Rollup merge of #82736 - spastorino:mir-opt-level-perf-changes, r=oli-obk

Bump optimization from mir_opt_level 2 to 3 and 3 to 4 and make "release" be level 2 by default

r? `@oli-obk`

compiler/rustc_interface/src/tests.rs

@@ -566,7 +566,7 @@ fn test_debugging_options_tracking_hash() {
     tracked!(link_only, true);
     tracked!(merge_functions, Some(MergeFunctions::Disabled));
     tracked!(mir_emit_retag, true);
-    tracked!(mir_opt_level, 3);
+    tracked!(mir_opt_level, Some(4));
     tracked!(mutable_noalias, true);
     tracked!(new_llvm_pass_manager, true);
     tracked!(no_codegen, true);

compiler/rustc_mir/src/transform/const_goto.rs

@@ -28,7 +28,7 @@ pub struct ConstGoto;
 
 impl<'tcx> MirPass<'tcx> for ConstGoto {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        if tcx.sess.opts.debugging_opts.mir_opt_level < 3 {
+        if tcx.sess.mir_opt_level() < 4 {
             return;
         }
         trace!("Running ConstGoto on {:?}", body.source);

compiler/rustc_mir/src/transform/const_prop.rs

@@ -725,7 +725,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             return None;
         }
 
-        if self.tcx.sess.opts.debugging_opts.mir_opt_level >= 3 {
+        if self.tcx.sess.mir_opt_level() >= 4 {
             self.eval_rvalue_with_identities(rvalue, place)
         } else {
             self.use_ecx(|this| this.ecx.eval_rvalue_into_place(rvalue, place))
@@ -903,7 +903,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
 
     /// Returns `true` if and only if this `op` should be const-propagated into.
     fn should_const_prop(&mut self, op: &OpTy<'tcx>) -> bool {
-        let mir_opt_level = self.tcx.sess.opts.debugging_opts.mir_opt_level;
+        let mir_opt_level = self.tcx.sess.mir_opt_level();
 
         if mir_opt_level == 0 {
             return false;
@@ -1071,9 +1071,9 @@ impl<'mir, 'tcx> MutVisitor<'tcx> for ConstPropagator<'mir, 'tcx> {
     fn visit_operand(&mut self, operand: &mut Operand<'tcx>, location: Location) {
         self.super_operand(operand, location);
 
-        // Only const prop copies and moves on `mir_opt_level=2` as doing so
+        // Only const prop copies and moves on `mir_opt_level=3` as doing so
         // currently slightly increases compile time in some cases.
-        if self.tcx.sess.opts.debugging_opts.mir_opt_level >= 2 {
+        if self.tcx.sess.mir_opt_level() >= 3 {
             self.propagate_operand(operand)
         }
     }
@@ -1253,7 +1253,7 @@ impl<'mir, 'tcx> MutVisitor<'tcx> for ConstPropagator<'mir, 'tcx> {
             TerminatorKind::SwitchInt { ref mut discr, .. } => {
                 // FIXME: This is currently redundant with `visit_operand`, but sadly
                 // always visiting operands currently causes a perf regression in LLVM codegen, so
-                // `visit_operand` currently only runs for propagates places for `mir_opt_level=3`.
+                // `visit_operand` currently only runs for propagates places for `mir_opt_level=4`.
                 self.propagate_operand(discr)
             }
             // None of these have Operands to const-propagate.
@@ -1272,7 +1272,7 @@ impl<'mir, 'tcx> MutVisitor<'tcx> for ConstPropagator<'mir, 'tcx> {
             // Every argument in our function calls have already been propagated in `visit_operand`.
             //
             // NOTE: because LLVM codegen gives slight performance regressions with it, so this is
-            // gated on `mir_opt_level=2`.
+            // gated on `mir_opt_level=3`.
             TerminatorKind::Call { .. } => {}
         }
 

compiler/rustc_mir/src/transform/deduplicate_blocks.rs

@@ -16,7 +16,7 @@ pub struct DeduplicateBlocks;
 
 impl<'tcx> MirPass<'tcx> for DeduplicateBlocks {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        if tcx.sess.opts.debugging_opts.mir_opt_level < 3 {
+        if tcx.sess.mir_opt_level() < 4 {
             return;
         }
         debug!("Running DeduplicateBlocks on `{:?}`", body.source);

