* CSE of constant loading in regs works properly again

  + if a constant is stored into memory using "mov const, ref" and
    there is a reg that contains this const, it is changed into
    "mov reg, ref"

compiler/csopt386.pas

@@ -486,7 +486,10 @@ begin
 end;
 
 Procedure ClearRegContentsFrom(reg: TRegister; p: pai);
-var hp: pai;
+var
+{$ifdef replaceregdebug}
+    hp: pai;
+{$endif replaceregdebug}
     tmpState: byte;
 begin
   tmpState := PPaiProp(p^.optInfo)^.Regs[reg].wState;
@@ -756,6 +759,39 @@ begin
 End;
 {$endif replacereg}
 
+{$ifdef arithopt}
+Function FindRegWithConst(p: Pai; size: topsize; l: longint; Var Res: TRegister): Boolean;
+{Finds a register which contains the constant l}
+Var Counter: TRegister;
+{$ifdef testing}
+    hp: pai;
+{$endif testing}
+    tmpresult: boolean;
+Begin
+  Counter := R_NO;
+  repeat
+     inc(counter);
+     tmpresult := (PPaiProp(p^.OptInfo)^.Regs[Counter].Typ = Con_Const) and
+       (paicpu(PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod)^.opsize = size) and
+       (paicpu(PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod)^.oper[0].val = l);
+{$ifdef testing}
+     if (PPaiProp(p^.OptInfo)^.Regs[Counter].Typ = Con_Const) then
+       begin
+         hp := new(pai_asm_comment,init(strpnew(
+           'checking const load of '+tostr(l)+' here...')));
+         hp^.next := PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod;
+         hp^.previous := PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod^.previous;
+         PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod^.previous := hp;
+         if assigned(hp^.previous) then
+           hp^.previous^.next := hp;
+       end;
+{$endif testing}
+  until tmpresult or (Counter = R_EDI);
+  res := counter;
+  FindRegWithConst := tmpResult;
+End;
+{$endif arithopt}
+
 Procedure DoCSE(AsmL: PAasmOutput; First, Last: Pai);
 {marks the instructions that can be removed by RemoveInstructs. They're not
  removed immediately because sometimes an instruction needs to be checked in
@@ -980,10 +1016,16 @@ Begin
                               If GetLastInstruction(p, hp1) Then
                                 With PPaiProp(hp1^.OptInfo)^.Regs[Reg32(Paicpu(p)^.oper[1].reg)] Do
                                   If (Typ = Con_Const) And
-                                     (StartMod = p) Then
+                                     (paicpu(startMod)^.opsize >= paicpu(p)^.opsize) and
+                                     (paicpu(StartMod)^.oper[0].val = paicpu(p)^.oper[0].val) Then
                                     PPaiProp(p^.OptInfo)^.CanBeRemoved := True;
                             End;
-{                          Top_Ref:;}
+{$ifdef arithopt}
+                          Top_Ref:
+                            if getLastInstruction(p,hp1) and
+                               findRegWithConst(hp1,paicpu(p)^.opsize,paicpu(p)^.oper[0].val,regCounter) then
+                              paicpu(p)^.loadreg(0,regCounter);
+{$endif arithopt}
                         End;
                       End;
                   End;
@@ -991,16 +1033,6 @@ Begin
               A_STD: If GetLastInstruction(p, hp1) And
                         (PPaiProp(hp1^.OptInfo)^.DirFlag = F_Set) Then
                         PPaiProp(Pai(p)^.OptInfo)^.CanBeRemoved := True;
-              A_XOR:
-                Begin
-                  If (Paicpu(p)^.oper[0].typ = top_reg) And
-                     (Paicpu(p)^.oper[0].typ = top_reg) And
-                     (Paicpu(p)^.oper[1].reg = Paicpu(p)^.oper[1].reg) And
-                     GetLastInstruction(p, hp1) And
-                     (PPaiProp(hp1^.OptInfo)^.Regs[Reg32(Paicpu(p)^.oper[1].reg)].typ = con_const) And
-                     (PPaiProp(hp1^.OptInfo)^.Regs[Reg32(Paicpu(p)^.oper[1].reg)].StartMod = nil)
-                    Then PPaiProp(p^.OptInfo)^.CanBeRemoved := True
-                End
             End
           End;
       End;
@@ -1061,7 +1093,13 @@ End.
 
 {
  $Log$
- Revision 1.35  1999-12-02 11:26:41  peter
+ Revision 1.36  1999-12-05 16:48:43  jonas
+   * CSE of constant loading in regs works properly again
+   + if a constant is stored into memory using "mov const, ref" and
+     there is a reg that contains this const, it is changed into
+     "mov reg, ref"
+
+ Revision 1.35  1999/12/02 11:26:41  peter
    * newoptimizations define added
 
  Revision 1.34  1999/11/21 13:09:41  jonas

compiler/daopt386.pas

@@ -115,8 +115,7 @@ type
 
   TContent = Packed Record
       {start and end of block instructions that defines the
-       content of this register. If Typ = con_const, then
-       Longint(StartMod) = value of the constant)}
+       content of this register.}
                StartMod: pai;
       {starts at 0, gets increased everytime the register is written to}
                WState: Byte;
@@ -818,23 +817,6 @@ Begin
             Not(Pai_Label(p)^.l^.is_used)));
 End;
 
