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* some new routines for register management:

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maybe_savetotemp,restorefromtemp, saveusedregisters,
     restoreusedregisters
This commit is contained in:
florian 1999-05-19 22:00:48 +00:00
parent 5f3a866333
commit 8c6426faf7
1 changed files with 100 additions and 5 deletions
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105
compiler/tgeni386.pas
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@ -39,9 +39,13 @@ unit tgeni386;
tregisterset = set of tregister;
tpushed = array[R_EAX..R_MM6] of boolean;
tsaved = array[R_EAX..R_MM6] of longint;
const
usablereg32 : byte = 4;
{ this value is used in tsaved, if the register isn't saved }
reg_not_saved = $7fffffff;
{$ifdef SUPPORT_MMX}
usableregmmx : byte = 8;
{$endif SUPPORT_MMX}
@ -61,11 +65,14 @@ unit tgeni386;
procedure del_reference(const ref : treference);
procedure del_locref(const location : tlocation);
{ pushs and restores registers }
procedure pushusedregisters(list : paasmoutput;var pushed : tpushed;b : byte);
procedure popusedregisters(list : paasmoutput;const pushed : tpushed);
{ saves and restores used registers to temp. values }
procedure saveusedregisters(list : paasmoutput;var saved : tsaved;b : byte);
procedure restoreusedregisters(list : paasmoutput;const saved : tsaved);
procedure clearregistercount;
procedure resetusableregisters;
@ -90,15 +97,13 @@ unit tgeni386;
implementation
uses
globtype;
globtype,temp_gen;
procedure pushusedregisters(list : paasmoutput;var pushed : tpushed;b : byte);
var
r : tregister;
{$ifdef SUPPORT_MMX}
hr : preference;
{$endif SUPPORT_MMX}
begin
usedinproc:=usedinproc or b;
@ -113,6 +118,7 @@ implementation
begin
{ then save it }
list^.concat(new(pai386,op_reg(A_PUSH,S_L,r)));
{ here was a big problem !!!!!}
{ you cannot do that for a register that is
globally assigned to a var
@ -147,6 +153,56 @@ implementation
{$endif SUPPORT_MMX}
end;
procedure saveusedregisters(list : paasmoutput;var saved : tsaved;b : byte);
var
r : tregister;
hr : treference;
begin
usedinproc:=usedinproc or b;
for r:=R_EAX to R_EBX do
begin
saved[r]:=reg_not_saved;
{ if the register is used by the calling subroutine }
if ((b and ($80 shr byte(r)))<>0) then
begin
{ and is present in use }
if not(r in unused) then
begin
{ then save it }
gettempofsizereference(4,hr);
saved[r]:=hr.offset;
list^.concat(new(pai386,op_reg_ref(A_MOV,S_L,r,newreference(hr))));
{ here was a big problem !!!!!}
{ you cannot do that for a register that is
globally assigned to a var
this also means that you must push it much more
often, but there must be a better way
maybe by putting the value back to the stack !! }
if not(is_reg_var[r]) then
unused:=unused+[r];
end;
end;
end;
{$ifdef SUPPORT_MMX}
for r:=R_MM0 to R_MM6 do
begin
saved[r]:=reg_not_saved;
{ if the mmx register is in use, save it }
if not(r in unused) then
begin
gettempofsizereference(8,hr);
list^.concat(new(pai386,op_reg_ref(
A_MOVQ,S_NO,r,newreference(hr))));
if not(is_reg_var[r]) then
unused:=unused+[r];
saved[r]:=hr.offset;
end;
end;
{$endif SUPPORT_MMX}
end;
procedure popusedregisters(list : paasmoutput;const pushed : tpushed);
var
@ -180,6 +236,40 @@ implementation
end;
end;
procedure restoreusedregisters(list : paasmoutput;const saved : tsaved);
var
r : tregister;
hr : treference;
begin
{ restore in reverse order: }
{$ifdef SUPPORT_MMX}
for r:=R_MM6 downto R_MM0 do
begin
if saved[r]<>reg_not_saved then
begin
reset_reference(hr);
hr.base:=frame_pointer;
hr.offset:=saved[r];
list^.concat(new(pai386,op_ref_reg(
A_MOVQ,S_NO,newreference(hr),r)));
unused:=unused-[r];
ungetiftemp(hr);
end;
end;
{$endif SUPPORT_MMX}
for r:=R_EBX downto R_EAX do
if saved[r]<>reg_not_saved then
begin
reset_reference(hr);
hr.base:=frame_pointer;
hr.offset:=saved[r];
list^.concat(new(pai386,op_ref_reg(A_MOV,S_L,newreference(hr),r)));
unused:=unused-[r];
ungetiftemp(hr);
end;
end;
procedure ungetregister(r : tregister);
begin
@ -373,7 +463,12 @@ begin
end.
{
$Log$
Revision 1.24 1999-05-18 21:58:34 florian
Revision 1.25 1999-05-19 22:00:48 florian
* some new routines for register management:
maybe_savetotemp,restorefromtemp, saveusedregisters,
restoreusedregisters
Revision 1.24 1999/05/18 21:58:34 florian
* fixed some bugs related to temp. ansistrings and functions results
which return records/objects/arrays which need init/final.