[ forwarded from http://bugs.debian.org/445536 ]
From: Samuel Tardieu <[EMAIL PROTECTED]>
% cat > t.c << EOF
void foo()
{ foo(); }
EOF
% gcc -O -S -o - -fomit-frame-pointer -Wall t.c
.file "t.c"
.text
.globl foo
.type foo, @function
foo:
rep ; ret
.size foo, .-foo
.ident "GCC: (GNU) 4.2.1 (Debian 4.2.1-5)"
.section .note.GNU-stack,"",@progbits
As far as I know, there are two acceptable behaviours for function foo():
- loop indefinitely (if tail recursion is used)
- overflow the stack (if tail recursion is not used)
As soon as -O is used on x86-32, GCC generates code that just returns
("rep ; ret").
Note that the bug is also present with the following Ada program:
procedure U is
begin
U;
end U;
although the Ada front-end warns about a possibly infinite recursion. The
very same code gets generated.
This may be platform-specific and generates bogus code with any non-O0
optimization level.
--
Summary: GCC generates wrong code for infinitely recursive
functions
Product: gcc
Version: 4.2.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: tbm at cyrius dot com
GCC target triplet: x86_64-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33826
