netchild's mega-patch to isolate compiler dependencies into a central

place.

This moves the dependency on GCC's and other compiler's features into
the central sys/cdefs.h file, while the individual source files can
then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to
refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42.

By now, GCC and ICC (the Intel compiler) have been actively tested on
IA32 platforms by netchild.  Extension to other compilers is supposed
to be possible, of course.

Submitted by:	netchild
Reviewed by:	various developers on arch@, some time ago

88 files changed, 584 insertions, 353 deletions

diff --git a/sys/alpha/include/_types.h b/sys/alpha/include/_types.h
index 885b241..a8acbbb 100644
--- a/sys/alpha/include/_types.h
+++ b/sys/alpha/include/_types.h
@@ -39,6 +39,10 @@
 #ifndef _MACHINE__TYPES_H_
 #define	_MACHINE__TYPES_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Basic types upon which most other types are built.
  */
@@ -97,7 +101,7 @@ typedef	__uint64_t	__vm_size_t;
 /*
  * Unusual type definitions.
  */
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifdef __GNUCLIKE_BUILTIN_VAALIST
 typedef __builtin_va_list	__va_list;	/* internally known to gcc */
 #else
 typedef	struct {
@@ -105,8 +109,9 @@ typedef	struct {
 	int	__offset;
 	int	__pad;
 } __va_list;
-#endif /* post GCC 2.95 */
-#if defined __GNUC__ && !defined(__GNUC_VA_LIST) && !defined(__NO_GNUC_VA_LIST)
+#endif /* __GNUCLIKE_BUILTIN_VAALIST */
+#if defined(__GNUC_VA_LIST_COMPATIBILITY) && !defined(__GNUC_VA_LIST) \
+    && !defined(__NO_GNUC_VA_LIST)
 #define __GNUC_VA_LIST
 typedef __va_list		__gnuc_va_list;	/* compatibility w/GNU headers*/
 #endif
diff --git a/sys/alpha/include/atomic.h b/sys/alpha/include/atomic.h
index 599700b..cc2dbb4 100644
--- a/sys/alpha/include/atomic.h
+++ b/sys/alpha/include/atomic.h
@@ -29,6 +29,10 @@
 #ifndef _MACHINE_ATOMIC_H_
 #define _MACHINE_ATOMIC_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 #include <machine/alpha_cpu.h>
 
 /*
@@ -50,7 +54,7 @@ static __inline void atomic_set_32(volatile u_int32_t *p, u_int32_t v)
 {
 	u_int32_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tldl_l %0, %2\n\t"		/* load old value */
 		"bis %0, %3, %0\n\t"		/* calculate new value */
@@ -66,7 +70,7 @@ static __inline void atomic_clear_32(volatile u_int32_t *p, u_int32_t v)
 {
 	u_int32_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tldl_l %0, %1\n\t"		/* load old value */
 		"bic %0, %2, %0\n\t"		/* calculate new value */
@@ -82,7 +86,7 @@ static __inline void atomic_add_32(volatile u_int32_t *p, u_int32_t v)
 {
 	u_int32_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tldl_l %0, %1\n\t"		/* load old value */
 		"addl %0, %2, %0\n\t"		/* calculate new value */
@@ -98,7 +102,7 @@ static __inline void atomic_subtract_32(volatile u_int32_t *p, u_int32_t v)
 {
 	u_int32_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tldl_l %0, %1\n\t"		/* load old value */
 		"subl %0, %2, %0\n\t"		/* calculate new value */
@@ -114,7 +118,7 @@ static __inline u_int32_t atomic_readandclear_32(volatile u_int32_t *addr)
 {
 	u_int32_t result,temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"wmb\n"			/* ensure pending writes have drained */
 		"1:\tldl_l %0,%2\n\t"	/* load current value, asserting lock */
@@ -133,7 +137,7 @@ static __inline void atomic_set_64(volatile u_int64_t *p, u_int64_t v)
 {
 	u_int64_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tldq_l %0, %1\n\t"		/* load old value */
 		"bis %0, %2, %0\n\t"		/* calculate new value */
@@ -149,7 +153,7 @@ static __inline void atomic_clear_64(volatile u_int64_t *p, u_int64_t v)
 {
 	u_int64_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tldq_l %0, %1\n\t"		/* load old value */
 		"bic %0, %2, %0\n\t"		/* calculate new value */
@@ -165,7 +169,7 @@ static __inline void atomic_add_64(volatile u_int64_t *p, u_int64_t v)
 {
 	u_int64_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tldq_l %0, %1\n\t"		/* load old value */
 		"addq %0, %2, %0\n\t"		/* calculate new value */
@@ -181,7 +185,7 @@ static __inline void atomic_subtract_64(volatile u_int64_t *p, u_int64_t v)
 {
 	u_int64_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tldq_l %0, %1\n\t"		/* load old value */
 		"subq %0, %2, %0\n\t"		/* calculate new value */
@@ -197,7 +201,7 @@ static __inline u_int64_t atomic_readandclear_64(volatile u_int64_t *addr)
 {
 	u_int64_t result,temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"wmb\n"			/* ensure pending writes have drained */
 		"1:\tldq_l %0,%2\n\t"	/* load current value, asserting lock */
@@ -336,7 +340,7 @@ atomic_cmpset_32(volatile u_int32_t* p, u_int32_t cmpval, u_int32_t newval)
 {
 	u_int32_t ret;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tldl_l %0, %1\n\t"		/* load old value */
 		"cmpeq %0, %2, %0\n\t"		/* compare */
@@ -363,7 +367,7 @@ atomic_cmpset_64(volatile u_int64_t* p, u_int64_t cmpval, u_int64_t newval)
 {
 	u_int64_t ret;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tldq_l %0, %1\n\t"		/* load old value */
 		"cmpeq %0, %2, %0\n\t"		/* compare */
diff --git a/sys/alpha/include/cpufunc.h b/sys/alpha/include/cpufunc.h
index 05bdbd4..5979987 100644
--- a/sys/alpha/include/cpufunc.h
+++ b/sys/alpha/include/cpufunc.h
@@ -35,9 +35,13 @@
 #include <machine/chipset.h>
 #include <machine/alpha_cpu.h>
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 struct thread;
 