compiler/rustc_mir/src/transform/dest_prop.rs

@@ -127,9 +127,9 @@ pub struct DestinationPropagation;
 
 impl<'tcx> MirPass<'tcx> for DestinationPropagation {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        // Only run at mir-opt-level=2 or higher for now (we don't fix up debuginfo and remove
+        // Only run at mir-opt-level=3 or higher for now (we don't fix up debuginfo and remove
         // storage statements at the moment).
-        if tcx.sess.opts.debugging_opts.mir_opt_level <= 1 {
+        if tcx.sess.mir_opt_level() < 3 {
             return;
         }
 

compiler/rustc_mir/src/transform/early_otherwise_branch.rs

@@ -26,7 +26,7 @@ pub struct EarlyOtherwiseBranch;
 
 impl<'tcx> MirPass<'tcx> for EarlyOtherwiseBranch {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        if tcx.sess.opts.debugging_opts.mir_opt_level < 2 {
+        if tcx.sess.mir_opt_level() < 3 {
             return;
         }
         trace!("running EarlyOtherwiseBranch on {:?}", body.source);

compiler/rustc_mir/src/transform/inline.rs

@@ -52,7 +52,7 @@ crate fn is_enabled(tcx: TyCtxt<'_>) -> bool {
         return enabled;
     }
 
-    tcx.sess.opts.debugging_opts.mir_opt_level >= 2
+    tcx.sess.mir_opt_level() >= 3
 }
 
 impl<'tcx> MirPass<'tcx> for Inline {

compiler/rustc_mir/src/transform/match_branches.rs

@@ -40,7 +40,7 @@ pub struct MatchBranchSimplification;
 
 impl<'tcx> MirPass<'tcx> for MatchBranchSimplification {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        if tcx.sess.opts.debugging_opts.mir_opt_level <= 1 {
+        if tcx.sess.mir_opt_level() < 3 {
             return;
         }
 

compiler/rustc_mir/src/transform/mod.rs

@@ -475,7 +475,7 @@ fn run_post_borrowck_cleanup_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tc
 }
 
 fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-    let mir_opt_level = tcx.sess.opts.debugging_opts.mir_opt_level;
+    let mir_opt_level = tcx.sess.mir_opt_level();
 
     // Lowering generator control-flow and variables has to happen before we do anything else
     // to them. We run some optimizations before that, because they may be harder to do on the state

compiler/rustc_mir/src/transform/multiple_return_terminators.rs

@@ -10,7 +10,7 @@ pub struct MultipleReturnTerminators;
 
 impl<'tcx> MirPass<'tcx> for MultipleReturnTerminators {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        if tcx.sess.opts.debugging_opts.mir_opt_level < 3 {
+        if tcx.sess.mir_opt_level() < 4 {
             return;
         }
 

compiler/rustc_mir/src/transform/nrvo.rs

@@ -34,7 +34,7 @@ pub struct RenameReturnPlace;
 
 impl<'tcx> MirPass<'tcx> for RenameReturnPlace {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut mir::Body<'tcx>) {
-        if tcx.sess.opts.debugging_opts.mir_opt_level == 0 {
+        if tcx.sess.mir_opt_level() == 0 {
             return;
         }
 

compiler/rustc_mir/src/transform/unreachable_prop.rs

@@ -12,8 +12,8 @@ pub struct UnreachablePropagation;
 
 impl MirPass<'_> for UnreachablePropagation {
     fn run_pass<'tcx>(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        if tcx.sess.opts.debugging_opts.mir_opt_level < 3 {
-            // Enable only under -Zmir-opt-level=3 as in some cases (check the deeply-nested-opt
+        if tcx.sess.mir_opt_level() < 4 {
+            // Enable only under -Zmir-opt-level=4 as in some cases (check the deeply-nested-opt
             // perf benchmark) LLVM may spend quite a lot of time optimizing the generated code.
             return;
         }

compiler/rustc_session/src/config.rs

@@ -1938,21 +1938,23 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
             Some(SymbolManglingVersion::V0) => {}
         }
 
