{
Copyright (c) 1998-2002 by Florian Klaempfl
Generate i386 assembler for math nodes
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 n386mat;
{$i fpcdefs.inc}
interface
uses
node,nmat,ncgmat,nx86mat;
type
ti386moddivnode = class(tmoddivnode)
procedure pass_generate_code;override;
end;
ti386shlshrnode = class(tcgshlshrnode)
procedure second_64bit;override;
function first_shlshr64bitint: tnode; override;
end;
ti386unaryminusnode = class(tx86unaryminusnode)
end;
ti386notnode = class(tx86notnode)
end;
implementation
uses
globtype,systems,
cutils,verbose,globals,
symconst,symdef,aasmbase,aasmtai,aasmdata,defutil,
cgbase,pass_2,
ncon,
cpubase,cpuinfo,
cga,ncgutil,cgobj,cgutils;
{*****************************************************************************
TI386MODDIVNODE
*****************************************************************************}
function log2(i : dword) : dword;
begin
result:=0;
i:=i shr 1;
while i<>0 do
begin
i:=i shr 1;
inc(result);
end;
end;
procedure ti386moddivnode.pass_generate_code;
var
hreg1,hreg2:Tregister;
power:longint;
hl:Tasmlabel;
op:Tasmop;
e : longint;
d,l,r,s,m,a,n,t : dword;
m_low,m_high,j,k : qword;
begin
secondpass(left);
if codegenerror then
exit;
secondpass(right);
if codegenerror then
exit;
if is_64bitint(resultdef) then
{ should be handled in pass_1 (JM) }
internalerror(200109052);
{ put numerator in register }
location_reset(location,LOC_REGISTER,OS_INT);
location_force_reg(current_asmdata.CurrAsmList,left.location,OS_INT,false);
hreg1:=left.location.register;
if (nodetype=divn) and (right.nodetype=ordconstn) then
begin
if ispowerof2(tordconstnode(right).value,power) then
begin
{ for signed numbers, the numerator must be adjusted before the
shift instruction, but not wih unsigned numbers! Otherwise,
"Cardinal($ffffffff) div 16" overflows! (JM) }
if is_signed(left.resultdef) Then
begin
if (current_settings.optimizecputype <> cpu_386) and
not(cs_opt_size in current_settings.optimizerswitches) then
{ use a sequence without jumps, saw this in
comp.compilers (JM) }
begin
{ no jumps, but more operations }
hreg2:=cg.getintregister(current_asmdata.CurrAsmList,OS_INT);
emit_reg_reg(A_MOV,S_L,hreg1,hreg2);
{If the left value is signed, hreg2=$ffffffff, otherwise 0.}
emit_const_reg(A_SAR,S_L,31,hreg2);
{If signed, hreg2=right value-1, otherwise 0.}
emit_const_reg(A_AND,S_L,tordconstnode(right).value-1,hreg2);
{ add to the left value }
emit_reg_reg(A_ADD,S_L,hreg2,hreg1);
{ do the shift }
emit_const_reg(A_SAR,S_L,power,hreg1);
end
else
begin
{ a jump, but less operations }
emit_reg_reg(A_TEST,S_L,hreg1,hreg1);
current_asmdata.getjumplabel(hl);
cg.a_jmp_flags(current_asmdata.CurrAsmList,F_NS,hl);
if power=1 then
emit_reg(A_INC,S_L,hreg1)
else
emit_const_reg(A_ADD,S_L,tordconstnode(right).value-1,hreg1);
cg.a_label(current_asmdata.CurrAsmList,hl);
emit_const_reg(A_SAR,S_L,power,hreg1);
end
end
else
emit_const_reg(A_SHR,S_L,power,hreg1);
location.register:=hreg1;
end
else
begin
if is_signed(left.resultdef) then
begin
e:=tordconstnode(right).value;
d:=abs(e);
{ Determine algorithm (a), multiplier (m), and shift factor (s) for 32-bit
signed integer division. Based on: Granlund, T.; Montgomery, P.L.:
"Division by Invariant Integers using Multiplication". SIGPLAN Notices,
Vol. 29, June 1994, page 61.
