Remove -Zfuel.

compiler/rustc_driver_impl/src/lib.rs

@@ -24,7 +24,6 @@ use rustc_codegen_ssa::{traits::CodegenBackend, CodegenErrors, CodegenResults};
 use rustc_data_structures::profiling::{
     get_resident_set_size, print_time_passes_entry, TimePassesFormat,
 };
-use rustc_data_structures::sync::SeqCst;
 use rustc_errors::registry::{InvalidErrorCode, Registry};
 use rustc_errors::{markdown, ColorConfig};
 use rustc_errors::{DiagnosticMessage, ErrorGuaranteed, Handler, PResult, SubdiagnosticMessage};
@@ -475,14 +474,6 @@ fn run_compiler(
             sess.print_perf_stats();
         }
 
-        if sess.opts.unstable_opts.print_fuel.is_some() {
-            eprintln!(
-                "Fuel used by {}: {}",
-                sess.opts.unstable_opts.print_fuel.as_ref().unwrap(),
-                sess.print_fuel.load(SeqCst)
-            );
-        }
-
         Ok(())
     })
 }

compiler/rustc_interface/src/tests.rs

@@ -779,7 +779,6 @@ fn test_unstable_options_tracking_hash() {
     tracked!(fewer_names, Some(true));
     tracked!(flatten_format_args, false);
     tracked!(force_unstable_if_unmarked, true);
-    tracked!(fuel, Some(("abc".to_string(), 99)));
     tracked!(function_sections, Some(false));
     tracked!(human_readable_cgu_names, true);
     tracked!(incremental_ignore_spans, true);
@@ -816,7 +815,6 @@ fn test_unstable_options_tracking_hash() {
     tracked!(plt, Some(true));
     tracked!(polonius, true);
     tracked!(precise_enum_drop_elaboration, false);
-    tracked!(print_fuel, Some("abc".to_string()));
     tracked!(profile, true);
     tracked!(profile_emit, Some(PathBuf::from("abc")));
     tracked!(profile_sample_use, Some(PathBuf::from("abc")));

compiler/rustc_middle/src/ty/context.rs

@@ -745,10 +745,6 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
-    pub fn consider_optimizing<T: Fn() -> String>(self, msg: T) -> bool {
-        self.sess.consider_optimizing(|| self.crate_name(LOCAL_CRATE), msg)
-    }
-
     /// Obtain all lang items of this crate and all dependencies (recursively)
     pub fn lang_items(self) -> &'tcx rustc_hir::lang_items::LanguageItems {
         self.get_lang_items(())

compiler/rustc_middle/src/ty/mod.rs

@@ -2174,11 +2174,6 @@ impl<'tcx> TyCtxt<'tcx> {
             flags.insert(ReprFlags::RANDOMIZE_LAYOUT);
         }
 
-        // This is here instead of layout because the choice must make it into metadata.
-        if !self.consider_optimizing(|| format!("Reorder fields of {:?}", self.def_path_str(did))) {
-            flags.insert(ReprFlags::IS_LINEAR);
-        }
-
         ReprOptions { int: size, align: max_align, pack: min_pack, flags, field_shuffle_seed }
     }
 

compiler/rustc_mir_transform/src/const_prop.rs

@@ -530,9 +530,6 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
         // type whose creation requires no write. E.g. a generator whose initial state
         // consists solely of uninitialized memory (so it doesn't capture any locals).
         let value = self.get_const(place)?;
-        if !self.tcx.consider_optimizing(|| format!("ConstantPropagation - {value:?}")) {
-            return None;
-        }
         trace!("replacing {:?} with {:?}", place, value);
 
         // FIXME: figure out what to do when read_immediate_raw fails

compiler/rustc_mir_transform/src/dest_prop.rs

@@ -222,11 +222,6 @@ impl<'tcx> MirPass<'tcx> for DestinationPropagation {
                 else {
                     continue;
                 };
-                if !tcx.consider_optimizing(|| {
-                    format!("{} round {}", tcx.def_path_str(def_id), round_count)
-                }) {
-                    break;
-                }
                 merges.insert(*src, *dest);
                 merged_locals.insert(*src);
                 merged_locals.insert(*dest);

compiler/rustc_mir_transform/src/early_otherwise_branch.rs

@@ -109,10 +109,6 @@ impl<'tcx> MirPass<'tcx> for EarlyOtherwiseBranch {
             let parent = BasicBlock::from_usize(i);
             let Some(opt_data) = evaluate_candidate(tcx, body, parent) else { continue };
 