-        if debugging_opts.mir_opt_level > 1 {
-            // Functions inlined during MIR transform can, at best, make it impossible to
-            // effectively cover inlined functions, and, at worst, break coverage map generation
-            // during LLVM codegen. For example, function counter IDs are only unique within a
-            // function. Inlining after these counters are injected can produce duplicate counters,
-            // resulting in an invalid coverage map (and ICE); so this option combination is not
-            // allowed.
-            early_warn(
-                error_format,
-                &format!(
-                    "`-Z mir-opt-level={}` (or any level > 1) enables function inlining, which \
+        if let Some(mir_opt_level) = debugging_opts.mir_opt_level {
+            if mir_opt_level > 1 {
+                // Functions inlined during MIR transform can, at best, make it impossible to
+                // effectively cover inlined functions, and, at worst, break coverage map generation
+                // during LLVM codegen. For example, function counter IDs are only unique within a
+                // function. Inlining after these counters are injected can produce duplicate counters,
+                // resulting in an invalid coverage map (and ICE); so this option combination is not
+                // allowed.
+                early_warn(
+                    error_format,
+                    &format!(
+                        "`-Z mir-opt-level={}` (or any level > 1) enables function inlining, which \
                     is incompatible with `-Z instrument-coverage`. Inlining will be disabled.",
-                    debugging_opts.mir_opt_level,
-                ),
-            );
+                        mir_opt_level,
+                    ),
+                );
+            }
         }
     }
 

compiler/rustc_session/src/options.rs

@@ -999,8 +999,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
     mir_emit_retag: bool = (false, parse_bool, [TRACKED],
         "emit Retagging MIR statements, interpreted e.g., by miri; implies -Zmir-opt-level=0 \
         (default: no)"),
-    mir_opt_level: usize = (1, parse_uint, [TRACKED],
-        "MIR optimization level (0-3; default: 1)"),
+    mir_opt_level: Option<usize> = (None, parse_opt_uint, [TRACKED],
+        "MIR optimization level (0-4; default: 1 in non optimized builds and 2 in optimized builds)"),
     mutable_noalias: bool = (false, parse_bool, [TRACKED],
         "emit noalias metadata for mutable references (default: no)"),
     new_llvm_pass_manager: bool = (false, parse_bool, [TRACKED],

compiler/rustc_session/src/session.rs

@@ -640,6 +640,12 @@ impl Session {
     pub fn binary_dep_depinfo(&self) -> bool {
         self.opts.debugging_opts.binary_dep_depinfo
     }
+    pub fn mir_opt_level(&self) -> usize {
+        self.opts
+            .debugging_opts
+            .mir_opt_level
+            .unwrap_or_else(|| if self.opts.optimize != config::OptLevel::No { 2 } else { 1 })
+    }
 
     /// Gets the features enabled for the current compilation session.
     /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents

src/test/codegen/issue-59352.rs

@@ -5,8 +5,8 @@
 // Once the optimizer can do that, mir-opt/issues/issue-59352.rs will need to be updated and this
 // test case should be removed as it will become redundant.
 
-// mir-opt-level=2 enables inlining and enables LLVM to optimize away the unreachable panic call.
-// compile-flags: -O -Z mir-opt-level=2
+// mir-opt-level=3 enables inlining and enables LLVM to optimize away the unreachable panic call.
+// compile-flags: -O -Z mir-opt-level=3
 
 #![crate_type = "rlib"]
 

src/test/codegen/naked-noinline.rs

@@ -1,5 +1,5 @@
 // Checks that naked functions are never inlined.
-// compile-flags: -O -Zmir-opt-level=2
+// compile-flags: -O -Zmir-opt-level=3
 // ignore-wasm32
 #![crate_type = "lib"]
 #![feature(asm)]

src/test/codegen/sanitizer-no-sanitize-inlining.rs

@@ -4,8 +4,8 @@
 // needs-sanitizer-address
 // needs-sanitizer-leak
 // revisions: ASAN LSAN
-//[ASAN] compile-flags: -Zsanitizer=address -C opt-level=3 -Z mir-opt-level=3
-//[LSAN] compile-flags: -Zsanitizer=leak    -C opt-level=3 -Z mir-opt-level=3
+//[ASAN] compile-flags: -Zsanitizer=address -C opt-level=3 -Z mir-opt-level=4
+//[LSAN] compile-flags: -Zsanitizer=leak    -C opt-level=3 -Z mir-opt-level=4
 
