Re: [PR64164] drop copyrename, integrate into expand

[Alexandre Oliva <aoliva@redhat.com>]

On Jul 16, 2015, Alexandre Oliva <aoliva@redhat.com> wrote:

> So, I decided to run a ppc64le-linux-gnu bootstrap, just in case, and
> there are issues with split complex parms that caused go and fortran
> libs to fail the build.

This incremental patch, along with the previously-posted patches, fix
split complex args handling with preassigned args RTL, and enables
ppc64le-linux-gnu bootstrap to succeed.

I'm not particularly happy with the abuse of DECL_CONTEXT to recognize
split complex args and leave their RTL alone, but that was the best that
occurred to me.  Any other suggestions?

Is the combined patch ok, assuming further (re)testing of embedded
targets passes?

for  gcc/ChangeLog (to be integrated with the approved patches)

	* function.c (split_complex_args): Take assign_parm_data_all
	argument.  Pass it to rtl_for_parm.  Set up rtl and context
	for split args.
	(assign_parms_augmented_arg_list): Adjust.
	(maybe_reset_rtl_for_parm): Recognize split complex args.
	* stor-layout.c (layout_decl): Don't set mem attributes of
	non-MEMs.
---
 gcc/function.c    |   39 +++++++++++++++++++++++++++++++++++++--
 gcc/stor-layout.c |    3 ++-
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/gcc/function.c b/gcc/function.c
index 753d889..6fba001 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -151,6 +151,8 @@ static bool contains (const_rtx, hash_table<insn_cache_hasher> *);
 static void prepare_function_start (void);
 static void do_clobber_return_reg (rtx, void *);
 static void do_use_return_reg (rtx, void *);
+static rtx rtl_for_parm (struct assign_parm_data_all *, tree);
+
 \f
 /* Stack of nested functions.  */
 /* Keep track of the cfun stack.  */
@@ -2267,7 +2269,7 @@ assign_parms_initialize_all (struct assign_parm_data_all *all)
    needed, else the old list.  */
 
 static void
-split_complex_args (vec<tree> *args)
+split_complex_args (struct assign_parm_data_all *all, vec<tree> *args)
 {
   unsigned i;
   tree p;
@@ -2278,6 +2280,7 @@ split_complex_args (vec<tree> *args)
       if (TREE_CODE (type) == COMPLEX_TYPE
 	  && targetm.calls.split_complex_arg (type))
 	{
+	  tree cparm = p;
 	  tree decl;
 	  tree subtype = TREE_TYPE (type);
 	  bool addressable = TREE_ADDRESSABLE (p);
@@ -2296,6 +2299,9 @@ split_complex_args (vec<tree> *args)
 	  DECL_ARTIFICIAL (p) = addressable;
 	  DECL_IGNORED_P (p) = addressable;
 	  TREE_ADDRESSABLE (p) = 0;
+	  /* Reset the RTL before layout_decl, or it may change the
+	     mode of the RTL of the original argument copied to P.  */
+	  SET_DECL_RTL (p, NULL_RTX);
 	  layout_decl (p, 0);
 	  (*args)[i] = p;
 
@@ -2307,6 +2313,25 @@ split_complex_args (vec<tree> *args)
 	  DECL_IGNORED_P (decl) = addressable;
 	  layout_decl (decl, 0);
 	  args->safe_insert (++i, decl);
+
+	  /* If we are assigning parameters for a function, rather
+	     than for a call, propagate the RTL of the complex parm to
+	     the split declarations, and set their contexts so that
+	     maybe_reset_rtl_for_parm can recognize them and refrain
+	     from resetting their RTL.  */
+	  if (cfun->gimple_df)
+	    {
+	      rtx rtl = rtl_for_parm (all, cparm);
+	      gcc_assert (!rtl || GET_CODE (rtl) == CONCAT);
+	      if (rtl)
+		{
+		  SET_DECL_RTL (p, XEXP (rtl, 0));
+		  SET_DECL_RTL (decl, XEXP (rtl, 1));
+
+		  DECL_CONTEXT (p) = cparm;
+		  DECL_CONTEXT (decl) = cparm;
+		}
+	    }
 	}
     }
 }
@@ -2369,7 +2394,7 @@ assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
 
   /* If the target wants to split complex arguments into scalars, do so.  */
   if (targetm.calls.split_complex_arg)
-    split_complex_args (&fnargs);
+    split_complex_args (all, &fnargs);
 
   return fnargs;
 }
@@ -2823,6 +2848,16 @@ maybe_reset_rtl_for_parm (tree parm)
 {
   gcc_assert (TREE_CODE (parm) == PARM_DECL
 	      || TREE_CODE (parm) == RESULT_DECL);
+
+  /* This is a split complex parameter, and its context was set to its
+     original PARM_DECL in split_complex_args so that we could
+     recognize it here and not reset its RTL.  */
+  if (DECL_CONTEXT (parm) && TREE_CODE (DECL_CONTEXT (parm)) == PARM_DECL)
+    {
+      DECL_CONTEXT (parm) = DECL_CONTEXT (DECL_CONTEXT (parm));
+      return;
+    }
+
   if ((flag_tree_coalesce_vars
        || (DECL_RTL_SET_P (parm) && DECL_RTL (parm) == pc_rtx))
       && is_gimple_reg (parm))
diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c
index 0d4f4a4..288227a 100644
--- a/gcc/stor-layout.c
+++ b/gcc/stor-layout.c
@@ -794,7 +794,8 @@ layout_decl (tree decl, unsigned int known_align)
     {
       PUT_MODE (rtl, DECL_MODE (decl));
       SET_DECL_RTL (decl, 0);
-      set_mem_attributes (rtl, decl, 1);
+      if (MEM_P (rtl))
+	set_mem_attributes (rtl, decl, 1);
       SET_DECL_RTL (decl, rtl);
     }
 }


-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer