a29k.h, [...]: (BITS_PER_UNIT): Delete.

	* a29k.h, alpha.h, arc.h, arm.h, avr.h, clipper.h, convex.h,
	cris.h, d30v.h, elxsi.h, fr30.h, h8300.h, i370.h, i386.h, i860.h,
	i960.h, ia64.h, m32r.h, m68hc11.h, m68k.h, m88k.h, mcore.h,
	mips.h, mmix.h, mn10200.h, mn10300.h, ns32k.h, pa.h, pdp11.h,
	pj.h, romp.h, rs6000.h, s390.h, sh.h, sparc.h, stormy16.h, v850.h,
	vax.h, we32k.h, xtensa.h: (BITS_PER_UNIT): Delete.
	* defaults.h (BITS_PER_UNIT): Define.
	* doc/tm.texi (BITS_PER_UNIT): Document default value.

From-SVN: r50235

43 files changed, 16 insertions, 116 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3ebfedb..eb73bd1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2002-03-02  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
+
+	* a29k.h, alpha.h, arc.h, arm.h, avr.h, clipper.h, convex.h,
+	cris.h, d30v.h, elxsi.h, fr30.h, h8300.h, i370.h, i386.h, i860.h,
+	i960.h, ia64.h, m32r.h, m68hc11.h, m68k.h, m88k.h, mcore.h,
+	mips.h, mmix.h, mn10200.h, mn10300.h, ns32k.h, pa.h, pdp11.h,
+	pj.h, romp.h, rs6000.h, s390.h, sh.h, sparc.h, stormy16.h, v850.h,
+	vax.h, we32k.h, xtensa.h: (BITS_PER_UNIT): Delete.
+	* defaults.h (BITS_PER_UNIT): Define.
+	* doc/tm.texi (BITS_PER_UNIT): Document default value.
+
 2002-03-02  Kazu Hirata  <kazu@hxi.com>
 
 	* config/h8300/h8300-protos.h: Add a prototype for
diff --git a/gcc/config/a29k/a29k.h b/gcc/config/a29k/a29k.h
index ff80dce..f499ea1 100644
--- a/gcc/config/a29k/a29k.h
+++ b/gcc/config/a29k/a29k.h
@@ -165,9 +165,6 @@ extern int target_flags;
    for them.  Might as well be consistent with bytes.  */
 #define WORDS_BIG_ENDIAN 1
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/alpha/alpha.h b/gcc/config/alpha/alpha.h
index b2363bc..6d78d3f 100644
--- a/gcc/config/alpha/alpha.h
+++ b/gcc/config/alpha/alpha.h
@@ -474,9 +474,6 @@ extern const char *alpha_mlat_string;	/* For -mmemory-latency= */
    for them.  Might as well be consistent with bytes.  */
 #define WORDS_BIG_ENDIAN 0
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/arc/arc.h b/gcc/config/arc/arc.h
index 523ea72..0a83854 100644
--- a/gcc/config/arc/arc.h
+++ b/gcc/config/arc/arc.h
@@ -191,9 +191,6 @@ do {				\
 #define LIBGCC2_WORDS_BIG_ENDIAN 0
 #endif
 
-/* Number of bits in an addressable storage unit.  */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index bf989f4..8f4c4a1 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -696,9 +696,6 @@ extern int arm_is_6_or_7;
    This is always true, even when in little-endian mode.  */
 #define FLOAT_WORDS_BIG_ENDIAN 1
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT  8
-
 #define BITS_PER_WORD  32
 
 #define UNITS_PER_WORD	4
diff --git a/gcc/config/avr/avr.h b/gcc/config/avr/avr.h
index 742c811..ffcfa26 100644
--- a/gcc/config/avr/avr.h
+++ b/gcc/config/avr/avr.h
@@ -126,9 +126,6 @@ extern int avr_enhanced_p;
    numbered.  */
 #define WORDS_BIG_ENDIAN 0
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';  */
 #define BITS_PER_WORD 8
diff --git a/gcc/config/clipper/clipper.h b/gcc/config/clipper/clipper.h
index 790202b..61845e4 100644
--- a/gcc/config/clipper/clipper.h
+++ b/gcc/config/clipper/clipper.h
@@ -69,9 +69,6 @@ extern int target_flags;
 
