paweld/fpc
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/fpc/source.git synced 2025-12-03 00:07:28 +01:00
Code Issues Packages Projects Releases Wiki Activity

+ enabled the use of the DIV/IDIV instruction for 16-bit div/mod on i8086

Browse Source 
* ti8086.moddivnode.pass_generate_code: use cg.a_op_const_reg, instead of
  emit_const_reg, in order to support generating plain 8086/8088 code
  (shr/shl/sar reg,const is 186+ if const is >= 2).

git-svn-id: trunk@26063 -
This commit is contained in:
nickysn 2013-11-11 22:34:41 +00:00
parent bd083c0b8e
commit dc432918da
1 changed files with 28 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
compiler/i8086/n8086mat.pas
View File

@ -30,6 +30,8 @@ interface
type
ti8086moddivnode = class(tmoddivnode)
function use_moddiv32bit_helper: boolean;
function first_moddivint: tnode; override;
procedure pass_generate_code;override;
end;
@ -61,6 +63,25 @@ implementation
ti8086moddivnode
*****************************************************************************}
function ti8086moddivnode.use_moddiv32bit_helper: boolean;
begin
result:=is_32bit(left.resultdef) or
is_64bit(left.resultdef) or
is_32bit(right.resultdef) or
is_64bit(right.resultdef);
end;
function ti8086moddivnode.first_moddivint: tnode;
begin
if use_moddiv32bit_helper then
result:=inherited first_moddivint
else
result:=nil;
end;
function log2(i : word) : word;
begin
result:=0;
@ -116,13 +137,13 @@ implementation
hreg2:=cg.getintregister(current_asmdata.CurrAsmList,OS_INT);
emit_reg_reg(A_MOV,S_W,hreg1,hreg2);
{If the left value is signed, hreg2=$ffff, otherwise 0.}
emit_const_reg(A_SAR,S_W,15,hreg2);
cg.a_op_const_reg(current_asmdata.CurrAsmList,OP_SAR,OS_16,15,hreg2);
{If signed, hreg2=right value-1, otherwise 0.}
emit_const_reg(A_AND,S_W,tordconstnode(right).value.svalue-1,hreg2);
{ add to the left value }
emit_reg_reg(A_ADD,S_W,hreg2,hreg1);
{ do the shift }
emit_const_reg(A_SAR,S_W,power,hreg1);
cg.a_op_const_reg(current_asmdata.CurrAsmList,OP_SAR,OS_16,power,hreg1);
end
else
begin
@ -135,11 +156,11 @@ implementation
else
emit_const_reg(A_ADD,S_W,tordconstnode(right).value.svalue-1,hreg1);
cg.a_label(current_asmdata.CurrAsmList,hl);
emit_const_reg(A_SAR,S_W,power,hreg1);
cg.a_op_const_reg(current_asmdata.CurrAsmList,OP_SAR,OS_16,power,hreg1);
end
end
else
emit_const_reg(A_SHR,S_W,power,hreg1);
cg.a_op_const_reg(current_asmdata.CurrAsmList,OP_SHR,OS_16,power,hreg1);
location.register:=hreg1;
end
else
@ -208,8 +229,8 @@ implementation
printf ("; quotient now in DX\n");
}
if s<>0 then
emit_const_reg(A_SAR,S_W,s,NR_DX);
emit_const_reg(A_SHR,S_W,15,NR_AX);
cg.a_op_const_reg(current_asmdata.CurrAsmList,OP_SAR,OS_16,s,NR_DX);
cg.a_op_const_reg(current_asmdata.CurrAsmList,OP_SHR,OS_16,15,NR_AX);
emit_reg_reg(A_ADD,S_W,NR_AX,NR_DX);
if e<0 then
emit_reg(A_NEG,S_W,NR_DX);
@ -304,7 +325,7 @@ implementation
emit_const_reg(A_ADC,S_W,0,NR_DX);
end;
if s<>0 then
emit_const_reg(A_SHR,S_W,aint(s),NR_DX);
cg.a_op_const_reg(current_asmdata.CurrAsmList,OP_SHR,OS_16,aint(s),NR_DX);
cg.ungetcpuregister(current_asmdata.CurrAsmList,NR_DX);
cg.ungetcpuregister(current_asmdata.CurrAsmList,NR_AX);
location.register:=cg.getintregister(current_asmdata.CurrAsmList,OS_INT);