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* optimize x </>= length(...) also if the operands are swapped

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This commit is contained in:
florian 2024-04-18 23:07:40 +02:00
parent 8b7dbb81b1
commit 2f9ed0576e
2 changed files with 33 additions and 1 deletions
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25
compiler/nadd.pas
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@ -1764,6 +1764,31 @@ implementation
exit;
end;
{
compile length(arr) > x as high(arr) >= x
compile length(arr) <= x as high(arr) < x
tested by tests/webtbs/tw40292.pp
}
if (nodetype in [lten,gtn]) and
(left.nodetype=inlinen) and (tinlinenode(left).inlinenumber=in_length_x) and
((is_dynamic_array(tinlinenode(left).left.resultdef)) or
(is_open_array(tinlinenode(left).left.resultdef))
) then
begin
case nodetype of
gtn:
result:=caddnode.create(gten,cinlinenode.create(in_high_x,false,tinlinenode(left).left),right);
lten:
result:=caddnode.create(ltn,cinlinenode.create(in_high_x,false,tinlinenode(left).left),right);
else
Internalerror(2024041701);
end;
right:=nil;
tinlinenode(left).left:=nil;
exit;
end;
{ using sqr(x) for reals instead of x*x might reduces register pressure and/or
memory accesses while sqr(<real>) has no drawback }
if

9
tests/webtbs/tw40292.pp
View File

@ -6,7 +6,14 @@ begin
setlength(arr,13+random(0));
if (x < length(arr)) <> (x <= high(arr)) then
halt(1);
if (length(arr) > x) <> (x <= high(arr)) then
halt(2);
x:=13+random(0);
if (x >= length(arr)) <> (x > high(arr)) then
halt(2);
halt(3);
if (length(arr) <= x) <> (x > high(arr)) then
halt(4);
end.