fpc/compiler/x86/rgx86.pas

576 lines
22 KiB
ObjectPascal

{
Copyright (c) 1998-2002 by Florian Klaempfl
This unit implements the x86 specific class for the register
allocator
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 rgx86;
{$i fpcdefs.inc}
interface
uses
cpubase,cgbase,cgutils,
aasmtai,aasmdata,aasmsym,aasmcpu,
rgobj;
type
trgx86 = class(trgobj)
function get_spill_subreg(r : tregister) : tsubregister;override;
function do_spill_replace(list:TAsmList;instr:tai_cpu_abstract_sym;orgreg:tsuperregister;const spilltemp:treference):boolean;override;
end;
tpushedsavedloc = record
case byte of
0: (pushed: boolean);
1: (ofs: longint);
end;
tpushedsavedfpu = array[tsuperregister] of tpushedsavedloc;
trgx86fpu = class
{ these counters contain the number of elements in the }
{ unusedregsxxx/usableregsxxx sets }
countunusedregsfpu : byte;
{ Contains the registers which are really used by the proc itself.
It doesn't take care of registers used by called procedures
}
used_in_proc : tcpuregisterset;
{reg_pushes_other : regvarother_longintarray;
is_reg_var_other : regvarother_booleanarray;
regvar_loaded_other : regvarother_booleanarray;}
fpuvaroffset : byte;
constructor create;
function getregisterfpu(list: TAsmList) : tregister;
procedure ungetregisterfpu(list: TAsmList; r : tregister);
{ pushes and restores registers }
procedure saveusedfpuregisters(list:TAsmList;
var saved:Tpushedsavedfpu;
const s:Tcpuregisterset);
procedure restoreusedfpuregisters(list:TAsmList;
const saved:Tpushedsavedfpu);
{ corrects the fpu stack register by ofs }
function correct_fpuregister(r : tregister;ofs : byte) : tregister;
end;
implementation
uses
verbose;
const
{ This value is used in tsaved. If the array value is equal
to this, then this means that this register is not used.}
reg_not_saved = $7fffffff;
{******************************************************************************
Trgcpu
******************************************************************************}
function trgx86.get_spill_subreg(r : tregister) : tsubregister;
begin
result:=getsubreg(r);
end;
{ Decide wether a "replace" spill is possible, i.e. wether we can replace a register
in an instruction by a memory reference. For example, in "mov ireg26d,0", the imaginary
register ireg26d can be replaced by a memory reference.}
function trgx86.do_spill_replace(list:TAsmList;instr:tai_cpu_abstract_sym;orgreg:tsuperregister;const spilltemp:treference):boolean;
{ returns true if opcde is an avx opcode which allows only the first (zero) operand might be a memory reference }
function avx_opcode_only_op0_may_be_memref(opcode : TAsmOp) : boolean;
begin
case opcode of
A_VMAXPD,
A_VMAXPS,
A_VMAXSD,
A_VMAXSS,
A_VMINPD,
A_VMINPS,
A_VMINSD,
A_VMINSS,
A_VMULSS,
A_VMULSD,
A_VSUBSS,
A_VSUBSD,
A_VADDSD,
A_VADDSS,
A_VDIVSD,
A_VDIVSS,
A_VSQRTSD,
A_VSQRTSS,
A_VCVTDQ2PD,
A_VCVTDQ2PS,
A_VCVTPD2DQ,
A_VCVTPD2PS,
A_VCVTPS2DQ,
A_VCVTPS2PD,
A_VCVTSD2SI,
A_VCVTSD2SS,
A_VCVTSI2SD,
A_VCVTSS2SD,
A_VCVTTPD2DQ,
A_VCVTTPS2DQ,
A_VCVTTSD2SI,
A_VCVTSI2SS,
A_VCVTSS2SI,
A_VCVTTSS2SI,
A_VXORPD,
A_VXORPS,
A_VORPD,
A_VORPS,
A_VANDPD,
A_VANDPS,
A_VUNPCKLPS,
A_VUNPCKHPS,
A_VSHUFPD,
A_VREDUCEPD,
A_VREDUCEPS,
A_VREDUCESD,
A_VREDUCESS,
A_VROUNDSS,
A_VROUNDSD:
result:=true;
else
result:=false;
end;
end;
var
n,replaceoper : longint;
is_subh: Boolean;
begin
result:=false;
with taicpu(instr) do
begin
replaceoper:=-1;
case ops of
1 :
begin
if (oper[0]^.typ=top_reg) and
(getregtype(oper[0]^.reg)=regtype) then
begin
if get_alias(getsupreg(oper[0]^.reg))<>orgreg then
internalerror(200410101);
replaceoper:=0;
end;
end;
2,3 :
begin
{ avx instruction?