 #![crate_type="lib"]
 #![feature(no_sanitize)]

src/test/codegen/try_identity.rs

@@ -1,4 +1,4 @@
-// compile-flags: -C no-prepopulate-passes -O -Z mir-opt-level=2 -Zunsound-mir-opts
+// compile-flags: -C no-prepopulate-passes -O -Z mir-opt-level=3 -Zunsound-mir-opts
 
 // Ensure that `x?` has no overhead on `Result<T, E>` due to identity `match`es in lowering.
 // This requires inlining to trigger the MIR optimizations in `SimplifyArmIdentity`.

src/test/mir-opt/const_prop/boolean_identities.rs

@@ -1,4 +1,4 @@
-// compile-flags: -O -Zmir-opt-level=3
+// compile-flags: -O -Zmir-opt-level=4
 
 // EMIT_MIR boolean_identities.test.ConstProp.diff
 pub fn test(x: bool, y: bool) -> bool {

src/test/mir-opt/const_prop/issue-66971.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 
 // Due to a bug in propagating scalar pairs the assertion below used to fail. In the expected
 // outputs below, after ConstProp this is how _2 would look like with the bug:

src/test/mir-opt/const_prop/issue-67019.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 
 // This used to ICE in const-prop
 

src/test/mir-opt/const_prop/mult_by_zero.rs

@@ -1,4 +1,4 @@
-// compile-flags: -O -Zmir-opt-level=3
+// compile-flags: -O -Zmir-opt-level=4
 
 // EMIT_MIR mult_by_zero.test.ConstProp.diff
 fn test(x : i32) -> i32 {

src/test/mir-opt/early_otherwise_branch.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=3
+// compile-flags: -Z mir-opt-level=4
 // EMIT_MIR early_otherwise_branch.opt1.EarlyOtherwiseBranch.diff
 fn opt1(x: Option<u32>, y: Option<u32>) -> u32 {
     match (x, y) {

src/test/mir-opt/early_otherwise_branch_3_element_tuple.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=3
+// compile-flags: -Z mir-opt-level=4
 
 // EMIT_MIR early_otherwise_branch_3_element_tuple.opt1.EarlyOtherwiseBranch.diff
 fn opt1(x: Option<u32>, y: Option<u32>, z: Option<u32>) -> u32 {

src/test/mir-opt/early_otherwise_branch_68867.rs

@@ -1,5 +1,5 @@
 // ignore-tidy-linelength
-// compile-flags: -Z mir-opt-level=3 -Zunsound-mir-opts
+// compile-flags: -Z mir-opt-level=4 -Zunsound-mir-opts
 
 // example from #68867
 type CSSFloat = f32;

src/test/mir-opt/early_otherwise_branch_noopt.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=3
+// compile-flags: -Z mir-opt-level=4
 
 // must not optimize as it does not follow the pattern of
 // left and right hand side being the same variant

src/test/mir-opt/inline/inline-into-box-place.rs

@@ -1,6 +1,6 @@
 // ignore-endian-big
 // ignore-wasm32-bare compiled with panic=abort by default
-// compile-flags: -Z mir-opt-level=3
+// compile-flags: -Z mir-opt-level=4
 // EMIT_MIR_FOR_EACH_BIT_WIDTH
 #![feature(box_syntax)]
 // EMIT_MIR inline_into_box_place.main.Inline.diff

src/test/mir-opt/inline/inline-trait-method_2.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z span_free_formats -Z mir-opt-level=3
+// compile-flags: -Z span_free_formats -Z mir-opt-level=4
 
 // EMIT_MIR inline_trait_method_2.test2.Inline.after.mir
 fn test2(x: &dyn X) -> bool {

src/test/mir-opt/issues/issue-59352.rs

@@ -7,7 +7,7 @@
 // removed.
 