 #define WORDS_BIG_ENDIAN 0
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/convex/convex.h b/gcc/config/convex/convex.h
index 8c0fffa..d662b2c 100644
--- a/gcc/config/convex/convex.h
+++ b/gcc/config/convex/convex.h
@@ -434,9 +434,6 @@ extern int target_flags;
 /* Define this if most significant word of a multiword number is numbered.  */
 #define WORDS_BIG_ENDIAN 1
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/cris/cris.h b/gcc/config/cris/cris.h
index 9ddd065..009b9aa 100644
--- a/gcc/config/cris/cris.h
+++ b/gcc/config/cris/cris.h
@@ -475,8 +475,6 @@ extern int target_flags;
    post-increment on DImode indirect.  */
 #define WORDS_BIG_ENDIAN 0
 
-#define BITS_PER_UNIT 8
-
 #define BITS_PER_WORD 32
 
 #define UNITS_PER_WORD 4
diff --git a/gcc/config/d30v/d30v.h b/gcc/config/d30v/d30v.h
index 37dd1cf..2174507 100644
--- a/gcc/config/d30v/d30v.h
+++ b/gcc/config/d30v/d30v.h
@@ -161,8 +161,6 @@ extern int target_flags;
 
 #define WORDS_BIG_ENDIAN 1
 
-#define BITS_PER_UNIT 8
-
 #define BITS_PER_WORD 32
 
 #define UNITS_PER_WORD 4
diff --git a/gcc/config/elxsi/elxsi.h b/gcc/config/elxsi/elxsi.h
index d5969d4..f06eda5 100644
--- a/gcc/config/elxsi/elxsi.h
+++ b/gcc/config/elxsi/elxsi.h
@@ -71,9 +71,6 @@ extern int target_flags;
 /* Define this if most significant word of a multiword number is numbered.  */
 #define WORDS_BIG_ENDIAN 1
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/fr30/fr30.h b/gcc/config/fr30/fr30.h
index dd19f75..32ba387 100644
--- a/gcc/config/fr30/fr30.h
+++ b/gcc/config/fr30/fr30.h
@@ -83,8 +83,6 @@ extern int target_flags;
 
 #define WORDS_BIG_ENDIAN 1
 
-#define BITS_PER_UNIT 	8
-
 #define BITS_PER_WORD 	32
 
 #define UNITS_PER_WORD 	4
diff --git a/gcc/config/h8300/h8300.h b/gcc/config/h8300/h8300.h
index c5852f5..b19c0b3 100644
--- a/gcc/config/h8300/h8300.h
+++ b/gcc/config/h8300/h8300.h
@@ -199,9 +199,6 @@ extern int target_flags;
    be consistent).  */
 #define WORDS_BIG_ENDIAN 1
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/i370/i370.h b/gcc/config/i370/i370.h
index 145f115..d1f72bb 100644
--- a/gcc/config/i370/i370.h
+++ b/gcc/config/i370/i370.h
@@ -86,10 +86,6 @@ extern int mvs_function_name_length;
 
 #define WORDS_BIG_ENDIAN 1
 
-/* Number of bits in an addressable storage unit.  */
-
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.  */
 
 #define BITS_PER_WORD 32
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 63dae01..a53a06f 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -721,9 +721,6 @@ extern int ix86_arch;
 /* Not true for 80386 */
 #define WORDS_BIG_ENDIAN 0
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 80386, this would still be 32.
diff --git a/gcc/config/i860/i860.h b/gcc/config/i860/i860.h
index ad5048c..97d7708 100644
--- a/gcc/config/i860/i860.h
+++ b/gcc/config/i860/i860.h
@@ -82,9 +82,6 @@ extern int target_flags;
    justify the trouble of changing this assumption.  */
 #define WORDS_BIG_ENDIAN 0
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/i960/i960.h b/gcc/config/i960/i960.h
index 4df5a6f..a067dea 100644
--- a/gcc/config/i960/i960.h
+++ b/gcc/config/i960/i960.h
@@ -397,9 +397,6 @@ extern int target_flags;
    numbered.  */
 #define WORDS_BIG_ENDIAN 0
 
