Option::<u32>::None;
+        _12 = const Option::<u32>::None;
         goto -> bb5;
     }
 
@@ -139,3 +139,7 @@ fn forward_loop(_1: u32, _2: u32, _3: impl Fn(u32)) -> () {
         resume;
     }
 }
+
+ALLOC0 (size: 8, align: 4) {
+    00 00 00 00 __ __ __ __                         │ ....░░░░
+}
diff --git a/tests/mir-opt/pre-codegen/range_iter.range_iter_next.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/range_iter.range_iter_next.PreCodegen.after.panic-abort.mir
index 6ed3d73b11d..f674f6a3009 100644
--- a/tests/mir-opt/pre-codegen/range_iter.range_iter_next.PreCodegen.after.panic-abort.mir
+++ b/tests/mir-opt/pre-codegen/range_iter.range_iter_next.PreCodegen.after.panic-abort.mir
@@ -46,7 +46,7 @@ fn range_iter_next(_1: &mut std::ops::Range<u32>) -> Option<u32> {
     bb1: {
         StorageDead(_3);
         StorageDead(_2);
-        _0 = Option::<u32>::None;
+        _0 = const Option::<u32>::None;
         goto -> bb4;
     }
 
@@ -71,3 +71,7 @@ fn range_iter_next(_1: &mut std::ops::Range<u32>) -> Option<u32> {
         return;
     }
 }
+
+ALLOC0 (size: 8, align: 4) {
+    00 00 00 00 __ __ __ __                         │ ....░░░░
+}
diff --git a/tests/mir-opt/pre-codegen/range_iter.range_iter_next.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/range_iter.range_iter_next.PreCodegen.after.panic-unwind.mir
index a030647deae..a5029dcad3a 100644
--- a/tests/mir-opt/pre-codegen/range_iter.range_iter_next.PreCodegen.after.panic-unwind.mir
+++ b/tests/mir-opt/pre-codegen/range_iter.range_iter_next.PreCodegen.after.panic-unwind.mir
@@ -46,7 +46,7 @@ fn range_iter_next(_1: &mut std::ops::Range<u32>) -> Option<u32> {
     bb1: {
         StorageDead(_3);
         StorageDead(_2);
-        _0 = Option::<u32>::None;
+        _0 = const Option::<u32>::None;
         goto -> bb4;
     }
 
@@ -71,3 +71,7 @@ fn range_iter_next(_1: &mut std::ops::Range<u32>) -> Option<u32> {
         return;
     }
 }
+
+ALLOC0 (size: 8, align: 4) {
+    00 00 00 00 __ __ __ __                         │ ....░░░░
+}
diff --git a/tests/mir-opt/pre-codegen/simple_option_map.ezmap.PreCodegen.after.mir b/tests/mir-opt/pre-codegen/simple_option_map.ezmap.PreCodegen.after.mir
index af5d385a979..718dba21a95 100644
--- a/tests/mir-opt/pre-codegen/simple_option_map.ezmap.PreCodegen.after.mir
+++ b/tests/mir-opt/pre-codegen/simple_option_map.ezmap.PreCodegen.after.mir
@@ -24,7 +24,7 @@ fn ezmap(_1: Option<i32>) -> Option<i32> {
     }
 
     bb1: {
-        _0 = Option::<i32>::None;
+        _0 = const Option::<i32>::None;
         goto -> bb3;
     }
 