-
-(*Function FindZeroreg(p: Pai; Var Result: TRegister): Boolean;
-{Finds a register which contains the constant zero}
-Var Counter: TRegister;
-Begin
-  Counter := R_EAX;
-  FindZeroReg := True;
-  While (Counter <= R_EDI) And
-        ((PPaiProp(p^.OptInfo)^.Regs[Counter].Typ <> Con_Const) or
-         (PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod <> Pointer(0))) Do
-    Inc(Byte(Counter));
-  If (PPaiProp(p^.OptInfo)^.Regs[Counter].Typ = Con_Const) And
-     (PPaiProp(p^.OptInfo)^.Regs[Counter].StartMod = Pointer(0))
-    Then Result := Counter
-    Else FindZeroReg := False;
-End;*)
-
 Procedure IncState(Var S: Byte);
 {Increases S by 1, wraps around at $ffff to 0 (so we won't get overflow
  errors}
@@ -1744,22 +1726,15 @@ Begin
                     DestroyOp(p, Paicpu(p)^.oper[2]);
             {$endif arithopt}
                 End;
-              A_XOR:
-                Begin
-                  ReadOp(CurProp, Paicpu(p)^.oper[0]);
-                  ReadOp(CurProp, Paicpu(p)^.oper[1]);
-                  If (Paicpu(p)^.oper[0].typ = top_reg) And
-                     (Paicpu(p)^.oper[1].typ = top_reg) And
-                     (Paicpu(p)^.oper[0].reg = Paicpu(p)^.oper[1].reg)
-                    Then
-                      Begin
-                        DestroyReg(CurProp, Paicpu(p)^.oper[0].reg, true);
-                        CurProp^.Regs[Reg32(Paicpu(p)^.oper[0].reg)].typ := Con_Const;
-                        CurProp^.Regs[Reg32(Paicpu(p)^.oper[0].reg)].StartMod := Pointer(0)
-                      End
-                    Else
-                      DestroyOp(p, Paicpu(p)^.oper[1]);
-                End
+{$ifdef arithopt}
+              A_LEA:
+                begin
+                  readop(curprop,paicpu(p)^.oper[0]);
+                  if reginref(paicpu(p)^.oper[1].reg,paicpu(p)^.oper[0].ref^) then
+                    AddInstr2RegContents(paicpu(p), paicpu(p)^.oper[1].reg)
+                  else destroyreg(curprop,paicpu(p)^.oper[1].reg,true);
+                end;
+{$endif arithopt}
               Else
                 Begin
                   Cnt := 1;
@@ -1943,7 +1918,13 @@ End.
 
 {
  $Log$
- Revision 1.74  1999-12-02 11:26:41  peter
+ Revision 1.75  1999-12-05 16:48:43  jonas
+   * CSE of constant loading in regs works properly again
+   + if a constant is stored into memory using "mov const, ref" and
+     there is a reg that contains this const, it is changed into
+     "mov reg, ref"
+
+ Revision 1.74  1999/12/02 11:26:41  peter
    * newoptimizations define added
 
  Revision 1.73  1999/11/27 23:45:43  jonas

compiler/popt386.pas

@@ -1061,15 +1061,6 @@ Begin
                                   Paicpu(p)^.LoadReg(1,Paicpu(hp1)^.oper[0].reg);
                                 End
                       End;
-                       {changes "mov $0, %reg" into "xor %reg, %reg"}
-                  If (Paicpu(p)^.oper[0].typ = Top_Const) And
-                     (Paicpu(p)^.oper[0].val = 0) And
-                     (Paicpu(p)^.oper[1].typ = Top_Reg)
-                    Then
-                      Begin
-                        Paicpu(p)^.opcode := A_XOR;
-                        Paicpu(p)^.LoadReg(0,Paicpu(p)^.oper[1].reg);
-                      End;
                 End;
               A_MOVZX:
                 Begin
@@ -1545,9 +1536,17 @@ Begin
                          End
                      End
                     Else
-
-
                  End;
+               A_XOR:
+                 If (Paicpu(p)^.oper[0].typ = top_reg) And
+                    (Paicpu(p)^.oper[1].typ = top_reg) And
+                    (Paicpu(p)^.oper[0].reg = Paicpu(p)^.oper[1].reg) then
+                  { temporarily change this to 'mov reg,0' to make it easier }
+                  { for the CSE. Will be changed back in pass 2              }
+                   begin
+                     paicpu(p)^.opcode := A_MOV;
+                     paicpu(p)^.loadconst(0,0);
+                   end;
             End;
             end; { if is_jmp }
           End;
@@ -1674,8 +1673,16 @@ Begin
                        Dispose(hp2,Done);
                        p := hp1
                      End;
-                   End;
+                   End
 {$endif foldArithOps}
+                  else if (Paicpu(p)^.oper[0].typ = Top_Const) And
+                     (Paicpu(p)^.oper[0].val = 0) And
+                     (Paicpu(p)^.oper[1].typ = Top_Reg) Then
+                    { change "mov $0, %reg" into "xor %reg, %reg" }
+                    Begin
+                      Paicpu(p)^.opcode := A_XOR;
+                      Paicpu(p)^.LoadReg(0,Paicpu(p)^.oper[1].reg);
+                    End
                 End;
               A_MOVZX:
                 Begin
@@ -1735,7 +1742,13 @@ End.
 
 {
  $Log$
- Revision 1.73  1999-12-02 11:26:41  peter
+ Revision 1.74  1999-12-05 16:48:43  jonas
+   * CSE of constant loading in regs works properly again
+   + if a constant is stored into memory using "mov const, ref" and
+     there is a reg that contains this const, it is changed into
+     "mov reg, ref"
+
+ Revision 1.73  1999/12/02 11:26:41  peter
    * newoptimizations define added
 
  Revision 1.72  1999/11/30 10:40:45  peter