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+ apply unary minus optimizations also to /

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* test extended
This commit is contained in:
florian 2021-09-23 22:43:51 +02:00
parent 8ae1b6eace
commit 5abfe21f39
2 changed files with 32 additions and 1 deletions
compiler
nmat.pas
tests/tbs
tb0685.pp

19
compiler/nmat.pas
View File

@ -980,7 +980,7 @@ implementation
}
if (left.nodetype=muln) and ((taddnode(left).left.nodetype=unaryminusn)) then
begin
result:=caddnode.create(muln,taddnode(left).right.getcopy,tunaryminusnode(taddnode(left).left).left.getcopy);
result:=caddnode.create(muln,tunaryminusnode(taddnode(left).left).left.getcopy,taddnode(left).right.getcopy);
exit;
end;
if (left.nodetype=muln) and ((taddnode(left).right.nodetype=unaryminusn)) then
@ -989,6 +989,23 @@ implementation
exit;
end;
{
-(-left/right) or -(left/-right) => right/left
this operation is always valid as reals do not use a two's complement representation for negative
numbers, -real means just flip the sign bit
}
if (left.nodetype=slashn) and ((taddnode(left).left.nodetype=unaryminusn)) then
begin
result:=caddnode.create(slashn,tunaryminusnode(taddnode(left).left).left.getcopy,taddnode(left).right.getcopy);
exit;
end;
if (left.nodetype=slashn) and ((taddnode(left).right.nodetype=unaryminusn)) then
begin
result:=caddnode.create(slashn,taddnode(left).left.getcopy,tunaryminusnode(taddnode(left).right).left.getcopy);
exit;
end;
{ --node => node
this operation is always valid as reals do not use a two's complement representation for negative
numbers, -real means just flip the sign bit

14
tests/tbs/tb0685.pp
View File

@ -58,5 +58,19 @@ begin
if (d3<>2.0) or (TDoubleRec(d3).Sign) then
halt(9);
d1:=1.0;
d2:=2.0;
d3:=-(d2/-d1);
writeln(d3);
if (d3<>2.0) or (TDoubleRec(d3).Sign) then
halt(10);
d1:=1.0;
d2:=2.0;
d3:=-(-d2/d1);
writeln(d3);
if (d3<>2.0) or (TDoubleRec(d3).Sign) then
halt(11);
writeln('ok');
end.