[Committed] Fix __builtin_thread_pointer for ILP32 and other like ABIs

[Andrew Pinski]

    Hi,
      With ILP32 AARCH64, Pmode (DImode) != ptrmode (SImode) so the
variable decl
    has a mode of SImode while the register is DImode.  So the target that gets
    passed down to expand_builtin_thread_pointer is NULL as expand does not
    know how to get a subreg for a pointer type.

    This fixes the problem by handling a NULL target like we are able to handle
    for a non register/correct mode target inside expand_builtin_thread_pointer.

    Committed as obvious after a build and test for both
aarch64-linux-gnu and x86_64-linux-gnu with no regressions.

    Thanks,
    Andrew Pinski

     * builtins.c (expand_builtin_thread_pointer): Create a new target
    when the target is NULL.

    Fix __builtin_thread_pointer for AARCH64 ILP32
    
    Hi,
      With ILP32 AARCH64, Pmode (DImode) != ptrmode (SImode) so the variable 
decl
    has a mode of SImode while the register is DImode.  So the target that gets
    passed down to expand_builtin_thread_pointer is NULL as expand does not
    know how to get a subreg for a pointer type.
    
    This fixes the problem by handling a NULL target like we are able to handle
    for a non register/correct mode target inside expand_builtin_thread_pointer.
    
    Thanks,
    Andrew Pinski
    
        * builtins.c (expand_builtin_thread_pointer): Create a new target
        when the target is NULL.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 616d8ec..570bff0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2014-02-24  Andrew Pinski  <apin...@cavium.com>
+
+       * builtins.c (expand_builtin_thread_pointer): Create a new target
+       when the target is NULL.
+
 2014-02-25  Vladimir Makarov  <vmaka...@redhat.com>
 
        PR rtl-optimization/60317
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 35969ad..7c6318e 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -5712,7 +5712,10 @@ expand_builtin_thread_pointer (tree exp, rtx target)
   if (icode != CODE_FOR_nothing)
     {
       struct expand_operand op;
-      if (!REG_P (target) || GET_MODE (target) != Pmode)
+      /* If the target is not sutitable then create a new target. */
+      if (target == NULL_RTX
+         || !REG_P (target)
+         || GET_MODE (target) != Pmode)
        target = gen_reg_rtx (Pmode);
       create_output_operand (&op, target, Pmode);
       expand_insn (icode, 1, &op);