[Bug c/24597] New: Function call with negated value after test is done wrongly

["jbglaw at lug-owl dot de" <gcc-bugzilla at gcc dot gnu dot org>]

I'm currently on the way writing a smallish libm for VAX, using GCC from SVN
plus some (mostly configury) patches. The code attached (it's hackish)
doesn't work. Basically, this flow of code is broken:

long double sinl (long double x) {
    if (x < 0.0)
        return -sin (-x)
    :
    :
}

After discovery on VAX, I tested it on my PC and it failed there, too.
The generated assembly (for VAX; i386 is near unreadable...) looks like

test x
if less_than_zero
    push x       ## negation is missing
    call sin();
    :
else
    something_else;

So this results in recursive calls until stack is full and VM kills the
test program.

The attached program can be compiled with:

$ make TARGET=xxxx

With "xxxx" being something like "i686-pc-linux-gnu-" if that's the
compiler you're testing with.

Thanks,
    Jan-Benedict Glaw


-- 
           Summary: Function call with negated value after test is done
                    wrongly
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jbglaw at lug-owl dot de
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24597