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Date: Thu, 15 Jul 2010 02:39:00 -0000
Subject: [Bug c/44942]  New: Bug in argument passing of long double
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From: "pdox at alum dot mit dot edu" <gcc-bugzilla@gcc.gnu.org>
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On X86-64, the following code demonstrates how passing a long double as a fixed
 argument causes corruption of the following variable arguments.

#include <stdio.h>
#include <assert.h>
#include <stdarg.h>

void test(int a, int b, int c, int d, int e, int f, int g, long double h, ...)
{
  int i;
  va_list ap;

  va_start(ap, h);
  i = va_arg(ap, int);
  printf("Got %d, expected %d\n", i, 123456789);
  va_end(ap);
}

int main() {
  test(0, 0, 0, 0, 0, 0, 0, (long double)0.0, (int)123456789);
  return 0;
}


-- 
           Summary: Bug in argument passing of long double
           Product: gcc
           Version: 4.4.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pdox at alum dot mit dot edu
 GCC build triplet: x86_64-linux-gnu
  GCC host triplet: x86_64-linux-gnu
GCC target triplet: x86_64-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44942