-/* Number of bits in an addressable storage unit.  */
-#define BITS_PER_UNIT 8
-
 /* Bitfields cannot cross word boundaries.  */
 #define BITFIELD_NBYTES_LIMITED 1
 
diff --git a/gcc/config/ia64/ia64.h b/gcc/config/ia64/ia64.h
index 1900717..3c1d6b7 100644
--- a/gcc/config/ia64/ia64.h
+++ b/gcc/config/ia64/ia64.h
@@ -244,8 +244,6 @@ extern const char *ia64_fixed_range_string;
 #define LIBGCC2_WORDS_BIG_ENDIAN 0
 #endif
 
-#define BITS_PER_UNIT 8
-
 #define BITS_PER_WORD 64
 
 #define UNITS_PER_WORD 8
diff --git a/gcc/config/m32r/m32r.h b/gcc/config/m32r/m32r.h
index e4554fb..44510a0 100644
--- a/gcc/config/m32r/m32r.h
+++ b/gcc/config/m32r/m32r.h
@@ -442,9 +442,6 @@ extern enum m32r_sdata m32r_sdata;
    value will be set based on preprocessor defines.  */
 /*#define LIBGCC2_WORDS_BIG_ENDIAN 1*/
 
-/* Number of bits in an addressable storage unit.  */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/m68hc11/m68hc11.h b/gcc/config/m68hc11/m68hc11.h
index 2965fa5..0e4b202 100644
--- a/gcc/config/m68hc11/m68hc11.h
+++ b/gcc/config/m68hc11/m68hc11.h
@@ -241,9 +241,6 @@ extern const struct processor_costs *m68hc11_cost;
 /* Define this if most significant word of a multiword number is numbered.  */
 #define WORDS_BIG_ENDIAN 	1
 
-/* Number of bits in an addressible storage unit */
-#define BITS_PER_UNIT		8
-
 /* Number of bits in a word */
 #define BITS_PER_WORD		16
 
diff --git a/gcc/config/m68k/m68k.h b/gcc/config/m68k/m68k.h
index d97978c..72ef2c9 100644
--- a/gcc/config/m68k/m68k.h
+++ b/gcc/config/m68k/m68k.h
@@ -321,9 +321,6 @@ extern int target_flags;
    So let's be consistent.  */
 #define WORDS_BIG_ENDIAN 1
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/m88k/m88k.h b/gcc/config/m88k/m88k.h
index c002809..11d8e54 100644
--- a/gcc/config/m88k/m88k.h
+++ b/gcc/config/m88k/m88k.h
@@ -336,9 +336,6 @@ extern int flag_pic;				/* -fpic */
    instructions for them.  */
 #define WORDS_BIG_ENDIAN 1
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/mcore/mcore.h b/gcc/config/mcore/mcore.h
index 9ab8551..ab02a2a 100644
--- a/gcc/config/mcore/mcore.h
+++ b/gcc/config/mcore/mcore.h
@@ -247,9 +247,6 @@ extern const char * mcore_stack_increment_string;
 #define LIBGCC2_WORDS_BIG_ENDIAN 0
 #endif
 