@@ -46,3 +46,7 @@ fn ezmap(_1: Option<i32>) -> Option<i32> {
         unreachable;
     }
 }
+
+ALLOC0 (size: 8, align: 4) {
+    00 00 00 00 __ __ __ __                         │ ....░░░░
+}
diff --git a/tests/mir-opt/pre-codegen/slice_filter.variant_a-{closure#0}.PreCodegen.after.mir b/tests/mir-opt/pre-codegen/slice_filter.variant_a-{closure#0}.PreCodegen.after.mir
index 05f16cdacce..cc009e45e7e 100644
--- a/tests/mir-opt/pre-codegen/slice_filter.variant_a-{closure#0}.PreCodegen.after.mir
+++ b/tests/mir-opt/pre-codegen/slice_filter.variant_a-{closure#0}.PreCodegen.after.mir
@@ -4,239 +4,217 @@ fn variant_a::{closure#0}(_1: &mut {closure@$DIR/slice_filter.rs:8:25: 8:39}, _2
     let mut _0: bool;
     let mut _3: &(usize, usize, usize, usize);
     let _4: &usize;
-    let mut _5: &(usize, usize, usize, usize);
+    let _5: &usize;
     let _6: &usize;
-    let mut _7: &(usize, usize, usize, usize);
-    let _8: &usize;
-    let mut _9: &(usize, usize, usize, usize);
-    let _10: &usize;
-    let mut _11: &&usize;
-    let _12: &usize;
-    let mut _13: &&usize;
-    let mut _18: bool;
-    let mut _19: &&usize;
-    let _20: &usize;
-    let mut _21: &&usize;
-    let mut _26: bool;
-    let mut _27: &&usize;
-    let _28: &usize;
-    let mut _29: &&usize;
-    let mut _34: bool;
-    let mut _35: &&usize;
-    let _36: &usize;
-    let mut _37: &&usize;
+    let _7: &usize;
+    let mut _8: &&usize;
+    let _9: &usize;
+    let mut _10: &&usize;
+    let mut _15: bool;
+    let mut _16: &&usize;
+    let _17: &usize;
+    let mut _18: &&usize;
+    let mut _23: bool;
+    let mut _24: &&usize;
+    let _25: &usize;
+    let mut _26: &&usize;
+    let mut _31: bool;
+    let mut _32: &&usize;
+    let _33: &usize;
+    let mut _34: &&usize;
     scope 1 {
         debug a => _4;
-        debug b => _6;
-        debug c => _8;
-        debug d => _10;
+        debug b => _5;
+        debug c => _6;
+        debug d => _7;
         scope 2 (inlined std::cmp::impls::<impl PartialOrd for &usize>::le) {
-            debug self => _11;
-            debug other => _13;
-            let mut _14: &usize;
-            let mut _15: &usize;
+            debug self => _8;
+            debug other => _10;
+            let mut _11: &usize;
+            let mut _12: &usize;
             scope 3 (inlined std::cmp::impls::<impl PartialOrd for usize>::le) {
-                debug self => _14;
-                debug other => _15;
-                let mut _16: usize;
-                let mut _17: usize;
+                debug self => _11;
+                debug other => _12;
+                let mut _13: usize;
+                let mut _14: usize;
             }
         }
         scope 4 (inlined std::cmp::impls::<impl PartialOrd for &usize>::le) {
-            debug self => _19;
-            debug other => _21;
-            let mut _22: &usize;
-            let mut _23: &usize;
+            debug self => _16;
+            debug other => _18;
+            let mut _19: &usize;
+            let mut _20: &usize;
             scope 5 (inlined std::cmp::impls::<impl PartialOrd for usize>::le) {
-                debug self => _22;
-                debug other => _23;
-                let mut _24: usize;
-                let mut _25: usize;
+                debug self => _19;
+                debug other => _20;
+                let mut _21: usize;
+                let mut _22: usize;
             }
         }
         scope 6 (inlined std::cmp::impls::<impl PartialOrd for &usize>::le) {
-            debug self => _27;
-            debug other => _29;
-            let mut _30: &usize;
-            let mut _31: &usize;
+            debug self => _24;
+            debug other => _26;
+            let mut _27: &usize;
+            let mut _28: &usize;
             scope 7 (inlined std::cmp::impls::<impl PartialOrd for usize>::le) {
-                debug self => _30;
-                debug other => _31;
-                let mut _32: usize;
-                let mut _33: usize;
+                debug self => _27;
+                debug other => _28;
+                let mut _29: usize;
+                let mut _30: usize;
             }
         }
         scope 8 (inlined std::cmp::impls::<impl PartialOrd for &usize>::le) {
-            debug self => _35;
-            debug other => _37;
-            let mut _38: &usize;
-            let mut _39: &usize;
+            debug self => _32;
+            debug other => _34;
+            let mut _35: &usize;
+            let mut _36: &usize;
             scope 9 (inlined std::cmp::impls::<impl PartialOrd for usize>::le) {
-                debug self => _38;
-                debug other => _39;
-                let mut _40: usize;
-                let mut _41: usize;
+                debug self => _35;
+                debug other => _36;
+                let mut _37: usize;
+                let mut _38: usize;
             }
         }
     }
 
