Run SingleUseConsts before DeadStoreElimination::Initial

saethlin · saethlin · commit 19c27feb9db3 · 2024-07-21T13:19:23.000-04:00
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
@@ -597,7 +597,7 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
             &gvn::GVN,
             &simplify::SimplifyLocals::AfterGVN,
             &dataflow_const_prop::DataflowConstProp,
-            &single_use_consts::SingleUseConsts,
+            &single_use_consts::SingleUseConsts::Initial,
             &o1(simplify_branches::SimplifyConstCondition::AfterConstProp),
             &jump_threading::JumpThreading,
             &early_otherwise_branch::EarlyOtherwiseBranch,
@@ -607,6 +607,7 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
             &o1(remove_noop_landing_pads::RemoveNoopLandingPads),
             &o1(simplify::SimplifyCfg::Final),
             &copy_prop::CopyProp,
+            &single_use_consts::SingleUseConsts::Final,
             &dead_store_elimination::DeadStoreElimination::Final,
             &nrvo::RenameReturnPlace,
             &simplify::SimplifyLocals::Final,
diff --git a/compiler/rustc_mir_transform/src/single_use_consts.rs b/compiler/rustc_mir_transform/src/single_use_consts.rs
@@ -18,13 +18,23 @@ use rustc_middle::ty::TyCtxt;
 ///
 /// It also removes *never*-used constants, since it had all the information
 /// needed to do that too, including updating the debug info.
-pub struct SingleUseConsts;
+pub enum SingleUseConsts {
+    Initial,
+    Final,
+}
 
 impl<'tcx> MirPass<'tcx> for SingleUseConsts {
     fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
         sess.mir_opt_level() > 0
     }
 
+    fn name(&self) -> &'static str {
+        match self {
+            SingleUseConsts::Initial => "SingleUseConsts-initial",
+            SingleUseConsts::Final => "SingleUseConsts-final",
+        }
+    }
+
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         let mut finder = SingleUseConstsFinder {
             ineligible_locals: BitSet::new_empty(body.local_decls.len()),
diff --git a/tests/mir-opt/const_debuginfo.main.SingleUseConsts-final.diff b/tests/mir-opt/const_debuginfo.main.SingleUseConsts-final.diff
@@ -1,5 +1,5 @@
-- // MIR for `main` before SingleUseConsts
-+ // MIR for `main` after SingleUseConsts
+- // MIR for `main` before SingleUseConsts-final
++ // MIR for `main` after SingleUseConsts-final
   
   fn main() -> () {
       let mut _0: ();
diff --git a/tests/mir-opt/const_debuginfo.rs b/tests/mir-opt/const_debuginfo.rs
@@ -1,4 +1,4 @@
-//@ test-mir-pass: SingleUseConsts
+//@ test-mir-pass: SingleUseConsts-final
 //@ compile-flags: -C overflow-checks=no -Zmir-enable-passes=+GVN -Zdump-mir-exclude-alloc-bytes
 
 #![allow(unused)]
@@ -8,7 +8,7 @@ struct Point {
     y: u32,
 }
 
-// EMIT_MIR const_debuginfo.main.SingleUseConsts.diff
+// EMIT_MIR const_debuginfo.main.SingleUseConsts-final.diff
 fn main() {
     // CHECK-LABEL: fn main(
     // CHECK: debug x => const 1_u8;
diff --git a/tests/mir-opt/single_use_consts.assign_const_to_return.SingleUseConsts-initial.panic-abort.diff b/tests/mir-opt/single_use_consts.assign_const_to_return.SingleUseConsts-initial.panic-abort.diff
@@ -1,5 +1,5 @@
-- // MIR for `assign_const_to_return` before SingleUseConsts
-+ // MIR for `assign_const_to_return` after SingleUseConsts
+- // MIR for `assign_const_to_return` before SingleUseConsts-initial
++ // MIR for `assign_const_to_return` after SingleUseConsts-initial
   
