fpc/compiler/llvm/nllvmbas.pas
Jonas Maebe 4f287207cd * initialise all register temps with "undef" for llvm, so that llvm knows
they exist even if we try to read them before writing to them (e.g.
    because they represent the uninitialised function result of an
    inlined function)

git-svn-id: trunk@32465 -
2015-11-22 11:49:15 +00:00

68 lines
2.2 KiB
ObjectPascal

{
Copyright (c) 2015 by Jonas Maebe
This unit implements llvm support for some basic 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 nllvmbas;
{$i fpcdefs.inc}
interface
uses
nbas,ncgbas;
type
tllvmtempcreatenode = class(tcgtempcreatenode)
procedure pass_generate_code;override;
end;
implementation
uses
aasmdata,
cgbase,cgutils,
llvmbase,aasmllvm
;
{*****************************************************************************
TTEMPCREATENODE
*****************************************************************************}
procedure tllvmtempcreatenode.pass_generate_code;
begin
inherited;
{ if a temp is in a register and we never assign anything to it (e.g.
because it's the register for an inlined function result that never
gets assigned a value), then llvm will be confused the first time
we try to read from it (since it's never been defined) -> always
immediately assign undef to such registers }
if tempinfo^.location.loc in [LOC_REGISTER,LOC_CREGISTER,LOC_FPUREGISTER,
LOC_CFPUREGISTER,LOC_MMREGISTER,LOC_CMMREGISTER] then
current_asmdata.CurrAsmList.concat(
taillvm.op_reg_size_undef(la_bitcast,tempinfo^.location.register,tempinfo^.typedef)
);
end;
begin
ctempcreatenode:=tllvmtempcreatenode;
end.