}
l:=log2(d);
j:=qword($80000000) mod qword(d);
k:=(qword(1) shl (32+l)) div (qword($80000000-j));
m_low:=((qword(1)) shl (32+l)) div d;
m_high:=(((qword(1)) shl (32+l)) + k) div d;
while ((m_low shr 1) < (m_high shr 1)) and (l > 0) do
begin
m_low:=m_low shr 1;
m_high:=m_high shr 1;
dec(l);
end;
m:=dword(m_high);
s:=l;
if (m_high shr 31)<>0 then
a:=1
else
a:=0;
cg.getcpuregister(current_asmdata.CurrAsmList,NR_EAX);
emit_const_reg(A_MOV,S_L,aint(m),NR_EAX);
cg.getcpuregister(current_asmdata.CurrAsmList,NR_EDX);
emit_reg(A_IMUL,S_L,hreg1);
emit_reg_reg(A_MOV,S_L,hreg1,NR_EAX);
if a<>0 then
begin
emit_reg_reg(A_ADD,S_L,NR_EAX,NR_EDX);
{
printf ("; dividend: memory location or register other than EAX or EDX\n");
printf ("\n");
printf ("MOV EAX, 0%08LXh\n", m);
printf ("IMUL dividend\n");
printf ("MOV EAX, dividend\n");
printf ("ADD EDX, EAX\n");
if (s) printf ("SAR EDX, %d\n", s);
printf ("SHR EAX, 31\n");
printf ("ADD EDX, EAX\n");
if (e < 0) printf ("NEG EDX\n");
printf ("\n");
printf ("; quotient now in EDX\n");
}
end;
{
printf ("; dividend: memory location of register other than EAX or EDX\n");
printf ("\n");
printf ("MOV EAX, 0%08LXh\n", m);
printf ("IMUL dividend\n");
printf ("MOV EAX, dividend\n");
if (s) printf ("SAR EDX, %d\n", s);
printf ("SHR EAX, 31\n");
printf ("ADD EDX, EAX\n");
if (e < 0) printf ("NEG EDX\n");
printf ("\n");
printf ("; quotient now in EDX\n");
}
if s<>0 then
emit_const_reg(A_SAR,S_L,s,NR_EDX);
emit_const_reg(A_SHR,S_L,31,NR_EAX);
emit_reg_reg(A_ADD,S_L,NR_EAX,NR_EDX);
if e<0 then
emit_reg(A_NEG,S_L,NR_EDX);
cg.ungetcpuregister(current_asmdata.CurrAsmList,NR_EDX);
cg.ungetcpuregister(current_asmdata.CurrAsmList,NR_EAX);
location.register:=cg.getintregister(current_asmdata.CurrAsmList,OS_INT);
cg.a_load_reg_reg(current_asmdata.CurrAsmList,OS_INT,OS_INT,NR_EDX,location.register)
end
else
begin
d:=tordconstnode(right).value;
if d>=$80000000 then
begin
emit_const_reg(A_CMP,S_L,aint(d),hreg1);
location.register:=cg.getintregister(current_asmdata.CurrAsmList,OS_INT);
emit_const_reg(A_MOV,S_L,0,location.register);
emit_const_reg(A_SBB,S_L,-1,location.register);
end
else
begin
{ Reduce divisor until it becomes odd }
n:=0;
t:=d;
while (t and 1)=0 do
begin
t:=t shr 1;
inc(n);
end;
{ Generate m, s for algorithm 0. Based on: Granlund, T.; Montgomery,
P.L.: "Division by Invariant Integers using Multiplication".
SIGPLAN Notices, Vol. 29, June 1994, page 61.
}
l:=log2(t)+1;
j:=qword($ffffffff) mod qword(t);
k:=(qword(1) shl (32+l)) div (qword($ffffffff-j));
m_low:=((qword(1)) shl (32+l)) div t;
m_high:=(((qword(1)) shl (32+l)) + k) div t;
while ((m_low shr 1) < (m_high shr 1)) and (l>0) do
begin
m_low:=m_low shr 1;
m_high:=m_high shr 1;
l:=l-1;
end;
if (m_high shr 32)=0 then
begin
m:=dword(m_high);
s:=l;
a:=0;
end
{ Generate m, s for algorithm 1. Based on: Magenheimer, D.J.; et al:
"Integer Multiplication and Division on the HP Precision Architecture".
IEEE Transactions on Computers, Vol 37, No. 8, August 1988, page 980.
