[Bug middle-end/18887] [4.0 Regression] libgcc2.h Improperly determines required built-in function size requirements.

["schlie at comcast dot net" <gcc-bugzilla@gcc.gnu.org>]

------- Additional Comments From schlie at comcast dot net  2004-12-21 20:19 -------
Minimal changes required to get avr to build:
(which disables DI/DF emulation modes which appear to exceed avr's allocatable registers. )

*** In File: config/avr.h, Beginning line: 111 ***

  #define BITS_BIG_ENDIAN 0
  #define BYTES_BIG_ENDIAN 0
  #define WORDS_BIG_ENDIAN 0
  
  #ifdef IN_LIBGCC2
- /* This is to get correct SI and DI modes in libgcc2.c (32 and 64 bits).  */
+ /* To map SI/DI modes in libgcc2.c to HI/SI modes (16 and 32 bits).  */
- #define UNITS_PER_WORD 4
+ #define UNITS_PER_WORD 2
  #else
  /* Width of a word, in units (bytes).  */
  #define UNITS_PER_WORD 1
  #endif
  
  #define POINTER_SIZE 16

*** In File: config/avr.h, Beginning line: 142 ***

  #define INT_TYPE_SIZE (TARGET_INT8 ? 8 : 16)
  #define SHORT_TYPE_SIZE (INT_TYPE_SIZE == 8 ? INT_TYPE_SIZE : 16)
  #define LONG_TYPE_SIZE (INT_TYPE_SIZE == 8 ? 16 : 32)
- #define LONG_LONG_TYPE_SIZE (INT_TYPE_SIZE == 8 ? 32 : 64)
+ #define LONG_LONG_TYPE_SIZE (INT_TYPE_SIZE == 8 ? 32 : 32)
  #define FLOAT_TYPE_SIZE 32
  #define DOUBLE_TYPE_SIZE 32
  #define LONG_DOUBLE_TYPE_SIZE 32
  
  #define DEFAULT_SIGNED_CHAR 1

+ #define SMALL_EH_ENCODEING 1
+
  #define SIZE_TYPE (INT_TYPE_SIZE == 8 ? "long unsigned int" : "unsigned int")
  #define PTRDIFF_TYPE (INT_TYPE_SIZE == 8 ? "long int" :"int")

*** In File: unwind.h, beginning line: 55 ***

  /* @@@ The IA-64 ABI uses a 64-bit word to identify the producer and
     consumer of an exception.  We'll go along with this for now even on
     32-bit machines.  We'll need to provide some other option for
     16-bit machines and for machines with > 8 bits per byte.  */
+ #include "tm.h" /* Fixme: just a temporary hack for small targets.  */
+ #if (SMALL_EH_ENCODEING)
+ typedef unsigned _Unwind_Exception_Class __attribute__((__mode__(__SI__)));
+ #else
  typedef unsigned _Unwind_Exception_Class __attribute__((__mode__(__DI__)));
+ #endif

  /* The unwind interface uses reason codes in several contexts to
     identify the reasons for failures or other actions.  */


*** In File: unwind-pe.h, beginning line: 37 ***

  /* If using C++, references to abort have to be qualified with std::.  */
  #if __cplusplus
  #define __gxx_abort std::abort
  #else
  #define __gxx_abort abort
  #endif

+ #include "tm.h" /* Fixme: just a temporary hack for small targets.  */
+
  /* Pointer encodings, from dwarf2.h.  */
  #define DW_EH_PE_absptr         0x00
  #define DW_EH_PE_omit           0xff


*** In File: unwind-pe.h, beginning line: 184 ***

  static const unsigned char *
  read_encoded_value_with_base (unsigned char encoding, _Unwind_Ptr base,
                    const unsigned char *p, _Unwind_Ptr *val)
  {
+ #if (SMALL_EH_ENCODEING) /* Fixme: just a temporary hack for small targets. */
+   union unaligned
+     {
+       void *ptr;
+       unsigned u2 __attribute__ ((mode (QI)));
+       unsigned u4 __attribute__ ((mode (HI)));
+       unsigned u8 __attribute__ ((mode (SI)));
+       signed s2 __attribute__ ((mode (QI)));
+       signed s4 __attribute__ ((mode (HI)));
+       signed s8 __attribute__ ((mode (SI)));
+     } __attribute__((__packed__));
+ #else
    union unaligned
      {
        void *ptr;
        unsigned u2 __attribute__ ((mode (HI)));
        unsigned u4 __attribute__ ((mode (SI)));
        unsigned u8 __attribute__ ((mode (DI)));
        signed s2 __attribute__ ((mode (HI)));
        signed s4 __attribute__ ((mode (SI)));
        signed s8 __attribute__ ((mode (DI)));
      } __attribute__((__packed__));
+ #endif
  
    const union unaligned *u = (const union unaligned *) p;
    _Unwind_Internal_Ptr result;

*** end ***


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18887