     bb0: {
         StorageLive(_4);
-        _3 = deref_copy (*_2);
+        _3 = (*_2);
         _4 = &((*_3).0: usize);
+        StorageLive(_5);
+        _5 = &((*_3).1: usize);
         StorageLive(_6);
-        _5 = deref_copy (*_2);
-        _6 = &((*_5).1: usize);
+        _6 = &((*_3).2: usize);
+        StorageLive(_7);
+        _7 = &((*_3).3: usize);
+        StorageLive(_15);
         StorageLive(_8);
-        _7 = deref_copy (*_2);
-        _8 = &((*_7).2: usize);
+        _8 = &_4;
         StorageLive(_10);
-        _9 = deref_copy (*_2);
-        _10 = &((*_9).3: usize);
-        StorageLive(_18);
-        StorageLive(_11);
-        _11 = &_4;
+        StorageLive(_9);
+        _9 = _6;
+        _10 = &_9;
+        _11 = _4;
+        _12 = _9;
         StorageLive(_13);
-        StorageLive(_12);
-        _12 = _8;
-        _13 = &_12;
+        _13 = (*_11);
         StorageLive(_14);
-        StorageLive(_15);
-        _14 = deref_copy _4;
-        _15 = deref_copy _12;
-        StorageLive(_16);
-        _16 = (*_14);
-        StorageLive(_17);
-        _17 = (*_15);
-        _18 = Le(move _16, move _17);
-        StorageDead(_17);
-        StorageDead(_16);
-        StorageDead(_15);
+        _14 = (*_12);
+        _15 = Le(move _13, move _14);
         StorageDead(_14);
-        switchInt(move _18) -> [0: bb1, otherwise: bb2];
+        StorageDead(_13);
+        switchInt(move _15) -> [0: bb1, otherwise: bb2];
     }
 
     bb1: {
-        StorageDead(_12);
-        StorageDead(_13);
-        StorageDead(_11);
+        StorageDead(_9);
+        StorageDead(_10);
+        StorageDead(_8);
         goto -> bb4;
     }
 
     bb2: {
-        StorageDead(_12);
-        StorageDead(_13);
-        StorageDead(_11);
-        StorageLive(_26);
-        StorageLive(_19);
-        _19 = &_10;
+        StorageDead(_9);
+        StorageDead(_10);
+        StorageDead(_8);
+        StorageLive(_23);
+        StorageLive(_16);
+        _16 = &_7;
+        StorageLive(_18);
+        StorageLive(_17);
+        _17 = _5;
+        _18 = &_17;
+        _19 = _7;
+        _20 = _17;
         StorageLive(_21);
-        StorageLive(_20);
-        _20 = _6;
-        _21 = &_20;
+        _21 = (*_19);
         StorageLive(_22);
-        StorageLive(_23);
-        _22 = deref_copy _10;
-        _23 = deref_copy _20;
-        StorageLive(_24);
-        _24 = (*_22);
-        StorageLive(_25);
-        _25 = (*_23);
-        _26 = Le(move _24, move _25);
-        StorageDead(_25);
-        StorageDead(_24);
-        StorageDead(_23);
+        _22 = (*_20);
+        _23 = Le(move _21, move _22);
         StorageDead(_22);
-        switchInt(move _26) -> [0: bb3, otherwise: bb8];
+        StorageDead(_21);
+        switchInt(move _23) -> [0: bb3, otherwise: bb8];
     }
 
     bb3: {
-        StorageDead(_20);
-        StorageDead(_21);
-        StorageDead(_19);
+        StorageDead(_17);
+        StorageDead(_18);
+        StorageDead(_16);
         goto -> bb4;
     }
 
