Re: [PATCH]: Fix PR 3120

[Andreas Jaeger <aj at suse dot de>]

Roger Sayle <roger@eyesopen.com> writes:

> This updates my previous patch "Resolve mainline builtin sqrt issues"
> http://gcc.gnu.org/ml/gcc-patches/2001-11/msg01328.html so that it
> applies cleanly to current mainline sources.  It fixes high priority
> PR c/3120 which is a regression from the 3.0 branch.
>
> I've retested this updated patch with "make bootstrap" and "make -k
> check" on i686-pc-linux-gnu with no new regressions.  Its been approved
> by Gabriel Dos Reis in a private e-mail.  Andreas, could you please
> apply this patch and close the PR?

I've bootstrapped your patch and noticed that the test in libstdc++
for sqrt now fails!  I get for this small input file:

int main() {
 __builtin_sqrt(0);
; return 0; }

This error:

gromit:~:[1]$  /builds/gcc/gcc-3.1-devel/gcc/xgcc -B/builds/gcc/gcc-3.1-devel/gcc/ -nostdinc++  -L/builds/gcc/gcc-3.1-devel/i686-pc-linux-gnu/libstdc++-v3/src -L/builds/gcc/gcc-3.1-devel/i686-pc-linux-gnu/libstdc++-v3/src/.libs -B/opt/gcc-3.1-devel/i686-pc-linux-gnu/bin/ -B/opt/gcc-3.1-devel/i686-pc-linux-gnu/lib/ -isystem /opt/gcc-3.1-devel/i686-pc-linux-gnu/include -c -g -O2 -Wall t.c -O2 -g
t.c: In function `main':
t.c:3: unrecognizable insn:
(insn 19 17 20 (set (reg:DF 61)
        (sqrt:DF (reg:DF 62))) -1 (insn_list 17 (nil))
    (nil))
t.c:3: Internal compiler error in extract_insn, at recog.c:2129
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.

Apparently, your patch seems to be somehow broken :-(

I get this on i686-linux with glibc 2.2.4,
Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de
    http://www.suse.de/~aj