}
else
begin
s:=log2(t);
m_low:=(qword(1) shl (32+s)) div qword(t);
r:=dword(((qword(1)) shl (32+s)) mod qword(t));
if (r < ((t>>1)+1)) then
m:=dword(m_low)
else
m:=dword(m_low)+1;
a:=1;
end;
{ Reduce multiplier for either algorithm to smallest possible }
while (m and 1)=0 do
begin
m:=m shr 1;
dec(s);
end;
{ Adjust multiplier for reduction of even divisors }
inc(s,n);
cg.getcpuregister(current_asmdata.CurrAsmList,NR_EAX);
emit_const_reg(A_MOV,S_L,aint(m),NR_EAX);
cg.getcpuregister(current_asmdata.CurrAsmList,NR_EDX);
emit_reg(A_MUL,S_L,hreg1);
if a<>0 then
begin
{
printf ("; dividend: register other than EAX or memory location\n");
printf ("\n");
printf ("MOV EAX, 0%08lXh\n", m);
printf ("MUL dividend\n");
printf ("ADD EAX, 0%08lXh\n", m);
printf ("ADC EDX, 0\n");
if (s) printf ("SHR EDX, %d\n", s);
printf ("\n");
printf ("; quotient now in EDX\n");
}
emit_const_reg(A_ADD,S_L,aint(m),NR_EAX);
emit_const_reg(A_ADC,S_L,0,NR_EDX);
end;
if s<>0 then
emit_const_reg(A_SHR,S_L,aint(s),NR_EDX);
cg.ungetcpuregister(current_asmdata.CurrAsmList,NR_EDX);
cg.ungetcpuregister(current_asmdata.CurrAsmList,NR_EAX);
location.register:=cg.getintregister(current_asmdata.CurrAsmList,OS_INT);
cg.a_load_reg_reg(current_asmdata.CurrAsmList,OS_INT,OS_INT,NR_EDX,location.register)
end;
end
end
end
else
begin
cg.getcpuregister(current_asmdata.CurrAsmList,NR_EAX);
emit_reg_reg(A_MOV,S_L,hreg1,NR_EAX);
cg.getcpuregister(current_asmdata.CurrAsmList,NR_EDX);
{Sign extension depends on the left type.}
if torddef(left.resultdef).ordtype=u32bit then
emit_reg_reg(A_XOR,S_L,NR_EDX,NR_EDX)
else
emit_none(A_CDQ,S_NO);
{Division depends on the right type.}
if Torddef(right.resultdef).ordtype=u32bit then
op:=A_DIV
else
op:=A_IDIV;
if right.location.loc in [LOC_REFERENCE,LOC_CREFERENCE] then
emit_ref(op,S_L,right.location.reference)
else if right.location.loc in [LOC_REGISTER,LOC_CREGISTER] then
emit_reg(op,S_L,right.location.register)
else
begin
hreg1:=cg.getintregister(current_asmdata.CurrAsmList,right.location.size);
cg.a_load_loc_reg(current_asmdata.CurrAsmList,OS_32,right.location,hreg1);
emit_reg(op,S_L,hreg1);
end;
{Copy the result into a new register. Release EAX & EDX.}
cg.ungetcpuregister(current_asmdata.CurrAsmList,NR_EDX);
cg.ungetcpuregister(current_asmdata.CurrAsmList,NR_EAX);
location.register:=cg.getintregister(current_asmdata.CurrAsmList,OS_INT);
if nodetype=divn then
cg.a_load_reg_reg(current_asmdata.CurrAsmList,OS_INT,OS_INT,NR_EAX,location.register)
else
cg.a_load_reg_reg(current_asmdata.CurrAsmList,OS_INT,OS_INT,NR_EDX,location.register);
end;
end;
{*****************************************************************************
TI386SHLRSHRNODE
*****************************************************************************}
function ti386shlshrnode.first_shlshr64bitint: tnode;
begin
result := nil;
end;
procedure ti386shlshrnode.second_64bit;
var
hreg64hi,hreg64lo:Tregister;
v : TConstExprInt;
l1,l2,l3:Tasmlabel;
begin
location_reset(location,LOC_REGISTER,OS_64);