     bb4: {
-        StorageLive(_34);
-        StorageLive(_27);
-        _27 = &_8;
+        StorageLive(_31);
+        StorageLive(_24);
+        _24 = &_6;
+        StorageLive(_26);
+        StorageLive(_25);
+        _25 = _4;
+        _26 = &_25;
+        _27 = _6;
+        _28 = _25;
         StorageLive(_29);
-        StorageLive(_28);
-        _28 = _4;
-        _29 = &_28;
+        _29 = (*_27);
         StorageLive(_30);
-        StorageLive(_31);
-        _30 = deref_copy _8;
-        _31 = deref_copy _28;
-        StorageLive(_32);
-        _32 = (*_30);
-        StorageLive(_33);
-        _33 = (*_31);
-        _34 = Le(move _32, move _33);
-        StorageDead(_33);
-        StorageDead(_32);
-        StorageDead(_31);
+        _30 = (*_28);
+        _31 = Le(move _29, move _30);
         StorageDead(_30);
-        switchInt(move _34) -> [0: bb5, otherwise: bb6];
+        StorageDead(_29);
+        switchInt(move _31) -> [0: bb5, otherwise: bb6];
     }
 
     bb5: {
-        StorageDead(_28);
-        StorageDead(_29);
-        StorageDead(_27);
+        StorageDead(_25);
+        StorageDead(_26);
+        StorageDead(_24);
         _0 = const false;
         goto -> bb7;
     }
 
     bb6: {
-        StorageDead(_28);
-        StorageDead(_29);
-        StorageDead(_27);
-        StorageLive(_35);
-        _35 = &_6;
+        StorageDead(_25);
+        StorageDead(_26);
+        StorageDead(_24);
+        StorageLive(_32);
+        _32 = &_5;
+        StorageLive(_34);
+        StorageLive(_33);
+        _33 = _7;
+        _34 = &_33;
+        _35 = _5;
+        _36 = _33;
         StorageLive(_37);
-        StorageLive(_36);
-        _36 = _10;
-        _37 = &_36;
+        _37 = (*_35);
         StorageLive(_38);
-        StorageLive(_39);
-        _38 = deref_copy _6;
-        _39 = deref_copy _36;
-        StorageLive(_40);
-        _40 = (*_38);
-        StorageLive(_41);
-        _41 = (*_39);
-        _0 = Le(move _40, move _41);
-        StorageDead(_41);
-        StorageDead(_40);
-        StorageDead(_39);
+        _38 = (*_36);
+        _0 = Le(move _37, move _38);
         StorageDead(_38);
-        StorageDead(_36);
         StorageDead(_37);
-        StorageDead(_35);
+        StorageDead(_33);
+        StorageDead(_34);
+        StorageDead(_32);
         goto -> bb7;
     }
 
     bb7: {
-        StorageDead(_34);
+        StorageDead(_31);
         goto -> bb9;
     }
 
     bb8: {
-        StorageDead(_20);
-        StorageDead(_21);
-        StorageDead(_19);
+        StorageDead(_17);
+        StorageDead(_18);
+        StorageDead(_16);
         _0 = const true;
         goto -> bb9;
     }
 
     bb9: {
-        StorageDead(_26);
-        StorageDead(_18);
-        StorageDead(_10);
-        StorageDead(_8);
+        StorageDead(_23);
+        StorageDead(_15);
+        StorageDead(_7);
         StorageDead(_6);
+        StorageDead(_5);
         StorageDead(_4);
         return;
     }
diff --git a/tests/mir-opt/pre-codegen/slice_filter.variant_b-{closure#0}.PreCodegen.after.mir b/tests/mir-opt/pre-codegen/slice_filter.variant_b-{closure#0}.PreCodegen.after.mir
index e2ed1d101dc..5477796512c 100644
--- a/tests/mir-opt/pre-codegen/slice_filter.variant_b-{closure#0}.PreCodegen.after.mir
+++ b/tests/mir-opt/pre-codegen/slice_filter.variant_b-{closure#0}.PreCodegen.after.mir
@@ -4,46 +4,40 @@ fn variant_b::{closure#0}(_1: &mut {closure@$DIR/slice_filter.rs:12:25: 12:41},
     let mut _0: bool;
     let mut _3: &(usize, usize, usize, usize);
     let _4: usize;
-    let mut _5: &(usize, usize, usize, usize);
+    let _5: usize;
     let _6: usize;
-    let mut _7: &(usize, usize, usize, usize);
-    let _8: usize;
-    let mut _9: &(usize, usize, usize, usize);
-    let _10: usize;
-    let mut _11: bool;
-    let mut _12: bool;
-    let mut _13: bool;
+    let _7: usize;
+    let mut _8: bool;
+    let mut _9: bool;
+    let mut _10: bool;
     scope 1 {
         debug a => _4;
-        debug b => _6;
-        debug c => _8;
-        debug d => _10;
+        debug b => _5;
+        debug c => _6;
+        debug d => _7;
     }
 
