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* a nil node is also a constant pointer node

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+ convert (v1=const1) and (v2=const2) into ((v1 xor const1) or (v2 xor const2))=0 if the expressions have no side effects

git-svn-id: trunk@45555 -
This commit is contained in:
florian 2020-06-01 20:50:38 +00:00
parent 19a66947bc
commit 792cf056eb
2 changed files with 71 additions and 2 deletions
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71
compiler/nadd.pas
View File

@ -493,7 +493,7 @@ implementation
t , vl, hp: tnode;
lt,rt : tnodetype;
hdef,
rd,ld : tdef;
rd,ld , inttype: tdef;
rv,lv,v : tconstexprint;
rvd,lvd : bestreal;
ws1,ws2 : pcompilerwidestring;
@ -505,6 +505,7 @@ implementation
res,
b : boolean;
cr, cl : Tconstexprint;
v2p, c2p, c1p, v1p: pnode;
begin
result:=nil;
l1:=0;
@ -1255,6 +1256,74 @@ implementation
exit;
end;
{
(v1=const1) and (v2=const2)
can be converted into
((v1 xor const1) or (v2 xor const2))=0
}
if (nodetype=andn) and
(left.nodetype=equaln) and
(right.nodetype=equaln) and
(not might_have_sideeffects(left)) and
(not might_have_sideeffects(right)) and
(is_constintnode(taddnode(left).left) or is_constintnode(taddnode(left).right) or
is_constpointernode(taddnode(left).left) or is_constpointernode(taddnode(left).right)) and
(is_constintnode(taddnode(right).left) or is_constintnode(taddnode(right).right) or
is_constpointernode(taddnode(right).left) or is_constpointernode(taddnode(right).right)) then
begin
if is_constnode(taddnode(left).left) then
begin
v1p:=@taddnode(left).right;
c1p:=@taddnode(left).left;
end
else
begin
v1p:=@taddnode(left).left;
c1p:=@taddnode(left).right;
end;
if is_constnode(taddnode(right).left) then
begin
v2p:=@taddnode(right).right;
c2p:=@taddnode(right).left;
end
else
begin
v2p:=@taddnode(right).left;
c2p:=@taddnode(right).right;
end;
if v1p^.resultdef.size=v2p^.resultdef.size then
begin
if not(is_integer(v1p^.resultdef)) or not(is_integer(v2p^.resultdef)) then
begin
case v1p^.resultdef.size of
2:
inttype:=u16inttype;
4:
inttype:=u32inttype;
8:
inttype:=u64inttype;
else
Internalerror(2020060101);
end;
result:=caddnode.create_internal(equaln,
caddnode.create_internal(orn,
caddnode.create_internal(xorn,ctypeconvnode.create_internal(v1p^.getcopy,inttype),
ctypeconvnode.create_internal(c1p^.getcopy,inttype)),
caddnode.create_internal(xorn,ctypeconvnode.create_internal(v2p^.getcopy,inttype),
ctypeconvnode.create_internal(c2p^.getcopy,inttype))
),
cordconstnode.create(0,inttype,false));
end
else
result:=caddnode.create_internal(equaln,
caddnode.create_internal(orn,
caddnode.create_internal(xorn,v1p^.getcopy,c1p^.getcopy),
caddnode.create_internal(xorn,v2p^.getcopy,c2p^.getcopy)
),
cordconstnode.create(0,v1p^.resultdef,false));
end;
end;
{ even when short circuit boolean evaluation is active, this
optimization cannot be performed in case the node has
side effects, because this can change the result (e.g., in an

2
compiler/node.pas
View File

@ -741,7 +741,7 @@ implementation
function is_constpointernode(p : tnode) : boolean;
begin
is_constpointernode:=(p.nodetype=pointerconstn);
is_constpointernode:=(p.nodetype in [pointerconstn,niln]);
end;
function is_conststringnode(p : tnode) : boolean;