fpc/compiler/mips/aoptcpu.pas
2013-11-25 13:57:19 +00:00

218 lines
6.9 KiB
ObjectPascal

{
Copyright (c) 1998-2004 by Jonas Maebe
This unit calls the optimization procedures to optimize the assembler
code for sparc
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
****************************************************************************
}
unit aoptcpu;
{$i fpcdefs.inc}
Interface
uses
cgbase, cpubase, aoptobj, aoptcpub, aopt, aasmtai;
Type
TCpuAsmOptimizer = class(TAsmOptimizer)
function TryRemoveMov(var p: tai; opcode: TAsmOp): boolean;
function PeepHoleOptPass1Cpu(var p: tai): boolean; override;
End;
Implementation
uses
aasmcpu;
function MatchInstruction(const instr: tai; const op: TAsmOp): boolean;
begin
result :=
(instr.typ = ait_instruction) and
(taicpu(instr).opcode = op);
end;
function MatchOperand(const oper: TOper; reg: TRegister): boolean;
begin
result:=(oper.typ=top_reg) and (oper.reg=reg);
end;
function IsSameReg(this,next: taicpu): boolean;
begin
result:=(next.oper[0]^.typ=top_reg) and
(next.oper[1]^.typ=top_reg) and
(next.oper[0]^.reg=next.oper[1]^.reg) and
(next.oper[0]^.reg=this.oper[0]^.reg);
end;
function TCpuAsmOptimizer.TryRemoveMov(var p: tai; opcode: TAsmOp): boolean;
var
next,hp1: tai;
alloc,dealloc: tai_regalloc;
begin
{ Fold
op $reg1,...
opcode $reg2,$reg1
dealloc $reg1
into
op $reg2,...
opcode may be A_MOVE, A_MOV_s, A_MOV_d, etc.
}
result:=false;
if GetNextInstruction(p,next) and
MatchInstruction(next,opcode) and
MatchOperand(taicpu(next).oper[1]^,taicpu(p).oper[0]^.reg) then
begin
dealloc:=FindRegDealloc(taicpu(p).oper[0]^.reg,tai(next.Next));
if assigned(dealloc) then
begin
{ taicpu(p).oper[0]^.reg is not used anymore, try to find its allocation
and remove it if possible }
GetLastInstruction(p,hp1);
asml.Remove(dealloc);
alloc:=FindRegAlloc(taicpu(p).oper[0]^.reg,tai(hp1.Next));
if assigned(alloc) then
begin
asml.Remove(alloc);
alloc.free;
dealloc.free;
end
else
asml.InsertAfter(dealloc,p);
{ try to move the allocation of the target register }
GetLastInstruction(next,hp1);
alloc:=FindRegAlloc(taicpu(next).oper[0]^.reg,tai(hp1.Next));
if assigned(alloc) then
begin
asml.Remove(alloc);
asml.InsertBefore(alloc,p);
{ adjust used regs }
IncludeRegInUsedRegs(taicpu(next).oper[0]^.reg,UsedRegs);
end;
{ finally get rid of the mov }
taicpu(p).loadreg(0,taicpu(next).oper[0]^.reg);
asml.remove(next);
next.free;
end;
end;
end;
function TCpuAsmOptimizer.PeepHoleOptPass1Cpu(var p: tai): boolean;
var
next,next2: tai;
begin
result:=false;
case p.typ of
ait_instruction:
begin
case taicpu(p).opcode of
A_SRL:
begin
{ Remove 'andi' in sequences
srl Rx,Ry,16
andi Rx,Rx,65535
srl Rx,Ry,24
andi Rx,Rx,255
since 'srl' clears all relevant upper bits }
if (taicpu(p).oper[2]^.typ=top_const) and
GetNextInstruction(p,next) and
MatchInstruction(next,A_ANDI) and
IsSameReg(taicpu(p),taicpu(next)) and
(taicpu(next).oper[2]^.typ=top_const) and
((
(taicpu(p).oper[2]^.val>=16) and
(taicpu(next).oper[2]^.val=65535)
) or (
(taicpu(p).oper[2]^.val>=24) and
(taicpu(next).oper[2]^.val=255)
)) then
begin
asml.remove(next);
next.free;
end
else
TryRemoveMov(p,A_MOVE);
end;
A_ANDI:
begin
{ Remove sign extension after 'andi' if bit 7/15 of const operand is clear }
if (taicpu(p).oper[2]^.typ=top_const) and
GetNextInstruction(p,next) and
MatchInstruction(next,A_SLL) and
GetNextInstruction(next,next2) and
MatchInstruction(next2,A_SRA) and
IsSameReg(taicpu(p),taicpu(next)) and
IsSameReg(taicpu(p),taicpu(next2)) and
(taicpu(next).oper[2]^.typ=top_const) and
(taicpu(next2).oper[2]^.typ=top_const) and
(taicpu(next).oper[2]^.val=taicpu(next2).oper[2]^.val) and
((
(taicpu(p).oper[2]^.val<=$7fff) and
(taicpu(next).oper[2]^.val=16)
) or (
(taicpu(p).oper[2]^.val<=$7f) and
(taicpu(next).oper[2]^.val=24)
)) then
begin
asml.remove(next);
asml.remove(next2);
next.free;
next2.free;
end
else
TryRemoveMov(p,A_MOVE);
end;
A_ADD,A_ADDU,
A_ADDI,A_ADDIU,
A_SUB,A_SUBU,
A_SRA,A_SRAV,
A_SRLV,
A_SLL,A_SLLV,
A_AND,A_OR,A_XOR,A_ORI,A_XORI:
TryRemoveMov(p,A_MOVE);
A_ADD_s, A_SUB_s, A_MUL_s, A_DIV_s,
A_ABS_s, A_NEG_s, A_SQRT_s,
A_CVT_s_w, A_CVT_s_l, A_CVT_s_d:
TryRemoveMov(p,A_MOV_s);
A_ADD_d, A_SUB_d, A_MUL_d, A_DIV_d,
A_ABS_d, A_NEG_d, A_SQRT_d,
A_CVT_d_w, A_CVT_d_l, A_CVT_d_s:
TryRemoveMov(p,A_MOV_d);
end;
end;
end;
end;
begin
casmoptimizer:=TCpuAsmOptimizer;
end.