-            if !tcx.consider_optimizing(|| format!("EarlyOtherwiseBranch {:?}", &opt_data)) {
-                break;
-            }
-
             trace!("SUCCESS: found optimization possibility to apply: {:?}", &opt_data);
 
             should_cleanup = true;

compiler/rustc_mir_transform/src/inline.rs

@@ -187,12 +187,6 @@ impl<'tcx> Inliner<'tcx> {
         let callee_body = try_instance_mir(self.tcx, callsite.callee.def)?;
         self.check_mir_body(callsite, callee_body, callee_attrs)?;
 
-        if !self.tcx.consider_optimizing(|| {
-            format!("Inline {:?} into {:?}", callsite.callee, caller_body.source)
-        }) {
-            return Err("optimization fuel exhausted");
-        }
-
         let Ok(callee_body) = callsite.callee.try_instantiate_mir_and_normalize_erasing_regions(
             self.tcx,
             self.param_env,

compiler/rustc_mir_transform/src/instsimplify.rs

@@ -7,6 +7,7 @@ use rustc_middle::mir::*;
 use rustc_middle::ty::layout::ValidityRequirement;
 use rustc_middle::ty::{self, GenericArgsRef, ParamEnv, Ty, TyCtxt};
 use rustc_span::symbol::Symbol;
+use rustc_span::DUMMY_SP;
 use rustc_target::abi::FieldIdx;
 
 pub struct InstSimplify;
@@ -26,10 +27,10 @@ impl<'tcx> MirPass<'tcx> for InstSimplify {
             for statement in block.statements.iter_mut() {
                 match statement.kind {
                     StatementKind::Assign(box (_place, ref mut rvalue)) => {
-                        ctx.simplify_bool_cmp(&statement.source_info, rvalue);
-                        ctx.simplify_ref_deref(&statement.source_info, rvalue);
-                        ctx.simplify_len(&statement.source_info, rvalue);
-                        ctx.simplify_cast(&statement.source_info, rvalue);
+                        ctx.simplify_bool_cmp(rvalue);
+                        ctx.simplify_ref_deref(rvalue);
+                        ctx.simplify_len(rvalue);
+                        ctx.simplify_cast(rvalue);
                     }
                     _ => {}
                 }
@@ -55,14 +56,8 @@ struct InstSimplifyContext<'tcx, 'a> {
 }
 
 impl<'tcx> InstSimplifyContext<'tcx, '_> {
-    fn should_simplify(&self, source_info: &SourceInfo, rvalue: &Rvalue<'tcx>) -> bool {
-        self.tcx.consider_optimizing(|| {
-            format!("InstSimplify - Rvalue: {rvalue:?} SourceInfo: {source_info:?}")
-        })
-    }
-
     /// Transform boolean comparisons into logical operations.
-    fn simplify_bool_cmp(&self, source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
+    fn simplify_bool_cmp(&self, rvalue: &mut Rvalue<'tcx>) {
         match rvalue {
             Rvalue::BinaryOp(op @ (BinOp::Eq | BinOp::Ne), box (a, b)) => {
                 let new = match (op, self.try_eval_bool(a), self.try_eval_bool(b)) {
@@ -93,7 +88,7 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
                     _ => None,
                 };
 
-                if let Some(new) = new && self.should_simplify(source_info, rvalue) {
+                if let Some(new) = new {
                     *rvalue = new;
                 }
             }
@@ -108,17 +103,13 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
     }
 
     /// Transform "&(*a)" ==> "a".
-    fn simplify_ref_deref(&self, source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
+    fn simplify_ref_deref(&self, rvalue: &mut Rvalue<'tcx>) {
         if let Rvalue::Ref(_, _, place) = rvalue {
             if let Some((base, ProjectionElem::Deref)) = place.as_ref().last_projection() {
                 if rvalue.ty(self.local_decls, self.tcx) != base.ty(self.local_decls, self.tcx).ty {
                     return;
                 }
 