   fn assign_const_to_return() -> bool {
       let mut _0: bool;
diff --git a/tests/mir-opt/single_use_consts.assign_const_to_return.SingleUseConsts-initial.panic-unwind.diff b/tests/mir-opt/single_use_consts.assign_const_to_return.SingleUseConsts-initial.panic-unwind.diff
@@ -1,5 +1,5 @@
-- // MIR for `assign_const_to_return` before SingleUseConsts
-+ // MIR for `assign_const_to_return` after SingleUseConsts
+- // MIR for `assign_const_to_return` before SingleUseConsts-initial
++ // MIR for `assign_const_to_return` after SingleUseConsts-initial
   
   fn assign_const_to_return() -> bool {
       let mut _0: bool;
diff --git a/tests/mir-opt/single_use_consts.if_const.SingleUseConsts-initial.panic-abort.diff b/tests/mir-opt/single_use_consts.if_const.SingleUseConsts-initial.panic-abort.diff
@@ -1,5 +1,5 @@
-- // MIR for `if_const` before SingleUseConsts
-+ // MIR for `if_const` after SingleUseConsts
+- // MIR for `if_const` before SingleUseConsts-initial
++ // MIR for `if_const` after SingleUseConsts-initial
   
   fn if_const() -> i32 {
       let mut _0: i32;
diff --git a/tests/mir-opt/single_use_consts.if_const.SingleUseConsts-initial.panic-unwind.diff b/tests/mir-opt/single_use_consts.if_const.SingleUseConsts-initial.panic-unwind.diff
@@ -1,5 +1,5 @@
-- // MIR for `if_const` before SingleUseConsts
-+ // MIR for `if_const` after SingleUseConsts
+- // MIR for `if_const` before SingleUseConsts-initial
++ // MIR for `if_const` after SingleUseConsts-initial
   
   fn if_const() -> i32 {
       let mut _0: i32;
diff --git a/tests/mir-opt/single_use_consts.if_const_debug.SingleUseConsts-initial.panic-abort.diff b/tests/mir-opt/single_use_consts.if_const_debug.SingleUseConsts-initial.panic-abort.diff
@@ -1,5 +1,5 @@
-- // MIR for `if_const_debug` before SingleUseConsts
-+ // MIR for `if_const_debug` after SingleUseConsts
+- // MIR for `if_const_debug` before SingleUseConsts-initial
++ // MIR for `if_const_debug` after SingleUseConsts-initial
   
   fn if_const_debug() -> i32 {
       let mut _0: i32;
diff --git a/tests/mir-opt/single_use_consts.if_const_debug.SingleUseConsts-initial.panic-unwind.diff b/tests/mir-opt/single_use_consts.if_const_debug.SingleUseConsts-initial.panic-unwind.diff
@@ -1,5 +1,5 @@
-- // MIR for `if_const_debug` before SingleUseConsts
-+ // MIR for `if_const_debug` after SingleUseConsts
+- // MIR for `if_const_debug` before SingleUseConsts-initial
++ // MIR for `if_const_debug` after SingleUseConsts-initial
   
   fn if_const_debug() -> i32 {
       let mut _0: i32;
diff --git a/tests/mir-opt/single_use_consts.keep_parameter.SingleUseConsts-initial.panic-abort.diff b/tests/mir-opt/single_use_consts.keep_parameter.SingleUseConsts-initial.panic-abort.diff
@@ -1,5 +1,5 @@
-- // MIR for `keep_parameter` before SingleUseConsts
-+ // MIR for `keep_parameter` after SingleUseConsts
+- // MIR for `keep_parameter` before SingleUseConsts-initial
++ // MIR for `keep_parameter` after SingleUseConsts-initial
   