currently this rule is sufficient but it might be extended }
if (ops=3) and (opcode<>A_SHRD) and (opcode<>A_SHLD) and (opcode<>A_IMUL) then
begin
{ BMI shifting/rotating instructions have special requirements regarding spilling, only
the middle operand can be replaced }
if ((opcode=A_RORX) or (opcode=A_SHRX) or (opcode=A_SARX) or (opcode=A_SHLX) or (opcode=A_BEXTR) or (opcode=A_BZHI)) then
begin
if (oper[1]^.typ=top_reg) and (getregtype(oper[1]^.reg)=regtype) and (get_alias(getsupreg(oper[1]^.reg))=orgreg) then
replaceoper:=1;
end
{ avx instructions allow only the first operand (at&t counting) to be a register operand
all operands must be registers ... }
else if (oper[0]^.typ=top_reg) and
(getregtype(oper[0]^.reg)=regtype) and
(oper[1]^.typ=top_reg) and
(oper[2]^.typ=top_reg) and
{ but they must be different }
((getregtype(oper[1]^.reg)<>regtype) or
(get_alias(getsupreg(oper[0]^.reg))<>get_alias(getsupreg(oper[1]^.reg)))
) and
((getregtype(oper[2]^.reg)<>regtype) or
(get_alias(getsupreg(oper[0]^.reg))<>get_alias(getsupreg(oper[2]^.reg)))
) and
(get_alias(getsupreg(oper[0]^.reg))=orgreg) then
replaceoper:=0;
end
else
begin
{ We can handle opcodes with 2 and 3-op imul/shrd/shld the same way, where the 3rd operand is const or CL,
that doesn't need spilling.
However, due to AT&T order inside the compiler, the 3rd operand is
numbered 0, so look at operand no. 1 and 2 if we have 3 operands by
adding a "n". }
n:=0;
if ops=3 then
n:=1;
{ lea is tricky: part of operand 0 can be spilled and the instruction can converted into an
add, if base or index shall be spilled and the other one is equal the destination }
if (opcode=A_LEA) then
begin
if (oper[0]^.ref^.offset=0) and
(oper[0]^.ref^.scalefactor in [0,1]) and
(((getregtype(oper[0]^.ref^.base)=regtype) and
(get_alias(getsupreg(oper[0]^.ref^.base))=orgreg) and
(getregtype(oper[0]^.ref^.index)=getregtype(oper[1]^.reg)) and
(get_alias(getsupreg(oper[0]^.ref^.index))=get_alias(getsupreg(oper[1]^.reg)))) or
((getregtype(oper[0]^.ref^.index)=regtype) and
(get_alias(getsupreg(oper[0]^.ref^.index))=orgreg) and
(getregtype(oper[0]^.ref^.base)=getregtype(oper[1]^.reg)) and
(get_alias(getsupreg(oper[0]^.ref^.base))=get_alias(getsupreg(oper[1]^.reg))))
) then
replaceoper:=0;
end
else if (oper[n+0]^.typ=top_reg) and
(oper[n+1]^.typ=top_reg) and
((getregtype(oper[n+0]^.reg)<>regtype) or
(getregtype(oper[n+1]^.reg)<>regtype) or
(get_alias(getsupreg(oper[n+0]^.reg))<>get_alias(getsupreg(oper[n+1]^.reg)))) then
begin
if (getregtype(oper[n+0]^.reg)=regtype) and
(get_alias(getsupreg(oper[n+0]^.reg))=orgreg) then
replaceoper:=0+n
