re PR target/59927 (ICE sorry, unimplemented: ms_abi attribute requires…

re PR target/59927 (ICE sorry, unimplemented: ms_abi attribute requires -maccumulate-outgoing-args or subtarget optimization implying it)

PR target/59927

        * calls.c (expand_call): Don't double-push for reg_parm_stack_space.
        * config/i386/i386.c (init_cumulative_args): Remove sorry for 64-bit
        ms-abi vs -mno-accumulate-outgoing-args.
        (ix86_expand_prologue): Unconditionally call ix86_eax_live_at_start_p.
        * config/i386/i386.h (ACCUMULATE_OUTGOING_ARGS): Fix comment with
        respect to ms-abi.

From-SVN: r207677

gcc/ChangeLog

+2014-02-10  Richard Henderson <rth@redhat.com>
+
+	PR target/59927
+	* calls.c (expand_call): Don't double-push for reg_parm_stack_space.
+	* config/i386/i386.c (init_cumulative_args): Remove sorry for 64-bit
+	ms-abi vs -mno-accumulate-outgoing-args.
+	(ix86_expand_prologue): Unconditionally call ix86_eax_live_at_start_p.
+	* config/i386/i386.h (ACCUMULATE_OUTGOING_ARGS): Fix comment with
+	respect to ms-abi.
+
 2014-02-10  Bernd Edlinger  <bernd.edlinger@hotmail.de>
 
 	PR middle-end/60080

gcc/calls.c

@@ -2955,6 +2955,7 @@ expand_call (tree exp, rtx target, int ignore)
       /* If we push args individually in reverse order, perform stack alignment
 	 before the first push (the last arg).  */
       if (PUSH_ARGS_REVERSED && argblock == 0
+          && adjusted_args_size.constant > reg_parm_stack_space
 	  && adjusted_args_size.constant != unadjusted_args_size)
 	{
 	  /* When the stack adjustment is pending, we get better code

gcc/config/i386/i386.c

@@ -6110,10 +6110,6 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
   cum->caller = caller;
 
   /* Set up the number of registers to use for passing arguments.  */
-
-  if (TARGET_64BIT && cum->call_abi == MS_ABI && !ACCUMULATE_OUTGOING_ARGS)
-    sorry ("ms_abi attribute requires -maccumulate-outgoing-args "
-	   "or subtarget optimization implying it");
   cum->nregs = ix86_regparm;
   if (TARGET_64BIT)
     {
@@ -11032,15 +11028,14 @@ ix86_expand_prologue (void)
 
       if (TARGET_64BIT)
         r10_live = (DECL_STATIC_CHAIN (current_function_decl) != 0);
-      if (!TARGET_64BIT_MS_ABI)
-        eax_live = ix86_eax_live_at_start_p ();
 
-      /* Note that SEH directives need to continue tracking the stack
-	 pointer even after the frame pointer has been set up.  */
+      eax_live = ix86_eax_live_at_start_p ();
       if (eax_live)
 	{
 	  insn = emit_insn (gen_push (eax));
 	  allocate -= UNITS_PER_WORD;
+	  /* Note that SEH directives need to continue tracking the stack
+	     pointer even after the frame pointer has been set up.  */
 	  if (sp_is_cfa_reg || TARGET_SEH)
 	    {
 	      if (sp_is_cfa_reg)

gcc/config/i386/i386.h

@@ -1537,12 +1537,12 @@ enum reg_class
    mode the difference is less drastic but visible.  
 
    FIXME: Unlike earlier implementations, the size of unwind info seems to
-   actually grouw with accumulation.  Is that because accumulated args
+   actually grow with accumulation.  Is that because accumulated args
    unwind info became unnecesarily bloated?
-   
-   64-bit MS ABI seem to require 16 byte alignment everywhere except for
-   function prologue and epilogue.  This is not possible without
-   ACCUMULATE_OUTGOING_ARGS.  
+
+   With the 64-bit MS ABI, we can generate correct code with or without
+   accumulated args, but because of OUTGOING_REG_PARM_STACK_SPACE the code
+   generated without accumulated args is terrible.
 
    If stack probes are required, the space used for large function
    arguments on the stack must also be probed, so enable