-                if !self.should_simplify(source_info, rvalue) {
-                    return;
-                }
-
                 *rvalue = Rvalue::Use(Operand::Copy(Place {
                     local: base.local,
                     projection: self.tcx.mk_place_elems(base.projection),
@@ -128,22 +119,18 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
     }
 
     /// Transform "Len([_; N])" ==> "N".
-    fn simplify_len(&self, source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
+    fn simplify_len(&self, rvalue: &mut Rvalue<'tcx>) {
         if let Rvalue::Len(ref place) = *rvalue {
             let place_ty = place.ty(self.local_decls, self.tcx).ty;
             if let ty::Array(_, len) = *place_ty.kind() {
-                if !self.should_simplify(source_info, rvalue) {
-                    return;
-                }
-
                 let const_ = Const::from_ty_const(len, self.tcx);
-                let constant = ConstOperand { span: source_info.span, const_, user_ty: None };
+                let constant = ConstOperand { span: DUMMY_SP, const_, user_ty: None };
                 *rvalue = Rvalue::Use(Operand::Constant(Box::new(constant)));
             }
         }
     }
 
-    fn simplify_cast(&self, _source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
+    fn simplify_cast(&self, rvalue: &mut Rvalue<'tcx>) {
         if let Rvalue::Cast(kind, operand, cast_ty) = rvalue {
             let operand_ty = operand.ty(self.local_decls, self.tcx);
             if operand_ty == *cast_ty {
@@ -223,16 +210,6 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
             return;
         }
 
-        if !self.tcx.consider_optimizing(|| {
-            format!(
-                "InstSimplify - Call: {:?} SourceInfo: {:?}",
-                (fn_def_id, fn_args),
-                terminator.source_info
-            )
-        }) {
-            return;
-        }
-
         let Some(arg_place) = args.pop().unwrap().place() else { return };
 
         statements.push(Statement {

compiler/rustc_mir_transform/src/match_branches.rs

@@ -51,10 +51,6 @@ impl<'tcx> MirPass<'tcx> for MatchBranchSimplification {
         let bbs = body.basic_blocks.as_mut();
         let mut should_cleanup = false;
         'outer: for bb_idx in bbs.indices() {
-            if !tcx.consider_optimizing(|| format!("MatchBranchSimplification {def_id:?} ")) {
-                continue;
-            }
-
             let (discr, val, first, second) = match bbs[bb_idx].terminator().kind {
                 TerminatorKind::SwitchInt {
                     discr: ref discr @ (Operand::Copy(_) | Operand::Move(_)),

compiler/rustc_mir_transform/src/multiple_return_terminators.rs

@@ -16,7 +16,6 @@ impl<'tcx> MirPass<'tcx> for MultipleReturnTerminators {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         // find basic blocks with no statement and a return terminator
         let mut bbs_simple_returns = BitSet::new_empty(body.basic_blocks.len());
-        let def_id = body.source.def_id();
         let bbs = body.basic_blocks_mut();
         for idx in bbs.indices() {
             if bbs[idx].statements.is_empty()
@@ -27,10 +26,6 @@ impl<'tcx> MirPass<'tcx> for MultipleReturnTerminators {
         }
 
         for bb in bbs {
-            if !tcx.consider_optimizing(|| format!("MultipleReturnTerminators {def_id:?} ")) {
-                break;
-            }
-
             if let TerminatorKind::Goto { target } = bb.terminator().kind {
                 if bbs_simple_returns.contains(target) {
                     bb.terminator_mut().kind = TerminatorKind::Return;

compiler/rustc_mir_transform/src/nrvo.rs

@@ -45,10 +45,6 @@ impl<'tcx> MirPass<'tcx> for RenameReturnPlace {
             return;
         };
 
