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* x86: Fixed bugs in and refactored and renamed

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DoSubAddOpt optimisation method
This commit is contained in:
J. Gareth "Curious Kit" Moreton 2022-04-20 16:12:31 +01:00 committed by FPK
parent 9e3483fbeb
commit 236febb148
1 changed files with 95 additions and 35 deletions
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130
compiler/x86/aoptx86.pas
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@ -146,7 +146,7 @@ unit aoptx86;
class function IsShrMovZFoldable(shr_size, movz_size: topsize; Shift: TCGInt): Boolean; static;
procedure RemoveLastDeallocForFuncRes(p : tai);
function DoSubAddOpt(var p : tai) : Boolean;
function DoArithCombineOpt(var p : tai) : Boolean;
function DoMovCmpMemOpt(var p : tai; const hp1: tai; UpdateTmpUsedRegs: Boolean) : Boolean;
function DoSETccLblRETOpt(var p: tai; const hp_label: tai_label) : Boolean;
@ -5422,9 +5422,13 @@ unit aoptx86;
Asml.InsertAfter(p, hp1);
p := hp1;
Result := True;
Exit;
end;
end;
end;
if DoArithCombineOpt(p) then
Result:=true;
end;
end;
@ -5859,53 +5863,109 @@ unit aoptx86;
end;
function TX86AsmOptimizer.DoSubAddOpt(var p: tai): Boolean;
function TX86AsmOptimizer.DoArithCombineOpt(var p: tai): Boolean;
var
hp1 : tai;
SubInstr: Boolean;
ThisConst: TCGInt;
const
OverflowMin: array[S_B..S_Q] of TCGInt = (-128, -32768, -2147483648, -2147483648);
{ Note: 64-bit-sized arithmetic instructions can only take signed 32-bit immediates }
OverflowMax: array[S_B..S_Q] of TCGInt = ( 255, 65535, $FFFFFFFF, 2147483647);
begin
DoSubAddOpt := False;
Result := False;
if taicpu(p).oper[0]^.typ <> top_const then
{ Should have been confirmed before calling }
InternalError(2021102601);
SubInstr := (taicpu(p).opcode = A_SUB);
if GetLastInstruction(p, hp1) and
(hp1.typ = ait_instruction) and
(taicpu(hp1).opsize = taicpu(p).opsize) then
case taicpu(hp1).opcode Of
A_DEC:
if MatchOperand(taicpu(hp1).oper[0]^,taicpu(p).oper[1]^) then
begin
taicpu(p).loadConst(0,taicpu(p).oper[0]^.val+1);
RemoveInstruction(hp1);
end;
A_SUB:
if (taicpu(hp1).oper[0]^.typ = top_const) and
MatchOperand(taicpu(hp1).oper[1]^,taicpu(p).oper[1]^) then
begin
taicpu(p).loadConst(0,taicpu(p).oper[0]^.val+taicpu(hp1).oper[0]^.val);
RemoveInstruction(hp1);
end;
A_ADD:
begin
begin
if not (taicpu(p).opsize in [S_B, S_W, S_L{$ifdef x86_64}, S_Q{$endif x86_64}]) then
{ Bad size }
InternalError(2022042001);
case taicpu(hp1).opcode Of
A_INC:
if MatchOperand(taicpu(hp1).oper[0]^,taicpu(p).oper[1]^) then
begin
if SubInstr then
ThisConst := taicpu(p).oper[0]^.val - 1
else
ThisConst := taicpu(p).oper[0]^.val + 1;
end
else
Exit;
A_DEC:
if MatchOperand(taicpu(hp1).oper[0]^,taicpu(p).oper[1]^) then
begin
if SubInstr then
ThisConst := taicpu(p).oper[0]^.val + 1
else
ThisConst := taicpu(p).oper[0]^.val - 1;
end
else
Exit;
A_SUB:
if (taicpu(hp1).oper[0]^.typ = top_const) and
MatchOperand(taicpu(hp1).oper[1]^,taicpu(p).oper[1]^) then
begin
taicpu(p).loadConst(0,taicpu(p).oper[0]^.val-taicpu(hp1).oper[0]^.val);
RemoveInstruction(hp1);
if (taicpu(p).oper[0]^.val = 0) then
begin
hp1 := tai(p.next);
RemoveInstruction(p); { Note, the choice to not use RemoveCurrentp is deliberate }
if not GetLastInstruction(hp1, p) then
p := hp1;
DoSubAddOpt := True;
end
end;
end;
else
;
end;
if SubInstr then
ThisConst := taicpu(p).oper[0]^.val + taicpu(hp1).oper[0]^.val
else
ThisConst := taicpu(p).oper[0]^.val - taicpu(hp1).oper[0]^.val;
end
else
Exit;
A_ADD:
if (taicpu(hp1).oper[0]^.typ = top_const) and
MatchOperand(taicpu(hp1).oper[1]^,taicpu(p).oper[1]^) then
begin
if SubInstr then
ThisConst := taicpu(p).oper[0]^.val - taicpu(hp1).oper[0]^.val
else
ThisConst := taicpu(p).oper[0]^.val + taicpu(hp1).oper[0]^.val;
end
else
Exit;
else
Exit;
end;
{ Check that the values are in range }
if (ThisConst < OverflowMin[taicpu(p).opsize]) or (ThisConst > OverflowMax[taicpu(p).opsize]) then
{ Overflow; abort }
Exit;
RemoveInstruction(hp1);
if (ThisConst = 0) then
begin
DebugMsg(SPeepholeOptimization + 'Arithmetic combine: ' +
debug_op2str(taicpu(hp1).opcode) + ' $' + debug_tostr(taicpu(hp1).oper[0]^.val) + ',' + debug_operstr(taicpu(hp1).oper[1]^) + '; ' +
debug_op2str(taicpu(p).opcode) + ' $' + debug_tostr(taicpu(p).oper[0]^.val) + ',' + debug_operstr(taicpu(p).oper[1]^) + ' cancel out (NOP)', p);
hp1 := tai(p.next);
RemoveInstruction(p); { Note, the choice to not use RemoveCurrentp is deliberate }
if not GetLastInstruction(hp1, p) then
p := hp1;
end
else
begin
DebugMsg(SPeepholeOptimization + 'Arithmetic combine: ' +
debug_op2str(taicpu(hp1).opcode) + ' $' + debug_tostr(taicpu(hp1).oper[0]^.val) + ',' + debug_operstr(taicpu(hp1).oper[1]^) + '; ' +
debug_op2str(taicpu(p).opcode) + ' $' + debug_tostr(taicpu(p).oper[0]^.val) + ',' + debug_operstr(taicpu(p).oper[1]^) + ' -> ' +
debug_op2str(taicpu(p).opcode) + ' $' + debug_tostr(ThisConst) + ' ' + debug_operstr(taicpu(p).oper[1]^), p);
taicpu(p).loadconst(0, ThisConst);
end;
Result := True;
end;
end;
@ -6398,7 +6458,7 @@ unit aoptx86;
end;
end;
{$endif i386}
if DoSubAddOpt(p) then
if DoArithCombineOpt(p) then
Result:=true;
end;
end;