-#ifdef __GNUC__
+#if defined(__GNUCLIKE_ASM)
 
 static __inline void
 breakpoint(void)
diff --git a/sys/alpha/include/critical.h b/sys/alpha/include/critical.h
index 22ff08c..4c9f729 100644
--- a/sys/alpha/include/critical.h
+++ b/sys/alpha/include/critical.h
@@ -46,7 +46,7 @@ __BEGIN_DECLS
  */
 void cpu_critical_fork_exit(void);
 
-#ifdef	__GNUC__
+#ifdef	__CC_SUPPORTS___INLINE
 
 /*
  *	cpu_critical_enter:
@@ -75,12 +75,12 @@ cpu_critical_exit(struct thread *td)
 	intr_restore(td->td_md.md_savecrit);
 }
 
-#else /* !__GNUC__ */
+#else /* !__CC_SUPPORTS___INLINE */
 
 void cpu_critical_enter(struct thread *td);
 void cpu_critical_exit(struct thread *td);
 
-#endif	/* __GNUC__ */
+#endif	/* __CC_SUPPORTS___INLINE */
 
 __END_DECLS
 
diff --git a/sys/alpha/include/endian.h b/sys/alpha/include/endian.h
index 1b11ffb..974ce16 100644
--- a/sys/alpha/include/endian.h
+++ b/sys/alpha/include/endian.h
@@ -64,7 +64,7 @@
 #define	BYTE_ORDER	_BYTE_ORDER
 #endif
 
-#ifdef __GNUC__
+#if defined(__CC_SUPPORTS___INLINE) && defined(__GNUCLIKE_ASM)
 
 static __inline __uint64_t
 __bswap64(__uint64_t _x)
@@ -113,7 +113,7 @@ __bswap16(__uint16_t _x)
 #define	__ntohl(x)	__bswap32(x)
 #define	__ntohs(x)	__bswap16(x)
 
-#else /* !__GNUC__ */
+#else /* !(__CC_SUPPORTS___INLINE && __GNUCLIKE_ASM) */
 
 /*
  * No optimizations are available for this compiler.  Fall back to
@@ -122,6 +122,6 @@ __bswap16(__uint16_t _x)
  */
 #define	_BYTEORDER_FUNC_DEFINED
 
-#endif /* __GNUC__ */
+#endif /* __CC_SUPPORTS___INLINE && __GNUCLIKE_ASM */
 
 #endif /* !_MACHINE_ENDIAN_H_ */
diff --git a/sys/alpha/include/in_cksum.h b/sys/alpha/include/in_cksum.h
index a899ef0..0992006 100644
--- a/sys/alpha/include/in_cksum.h
+++ b/sys/alpha/include/in_cksum.h
@@ -45,7 +45,7 @@
  * in the normal case (where there are no options and the header length is
  * therefore always exactly five 32-bit words.
  */
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS___INLINE
 
 static __inline void
 in_cksum_update(struct ip *ip)
diff --git a/sys/alpha/include/ioctl_bt848.h b/sys/alpha/include/ioctl_bt848.h
index 7ef237b..ca83a36 100644
--- a/sys/alpha/include/ioctl_bt848.h
+++ b/sys/alpha/include/ioctl_bt848.h
@@ -29,7 +29,9 @@
 #ifndef	_MACHINE_IOCTL_BT848_H_
 #define	_MACHINE_IOCTL_BT848_H_
 
