From: Mark Kettenis <kettenis@gnu.org>
Date: Wed, 13 Jun 2012 21:21:25 +0000 (+0000)
Subject:         PR tdep/14222
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=284c5a60c3012c2b47a0772c34b805553053cce3;p=binutils-gdb.git

    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 34b75ceb91d..cdf6a01ea5f 100644
--- 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 6333556c994..ce4c8a4cac2 100644
--- 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;
 	}
     }