 // EMIT_MIR issue_59352.num_to_digit.PreCodegen.after.mir
-// compile-flags: -Z mir-opt-level=2 -Z span_free_formats
+// compile-flags: -Z mir-opt-level=3 -Z span_free_formats
 
 pub fn num_to_digit(num: char) -> u32 {
     // CHECK-NOT: panic

src/test/mir-opt/multiple_return_terminators.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=3
+// compile-flags: -Z mir-opt-level=4
 // EMIT_MIR multiple_return_terminators.test.MultipleReturnTerminators.diff
 
 fn test(x: bool) {

src/test/mir-opt/simplify-arm-identity.rs

@@ -1,7 +1,7 @@
 // Checks that `SimplifyArmIdentity` is not applied if enums have incompatible layouts.
 // Regression test for issue #66856.
 //
-// compile-flags: -Zmir-opt-level=2
+// compile-flags: -Zmir-opt-level=3
 // EMIT_MIR_FOR_EACH_BIT_WIDTH
 
 enum Src {

src/test/mir-opt/simplify-arm.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2 -Zunsound-mir-opts
+// compile-flags: -Z mir-opt-level=3 -Zunsound-mir-opts
 // EMIT_MIR simplify_arm.id.SimplifyArmIdentity.diff
 // EMIT_MIR simplify_arm.id.SimplifyBranchSame.diff
 // EMIT_MIR simplify_arm.id_result.SimplifyArmIdentity.diff

src/test/ui/const-generics/issues/issue-75299.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Zmir-opt-level=3
+// compile-flags: -Zmir-opt-level=4
 // run-pass
 
 #![feature(const_generics)]

src/test/ui/const_prop/inline_spans.rs

@@ -1,5 +1,5 @@
 // build-fail
-// compile-flags: -Zmir-opt-level=2
+// compile-flags: -Zmir-opt-level=3
 
 #![deny(warnings)]
 

src/test/ui/const_prop/inline_spans_lint_attribute.rs

@@ -1,6 +1,6 @@
 // Must be build-pass, because check-pass will not run const prop and thus not emit the lint anyway.
 // build-pass
-// compile-flags: -Zmir-opt-level=2
+// compile-flags: -Zmir-opt-level=3
 
 #![deny(warnings)]
 

src/test/ui/consts/issue-66345.rs

@@ -1,8 +1,8 @@
 // run-pass
-// compile-flags: -Z mir-opt-level=3
+// compile-flags: -Z mir-opt-level=4
 
 // Checks that the compiler does not ICE when passing references to field of by-value struct
-// with -Z mir-opt-level=3
+// with -Z mir-opt-level=4
 
 fn do_nothing(_: &()) {}
 

src/test/ui/consts/issue-67529.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 // run-pass
 
 struct Baz<T: ?Sized> {

src/test/ui/consts/issue-67640.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=3
+// compile-flags: -Z mir-opt-level=4
 // run-pass
 
 struct X {

src/test/ui/consts/issue-67641.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 // run-pass
 
 use std::cell::Cell;

src/test/ui/consts/issue-67862.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 // run-pass
 
 fn e220() -> (i64, i64) {

src/test/ui/consts/trait_specialization.rs

@@ -1,5 +1,5 @@
 // ignore-wasm32-bare which doesn't support `std::process:exit()`
-// compile-flags: -Zmir-opt-level=2
+// compile-flags: -Zmir-opt-level=3
 // run-pass
 
 // Tests that specialization does not cause optimizations running on polymorphic MIR to resolve

src/test/ui/dest-prop/skeptic-miscompile.rs

@@ -1,6 +1,6 @@
 // run-pass
 
-// compile-flags: -Zmir-opt-level=2
+// compile-flags: -Zmir-opt-level=3
 
 trait IterExt: Iterator {
     fn fold_ex<B, F>(mut self, init: B, mut f: F) -> B

src/test/ui/issues/issue-50411.rs

@@ -3,7 +3,7 @@
 // elaborate-drops invoked on it) and then try to elaboate drops a
 // second time. Uncool.
 
-// compile-flags:-Zmir-opt-level=3
+// compile-flags:-Zmir-opt-level=4
 // build-pass
 
 fn main() {

src/test/ui/issues/issue-50865-private-impl-trait/auxiliary/lib.rs

@@ -1,5 +1,5 @@
 // revisions: default miropt
-//[miropt]compile-flags: -Z mir-opt-level=2
+//[miropt]compile-flags: -Z mir-opt-level=3
 // ~^ This flag is for #77668, it used to be ICE.
 