{ load left operator in a register }
location_force_reg(current_asmdata.CurrAsmList,left.location,OS_64,false);
hreg64hi:=left.location.register64.reghi;
hreg64lo:=left.location.register64.reglo;
{ shifting by a constant directly coded: }
if (right.nodetype=ordconstn) then
begin
v:=Tordconstnode(right).value and 63;
if v>31 then
begin
if nodetype=shln then
begin
emit_reg_reg(A_XOR,S_L,hreg64hi,hreg64hi);
if ((v and 31) <> 0) then
emit_const_reg(A_SHL,S_L,v and 31,hreg64lo);
end
else
begin
emit_reg_reg(A_XOR,S_L,hreg64lo,hreg64lo);
if ((v and 31) <> 0) then
emit_const_reg(A_SHR,S_L,v and 31,hreg64hi);
end;
location.register64.reghi:=hreg64lo;
location.register64.reglo:=hreg64hi;
end
else
begin
if nodetype=shln then
begin
emit_const_reg_reg(A_SHLD,S_L,v and 31,hreg64lo,hreg64hi);
emit_const_reg(A_SHL,S_L,v and 31,hreg64lo);
end
else
begin
emit_const_reg_reg(A_SHRD,S_L,v and 31,hreg64hi,hreg64lo);
emit_const_reg(A_SHR,S_L,v and 31,hreg64hi);
end;
location.register64.reglo:=hreg64lo;
location.register64.reghi:=hreg64hi;
end;
end
else
begin
{ load right operators in a register }
cg.getcpuregister(current_asmdata.CurrAsmList,NR_ECX);
cg.a_load_loc_reg(current_asmdata.CurrAsmList,OS_32,right.location,NR_ECX);
{ left operator is already in a register }
{ hence are both in a register }
{ is it in the case ECX ? }
{ the damned shift instructions work only til a count of 32 }
{ so we've to do some tricks here }
current_asmdata.getjumplabel(l1);
current_asmdata.getjumplabel(l2);
current_asmdata.getjumplabel(l3);
emit_const_reg(A_CMP,S_L,64,NR_ECX);
cg.a_jmp_flags(current_asmdata.CurrAsmList,F_L,l1);
emit_reg_reg(A_XOR,S_L,hreg64lo,hreg64lo);
emit_reg_reg(A_XOR,S_L,hreg64hi,hreg64hi);
cg.a_jmp_always(current_asmdata.CurrAsmList,l3);
cg.a_label(current_asmdata.CurrAsmList,l1);
emit_const_reg(A_CMP,S_L,32,NR_ECX);
cg.a_jmp_flags(current_asmdata.CurrAsmList,F_L,l2);
emit_const_reg(A_SUB,S_L,32,NR_ECX);
if nodetype=shln then
begin
emit_reg_reg(A_SHL,S_L,NR_CL,hreg64lo);
emit_reg_reg(A_MOV,S_L,hreg64lo,hreg64hi);
emit_reg_reg(A_XOR,S_L,hreg64lo,hreg64lo);
cg.a_jmp_always(current_asmdata.CurrAsmList,l3);
cg.a_label(current_asmdata.CurrAsmList,l2);
emit_reg_reg_reg(A_SHLD,S_L,NR_CL,hreg64lo,hreg64hi);
emit_reg_reg(A_SHL,S_L,NR_CL,hreg64lo);
end
else
begin
emit_reg_reg(A_SHR,S_L,NR_CL,hreg64hi);
emit_reg_reg(A_MOV,S_L,hreg64hi,hreg64lo);
emit_reg_reg(A_XOR,S_L,hreg64hi,hreg64hi);
cg.a_jmp_always(current_asmdata.CurrAsmList,l3);
cg.a_label(current_asmdata.CurrAsmList,l2);
emit_reg_reg_reg(A_SHRD,S_L,NR_CL,hreg64hi,hreg64lo);
emit_reg_reg(A_SHR,S_L,NR_CL,hreg64hi);
end;
cg.a_label(current_asmdata.CurrAsmList,l3);
cg.ungetcpuregister(current_asmdata.CurrAsmList,NR_ECX);
location.register64.reglo:=hreg64lo;
location.register64.reghi:=hreg64hi;
end;
end;
begin
cunaryminusnode:=ti386unaryminusnode;
cmoddivnode:=ti386moddivnode;
cshlshrnode:=ti386shlshrnode;
cnotnode:=ti386notnode;
end.
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