Auto merge of rust-lang#142879 - Mark-Simulacrum:opt-cleanup, r=WaffleLapkin

Remove dead instructions in terminate blocks

Terminate blocks look pretty in the IR I've looked at, so no actual perf delta from this. But it seems reasonable to note produce unused IR.

Author: bors

compiler/rustc_codegen_gcc/src/builder.rs

@@ -1591,9 +1591,9 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
         (value1, value2)
     }
 
-    fn filter_landing_pad(&mut self, pers_fn: RValue<'gcc>) -> (RValue<'gcc>, RValue<'gcc>) {
+    fn filter_landing_pad(&mut self, pers_fn: RValue<'gcc>) {
         // TODO(antoyo): generate the correct landing pad
-        self.cleanup_landing_pad(pers_fn)
+        self.cleanup_landing_pad(pers_fn);
     }
 
     #[cfg(feature = "master")]

compiler/rustc_codegen_llvm/src/builder.rs

@@ -1166,11 +1166,10 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         (self.extract_value(landing_pad, 0), self.extract_value(landing_pad, 1))
     }
 
-    fn filter_landing_pad(&mut self, pers_fn: &'ll Value) -> (&'ll Value, &'ll Value) {
+    fn filter_landing_pad(&mut self, pers_fn: &'ll Value) {
         let ty = self.type_struct(&[self.type_ptr(), self.type_i32()], false);
         let landing_pad = self.landing_pad(ty, pers_fn, 1);
         self.add_clause(landing_pad, self.const_array(self.type_ptr(), &[]));
-        (self.extract_value(landing_pad, 0), self.extract_value(landing_pad, 1))
     }
 
     fn resume(&mut self, exn0: &'ll Value, exn1: &'ll Value) {

compiler/rustc_codegen_ssa/src/traits/builder.rs

@@ -516,7 +516,7 @@ pub trait BuilderMethods<'a, 'tcx>:
 
     // These are used by everyone except msvc
     fn cleanup_landing_pad(&mut self, pers_fn: Self::Function) -> (Self::Value, Self::Value);
-    fn filter_landing_pad(&mut self, pers_fn: Self::Function) -> (Self::Value, Self::Value);
+    fn filter_landing_pad(&mut self, pers_fn: Self::Function);
     fn resume(&mut self, exn0: Self::Value, exn1: Self::Value);
 
     // These are used only by msvc