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--==_Exmh_-14003037170
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> On Wed, 19 Aug 1998, Richard Earnshaw wrote:
> 
> : This will work, but my experiments show that the code will be less 
> : efficient that the code generated by the old 2.7 compiler.  I'm currently 
> : working on a patch that would give us something like the Norcroft 
> : compiler's "return_in_regs" attribute, but it won't be in the official 
> : egcs 1.1 releases since these are now feature-frozen.
> 
> This is fine, though, for us - if you have the time to do it and have a
> working fix, I can dump the diff right into the NetBSD tree so it will be
> thereeven if egcs doesn't have it.
> 
Included below is a *HACK* that will make softfloat.c compile in the way 
we want it to.  Note that the hack does not work in general (it works ok 
for structs that are exactly 2 or four words long, but not for other sized 
structs -- for reasons that I won't dive into here).  So it really needs 
substantially more work before it can be documented and included by 
default.

The Norcroft compiler works by attaching the "attribute" to the function 
-- not to the structure -- but to implement this in gcc would need mid-end 
modifications to the compiler which I need to discuss first on the egcs 
lists.

Note, the patch to softfloat.h is to show you what needs to be done.  It 
should really be dressed up in #ifdefs to check the compiler version is at 
least 2.8 (so that 2.7 won't emit warnings on the unrecognized attribute).

> Thanks for your help, btw.  _I_ appreciate it personally.  :>

No problem -- I have two machines with StrongARM's in, both running 
NetBSD, which I use for testing egcs -- I think you could say I have a 
vested interest in getting this to work.

Richard.

--==_Exmh_-14003037170
Content-Type: application/x-patch ; name="sf.patch"
Content-Description: sf.patch
Content-Disposition: attachment; filename="sf.patch"

*** softfloat.h~	Thu Jul 16 13:05:46 1998
--- softfloat.h	Thu Jul 16 13:15:35 1998
*************** Software IEC/IEEE floating-point types.
*** 37,43 ****
  typedef unsigned int float32;
  typedef struct {
      unsigned int high, low;
! } float64;
  
  /*
  -------------------------------------------------------------------------------
--- 37,43 ----
  typedef unsigned int float32;
  typedef struct {
      unsigned int high, low;
! } __attribute__((return_in_regs)) float64;
  
  /*
  -------------------------------------------------------------------------------

--==_Exmh_-14003037170
Content-Type: application/x-patch ; name="retreg.patch"
Content-Description: retreg.patch
Content-Disposition: attachment; filename="retreg.patch"

? t-semi.keep
Index: arm.c
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/config/arm/arm.c,v
retrieving revision 1.11
diff -p -r1.11 arm.c
*** arm.c	1998/06/26 07:13:23	1.11
--- arm.c	1998/08/19 15:57:26
*************** int
*** 1128,1134 ****
  arm_return_in_memory (type)
       tree type;
  {
!   if (TREE_CODE (type) == RECORD_TYPE)
      {
        tree field;
  
--- 1127,1145 ----
  arm_return_in_memory (type)
       tree type;
  {
!   /* If the type has been given the attribute "return_in_regs" always try
!      to honour it.  aggregate_type_p may still force it in to memory,
!      but there is nothing we can do about that.  */
!   if (lookup_attribute ("return_in_regs", TYPE_ATTRIBUTES (type)))
!     return 0;
!   /* Otherwise, BLKmode always needs memory.  */
!   else if (TYPE_MODE (type) == BLKmode)
!     return 1;
!   /* And non-aggregates never need memory */
!   else if (! AGGREGATE_TYPE_P (type))
!     return 0;
!   /* For aggregates, obey the APCS rules */
!   else if (TREE_CODE (type) == RECORD_TYPE)
      {
        tree field;
  
*************** arm_return_in_memory (type)
*** 1157,1164 ****
  	}
        return 0;
      }
!   /* XXX Not sure what should be done for other aggregates, so put them in
!      memory. */
    return 1;
  }
  