 #![crate_type = "lib"]

src/test/ui/issues/issue-77002.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Zmir-opt-level=2 -Copt-level=0
+// compile-flags: -Zmir-opt-level=3 -Copt-level=0
 // run-pass
 
 type M = [i64; 2];

src/test/ui/mir/auxiliary/issue_76375_aux.rs

@@ -1,5 +1,5 @@
 // edition:2018
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 
 #[inline(always)]
 pub fn copy_prop(s: bool) -> String {

src/test/ui/mir/issue-66851.rs

@@ -2,7 +2,7 @@
 // did not check that the types matched up in the `Ok(r)` branch.
 //
 // run-pass
-// compile-flags: -Zmir-opt-level=2
+// compile-flags: -Zmir-opt-level=3
 
 #[derive(Debug, PartialEq, Eq)]
 enum SpecialsRes { Res(u64) }

src/test/ui/mir/issue-67639-normalization-ice.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=3
+// compile-flags: -Z mir-opt-level=4
 // build-pass
 
 // This used to ICE in const-prop due

src/test/ui/mir/issue-67710-inline-projection.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 // build-pass
 
 // This used to ICE due to the inling pass not examining projections

src/test/ui/mir/issue-68841.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 // edition:2018
 // build-pass
 

src/test/ui/mir/issue-71793-inline-args-storage.rs

@@ -4,7 +4,7 @@
 //
 // check-pass
 // edition:2018
-// compile-args: -Zmir-opt-level=2
+// compile-args: -Zmir-opt-level=3
 
 #![crate_type = "lib"]
 

src/test/ui/mir/issue-75053.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 // build-pass
 
 #![feature(type_alias_impl_trait)]

src/test/ui/mir/issue-76248.rs

@@ -3,7 +3,7 @@
 // Regression test for #76248.
 //
 // build-pass
-// compile-flags: -Zmir-opt-level=2
+// compile-flags: -Zmir-opt-level=3
 
 const N: usize = 1;
 

src/test/ui/mir/issue-76375.rs

@@ -2,7 +2,7 @@
 //
 // edition:2018
 // build-pass
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 // aux-build:issue_76375_aux.rs
 
 #![crate_type = "lib"]

src/test/ui/mir/issue-76740-copy-propagation.rs

@@ -1,6 +1,6 @@
 // Regression test for issue #76740.
 // run-pass
-// compile-flags: -Zmir-opt-level=3
+// compile-flags: -Zmir-opt-level=4
 
 #[derive(Copy, Clone)]
 pub struct V([usize; 4]);

src/test/ui/mir/issue-77911.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 // build-pass
 
 use std::fs::File;

src/test/ui/mir/issue-78496.rs

@@ -1,5 +1,5 @@
 // run-pass
-// compile-flags: -Z mir-opt-level=2 -C opt-level=0
+// compile-flags: -Z mir-opt-level=3 -C opt-level=0
 
 // example from #78496
 pub enum E<'a> {

src/test/ui/mir/issue66339.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 // build-pass
 
 // This used to ICE in const-prop

src/test/ui/mir/mir-inlining/array-clone-with-generic-size.rs

@@ -2,7 +2,7 @@
 // Regression test for issue #79269.
 //
 // build-pass
-// compile-flags: -Zmir-opt-level=2 -Zvalidate-mir
+// compile-flags: -Zmir-opt-level=3 -Zvalidate-mir
 #[derive(Clone)]
 struct Array<T, const N: usize>([T; N]);
 

src/test/ui/mir/mir-inlining/ice-issue-45493.rs

@@ -1,5 +1,5 @@
 // run-pass
-// compile-flags:-Zmir-opt-level=2
+// compile-flags:-Zmir-opt-level=3
 
 trait Array {
     type Item;

src/test/ui/mir/mir-inlining/ice-issue-45885.rs

@@ -1,5 +1,5 @@
 // run-pass
-// compile-flags:-Zmir-opt-level=2
+// compile-flags:-Zmir-opt-level=3
 
 pub enum Enum {
     A,

src/test/ui/mir/mir-inlining/ice-issue-68347.rs

@@ -1,5 +1,5 @@
 // run-pass
-// compile-flags:-Zmir-opt-level=2
+// compile-flags:-Zmir-opt-level=3
 pub fn main() {
     let _x: fn() = handle_debug_column;
 }

src/test/ui/mir/mir-inlining/ice-issue-77306-1.rs

@@ -1,5 +1,5 @@
 // run-pass
-// compile-flags:-Zmir-opt-level=2
+// compile-flags:-Zmir-opt-level=3
 
