Start fixing the stack frame layout

gcc/config.gcc

@@ -1764,7 +1764,7 @@ epiphany-*-elf | epiphany-*-rtems*)
 	extra_headers="epiphany_intrinsics.h"
 	;;
 *-fcx-*)
-	tm_file="${tm_file} elfos.h gnu-user.h freebsd-spec.h newlib-stdint.h rs6000/sysv4.h rs6000/eabi.h rs6000/eabialtivec.h"
+	tm_file="${tm_file} elfos.h gnu-user.h freebsd-spec.h newlib-stdint.h rs6000/sysv4.h rs6000/eabi.h rs6000/eabialtivec.h rs6000/xenon.h"
 	extra_options="${extra_options} rs6000/sysv4.opt"
 	tmake_file="rs6000/t-fprules rs6000/t-ppcendian rs6000/t-ppccomm"
 	use_gcc_stdint=wrap

gcc/config/rs6000/rs6000-c.cc

@@ -753,6 +753,8 @@ rs6000_cpu_cpp_builtins (cpp_reader *pfile)
     case ABI_DARWIN:
       builtin_define ("_CALL_DARWIN");
       break;
+    case ABI_XENON:
+      builtin_define ("_CALL_SYSV"); /* Should be okay? */
     default:
       break;
     }

gcc/config/rs6000/rs6000-logue.cc

@@ -851,6 +851,23 @@ rs6000_stack_info (void)
 
       info->ehrd_offset -= ehrd_size;
       info->lr_save_offset = reg_size;
+      break;
+
+    case ABI_XENON:
+      info->gp_save_offset = -0xC - info->gp_size;
+      info->fp_save_offset = info->gp_save_offset - info->fp_size;
+      info->vrsave_save_offset = info->fp_save_offset - info->vrsave_size;
+
+	  /* Align stack so vector save area is on a quadword boundary.  */
+	  if (info->altivec_size != 0)
+	    info->altivec_padding_size = 16 - (-info->vrsave_save_offset % 16);
+
+	  info->altivec_save_offset = info->vrsave_save_offset
+				      - info->altivec_padding_size
+				      - info->altivec_size;
+
+      info->lr_save_offset = -0x8;
+      break;
     }
 
   save_align = (TARGET_ALTIVEC_ABI || DEFAULT_ABI == ABI_DARWIN) ? 16 : 8;
@@ -870,12 +887,18 @@ rs6000_stack_info (void)
   info->total_size = RS6000_ALIGN (non_fixed_size + info->fixed_size,
 				   ABI_STACK_BOUNDARY / BITS_PER_UNIT);
 
+  if(DEFAULT_ABI == ABI_XENON)
+    /* 0x10 == unknown area (empty?), 0x40 == slots for callee to store r3->r10, */
+    /* 0xC == space before saved regs */
+    info->total_size += RS6000_ALIGN(0x10 + 0x40 + 0xC, ABI_STACK_BOUNDARY / BITS_PER_UNIT);
+
   /* Determine if we need to save the link register.  */
   if (info->calls_p
       || ((DEFAULT_ABI == ABI_AIX || DEFAULT_ABI == ABI_ELFv2)
 	  && crtl->profile
 	  && !TARGET_PROFILE_KERNEL)
       || (DEFAULT_ABI == ABI_V4 && cfun->calls_alloca)
+      || DEFAULT_ABI == ABI_XENON
 #ifdef TARGET_RELOCATABLE
       || (DEFAULT_ABI == ABI_V4
 	  && (TARGET_RELOCATABLE || flag_pic > 1)
@@ -948,6 +971,7 @@ debug_stack_info (rs6000_stack_t *info)
     case ABI_ELFv2:	 abi_string = "ELFv2";		break;
     case ABI_DARWIN:	 abi_string = "Darwin";		break;
     case ABI_V4:	 abi_string = "V.4";		break;
+    case ABI_XENON:   abi_string = "Xenon";     break;
     }
 
   fprintf (stderr, "\tABI                 = %5s\n", abi_string);

gcc/config/rs6000/rs6000-opts.h

@@ -102,7 +102,8 @@ enum rs6000_abi {
   ABI_AIX,			/* IBM's AIX, or Linux ELFv1 */
   ABI_ELFv2,			/* Linux ELFv2 ABI */
   ABI_V4,			/* System V.4/eabi */
-  ABI_DARWIN			/* Apple's Darwin (OS X kernel) */
+  ABI_DARWIN,			/* Apple's Darwin (OS X kernel) */
+  ABI_XENON         /* Xbox 360 OS */
 };
 
 /* Small data support types.  */

gcc/config/rs6000/sysv4.h

@@ -103,6 +103,8 @@ do {									\
     rs6000_current_abi = ABI_V4;					\
   else if (!strcmp (rs6000_abi_name, "openbsd"))			\
     rs6000_current_abi = ABI_V4;					\
+  else if (!strcmp (rs6000_abi_name, "xenon")) \
+    rs6000_current_abi = ABI_XENON; \
   else if (!strcmp (rs6000_abi_name, "i960-old"))			\
     {									\
       rs6000_current_abi = ABI_V4;					\

gcc/config/rs6000/xenon.h

@@ -0,0 +1,28 @@
+/* Specify Xenon ABI */
+#undef RS6000_ABI_NAME
+#define RS6000_ABI_NAME "xenon"
+
+/* Change the fixed area for the 360's stack frame convention */
+#undef RS6000_SAVE_AREA
+#define RS6000_SAVE_AREA \
+    (0x10 + (RS6000_ALIGN (crtl->outgoing_args_size, 16) - crtl->outgoing_args_size) + 0x40)
+
+/* Redefine the starting frame offset, since it relies on the size of the fixed area */
+#undef RS6000_STARTING_FRAME_OFFSET
+#define RS6000_STARTING_FRAME_OFFSET \
+    (cfun->calls_alloca \
+        ? (RS6000_ALIGN (crtl->outgoing_args_size + RS6000_SAVE_AREA, 16)) \
+        : (RS6000_ALIGN (crtl->outgoing_args_size, 16) + RS6000_SAVE_AREA))
+
+/* Redefine the offset of the first stack argument, since it relies on the size of the fixed area */
+#undef FIRST_PARM_OFFSET
+#define FIRST_PARM_OFFSET(FNDECL) RS6000_SAVE_AREA
+
+/* Redefine stack pointer offset, since it relies on the size of the fixed area */
+#undef STACK_POINTER_OFFSET
+#define STACK_POINTER_OFFSET RS6000_SAVE_AREA
+
+/* Redefine the offset from the stack pointer to items allocated by alloca() and friends */
+#undef STACK_DYNAMIC_OFFSET
+#define STACK_DYNAMIC_OFFSET(FUNDECL) \
+    RS6000_ALIGN (crtl->outgoing_args_size.to_constant () + STACK_POINTER_OFFSET, 16)