wont generate mov from tmp_a to tmp_a in intermediate block. No longer

put binop/move as tree child

src/compiler/backend/arch/x86_64/asm_backend.rs

@@ -4485,7 +4485,12 @@ pub fn spill_rewrite(
                         .clone_value();
 
                     // maintain mapping
-                    trace!("reg {} used in Inst{} is replaced as {}", val_reg, i, temp);
+                    trace!(
+                        "reg {} used in Inst{} is replaced as {}",
+                        val_reg.id(),
+                        i,
+                        temp
+                    );
                     spilled_scratch_temps.insert(temp.id(), reg);
 
                     // generate a load
@@ -4542,7 +4547,7 @@ pub fn spill_rewrite(
                     };
                     trace!(
                         "reg {} defined in Inst{} is replaced as {}",
-                        val_reg,
+                        val_reg.id(),
                         i,
                         temp
                     );

src/compiler/backend/reg_alloc/graph_coloring/liveness.rs

@@ -243,13 +243,13 @@ impl InterferenceGraph {
                 self.adj_list.get_mut(&u).unwrap().insert(v);
                 let degree = self.get_degree_of(u);
                 self.set_degree_of(u, degree + 1);
-                trace!("increase degree of {} to {}", u, degree + 1);
+                trace!("  increase degree of {} to {}", u, degree + 1);
             }
             if !is_precolored(v) {
                 self.adj_list.get_mut(&v).unwrap().insert(u);
                 let degree = self.get_degree_of(v);
                 self.set_degree_of(v, degree + 1);
-                trace!("increase degree of {} to {}", v, degree + 1);
+                trace!("  increase degree of {} to {}", v, degree + 1);
             }
         }
     }
@@ -310,7 +310,7 @@ impl InterferenceGraph {
     }
 
     pub fn set_degree_of(&mut self, reg: MuID, degree: usize) {
-        debug!("DEGREE({}) SET TO {}", reg, degree);
+        trace!("  set degree({}) = {}", reg, degree);
         self.degree.insert(reg, degree);
     }
 

src/compiler/mod.rs

@@ -54,6 +54,7 @@ impl<'vm> Compiler<'vm> {
     /// compiles a certain function version
     pub fn compile(&self, func: &mut MuFunctionVersion) {
         info!("");
+        info!("compilation_start {}", func.id());
         info!("Start compiling {}", func);
         info!("");
         debug!("{:?}", func);
@@ -78,6 +79,7 @@ impl<'vm> Compiler<'vm> {
             // build exception table for this function
             unimplemented!()
         }
+        info!("compilation_end {}", func.id());
     }
 }
 

src/compiler/passes/gen_mov_phi.rs

@@ -324,6 +324,10 @@ impl CompilerPass for GenMovPhi {
                         // move every from_arg to target_arg
                         let mut i = 0;
                         for arg in block_info.from_args.iter() {
+                            let ref target_arg = target_args[i];
+                            // when a block branches to itself, it is possible that
+                            // arg is the same as target_arg
+                            if arg.as_value() != target_arg {
                                 let m = func.new_inst(Instruction {
                                     hdr: MuEntityHeader::unnamed(vm.next_id()),
                                     value: Some(vec![target_args[i].clone()]),
@@ -332,6 +336,7 @@ impl CompilerPass for GenMovPhi {
                                 });
 
                                 vec.push(m);
+                            }
 
                             i += 1;
                         }

src/compiler/passes/tree_gen.rs

@@ -89,8 +89,8 @@ fn is_suitable_child(inst: &Instruction) -> bool {
         AtomicRMW { .. } |
         Store { .. } => false,
 
-        BinOp(_, _, _) |
-        BinOpWithStatus(_, _, _, _) |
+        BinOp(_, _, _) | BinOpWithStatus(_, _, _, _) | CommonInst_GetThreadLocal | Move(_) => false,
+
         CmpOp(_, _, _) |
         ConvOp { .. } |
         Load { .. } |
@@ -98,9 +98,7 @@ fn is_suitable_child(inst: &Instruction) -> bool {
         GetFieldIRef { .. } |
         GetElementIRef { .. } |
         ShiftIRef { .. } |
-        GetVarPartIRef { .. } |
-        CommonInst_GetThreadLocal |
-        Move(_) => true
+        GetVarPartIRef { .. } => true
     }
 }