--- 1168,1175 ----
  	}
        return 0;
      }
!   /* XXX Not sure what should be done for other aggregates
!      (QUAL_UNIONs, ARRAYs and SETs), so put them in memory. */
    return 1;
  }
  
*************** multi_register_push (op, mode)
*** 2783,2788 ****
--- 2794,2819 ----
  
  
  /* Routines for use with attributes */
+ 
+ /* If defined, a C expression whose value is nonzero if IDENTIFIER
+    with arguments ARGS is a valid machine specific attribute for TYPE.
+    The attributes in ATTRIBUTES have previously been assigned to TYPE.  */
+ 
+ int
+ arm_valid_type_attribute_p (type, attributes, identifier, args)
+      tree type;
+      tree attributes ATTRIBUTE_UNUSED;
+      tree identifier;
+      tree args;
+ {
+   if (! AGGREGATE_TYPE_P(type))
+     return 0;
+ 
+   if (is_attribute_p ("return_in_regs", identifier))
+     return (args == NULL_TREE);
+ 
+   return 0;
+ }
  
  /* Return nonzero if ATTR is a valid attribute for DECL.
     ATTRIBUTES are any existing attributes and ARGS are the arguments
Index: arm.h
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/config/arm/arm.h,v
retrieving revision 1.11
diff -p -r1.11 arm.h
*** arm.h	1998/08/18 03:24:05	1.11
--- arm.h	1998/08/19 15:57:28
*************** do {									\
*** 1012,1020 ****
  /* How large values are returned */
  /* A C expression which can inhibit the returning of certain function values
     in registers, based on the type of value. */
! #define RETURN_IN_MEMORY(TYPE) 						\
!   (TYPE_MODE ((TYPE)) == BLKmode ||					\
!    (AGGREGATE_TYPE_P ((TYPE)) && arm_return_in_memory ((TYPE))))
  
  /* Define DEFAULT_PCC_STRUCT_RETURN to 1 if all structure and union return
     values must be in memory.  On the ARM, they need only do so if larger
--- 1012,1018 ----
  /* How large values are returned */
  /* A C expression which can inhibit the returning of certain function values
     in registers, based on the type of value. */
! #define RETURN_IN_MEMORY(TYPE) 	arm_return_in_memory ((TYPE))
  
  /* Define DEFAULT_PCC_STRUCT_RETURN to 1 if all structure and union return
     values must be in memory.  On the ARM, they need only do so if larger
*************** do {									\
*** 1239,1244 ****
--- 1237,1250 ----
    emit_move_insn (gen_rtx (MEM, SImode, plus_constant ((TRAMP), 12)),	\
  		  (FNADDR));						\
  }
+ 
+ /* If defined, a C expression whose value is nonzero if IDENTIFIER
+    with arguments ARGS is a valid machine specific attribute for TYPE.
+    The attributes in ATTRIBUTES have previously been assigned to TYPE.  */
+ 
+ #define VALID_MACHINE_TYPE_ATTRIBUTE(TYPE, ATTRIBUTES, NAME, ARGS) \
+   (arm_valid_type_attribute_p (TYPE, ATTRIBUTES, NAME, ARGS))
+ 
  
  
  /* Addressing modes, and classification of registers for them.  */
*************** int store_multiple_sequence (/* struct r
*** 2072,2077 ****
--- 2078,2085 ----
  				HOST_WIDE_INT * */);
  char *emit_stm_seq (/* struct rtx_def **, int */);
  int multi_register_push (/* struct rtx_def *, enum machine_mode */);
+ int arm_valid_type_attribute_p (/* union tree_node *, union tree_node *,
+ 				   union tree_node *, union tree_node * */);
  int arm_valid_machine_decl_attribute (/* union tree_node *, union tree_node *,
  					 union tree_node *,
  					 union tree_node * */);

--==_Exmh_-14003037170--