     bb0: {
-        _3 = deref_copy (*_2);
+        _3 = (*_2);
         _4 = ((*_3).0: usize);
-        _5 = deref_copy (*_2);
-        _6 = ((*_5).1: usize);
-        _7 = deref_copy (*_2);
-        _8 = ((*_7).2: usize);
-        _9 = deref_copy (*_2);
-        _10 = ((*_9).3: usize);
-        StorageLive(_11);
-        _11 = Le(_4, _8);
-        switchInt(move _11) -> [0: bb2, otherwise: bb1];
+        _5 = ((*_3).1: usize);
+        _6 = ((*_3).2: usize);
+        _7 = ((*_3).3: usize);
+        StorageLive(_8);
+        _8 = Le(_4, _6);
+        switchInt(move _8) -> [0: bb2, otherwise: bb1];
     }
 
     bb1: {
-        StorageLive(_12);
-        _12 = Le(_10, _6);
-        switchInt(move _12) -> [0: bb2, otherwise: bb6];
+        StorageLive(_9);
+        _9 = Le(_7, _5);
+        switchInt(move _9) -> [0: bb2, otherwise: bb6];
     }
 
     bb2: {
-        StorageLive(_13);
-        _13 = Le(_8, _4);
-        switchInt(move _13) -> [0: bb3, otherwise: bb4];
+        StorageLive(_10);
+        _10 = Le(_6, _4);
+        switchInt(move _10) -> [0: bb3, otherwise: bb4];
     }
 
     bb3: {
@@ -52,12 +46,12 @@ fn variant_b::{closure#0}(_1: &mut {closure@$DIR/slice_filter.rs:12:25: 12:41},
     }
 
     bb4: {
-        _0 = Le(_6, _10);
+        _0 = Le(_5, _7);
         goto -> bb5;
     }
 
     bb5: {
-        StorageDead(_13);
+        StorageDead(_10);
         goto -> bb7;
     }
 
@@ -67,8 +61,8 @@ fn variant_b::{closure#0}(_1: &mut {closure@$DIR/slice_filter.rs:12:25: 12:41},
     }
 
     bb7: {
-        StorageDead(_12);
-        StorageDead(_11);
+        StorageDead(_9);
+        StorageDead(_8);
         return;
     }
 }
diff --git a/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-abort.mir
index e4d9060d4cf..a12411a0413 100644
--- a/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-abort.mir
+++ b/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-abort.mir
@@ -50,7 +50,6 @@ fn slice_get_mut_usize(_1: &mut [u32], _2: usize) -> Option<&mut u32> {
     }
 
     bb0: {
-        StorageLive(_7);
         StorageLive(_4);
         StorageLive(_3);
         _3 = Len((*_1));
@@ -86,7 +85,6 @@ fn slice_get_mut_usize(_1: &mut [u32], _2: usize) -> Option<&mut u32> {
 
     bb3: {
         StorageDead(_4);
-        StorageDead(_7);
         return;
     }
 }
diff --git a/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-unwind.mir
index e4d9060d4cf..a12411a0413 100644
--- a/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-unwind.mir
+++ b/tests/mir-opt/pre-codegen/slice_index.slice_get_mut_usize.PreCodegen.after.panic-unwind.mir
@@ -50,7 +50,6 @@ fn slice_get_mut_usize(_1: &mut [u32], _2: usize) -> Option<&mut u32> {
     }
 