   fn keep_parameter(_1: i32) -> () {
       debug other => _1;
diff --git a/tests/mir-opt/single_use_consts.keep_parameter.SingleUseConsts-initial.panic-unwind.diff b/tests/mir-opt/single_use_consts.keep_parameter.SingleUseConsts-initial.panic-unwind.diff
@@ -1,5 +1,5 @@
-- // MIR for `keep_parameter` before SingleUseConsts
-+ // MIR for `keep_parameter` after SingleUseConsts
+- // MIR for `keep_parameter` before SingleUseConsts-initial
++ // MIR for `keep_parameter` after SingleUseConsts-initial
   
   fn keep_parameter(_1: i32) -> () {
       debug other => _1;
diff --git a/tests/mir-opt/single_use_consts.match_const.SingleUseConsts-initial.panic-abort.diff b/tests/mir-opt/single_use_consts.match_const.SingleUseConsts-initial.panic-abort.diff
@@ -1,5 +1,5 @@
-- // MIR for `match_const` before SingleUseConsts
-+ // MIR for `match_const` after SingleUseConsts
+- // MIR for `match_const` before SingleUseConsts-initial
++ // MIR for `match_const` after SingleUseConsts-initial
   
   fn match_const() -> &str {
       let mut _0: &str;
diff --git a/tests/mir-opt/single_use_consts.match_const.SingleUseConsts-initial.panic-unwind.diff b/tests/mir-opt/single_use_consts.match_const.SingleUseConsts-initial.panic-unwind.diff
@@ -1,5 +1,5 @@
-- // MIR for `match_const` before SingleUseConsts
-+ // MIR for `match_const` after SingleUseConsts
+- // MIR for `match_const` before SingleUseConsts-initial
++ // MIR for `match_const` after SingleUseConsts-initial
   
   fn match_const() -> &str {
       let mut _0: &str;
diff --git a/tests/mir-opt/single_use_consts.match_const_debug.SingleUseConsts-initial.panic-abort.diff b/tests/mir-opt/single_use_consts.match_const_debug.SingleUseConsts-initial.panic-abort.diff
@@ -1,5 +1,5 @@
-- // MIR for `match_const_debug` before SingleUseConsts
-+ // MIR for `match_const_debug` after SingleUseConsts
+- // MIR for `match_const_debug` before SingleUseConsts-initial
++ // MIR for `match_const_debug` after SingleUseConsts-initial
   
   fn match_const_debug() -> &str {
       let mut _0: &str;
diff --git a/tests/mir-opt/single_use_consts.match_const_debug.SingleUseConsts-initial.panic-unwind.diff b/tests/mir-opt/single_use_consts.match_const_debug.SingleUseConsts-initial.panic-unwind.diff
@@ -1,5 +1,5 @@
-- // MIR for `match_const_debug` before SingleUseConsts
-+ // MIR for `match_const_debug` after SingleUseConsts
+- // MIR for `match_const_debug` before SingleUseConsts-initial
++ // MIR for `match_const_debug` after SingleUseConsts-initial
   
   fn match_const_debug() -> &str {
       let mut _0: &str;
diff --git a/tests/mir-opt/single_use_consts.never_used_debug.SingleUseConsts-initial.panic-abort.diff b/tests/mir-opt/single_use_consts.never_used_debug.SingleUseConsts-initial.panic-abort.diff
@@ -1,5 +1,5 @@
-- // MIR for `never_used_debug` before SingleUseConsts
-+ // MIR for `never_used_debug` after SingleUseConsts
+- // MIR for `never_used_debug` before SingleUseConsts-initial
++ // MIR for `never_used_debug` after SingleUseConsts-initial
   
   fn never_used_debug() -> () {
       let mut _0: ();
diff --git a/tests/mir-opt/single_use_consts.never_used_debug.SingleUseConsts-initial.panic-unwind.diff b/tests/mir-opt/single_use_consts.never_used_debug.SingleUseConsts-initial.panic-unwind.diff
@@ -1,5 +1,5 @@
-- // MIR for `never_used_debug` before SingleUseConsts
-+ // MIR for `never_used_debug` after SingleUseConsts
+- // MIR for `never_used_debug` before SingleUseConsts-initial
++ // MIR for `never_used_debug` after SingleUseConsts-initial
   
   fn never_used_debug() -> () {
       let mut _0: ();
diff --git a/tests/mir-opt/single_use_consts.rs b/tests/mir-opt/single_use_consts.rs
@@ -1,4 +1,4 @@
-//@ test-mir-pass: SingleUseConsts
+//@ test-mir-pass: SingleUseConsts-initial
 //@ compile-flags: -C debuginfo=full
 // EMIT_MIR_FOR_EACH_PANIC_STRATEGY
 