 // Previously ICEd because we did not normalize during inlining,
 // see https://github.com/rust-lang/rust/pull/77306 for more discussion.

src/test/ui/mir/mir-inlining/ice-issue-77306-2.rs

@@ -1,5 +1,5 @@
 // run-pass
-// compile-flags:-Zmir-opt-level=2
+// compile-flags:-Zmir-opt-level=3
 
 struct Cursor {}
 struct TokenTree {}

src/test/ui/mir/mir-inlining/ice-issue-77564.rs

@@ -1,5 +1,5 @@
 // run-pass
-// compile-flags:-Zmir-opt-level=2
+// compile-flags:-Zmir-opt-level=3
 
 use std::mem::MaybeUninit;
 const N: usize = 2;

src/test/ui/mir/mir-inlining/inline-instrument-coverage-fail.rs

@@ -1,9 +1,9 @@
-// Ensures -Zmir-opt-level=2 (specifically, inlining) is not allowed with -Zinstrument-coverage.
+// Ensures -Zmir-opt-level=3 (specifically, inlining) is not allowed with -Zinstrument-coverage.
 // Regression test for issue #80060.
 //
 // needs-profiler-support
 // build-pass
-// compile-flags: -Zmir-opt-level=2 -Zinstrument-coverage
+// compile-flags: -Zmir-opt-level=3 -Zinstrument-coverage
 #[inline(never)]
 fn foo() {}
 

src/test/ui/mir/mir-inlining/inline-instrument-coverage-fail.stderr

@@ -1,2 +1,2 @@
-warning: `-Z mir-opt-level=2` (or any level > 1) enables function inlining, which is incompatible with `-Z instrument-coverage`. Inlining will be disabled.
+warning: `-Z mir-opt-level=3` (or any level > 1) enables function inlining, which is incompatible with `-Z instrument-coverage`. Inlining will be disabled.
 

src/test/ui/mir/mir-inlining/no-trait-method-issue-40473.rs

@@ -1,5 +1,5 @@
 // run-pass
-// compile-flags:-Zmir-opt-level=2
+// compile-flags:-Zmir-opt-level=3
 pub trait Foo {
     fn bar(&self) -> usize { 2 }
 }

src/test/ui/mir/mir-inlining/var-debuginfo-issue-67586.rs

@@ -1,5 +1,5 @@
 // run-pass
-// compile-flags: -Z mir-opt-level=2 -C opt-level=0 -C debuginfo=2
+// compile-flags: -Z mir-opt-level=3 -C opt-level=0 -C debuginfo=2
 
 #[inline(never)]
 pub fn foo(bar: usize) -> usize {

src/test/ui/mir/mir_const_prop_tuple_field_reorder.rs

@@ -1,4 +1,4 @@
-// compile-flags: -Z mir-opt-level=2
+// compile-flags: -Z mir-opt-level=3
 // build-pass
 #![crate_type="lib"]
 

src/test/ui/mir/ssa-analysis-regression-50041.rs

@@ -1,5 +1,5 @@
 // build-pass
-// compile-flags: -Z mir-opt-level=3
+// compile-flags: -Z mir-opt-level=4
 
 #![crate_type="lib"]
 #![feature(lang_items)]

src/test/ui/polymorphization/promoted-function-3.rs

@@ -1,5 +1,5 @@
 // run-pass
-// compile-flags: -Zpolymorphize=on -Zmir-opt-level=3
+// compile-flags: -Zpolymorphize=on -Zmir-opt-level=4
 
 fn caller<T, U>() -> &'static usize {
     callee::<U>()

src/test/ui/rfc-2091-track-caller/caller-location-intrinsic.rs

@@ -1,6 +1,6 @@
 // run-pass
 // revisions: default mir-opt
-//[mir-opt] compile-flags: -Zmir-opt-level=3
+//[mir-opt] compile-flags: -Zmir-opt-level=4
 
 #[inline(never)]
 #[track_caller]

src/test/ui/rfc-2091-track-caller/const-caller-location.rs

@@ -1,6 +1,6 @@
 // run-pass
 // revisions: default mir-opt
-//[mir-opt] compile-flags: -Zmir-opt-level=3
+//[mir-opt] compile-flags: -Zmir-opt-level=4
 
