Re: [Patch PR43399] Fix bootstrap on arm-linux-gnueabi with VTA changes.

[Ramana Radhakrishnan <ramana dot radhakrishnan at arm dot com>]

On Thu, 2010-03-18 at 22:47 +0100, Paolo Carlini wrote:
> On 03/18/2010 10:39 PM, Ramana Radhakrishnan wrote:
> > Ok to commit for trunk and backport to the 4.4 branch if this is a
> > regression there as well ? 
> >   
> In any case, please wrap to 80 columns those loooooong lines.
  
Sorry about that. Done and rationalized the comments. 

Ok to commit to trunk ?

cheers
Ramana

Index: arm.c
===================================================================
--- arm.c	(revision 157543)
+++ arm.c	(working copy)
@@ -11655,9 +11655,14 @@ vfp_emit_fstmd (int base_reg, int count)
 
   XVECEXP (par, 0, 0)
     = gen_rtx_SET (VOIDmode,
-		   gen_frame_mem (BLKmode,
-				  gen_rtx_PRE_DEC (BLKmode,
-						   stack_pointer_rtx)),
+		   gen_frame_mem
+		   (BLKmode,
+		    gen_rtx_PRE_MODIFY (Pmode,
+					stack_pointer_rtx,
+					plus_constant
+					(stack_pointer_rtx,
+					 - (count * 8)))
+		    ),
 		   gen_rtx_UNSPEC (BLKmode,
 				   gen_rtvec (1, reg),
 				   UNSPEC_PUSH_MULT));
@@ -13910,16 +13915,17 @@ emit_multi_reg_push (unsigned long mask)
 
   /* For the body of the insn we are going to generate an UNSPEC in
      parallel with several USEs.  This allows the insn to be recognized
-     by the push_multi pattern in the arm.md file.  The insn looks
-     something like this:
+     by the push_multi pattern in the arm.md file.
+
+     The body of the insn looks something like this:
 
        (parallel [
-           (set (mem:BLK (pre_dec:BLK (reg:SI sp)))
+           (set (mem:BLK (pre_modify:SI (reg:SI sp)
+	                                (const_int:SI <num>)))
 	        (unspec:BLK [(reg:SI r4)] UNSPEC_PUSH_MULT))
-           (use (reg:SI 11 fp))
-           (use (reg:SI 12 ip))
-           (use (reg:SI 14 lr))
-           (use (reg:SI 15 pc))
+           (use (reg:SI XX))
+           (use (reg:SI YY))
+	   ...
         ])
 
      For the frame note however, we try to be more explicit and actually
@@ -13932,13 +13938,20 @@ emit_multi_reg_push (unsigned long mask)
       (sequence [
            (set (reg:SI sp) (plus:SI (reg:SI sp) (const_int -20)))
            (set (mem:SI (reg:SI sp)) (reg:SI r4))
-           (set (mem:SI (plus:SI (reg:SI sp) (const_int 4))) (reg:SI fp))
-           (set (mem:SI (plus:SI (reg:SI sp) (const_int 8))) (reg:SI ip))
-           (set (mem:SI (plus:SI (reg:SI sp) (const_int 12))) (reg:SI lr))
+           (set (mem:SI (plus:SI (reg:SI sp) (const_int 4))) (reg:SI XX))
+           (set (mem:SI (plus:SI (reg:SI sp) (const_int 8))) (reg:SI YY))
+	   ...
         ])
 
-      This sequence is used both by the code to support stack unwinding for
-      exceptions handlers and the code to generate dwarf2 frame debugging.  */
+     FIXME:: In an ideal world the PRE_MODIFY would not exist and
+     instead we'd have a parallel expression detailing all
+     the stores to the various memory addresses so that debug
+     information is more up-to-date. Remember however while writing
+     this to take care of the constraints with the push instruction.
+
+     Note also that this has to be taken care of for the VFP registers.
+
+     For more see PR43399.  */
 
   par = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num_regs));
   dwarf = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (num_dwarf_regs + 1));
@@ -13952,9 +13965,14 @@ emit_multi_reg_push (unsigned long mask)
 
 	  XVECEXP (par, 0, 0)
 	    = gen_rtx_SET (VOIDmode,
-			   gen_frame_mem (BLKmode,
-					  gen_rtx_PRE_DEC (BLKmode,
-							   stack_pointer_rtx)),
+			   gen_frame_mem
+			   (BLKmode,
+			    gen_rtx_PRE_MODIFY (Pmode,
+						stack_pointer_rtx,
+						plus_constant
+						(stack_pointer_rtx,
+						 -4 * num_regs))
+			    ),
 			   gen_rtx_UNSPEC (BLKmode,
 					   gen_rtvec (1, reg),
 					   UNSPEC_PUSH_MULT));
@@ -13985,9 +14003,10 @@ emit_multi_reg_push (unsigned long mask)
 	    {
 	      tmp
 		= gen_rtx_SET (VOIDmode,
-			       gen_frame_mem (SImode,
-					      plus_constant (stack_pointer_rtx,
-							     4 * j)),
+			       gen_frame_mem
+			       (SImode,
+				plus_constant (stack_pointer_rtx,
+					       4 * j)),
 			       reg);
 	      RTX_FRAME_RELATED_P (tmp) = 1;
 	      XVECEXP (dwarf, 0, dwarf_par_index++) = tmp;
@@ -14039,9 +14058,14 @@ emit_sfm (int base_reg, int count)
 
   XVECEXP (par, 0, 0)
     = gen_rtx_SET (VOIDmode,
-		   gen_frame_mem (BLKmode,
-				  gen_rtx_PRE_DEC (BLKmode,
-						   stack_pointer_rtx)),
+		   gen_frame_mem
+		   (BLKmode,
+		    gen_rtx_PRE_MODIFY (Pmode,
+					stack_pointer_rtx,
+					plus_constant
+					(stack_pointer_rtx,
+					 -12 * count))
+		    ),
 		   gen_rtx_UNSPEC (BLKmode,
 				   gen_rtvec (1, reg),
 				   UNSPEC_PUSH_MULT));