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* New block node optimisation that attempts to

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flatten nested blocks (makes labels and later
    optimisation more efficient).
This commit is contained in:
J. Gareth "Curious Kit" Moreton 2024-02-12 16:02:18 +00:00 committed by FPK
parent 5a9d4d44fa
commit 63e8633262
1 changed files with 49 additions and 1 deletions
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50
compiler/nbas.pas
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@ -744,8 +744,9 @@ implementation
function tblocknode.simplify(forinline : boolean): tnode;
{$ifdef break_inlining}
var
n, p, first, last: tstatementnode;
{$ifdef break_inlining}
a : array[0..3] of tstatementnode;
{$endif break_inlining}
begin
@ -783,6 +784,53 @@ implementation
else
;
end;
end
else
begin
n := TStatementNode(left);
while Assigned(n) and Assigned(n.right) do
begin
{ Look one statement ahead in case it can be deleted - we
need the previous statement to stitch the tree correctly
}
p := TStatementNode(n.Next);
if Assigned(p.left) then
begin
case p.left.nodetype of
blockn:
if (bnf_strippable in TBlockNode(p.left).blocknodeflags) and
((p.left.flags * [nf_block_with_exit] = []) or no_exit_statement_in_block(p.left)) then
begin
{ Attempt to merge this block into the main statement
set }
{ Find last statement }
first := TStatementNode(TBlockNode(p.left).PruneKeepLeft());
if Assigned(first) then
begin
last := first;
while Assigned(last.right) do
last := TStatementNode(last.right);
n.right := first;
end
else
last := n;
last.right := p.PruneKeepRight();
{ make sure the nf_usercode_entry flag is safeguarded }
Flags := Flags + (p.left.flags * [nf_usercode_entry]);
p.Free;
Continue;
end;
else
;
end;
end;
n := TStatementNode(n.Next);
end;
end;
end;
{$ifdef break_inlining}