-/* Number of bits in an addressable storage unit.  */
-#define BITS_PER_UNIT  8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/mips/mips.h b/gcc/config/mips/mips.h
index 7a5482c..66c3621 100644
--- a/gcc/config/mips/mips.h
+++ b/gcc/config/mips/mips.h
@@ -1569,9 +1569,6 @@ do {							\
 #define LIBGCC2_WORDS_BIG_ENDIAN 0
 #endif
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/mmix/mmix.h b/gcc/config/mmix/mmix.h
index 74229ac..3861e6e 100644
--- a/gcc/config/mmix/mmix.h
+++ b/gcc/config/mmix/mmix.h
@@ -251,7 +251,6 @@ extern int target_flags;
 #define BYTES_BIG_ENDIAN 1
 #define WORDS_BIG_ENDIAN 1
 #define FLOAT_WORDS_BIG_ENDIAN 1
-#define BITS_PER_UNIT 8
 #define BITS_PER_WORD 64
 #define UNITS_PER_WORD 8
 #define POINTER_SIZE 64
diff --git a/gcc/config/mn10200/mn10200.h b/gcc/config/mn10200/mn10200.h
index f9b2d30..6a81b6f 100644
--- a/gcc/config/mn10200/mn10200.h
+++ b/gcc/config/mn10200/mn10200.h
@@ -81,9 +81,6 @@ extern int target_flags;
    This is not true on the Matsushita MN10200.  */
 #define WORDS_BIG_ENDIAN 0
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/mn10300/mn10300.h b/gcc/config/mn10300/mn10300.h
index ddd872e..184aef1 100644
--- a/gcc/config/mn10300/mn10300.h
+++ b/gcc/config/mn10300/mn10300.h
@@ -90,9 +90,6 @@ extern int target_flags;
    This is not true on the Matsushita MN10300.  */
 #define WORDS_BIG_ENDIAN 0
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/ns32k/ns32k.h b/gcc/config/ns32k/ns32k.h
index 159148d..8ef5aeb 100644
--- a/gcc/config/ns32k/ns32k.h
+++ b/gcc/config/ns32k/ns32k.h
@@ -196,9 +196,6 @@ while (0)
    numbered. This is not true on the ns32k.  */
 #define WORDS_BIG_ENDIAN 0
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 32000, this would still be 32.
diff --git a/gcc/config/pa/pa.h b/gcc/config/pa/pa.h
index 715ae81..6960684 100644
--- a/gcc/config/pa/pa.h
+++ b/gcc/config/pa/pa.h
@@ -389,9 +389,6 @@ extern int target_flags;
    numbered.  */
 #define WORDS_BIG_ENDIAN 1
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/pdp11/pdp11.h b/gcc/config/pdp11/pdp11.h
index 2c16aa8..2b6edd3 100644
--- a/gcc/config/pdp11/pdp11.h
+++ b/gcc/config/pdp11/pdp11.h
@@ -165,9 +165,6 @@ extern int target_flags;
 /* Define this if most significant word of a multiword number is numbered.  */
 #define WORDS_BIG_ENDIAN 1
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/pj/pj.h b/gcc/config/pj/pj.h
index 0adf02a..804f396 100644
--- a/gcc/config/pj/pj.h
+++ b/gcc/config/pj/pj.h
@@ -133,9 +133,6 @@ extern int target_flags;
 #define LIBGCC2_WORDS_BIG_ENDIAN 1
 #endif
 
-/* Number of bits in an addressable storage unit.  */
-#define BITS_PER_UNIT  8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/romp/romp.h b/gcc/config/romp/romp.h
index 23c73e7..5ce44f0 100644
--- a/gcc/config/romp/romp.h
+++ b/gcc/config/romp/romp.h
@@ -90,9 +90,6 @@ extern int target_flags;
    for them.  Might as well be consistent with bits and bytes.  */
 #define WORDS_BIG_ENDIAN 1
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h
index fae0b83..fccf3d3 100644
--- a/gcc/config/rs6000/rs6000.h
+++ b/gcc/config/rs6000/rs6000.h
@@ -522,9 +522,6 @@ extern int rs6000_altivec_abi;
    instructions for them.  Might as well be consistent with bits and bytes.  */
 #define WORDS_BIG_ENDIAN 1
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/s390/s390.h b/gcc/config/s390/s390.h
index 6756e60..e395f85 100644
--- a/gcc/config/s390/s390.h
+++ b/gcc/config/s390/s390.h
@@ -106,10 +106,6 @@ extern int current_function_outgoing_args_size;
 
 #define WORDS_BIG_ENDIAN 1
 
-/* Number of bits in an addressable storage unit.  */
-
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.  */
 
 #define BITS_PER_WORD (TARGET_64BIT ? 64 : 32)
diff --git a/gcc/config/sh/sh.h b/gcc/config/sh/sh.h
index 1a48621..e919597 100644
--- a/gcc/config/sh/sh.h
+++ b/gcc/config/sh/sh.h
@@ -430,9 +430,6 @@ do {									\
 #define LIBGCC2_WORDS_BIG_ENDIAN 1
 #endif
 