     bb0: {
-        StorageLive(_7);
         StorageLive(_4);
         StorageLive(_3);
         _3 = Len((*_1));
@@ -86,7 +85,6 @@ fn slice_get_mut_usize(_1: &mut [u32], _2: usize) -> Option<&mut u32> {
 
     bb3: {
         StorageDead(_4);
-        StorageDead(_7);
         return;
     }
 }
diff --git a/tests/mir-opt/pre-codegen/slice_iter.range_loop.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/slice_iter.range_loop.PreCodegen.after.panic-abort.mir
index db6922968ae..6a99f15774f 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.range_loop.PreCodegen.after.panic-abort.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.range_loop.PreCodegen.after.panic-abort.mir
@@ -84,7 +84,7 @@ fn range_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
     bb2: {
         StorageDead(_8);
         StorageDead(_7);
-        _12 = Option::<usize>::None;
+        _12 = const Option::<usize>::None;
         goto -> bb5;
     }
 
@@ -147,3 +147,7 @@ fn range_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
         unreachable;
     }
 }
+
+ALLOC0 (size: 16, align: 8) {
+    00 00 00 00 00 00 00 00 __ __ __ __ __ __ __ __ │ ........░░░░░░░░
+}
diff --git a/tests/mir-opt/pre-codegen/slice_iter.range_loop.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/slice_iter.range_loop.PreCodegen.after.panic-unwind.mir
index 81d1832eebb..4f028fa0a64 100644
--- a/tests/mir-opt/pre-codegen/slice_iter.range_loop.PreCodegen.after.panic-unwind.mir
+++ b/tests/mir-opt/pre-codegen/slice_iter.range_loop.PreCodegen.after.panic-unwind.mir
@@ -84,7 +84,7 @@ fn range_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
     bb2: {
         StorageDead(_8);
         StorageDead(_7);
-        _12 = Option::<usize>::None;
+        _12 = const Option::<usize>::None;
         goto -> bb5;
     }
 
@@ -155,3 +155,7 @@ fn range_loop(_1: &[T], _2: impl Fn(usize, &T)) -> () {
         resume;
     }
 }
+
+ALLOC0 (size: 16, align: 8) {
+    00 00 00 00 00 00 00 00 __ __ __ __ __ __ __ __ │ ........░░░░░░░░
+}
diff --git a/tests/mir-opt/simplify_match.main.ConstProp.panic-abort.diff b/tests/mir-opt/simplify_match.main.ConstProp.panic-abort.diff
index 6025abb7382..2bb54d5a666 100644
--- a/tests/mir-opt/simplify_match.main.ConstProp.panic-abort.diff
+++ b/tests/mir-opt/simplify_match.main.ConstProp.panic-abort.diff
@@ -3,16 +3,14 @@
   
   fn main() -> () {
       let mut _0: ();
-      let mut _1: bool;
-      let _2: bool;
+      let _1: bool;
       scope 1 {
-          debug x => _2;
+          debug x => _1;
       }
   
       bb0: {
-          _2 = const false;
--         switchInt(_2) -> [0: bb1, otherwise: bb2];
-+         switchInt(const false) -> [0: bb1, otherwise: bb2];
+          _1 = const false;
+          switchInt(const false) -> [0: bb1, otherwise: bb2];
       }
   
       bb1: {
diff --git a/tests/mir-opt/simplify_match.main.ConstProp.panic-unwind.diff b/tests/mir-opt/simplify_match.main.ConstProp.panic-unwind.diff
index c881dec28c7..2d60e234e06 100644
--- a/tests/mir-opt/simplify_match.main.ConstProp.panic-unwind.diff
+++ b/tests/mir-opt/simplify_match.main.ConstProp.panic-unwind.diff
@@ -3,16 +3,14 @@
   
   fn main() -> () {
       let mut _0: ();
-      let mut _1: bool;
-      let _2: bool;
+      let _1: bool;
       scope 1 {
-          debug x => _2;
+          debug x => _1;
       }
   
       bb0: {
-          _2 = const false;
--         switchInt(_2) -> [0: bb1, otherwise: bb2];
-+         switchInt(const false) -> [0: bb1, otherwise: bb2];
+          _1 = const false;
+          switchInt(const false) -> [0: bb1, otherwise: bb2];
       }
   
       bb1: {