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* made the remove_dummy_load_stores() implementation more extensible
and skip comments (so it works again when -ar is used, because
tlhcgjvm.inc/decstack() insert comments in that case)
git-svn-id: branches/jvmbackend@18340 -
This commit is contained in:
Jonas Maebe
parent
b023627f6a
commit
fda72aaed6
@ -74,7 +74,21 @@ implementation
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class procedure trgcpu.remove_dummy_load_stores(list: TAsmList; headertai: tai);
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function issimpleregstore(p: tai; reg: tregister; doubleprecisionok: boolean): boolean;
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type
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taitypeset = set of taitype;
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function nextskipping(p: tai; const skip: taitypeset): tai;
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begin
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result:=p;
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if not assigned(result) then
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exit;
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repeat
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result:=tai(result.next);
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until not assigned(result) or
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not(result.typ in skip);
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end;
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function issimpleregstore(p: tai; var reg: tregister; doubleprecisionok: boolean): boolean;
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const
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simplestoressp = [a_astore,a_fstore,a_istore];
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simplestoresdp = [a_dstore,a_lstore];
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@ -88,9 +102,12 @@ implementation
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((reg=NR_NO) or
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(taicpu(p).oper[0]^.typ=top_reg) and
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(taicpu(p).oper[0]^.reg=reg));
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if result and
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(reg=NR_NO) then
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reg:=taicpu(p).oper[0]^.reg;
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end;
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function issimpleregload(p: tai; reg: tregister; doubleprecisionok: boolean): boolean;
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function issimpleregload(p: tai; var reg: tregister; doubleprecisionok: boolean): boolean;
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const
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simpleloadssp = [a_aload,a_fload,a_iload];
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simpleloadsdp = [a_dload,a_lload];
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@ -104,56 +121,60 @@ implementation
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((reg=NR_NO) or
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(taicpu(p).oper[0]^.typ=top_reg) and
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(taicpu(p).oper[0]^.reg=reg));
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if result and
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(reg=NR_NO) then
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reg:=taicpu(p).oper[0]^.reg;
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end;
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function isregallocoftyp(p: tai; typ: TRegAllocType;var reg: tregister): boolean;
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begin
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result:=
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assigned(p) and
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(p.typ=ait_regalloc) and
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(tai_regalloc(p).ratype=typ);
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if result then
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if reg=NR_NO then
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reg:=tai_regalloc(p).reg
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else
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result:=tai_regalloc(p).reg=reg;
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end;
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function try_remove_alloc_store_dealloc_load(var p: tai; reg: tregister): boolean;
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function try_remove_store_dealloc_load(var p: tai): boolean;
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var
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q: tai;
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dealloc,
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load: tai;
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reg: tregister;
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begin
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result:=false;
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{ check for:
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alloc regx
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store regx
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dealloc regx
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load regx
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and remove. We don't have to check that the load/store
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types match, because they have to for this to be
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valid JVM code }
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if issimpleregstore(tai(p.next),reg,true) and
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assigned(p.next.next) and
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(tai(p.next.next).typ=ait_regalloc) and
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(tai_regalloc(p.next.next).ratype=ra_dealloc) and
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(tai_regalloc(p.next.next).reg=reg) and
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issimpleregload(tai(p.next.next.next),reg,true) then
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dealloc:=nextskipping(p,[ait_comment]);
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load:=nextskipping(dealloc,[ait_comment]);
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reg:=NR_NO;
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if issimpleregstore(p,reg,true) and
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isregallocoftyp(dealloc,ra_dealloc,reg) and
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issimpleregload(load,reg,true) then
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begin
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{ remove the whole sequence: the allocation }
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q:=Tai(p.next);
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{ remove the whole sequence: the store }
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list.remove(p);
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p.free;
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p:=q;
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{ the store }
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q:=Tai(p.next);
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list.remove(p);
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p.free;
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p:=q;
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{ the dealloc }
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q:=Tai(p.next);
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list.remove(p);
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p.free;
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p:=q;
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p:=Tai(load.next);
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{ the load }
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q:=Tai(p.next);
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list.remove(p);
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p.free;
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p:=q;
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list.remove(load);
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load.free;
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result:=true;
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end;
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end;
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var
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p: tai;
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p,next: tai;
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reg: tregister;
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removedsomething: boolean;
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begin
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@ -165,31 +186,48 @@ implementation
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case p.typ of
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ait_regalloc:
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begin
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if (tai_regalloc(p).ratype=ra_alloc) then
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reg:=NR_NO;
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next:=nextskipping(p,[ait_comment]);
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{ remove
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alloc reg
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dealloc reg
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(can appear after optimisations, necessary to prevent
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useless stack slot allocations) }
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if isregallocoftyp(p,ra_alloc,reg) and
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isregallocoftyp(next,ra_dealloc,reg) then
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begin
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reg:=tai_regalloc(p).reg;
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if try_remove_alloc_store_dealloc_load(p,reg) then
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begin
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removedsomething:=true;
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continue;
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end;
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{ todo in peephole optimizer:
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alloc regx // not double precision
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store regx // not double precision
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load regy or memy
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dealloc regx
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load regx
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-> change into
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load regy or memy
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swap // can only handle single precision
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and then
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swap
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<commutative op>
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-> remove swap
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}
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list.remove(p);
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p.free;
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p:=tai(next.next);
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list.remove(next);
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next.free;
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removedsomething:=true;
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continue;
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end;
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end;
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ait_instruction:
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begin
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if try_remove_store_dealloc_load(p) then
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begin
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removedsomething:=true;
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continue;
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end;
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{ todo in peephole optimizer:
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alloc regx // not double precision
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store regx // not double precision
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load regy or memy
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dealloc regx
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load regx
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-> change into
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load regy or memy
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swap // can only handle single precision
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and then
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swap
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<commutative op>
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-> remove swap
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}
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end;
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end;
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p:=tai(p.next);
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end;
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