else if (getregtype(oper[n+1]^.reg)=regtype) and
(get_alias(getsupreg(oper[n+1]^.reg))=orgreg) then
replaceoper:=1+n;
end
else if (oper[n+0]^.typ=top_reg) and
(oper[n+1]^.typ=top_const) then
begin
if (getregtype(oper[0+n]^.reg)=regtype) and
(get_alias(getsupreg(oper[0+n]^.reg))=orgreg) then
replaceoper:=0+n
else
internalerror(200704282);
end
else if (oper[n+0]^.typ=top_const) and
(oper[n+1]^.typ=top_reg) then
begin
if (getregtype(oper[1+n]^.reg)=regtype) and
(get_alias(getsupreg(oper[1+n]^.reg))=orgreg) then
replaceoper:=1+n
else
internalerror(200704283);
end;
case replaceoper of
0 :
begin
{ Some instructions don't allow memory references
for source }
case opcode of
A_BT,
A_BTS,
A_BTC,
A_BTR,
{ shufp*/unpcklp* would require 16 byte alignment for memory locations so we force the source
operand into a register }
A_SHUFPD,
A_SHUFPS,
A_UNPCKLPD,
A_UNPCKLPS :
replaceoper:=-1;
{ movlhps/movhlps requires the second parameter to be XMM registers }
A_MOVHLPS,
A_MOVLHPS:
replaceoper:=-1;
else
;
end;
end;
1 :
begin
{ Some instructions don't allow memory references
for destination }
case opcode of
A_CMOVcc,
A_MOVZX,
A_MOVSX,
{$ifdef x86_64}
A_MOVSXD,
{$endif x86_64}
A_MULSS,
A_MULSD,
A_SUBSS,
A_SUBSD,
A_ADDSD,
A_ADDSS,
A_DIVSD,
A_DIVSS,
A_SQRTSD,
A_SQRTSS,
A_SHLD,
A_SHRD,
A_COMISD,
A_COMISS,
A_CVTDQ2PD,
A_CVTDQ2PS,
A_CVTPD2DQ,
A_CVTPD2PI,
A_CVTPD2PS,
A_CVTPI2PD,
A_CVTPS2DQ,
A_CVTPS2PD,
A_CVTSD2SI,
A_CVTSD2SS,
A_CVTSI2SD,
A_CVTSS2SD,
A_CVTTPD2PI,
A_CVTTPD2DQ,
A_CVTTPS2DQ,
A_CVTTSD2SI,
A_CVTPI2PS,
A_CVTPS2PI,
A_CVTSI2SS,
A_CVTSS2SI,
A_CVTTPS2PI,
A_CVTTSS2SI,
A_XORPD,
A_XORPS,
A_PXOR,
A_PAND,
A_POR,
A_ORPD,
A_ORPS,
A_ANDPD,
A_ANDPS,
A_UNPCKLPS,
A_UNPCKHPS,
A_SHUFPD,
A_SHUFPS,
A_VCOMISD,
A_VCOMISS,
A_MINSS,
A_MINSD,
A_MINPS,
A_MINPD,
A_MAXSS,
A_MAXSD,
A_MAXPS,
A_MAXPD:
replaceoper:=-1;
A_IMUL:
if ops<>3 then
replaceoper:=-1;
{$ifdef x86_64}
A_MOV:
{ 64 bit constants can only be moved into registers }
if (oper[0]^.typ=top_const) and
(oper[1]^.typ=top_reg) and
((oper[0]^.val<low(longint)) or
(oper[0]^.val>high(longint))) then
replaceoper:=-1;
{$endif x86_64}
else
if avx_opcode_only_op0_may_be_memref(opcode) then
replaceoper:=-1;
end;
end;
2 :
begin
{ Some 3-op instructions don't allow memory references
for destination }
case instr.opcode of
A_IMUL:
replaceoper:=-1;
else
if avx_opcode_only_op0_may_be_memref(opcode) then
replaceoper:=-1;
end;
end;
end;
end;
end;
end;
{$ifdef x86_64}
{ 32 bit operations on 32 bit registers on x86_64 can result in
zeroing the upper 32 bits of the register. This does not happen
with memory operations, so we have to perform these calculations
in registers.