-#ifdef __GNUC__
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning Include dev/bktr/ioctl_bt848.h instead of this header.
 #endif
 
diff --git a/sys/alpha/include/ioctl_meteor.h b/sys/alpha/include/ioctl_meteor.h
index 69d033e..0322f1e 100644
--- a/sys/alpha/include/ioctl_meteor.h
+++ b/sys/alpha/include/ioctl_meteor.h
@@ -29,7 +29,9 @@
 #ifndef	_MACHINE_IOCTL_METEOR_H_
 #define	_MACHINE_IOCTL_METEOR_H_
 
-#ifdef __GNUC__
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning Include dev/bktr/ioctl_meteor.h instead of this header.
 #endif
 
diff --git a/sys/alpha/include/limits.h b/sys/alpha/include/limits.h
index a02c8e1..9444760 100644
--- a/sys/alpha/include/limits.h
+++ b/sys/alpha/include/limits.h
@@ -34,7 +34,9 @@
 #ifndef _MACHINE_LIMITS_H_
 #define	_MACHINE_LIMITS_H_
 
-#if __GNUC__
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning "machine/limits.h is deprecated.  Include sys/limits.h instead."
 #endif
 
diff --git a/sys/alpha/include/stdarg.h b/sys/alpha/include/stdarg.h
index bd67f1f..1344962 100644
--- a/sys/alpha/include/stdarg.h
+++ b/sys/alpha/include/stdarg.h
@@ -47,7 +47,7 @@
 typedef	__va_list	va_list;
 #endif
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifdef __GNUCLIKE_BUILTIN_STDARG
 
 #define	va_start(ap, last) \
 	__builtin_stdarg_start((ap), (last))
@@ -63,7 +63,7 @@ typedef	__va_list	va_list;
 #define	va_end(ap) \
 	__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* !__GNUCLIKE_BUILTIN_STDARG */
 
 #ifdef __lint__
 #define	__builtin_saveregs()		(0)
@@ -87,6 +87,6 @@ typedef	__va_list	va_list;
 
 #define	va_end(ap)	((void)0)
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_STDARG */
 
 #endif /* !_MACHINE_STDARG_H_ */
diff --git a/sys/alpha/include/varargs.h b/sys/alpha/include/varargs.h
index 8565a3c..b05a9a5 100644
--- a/sys/alpha/include/varargs.h
+++ b/sys/alpha/include/varargs.h
@@ -44,7 +44,11 @@
 #ifndef _MACHINE_VARARGS_H_
 #define	_MACHINE_VARARGS_H_
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
+#if defined(__GNUCLIKE_BUILTIN_VARARGS)
 
 #include <sys/_types.h>
 
@@ -61,23 +65,21 @@ typedef int __builtin_va_alist_t __attribute__((__mode__(__word__)));
 #define	va_arg(ap, type)	__builtin_va_arg((ap), type)
 #define	va_end(ap)		__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* ! __GNUCLIKE_BUILTIN_VARARGS */
 
 #include <machine/stdarg.h>
 
-#if __GNUC__ == 1
-#define	__va_ellipsis
-#else
 #define	__va_ellipsis	...
-#endif
 
+#ifdef __GNUCLIKE_BUILTIN_VAALIST
 #define	va_alist	__builtin_va_alist
 #define	va_dcl		long __builtin_va_alist; __va_ellipsis
+#endif
 
 #undef va_start
 #define	va_start(ap) \
 	((ap) = *(va_list *)__builtin_saveregs(), (ap).__pad = 0)
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_VARARGS */
 
 #endif /* !_MACHINE_VARARGS_H_ */
diff --git a/sys/amd64/amd64/fpu.c b/sys/amd64/amd64/fpu.c
index 0b2071e..d727a41 100644
--- a/sys/amd64/amd64/fpu.c
+++ b/sys/amd64/amd64/fpu.c
@@ -63,7 +63,7 @@ __FBSDID("$FreeBSD$");
  * Floating point support.
  */
 
-#if defined(__GNUC__) && !defined(lint)
+#if defined(__GNUCLIKE_ASM) && !defined(lint)
 
 #define	fldcw(addr)		__asm("fldcw %0" : : "m" (*(addr)))
 #define	fnclex()		__asm("fnclex")
@@ -77,7 +77,7 @@ __FBSDID("$FreeBSD$");
 				      : : "n" (CR0_TS) : "ax")
 #define	stop_emulating()	__asm("clts")
 
-#else	/* not __GNUC__ */
+#else	/* !__GNUCLIKE_ASM */
 
 void	fldcw(caddr_t addr);
 void	fnclex(void);
@@ -89,7 +89,7 @@ void	fxrstor(caddr_t addr);
 void	start_emulating(void);
 void	stop_emulating(void);
 