@@ -7,14 +7,14 @@ trait MyTrait {
     const ASSOC_INT: i32;
 }
 
-// EMIT_MIR single_use_consts.if_const.SingleUseConsts.diff
+// EMIT_MIR single_use_consts.if_const.SingleUseConsts-initial.diff
 fn if_const<T: MyTrait>() -> i32 {
     // CHECK-LABEL: fn if_const(
     // CHECK: switchInt(const <T as MyTrait>::ASSOC_BOOL)
     if T::ASSOC_BOOL { 7 } else { 42 }
 }
 
-// EMIT_MIR single_use_consts.match_const.SingleUseConsts.diff
+// EMIT_MIR single_use_consts.match_const.SingleUseConsts-initial.diff
 fn match_const<T: MyTrait>() -> &'static str {
     // CHECK-LABEL: fn match_const(
     // CHECK: switchInt(const <T as MyTrait>::ASSOC_INT)
@@ -25,7 +25,7 @@ fn match_const<T: MyTrait>() -> &'static str {
     }
 }
 
-// EMIT_MIR single_use_consts.if_const_debug.SingleUseConsts.diff
+// EMIT_MIR single_use_consts.if_const_debug.SingleUseConsts-initial.diff
 fn if_const_debug<T: MyTrait>() -> i32 {
     // CHECK-LABEL: fn if_const_debug(
     // CHECK: my_bool => const <T as MyTrait>::ASSOC_BOOL;
@@ -37,7 +37,7 @@ fn if_const_debug<T: MyTrait>() -> i32 {
     if my_bool { 7 } else { 42 }
 }
 
-// EMIT_MIR single_use_consts.match_const_debug.SingleUseConsts.diff
+// EMIT_MIR single_use_consts.match_const_debug.SingleUseConsts-initial.diff
 fn match_const_debug<T: MyTrait>() -> &'static str {
     // CHECK-LABEL: fn match_const_debug(
     // CHECK: my_int => const <T as MyTrait>::ASSOC_INT;
@@ -51,7 +51,7 @@ fn match_const_debug<T: MyTrait>() -> &'static str {
     }
 }
 
-// EMIT_MIR single_use_consts.never_used_debug.SingleUseConsts.diff
+// EMIT_MIR single_use_consts.never_used_debug.SingleUseConsts-initial.diff
 #[allow(unused_variables)]
 fn never_used_debug<T: MyTrait>() {
     // CHECK-LABEL: fn never_used_debug(
@@ -62,14 +62,14 @@ fn never_used_debug<T: MyTrait>() {
     let my_int = T::ASSOC_INT;
 }
 
-// EMIT_MIR single_use_consts.assign_const_to_return.SingleUseConsts.diff
+// EMIT_MIR single_use_consts.assign_const_to_return.SingleUseConsts-initial.diff
 fn assign_const_to_return<T: MyTrait>() -> bool {
     // CHECK-LABEL: fn assign_const_to_return(
     // CHECK: _0 = const <T as MyTrait>::ASSOC_BOOL;
     T::ASSOC_BOOL
 }
 
-// EMIT_MIR single_use_consts.keep_parameter.SingleUseConsts.diff
+// EMIT_MIR single_use_consts.keep_parameter.SingleUseConsts-initial.diff
 fn keep_parameter<T: MyTrait>(mut other: i32) {
     // CHECK-LABEL: fn keep_parameter(
     // CHECK: _1 = const <T as MyTrait>::ASSOC_INT;
