PR tdep/14222

        * i386-tdep.c (i386_push_dummy_call): Unconditionally align the
        stack on a 16-byte boundary.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 34b75ce..cdf6a01 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2012-06-13  Mark Kettenis  <kettenis@gnu.org>
+           Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+       PR tdep/14222
+       * i386-tdep.c (i386_push_dummy_call): Unconditionally align the
+       stack on a 16-byte boundary.
+
 2012-06-13  Kaushik Srenevasan  <kaushik@twitter.com>
 
        * jit.c (finalize_symtab): Set function's return type to 'void' by

diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 6333556..ce4c8a4 100644 (file)
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -2351,7 +2351,6 @@ i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
   for (write_pass = 0; write_pass < 2; write_pass++)
     {
       int args_space_used = 0;
-      int have_16_byte_aligned_arg = 0;
 
       if (struct_return)
        {
@@ -2389,19 +2388,20 @@ i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
          else
            {
              if (i386_16_byte_align_p (value_enclosing_type (args[i])))
-               {
-                 args_space = align_up (args_space, 16);
-                 have_16_byte_aligned_arg = 1;
-               }
+               args_space = align_up (args_space, 16);
              args_space += align_up (len, 4);
            }
        }
 
       if (!write_pass)
        {
-         if (have_16_byte_aligned_arg)
-           args_space = align_up (args_space, 16);
          sp -= args_space;
+
+         /* The original System V ABI only requires word alignment,
+            but modern incarnations need 16-byte alignment in order
+            to support SSE.  Since wasting a few bytes here isn't
+            harmful we unconditionally enforce 16-byte alignment.  */
+         sp &= ~0xf;
        }
     }