diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 101f6a8e030..111fcaa9c4a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2002-03-29  Richard Henderson  <rth@redhat.com>
+
+	* config/ia64/aix.h (CPP_PREDEFINES): Add -D_LP64.
+	* config/ia64/hpux.h, config/ia64/linux.h: Likewise.
+
 2002-03-29  Richard Henderson  <rth@redhat.com>
 
 	* config/i386/i386.c (x86_arch_always_fancy_math_387): New.
diff --git a/gcc/config/ia64/aix.h b/gcc/config/ia64/aix.h
index 1e57c2b3f65..1e2e922a830 100644
--- a/gcc/config/ia64/aix.h
+++ b/gcc/config/ia64/aix.h
@@ -87,7 +87,8 @@ Boston, MA 02111-1307, USA.  */
 #undef CPP_PREDEFINES
 #define CPP_PREDEFINES "\
 -D__ia64 -D__ia64__ -D_AIX -D_AIX64 -D_LONGLONG -Dunix \
--D__LP64__ -D__ELF__ -Asystem=unix -Asystem=aix -Acpu=ia64 -Amachine=ia64 \
+-D_LP64 -D__LP64__ -D__ELF__ \
+-Asystem=unix -Asystem=aix -Acpu=ia64 -Amachine=ia64 \
 -D__64BIT__ -D_LONG_LONG -D_IA64 -D__int128=__size128_t"
 
 /* The GNU C++ standard library requires that these macros be defined.  */
diff --git a/gcc/config/ia64/hpux.h b/gcc/config/ia64/hpux.h
index 89b2902bf85..5f272d67612 100644
--- a/gcc/config/ia64/hpux.h
+++ b/gcc/config/ia64/hpux.h
@@ -40,7 +40,7 @@ Boston, MA 02111-1307, USA.  */
 #undef CPP_SPEC
 #define CPP_SPEC "\
   %{mcpu=itanium:-D__itanium__} \
-  %{mlp64:-D__LP64__ -D__LONG_MAX__=9223372036854775807L} \
+  %{mlp64:-D__LP64__ -D_LP64 -D__LONG_MAX__=9223372036854775807L} \
   %{!ansi:%{!std=c*:%{!std=i*: -D_HPUX_SOURCE -D__STDC_EXT__}}} \
   -D__fpreg=long\\ double \
   -D__float80=long\\ double \
diff --git a/gcc/config/ia64/linux.h b/gcc/config/ia64/linux.h
index ac77af2e01b..2f57d6ff547 100644
--- a/gcc/config/ia64/linux.h
+++ b/gcc/config/ia64/linux.h
@@ -12,7 +12,7 @@
 /* ??? Maybe this should be in sysv4.h?  */
 #define CPP_PREDEFINES "\
 -D__ia64 -D__ia64__ -D__linux -D__linux__ -D_LONGLONG -Dlinux -Dunix \
--D__LP64__ -D__ELF__ -Asystem=linux -Acpu=ia64 -Amachine=ia64"
+-D_LP64 -D__LP64__ -D__ELF__ -Asystem=linux -Acpu=ia64 -Amachine=ia64"
 
 /* ??? ia64 gas doesn't accept standard svr4 assembler options?  */
 #undef ASM_SPEC