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* Dead code in TAddNode.Simplify has been stripped

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J. Gareth "Curious Kit" Moreton 2022-12-01 19:22:12 +00:00 committed by FPK
parent 487ca08cf3
commit c4899b5dc0
1 changed files with 15 additions and 82 deletions

97
compiler/nadd.pas
View File

@ -891,94 +891,27 @@ implementation
if assigned(result) then
exit;
end;
if is_constintnode(left) and (is_integer(rd) or is_pointer(rd)) then
{ Deal with anti-commutative subtraction }
if (nodetype = subn) then
begin
if (tordconstnode(left).value = 0) and (nodetype in [addn,orn,xorn,subn,andn,muln]) then
{ change "0 - val" to "-val" }
if is_constintnode(left) and (is_integer(right.resultdef) or is_pointer(right.resultdef)) then
begin
case nodetype of
addn,orn,xorn:
result := PruneKeepRight();
subn:
result := ctypeconvnode.create_internal(cunaryminusnode.create(PruneKeepRight()),rd);
andn,muln:
begin
if (cs_opt_level4 in current_settings.optimizerswitches) or
not might_have_sideeffects(right) then
result:=cordconstnode.create(0,resultdef,true);
end;
else
;
end;
if (tordconstnode(left).value = 0) then
result := ctypeconvnode.create_internal(cunaryminusnode.create(right.getcopy),right.resultdef);
end
else if (tordconstnode(left).value = 1) and (nodetype=muln) then
{ insert type conversion in case it is a 32*32 to 64 bit multiplication optimization,
the type conversion does not hurt because it is normally removed later on
}
result := ctypeconvnode.create_internal(PruneKeepRight(),resultdef)
else if (tordconstnode(left).value = -1) and (nodetype=muln) then
result := ctypeconvnode.create_internal(cunaryminusnode.create(PruneKeepRight()),rd)
{ try to fold
op
/ \
const1 op
/ \
const2 val
}
else if (right.nodetype=nodetype) and
{ there might be a mul operation e.g. longint*longint => int64 in this case
we cannot do this optimziation, see e.g. tests/webtbs/tw36587.pp on arm }
(compare_defs(resultdef,rd,nothingn)=te_exact) then
{ convert n - n mod const into n div const*const }
else if (right.nodetype=modn) and is_constintnode(tmoddivnode(right).right) and
(left.isequal(tmoddivnode(right).left)) and not(might_have_sideeffects(left)) { and
not(cs_check_overflow in localswitches) } then
begin
if is_constintnode(taddnode(right).left) then
begin
case right.nodetype of
xorn,
addn,
andn,
orn,
muln:
Result:=SwapLeftWithRightRight;
else
;
end;
end
else if is_constintnode(taddnode(right).right) then
begin
case right.nodetype of
xorn,
addn,
andn,
orn,
muln:
Result:=SwapLeftWithRightLeft;
else
;
end;
end
result:=caddnode.create(muln,cmoddivnode.create(divn,left,tmoddivnode(right).right.getcopy),tmoddivnode(right).right);
left:=nil;
tmoddivnode(right).right:=nil;
exit;
end;
if assigned(result) then
exit;
end;
{ convert n - n mod const into n div const*const }
if (nodetype=subn) and (right.nodetype=modn) and is_constintnode(tmoddivnode(right).right) and
(left.isequal(tmoddivnode(right).left)) and not(might_have_sideeffects(left)) { and
not(cs_check_overflow in localswitches) } then
begin
t := tmoddivnode(right).PruneKeepRight();
result := caddnode.create(
muln,
cmoddivnode.create(
divn,
PruneKeepLeft(),
t.getcopy
),
t
);
exit;
end;
{ both real constants ? }