However, for instructions not modifying registers, this is not a problem }
if (opsize=S_L) and (opcode<>A_CMP) and (opcode<>A_TEST) and (opcode<>A_BT) then
replaceoper:=-1;
{$endif x86_64}
{ Replace register with spill reference }
if replaceoper<>-1 then
begin
if opcode=A_LEA then
begin
opcode:=A_ADD;
oper[0]^.ref^:=spilltemp;
end
else
begin
is_subh:=getsubreg(oper[replaceoper]^.reg)=R_SUBH;
oper[replaceoper]^.typ:=top_ref;
new(oper[replaceoper]^.ref);
oper[replaceoper]^.ref^:=spilltemp;
if is_subh then
inc(oper[replaceoper]^.ref^.offset);
{ memory locations aren't guaranteed to be aligned }
case opcode of
A_MOVAPS:
opcode:=A_MOVSS;
A_MOVAPD:
opcode:=A_MOVSD;
A_VMOVAPS:
opcode:=A_VMOVSS;
A_VMOVAPD:
opcode:=A_VMOVSD;
else
;
end;
end;
result:=true;
end;
end;
end;
{******************************************************************************
Trgx86fpu
******************************************************************************}
constructor Trgx86fpu.create;
begin
used_in_proc:=[];
end;
function trgx86fpu.getregisterfpu(list: TAsmList) : tregister;
begin
{ note: don't return R_ST0, see comments above implementation of }
{ a_loadfpu_* methods in cgcpu (JM) }
result:=NR_ST;
end;
procedure trgx86fpu.ungetregisterfpu(list : TAsmList; r : tregister);
begin
{ nothing to do, fpu stack management is handled by the load/ }
{ store operations in cgcpu (JM) }
end;
function trgx86fpu.correct_fpuregister(r : tregister;ofs : byte) : tregister;
begin
correct_fpuregister:=r;
setsupreg(correct_fpuregister,ofs);
end;
procedure trgx86fpu.saveusedfpuregisters(list: TAsmList;
var saved : tpushedsavedfpu;
const s: tcpuregisterset);
{ var
r : tregister;
hr : treference; }
begin
used_in_proc:=used_in_proc+s;
{ TODO: firstsavefpureg}
(*
{ don't try to save the fpu registers if not desired (e.g. for }
{ the 80x86) }
if firstsavefpureg <> R_NO then
for r.enum:=firstsavefpureg to lastsavefpureg do
begin
saved[r.enum].ofs:=reg_not_saved;
{ if the register is used by the calling subroutine and if }
{ it's not a regvar (those are handled separately) }
if not is_reg_var_other[r.enum] and
(r.enum in s) and
{ and is present in use }
not(r.enum in unusedregsfpu) then
begin
{ then save it }
tg.GetTemp(list,extended_size,tt_persistent,hr);
saved[r.enum].ofs:=hr.offset;
cg.a_loadfpu_reg_ref(list,OS_FLOAT,OS_FLOAT,r,hr);
cg.a_reg_dealloc(list,r);
include(unusedregsfpu,r.enum);
inc(countunusedregsfpu);
end;
end;
*)
end;
procedure trgx86fpu.restoreusedfpuregisters(list : TAsmList;
const saved : tpushedsavedfpu);
{
var
r,r2 : tregister;
hr : treference;
}
begin
{ TODO: firstsavefpureg}
(*
if firstsavefpureg <> R_NO then
for r.enum:=lastsavefpureg downto firstsavefpureg do
begin
if saved[r.enum].ofs <> reg_not_saved then
begin
r2.enum:=R_INTREGISTER;
r2.number:=NR_FRAME_POINTER_REG;
reference_reset_base(hr,r2,saved[r.enum].ofs);
cg.a_reg_alloc(list,r);
cg.a_loadfpu_ref_reg(list,OS_FLOAT,OS_FLOAT,hr,r);
if not (r.enum in unusedregsfpu) then
{ internalerror(10)
in n386cal we always save/restore the reg *state*
using save/restoreunusedstate -> the current state
may not be real (JM) }
else
begin
dec(countunusedregsfpu);
exclude(unusedregsfpu,r.enum);
end;
tg.UnGetTemp(list,hr);
end;
end;
*)
end;
(*
procedure Trgx86fpu.saveotherregvars(list: TAsmList; const s: totherregisterset);
var
r: Tregister;
begin
if not(cs_opt_regvar in current_settings.optimizerswitches) then
exit;
if firstsavefpureg <> NR_NO then
for r.enum := firstsavefpureg to lastsavefpureg do
if is_reg_var_other[r.enum] and
(r.enum in s) then
store_regvar(list,r);
end;
*)
end.