* further look ahead for temp. deallocation for FstpFldFstp2Fstp and FstpFld2<Nop>

compiler/aoptobj.pas

@@ -338,6 +338,12 @@ Unit AoptObj;
           reloaded with a new value or it is deallocated afterwards }
         function RegEndOfLife(reg: TRegister;p: taicpu): boolean;
 
+        { Returns the next ait_tempalloc object with allocation=false
+          for Offset which is found in the block of Tai's starting with StartPai
+          and ending with the next "real" instruction. If none is found, it returns
+          nil                                                                        }
+        class function FindTempDeAlloc(Offset: ASizeInt; StartPai: Tai): tai_tempalloc;
+
         { removes p from asml, updates registers and replaces it by a valid value, if this is the case true is returned }
         function RemoveCurrentP(var p : tai): boolean;
 
@@ -1358,6 +1364,32 @@ Unit AoptObj;
        End;
 
 
+      class function TAOptObj.FindTempDeAlloc(Offset: ASizeInt; StartPai: Tai): tai_tempalloc;
+      Begin
+         Result:=nil;
+         Repeat
+           While Assigned(StartPai) And
+                 ((StartPai.typ in (SkipInstr - [ait_tempalloc])) Or
+                  ((StartPai.typ = ait_label) and
+                   Not(Tai_Label(StartPai).labsym.Is_Used))) Do
+             StartPai := Tai(StartPai.Next);
+           If Assigned(StartPai) And
+              (StartPai.typ = ait_tempalloc) Then
+             Begin
+               if not(tai_tempalloc(StartPai).allocation) and
+                 (tai_tempalloc(StartPai).temppos = Offset) then
+                begin
+                  Result:=tai_tempalloc(StartPai);
+                  exit;
+                end;
+               StartPai := Tai(StartPai.Next);
+             End
+           else
+             exit;
+         Until false;
+       End;
+
+
     { allocates register reg between (and including) instructions p1 and p2
       the type of p1 and p2 must not be in SkipInstr }
     procedure TAOptObj.AllocRegBetween(reg: tregister; p1, p2: tai; var initialusedregs: TAllUsedRegs);

compiler/x86/aoptx86.pas

@@ -7106,10 +7106,9 @@ unit aoptx86;
                  fld  <temp>
                  <dealloc> <temp>
                }
-               (SetAndTest(tai(hp1.next),hp2) and (hp2.typ = ait_tempalloc) and
+               ((taicpu(p).oper[0]^.ref^.base = current_procinfo.FramePointer) and
-                (tai_tempalloc(hp2).allocation=false) and
-                (taicpu(p).oper[0]^.ref^.base = current_procinfo.FramePointer) and
                 (taicpu(p).oper[0]^.ref^.index = NR_NO) and
+                SetAndTest(FindTempDeAlloc(taicpu(p).oper[0]^.ref^.offset,tai(hp1.next)),hp2) and
                 (tai_tempalloc(hp2).temppos=taicpu(p).oper[0]^.ref^.offset) and
                 (((taicpu(p).opsize=S_FX) and (tai_tempalloc(hp2).tempsize=16)) or
                  ((taicpu(p).opsize in [S_IQ,S_FL]) and (tai_tempalloc(hp2).tempsize=8)) or
@@ -7136,10 +7135,9 @@ unit aoptx86;
                 (taicpu(p).opcode=taicpu(hp2).opcode) and
                 (taicpu(p).opsize=taicpu(hp2).opsize) then
                 begin
-                  if SetAndTest(tai(hp2.next),hp3) and (hp3.typ = ait_tempalloc) and
+                  if (taicpu(p).oper[0]^.ref^.base = current_procinfo.FramePointer) and
-                    (tai_tempalloc(hp3).allocation=false) and
-                    (taicpu(p).oper[0]^.ref^.base = current_procinfo.FramePointer) and
                     (taicpu(p).oper[0]^.ref^.index = NR_NO) and
+                    SetAndTest(FindTempDeAlloc(taicpu(p).oper[0]^.ref^.offset,tai(hp2.next)),hp3) and
                     MatchOperand(taicpu(p).oper[0]^,taicpu(hp1).oper[0]^) and
                     (tai_tempalloc(hp3).temppos=taicpu(p).oper[0]^.ref^.offset) and
                     (((taicpu(p).opsize=S_FX) and (tai_tempalloc(hp3).tempsize=16)) or