-        if !tcx.consider_optimizing(|| format!("RenameReturnPlace {def_id:?}")) {
-            return;
-        }
-
         debug!(
             "`{:?}` was eligible for NRVO, making {:?} the return place",
             def_id, returned_local

compiler/rustc_mir_transform/src/remove_unneeded_drops.rs

@@ -27,9 +27,6 @@ impl<'tcx> MirPass<'tcx> for RemoveUnneededDrops {
                 if ty.ty.needs_drop(tcx, param_env) {
                     continue;
                 }
-                if !tcx.consider_optimizing(|| format!("RemoveUnneededDrops {did:?} ")) {
-                    continue;
-                }
                 debug!("SUCCESS: replacing `drop` with goto({:?})", target);
                 terminator.kind = TerminatorKind::Goto { target };
                 should_simplify = true;

compiler/rustc_mir_transform/src/remove_zsts.rs

@@ -89,16 +89,12 @@ impl<'tcx> MutVisitor<'tcx> for Replacer<'_, 'tcx> {
         }
     }
 
-    fn visit_operand(&mut self, operand: &mut Operand<'tcx>, loc: Location) {
+    fn visit_operand(&mut self, operand: &mut Operand<'tcx>, _: Location) {
         if let Operand::Constant(_) = operand {
             return;
         }
         let op_ty = operand.ty(self.local_decls, self.tcx);
-        if self.known_to_be_zst(op_ty)
-            && self.tcx.consider_optimizing(|| {
-                format!("RemoveZsts - Operand: {operand:?} Location: {loc:?}")
-            })
-        {
+        if self.known_to_be_zst(op_ty) {
             *operand = Operand::Constant(Box::new(self.make_zst(op_ty)))
         }
     }
@@ -125,9 +121,6 @@ impl<'tcx> MutVisitor<'tcx> for Replacer<'_, 'tcx> {
         if let Some(place_for_ty) = place_for_ty
             && let ty = place_for_ty.ty(self.local_decls, self.tcx).ty
             && self.known_to_be_zst(ty)
-            && self.tcx.consider_optimizing(|| {
-                format!("RemoveZsts - Place: {:?} SourceInfo: {:?}", place_for_ty, statement.source_info)
-            })
         {
             statement.make_nop();
         } else {

compiler/rustc_mir_transform/src/unreachable_prop.rs

@@ -43,24 +43,12 @@ impl MirPass<'_> for UnreachablePropagation {
 
         // We do want do keep some unreachable blocks, but make them empty.
         for bb in unreachable_blocks {
-            if !tcx.consider_optimizing(|| {
-                format!("UnreachablePropagation {:?} ", body.source.def_id())
-            }) {
-                break;
-            }
-
             body.basic_blocks_mut()[bb].statements.clear();
         }
 
         let replaced = !replacements.is_empty();
 
         for (bb, terminator_kind) in replacements {
-            if !tcx.consider_optimizing(|| {
-                format!("UnreachablePropagation {:?} ", body.source.def_id())
-            }) {
-                break;
-            }
-
             body.basic_blocks_mut()[bb].terminator_mut().kind = terminator_kind;
         }
 

compiler/rustc_session/messages.ftl

@@ -80,7 +80,6 @@ session_not_supported = not supported
 session_nul_in_c_str = null characters in C string literals are not supported
 
 session_octal_float_literal_not_supported = octal float literal is not supported
-session_optimization_fuel_exhausted = optimization-fuel-exhausted: {$msg}
 
 session_profile_sample_use_file_does_not_exist = file `{$path}` passed to `-C profile-sample-use` does not exist.
 

compiler/rustc_session/src/config.rs

@@ -2130,10 +2130,6 @@ fn check_thread_count(handler: &EarlyErrorHandler, unstable_opts: &UnstableOptio
     if unstable_opts.threads == 0 {
         handler.early_error("value for threads must be a positive non-zero integer");
     }
-
-    if unstable_opts.threads > 1 && unstable_opts.fuel.is_some() {
-        handler.early_error("optimization fuel is incompatible with multiple threads");
-    }
 }
 
 fn collect_print_requests(

compiler/rustc_session/src/errors.rs

@@ -442,12 +442,6 @@ pub fn report_lit_error(sess: &ParseSess, err: LitError, lit: token::Lit, span:
     }
 }
 
-#[derive(Diagnostic)]
-#[diag(session_optimization_fuel_exhausted)]
-pub struct OptimisationFuelExhausted {
-    pub msg: String,
-}
-
 #[derive(Diagnostic)]
 #[diag(session_incompatible_linker_flavor)]
 #[note]