Ditch stack_check instruction

lib/codegen/src/legalizer/mod.rs

@@ -269,35 +269,3 @@ fn expand_fconst(
     };
     pos.func.dfg.replace(inst).bitcast(ty, ival);
 }
-
-/// Expand the stack check instruction.
-pub fn expand_stack_check(
-    inst: ir::Inst,
-    func: &mut ir::Function,
-    _cfg: &mut ControlFlowGraph,
-    isa: &TargetIsa,
-) {
-    use ir::condcodes::IntCC;
-
-    let gv = match func.dfg[inst] {
-        ir::InstructionData::UnaryGlobalVar { global_var, .. } => global_var,
-        _ => panic!("Want stack_check: {}", func.dfg.display_inst(inst, isa)),
-    };
-    let ptr_ty = isa.pointer_type();
-
-    let mut pos = FuncCursor::new(func).at_inst(inst);
-    pos.use_srcloc(inst);
-
-    let limit_addr = pos.ins().global_addr(ptr_ty, gv);
-
-    let mut mflags = ir::MemFlags::new();
-    mflags.set_aligned();
-    mflags.set_notrap();
-    let limit = pos.ins().load(ptr_ty, mflags, limit_addr, 0);
-    let cflags = pos.ins().ifcmp_sp(limit);
-    pos.func.dfg.replace(inst).trapif(
-        IntCC::UnsignedGreaterThanOrEqual,
-        cflags,
-        ir::TrapCode::StackOverflow,
-    );
-}