-/* Number of bits in an addressable storage unit.  */
-#define BITS_PER_UNIT  8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/sparc/sparc.h b/gcc/config/sparc/sparc.h
index 779a39c..3faf25b 100644
--- a/gcc/config/sparc/sparc.h
+++ b/gcc/config/sparc/sparc.h
@@ -710,9 +710,6 @@ extern struct sparc_cpu_select sparc_select[];
 #define LIBGCC2_WORDS_BIG_ENDIAN 1
 #endif
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/stormy16/stormy16.h b/gcc/config/stormy16/stormy16.h
index b2a2ad1..c2fd617 100644
--- a/gcc/config/stormy16/stormy16.h
+++ b/gcc/config/stormy16/stormy16.h
@@ -89,8 +89,6 @@ extern int target_flags;
 
 #define WORDS_BIG_ENDIAN 0
 
-#define BITS_PER_UNIT 8
-
 #define BITS_PER_WORD 16
 
 #define UNITS_PER_WORD 2
diff --git a/gcc/config/v850/v850.h b/gcc/config/v850/v850.h
index 6c5a4a6..b20c1f4 100644
--- a/gcc/config/v850/v850.h
+++ b/gcc/config/v850/v850.h
@@ -228,9 +228,6 @@ extern struct small_memory_info small_memory[(int)SMALL_MEMORY_max];
    This is not true on the NEC V850.  */
 #define WORDS_BIG_ENDIAN 0
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/vax/vax.h b/gcc/config/vax/vax.h
index 26e767d..fbd3e38 100644
--- a/gcc/config/vax/vax.h
+++ b/gcc/config/vax/vax.h
@@ -105,9 +105,6 @@ extern int target_flags;
 /* This is not true on the VAX.  */
 #define WORDS_BIG_ENDIAN 0
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a 68000, this would still be 32.
diff --git a/gcc/config/we32k/we32k.h b/gcc/config/we32k/we32k.h
index 12f105d..7d9ac44 100644
--- a/gcc/config/we32k/we32k.h
+++ b/gcc/config/we32k/we32k.h
@@ -62,9 +62,6 @@ extern int target_flags;
    since there are no machine instructions for them.  */
 #define WORDS_BIG_ENDIAN 1
 
-/* number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.
    Note that this is not necessarily the width of data type `int';
    if using 16-bit ints on a we32000, this would still be 32.
diff --git a/gcc/config/xtensa/xtensa.h b/gcc/config/xtensa/xtensa.h
index 0cfbdb2..709ed06 100644
--- a/gcc/config/xtensa/xtensa.h
+++ b/gcc/config/xtensa/xtensa.h
@@ -235,9 +235,6 @@ extern unsigned xtensa_current_frame_size;
 /* Define this if most significant word of a multiword number is the lowest. */
 #define WORDS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
 
-/* Number of bits in an addressable storage unit */
-#define BITS_PER_UNIT 8
-
 /* Width in bits of a "word", which is the contents of a machine register.  */
 #define BITS_PER_WORD 32
 #define MAX_BITS_PER_WORD 32
diff --git a/gcc/defaults.h b/gcc/defaults.h
index 3071f1f3..2d0005d 100644
--- a/gcc/defaults.h
+++ b/gcc/defaults.h
@@ -281,6 +281,10 @@ do {								\
    your target, you should override these values by defining the
    appropriate symbols in your tm.h file.  */
 
+#ifndef BITS_PER_UNIT
+#define BITS_PER_UNIT 8
+#endif
+
 #ifndef CHAR_TYPE_SIZE
 #define CHAR_TYPE_SIZE BITS_PER_UNIT
 #endif
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index dd22fd0..1a58557 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -924,7 +924,7 @@ multi-word integers.
 @findex BITS_PER_UNIT
 @item BITS_PER_UNIT
 Define this macro to be the number of bits in an addressable storage
-unit (byte); normally 8.
+unit (byte).  If you do not define this macro the default is 8.
 
 @findex BITS_PER_WORD
 @item BITS_PER_WORD