 #![feature(const_caller_location, const_fn)]
 

src/test/ui/rfc-2091-track-caller/intrinsic-wrapper.rs

@@ -1,6 +1,6 @@
 // run-pass
 // revisions: default mir-opt
-//[mir-opt] compile-flags: -Zmir-opt-level=3
+//[mir-opt] compile-flags: -Zmir-opt-level=4
 
 macro_rules! caller_location_from_macro {
     () => (core::panic::Location::caller());

src/test/ui/rfc-2091-track-caller/pass.rs

@@ -1,6 +1,6 @@
 // run-pass
 // revisions: default mir-opt
-//[mir-opt] compile-flags: -Zmir-opt-level=3
+//[mir-opt] compile-flags: -Zmir-opt-level=4
 
 #[track_caller]
 fn f() {}

src/test/ui/rfc-2091-track-caller/std-panic-locations.rs

@@ -1,7 +1,7 @@
 // run-pass
 // ignore-wasm32-bare compiled with panic=abort by default
 // revisions: default mir-opt
-//[mir-opt] compile-flags: -Zmir-opt-level=3
+//[mir-opt] compile-flags: -Zmir-opt-level=4
 
 #![feature(option_expect_none, option_unwrap_none)]
 #![allow(unconditional_panic)]

src/test/ui/rfc-2091-track-caller/track-caller-attribute.rs

@@ -1,6 +1,6 @@
 // run-pass
 // revisions: default mir-opt
-//[mir-opt] compile-flags: -Zmir-opt-level=3
+//[mir-opt] compile-flags: -Zmir-opt-level=4
 
 use std::panic::Location;
 

src/test/ui/rfc-2091-track-caller/tracked-fn-ptr-with-arg.rs

@@ -1,6 +1,6 @@
 // run-pass
 // revisions: default mir-opt
-//[mir-opt] compile-flags: -Zmir-opt-level=3
+//[mir-opt] compile-flags: -Zmir-opt-level=4
 
 fn pass_to_ptr_call<T>(f: fn(T), x: T) {
     f(x);

src/test/ui/rfc-2091-track-caller/tracked-fn-ptr.rs

@@ -1,6 +1,6 @@
 // run-pass
 // revisions: default mir-opt
-//[mir-opt] compile-flags: -Zmir-opt-level=3
+//[mir-opt] compile-flags: -Zmir-opt-level=4
 
 fn ptr_call(f: fn()) {
     f();

src/test/ui/simd-intrinsic/simd-intrinsic-inlining-issue67557-ice.rs

@@ -2,7 +2,7 @@
 // passed the wrong Instance, causing issues with inlining. See #67557.
 //
 // run-pass
-// compile-flags: -Zmir-opt-level=3
+// compile-flags: -Zmir-opt-level=4
 #![feature(platform_intrinsics, repr_simd)]
 
 extern "platform-intrinsic" {

src/test/ui/simd-intrinsic/simd-intrinsic-inlining-issue67557.rs

@@ -2,7 +2,7 @@
 // the wrong Instance, causing issues with inlining. See #67557.
 //
 // run-pass
-// compile-flags: -Zmir-opt-level=3
+// compile-flags: -Zmir-opt-level=4
 #![feature(platform_intrinsics, repr_simd)]
 
 extern "platform-intrinsic" {

src/tools/clippy/src/driver.rs

@@ -83,7 +83,7 @@ impl rustc_driver::Callbacks for ClippyCallbacks {
         // run on the unoptimized MIR. On the other hand this results in some false negatives. If
         // MIR passes can be enabled / disabled separately, we should figure out, what passes to
         // use for Clippy.
-        config.opts.debugging_opts.mir_opt_level = 0;
+        config.opts.debugging_opts.mir_opt_level = Some(0);
     }
 }
 

src/tools/compiletest/src/runtest.rs

@@ -1960,7 +1960,7 @@ impl<'test> TestCx<'test> {
                 rustc.args(&[
                     "-Copt-level=1",
                     "-Zdump-mir=all",
-                    "-Zmir-opt-level=3",
+                    "-Zmir-opt-level=4",
                     "-Zvalidate-mir",
                     "-Zdump-mir-exclude-pass-number",
                 ]);