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* first part of fixing #38267: do not bail out early during constant folding

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if the constant is 1 or -1

git-svn-id: trunk@47933 -
This commit is contained in:
florian 2021-01-01 15:26:13 +00:00
parent 8311837468
commit 97abf6b495
3 changed files with 53 additions and 20 deletions
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1
.gitattributes vendored
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@ -18620,6 +18620,7 @@ tests/webtbs/tw38225.pp svneol=native#text/pascal
tests/webtbs/tw38238.pp svneol=native#text/pascal
tests/webtbs/tw38249.pp svneol=native#text/pascal
tests/webtbs/tw38259.pp svneol=native#text/pascal
tests/webtbs/tw38267a.pp svneol=native#text/pascal
tests/webtbs/tw3827.pp svneol=native#text/plain
tests/webtbs/tw3829.pp svneol=native#text/plain
tests/webtbs/tw3833.pp svneol=native#text/plain

29
compiler/nadd.pas
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@ -708,9 +708,9 @@ implementation
end;
{ Add,Sub,Mul,Or,Xor,Andn with constant 0, 1 or -1? }
if is_constintnode(right) and (is_integer(left.resultdef) or is_pointer(left.resultdef)) then
if is_constintnode(right) and (is_integer(left.resultdef) or is_pointer(left.resultdef)) then
begin
if tordconstnode(right).value = 0 then
if (tordconstnode(right).value = 0) and (nodetype in [addn,subn,orn,xorn,andn,muln]) then
begin
case nodetype of
addn,subn,orn,xorn:
@ -725,24 +725,13 @@ implementation
;
end;
end
else if tordconstnode(right).value = 1 then
begin
case nodetype of
muln:
result := left.getcopy;
else
;
end;
end
else if tordconstnode(right).value = -1 then
begin
case nodetype of
muln:
result := ctypeconvnode.create_internal(cunaryminusnode.create(left.getcopy),left.resultdef);
else
;
end;
end
else if (tordconstnode(right).value = 1) and (nodetype=muln) then
result := left.getcopy
else if (tordconstnode(right).value = -1) and (nodetype=muln) then
result := ctypeconvnode.create_internal(cunaryminusnode.create(left.getcopy),left.resultdef)
{ try to fold
op op
/ \ / \

43
tests/webtbs/tw38267a.pp Normal file
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@ -0,0 +1,43 @@
{ %OPT=-O3 }
{$goto on}
label start0, end0, start1, end1;
var
x: int16;
begin
x := random(2);
writeln('x := ', x);
writeln;
start0:
x :=
1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+
1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+
1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+
1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+x;
end0:
writeln('x := 1 + 1 + ...100 times ... + x, x = ', x, ': ');
writeln(SizeUint(CodePointer(@end0) - CodePointer(@start0)), ' b of code');
{ hundred is actually arbitrarily chosen but should be sufficient for all targets
to show that constant folding works }
if SizeUint(CodePointer(@end0) - CodePointer(@start0))>100 then
halt(1);
writeln;
start1:
x := x+
1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+
1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+
1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+
1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1;
end1:
writeln('x := x + 1 + 1 + ...100 times ..., x = ', x, ': ');
{ hundred is actually arbitrarily chosen but should be sufficient for all targets
to show that constant folding works }
writeln(SizeUint(CodePointer(@end1) - CodePointer(@start1)), ' b of code');
if SizeUint(CodePointer(@end1) - CodePointer(@start1))>100 then
halt(2);
writeln('ok');
end.