-#endif	/* __GNUC__ */
+#endif	/* __GNUCLIKE_ASM */
 
 #define GET_FPU_CW(thread) ((thread)->td_pcb->pcb_save.sv_env.en_cw)
 #define GET_FPU_SW(thread) ((thread)->td_pcb->pcb_save.sv_env.en_sw)
diff --git a/sys/amd64/amd64/prof_machdep.c b/sys/amd64/amd64/prof_machdep.c
index e797cc0..1449f3f 100644
--- a/sys/amd64/amd64/prof_machdep.c
+++ b/sys/amd64/amd64/prof_machdep.c
@@ -69,7 +69,7 @@ static struct gmonparam saved_gmp;
 #endif
 #endif /* GUPROF */
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 __asm("								\n\
 GM_STATE	=	0					\n\
 GMON_PROF_OFF	=	3					\n\
@@ -140,9 +140,9 @@ __cyg_profile_func_enter:					\n\
 .mcount_exit:							\n\
 	ret							\n\
 ");
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
-#error
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#else /* !__GNUCLIKE_ASM */
+#error this file needs to be ported to your compiler
+#endif /* __GNUCLIKE_ASM */
 
 #ifdef GUPROF
 /*
@@ -151,7 +151,7 @@ __cyg_profile_func_enter:					\n\
  * dependent file together with cputime(), __mcount and [.]mcount.  cputime()
  * can't just be put in machdep.c because it has to be compiled without -pg.
  */
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 __asm("								\n\
 	.text							\n\
 #								\n\
@@ -194,9 +194,9 @@ __cyg_profile_func_exit:					\n\
 .mexitcount_exit:						\n\
 	ret							\n\
 ");
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
-#error
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#else /* !__GNUCLIKE_ASM */
+#error this file needs to be ported to your compiler
+#endif /* __GNUCLIKE_ASM */
 
 /*
  * Return the time elapsed since the last call.  The units are machine-
@@ -379,7 +379,7 @@ stopguprof(gp)
 }
 
 #else /* !GUPROF */
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 __asm("								\n\
 	.text							\n\
 	.p2align 4,0x90						\n\
@@ -387,7 +387,7 @@ __asm("								\n\
 " __XSTRING(HIDENAME(mexitcount)) ":				\n\
 	ret							\n\
 ");
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
-#error
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#else /* !__GNUCLIKE_ASM */
+#error this file needs to be ported to your compiler
+#endif /* __GNUCLIKE_ASM */
 #endif /* GUPROF */
diff --git a/sys/amd64/include/_types.h b/sys/amd64/include/_types.h
index 4a7b6e7..709cc16 100644
--- a/sys/amd64/include/_types.h
+++ b/sys/amd64/include/_types.h
@@ -39,6 +39,10 @@
 #ifndef _MACHINE__TYPES_H_
 #define	_MACHINE__TYPES_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Basic types upon which most other types are built.
  */
@@ -97,12 +101,13 @@ typedef	__uint64_t	__vm_size_t;
 /*
  * Unusual type definitions.
  */
-#if defined(__GNUC__)
+#ifdef __GNUCLIKE_BUILTIN_VARARGS
 typedef	__builtin_va_list	__va_list;	/* internally known to gcc */
 #elif defined(lint)
 typedef	char *			__va_list;	/* pretend */
 #endif
-#if defined __GNUC__ && !defined(__GNUC_VA_LIST) && !defined(__NO_GNUC_VA_LIST)
+#if defined(__GNUC_VA_LIST_COMPATIBILITY) && !defined(__GNUC_VA_LIST) \
+    && !defined(__NO_GNUC_VA_LIST)
 #define	__GNUC_VA_LIST
 typedef	__va_list	__gnuc_va_list;		/* compatibility w/GNU headers*/
 #endif
diff --git a/sys/amd64/include/atomic.h b/sys/amd64/include/atomic.h
index cbee271..eaf8068 100644
--- a/sys/amd64/include/atomic.h
+++ b/sys/amd64/include/atomic.h
@@ -28,6 +28,10 @@
 #ifndef _MACHINE_ATOMIC_H_
 #define _MACHINE_ATOMIC_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Various simple arithmetic on memory which is atomic in the presence
  * of interrupts and multiple processors.
@@ -76,7 +80,7 @@ void		atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
 #else /* !KLD_MODULE */
 
-#ifdef __GNUC__
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 /*
  * For userland, assume the SMP case and use lock prefixes so that
@@ -102,12 +106,12 @@ atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 }							\
 struct __hack
 
-#else /* !__GNUC__ */
+#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
 
 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V)				\
 extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
-#endif /* __GNUC__ */
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
 /*
  * Atomic compare and set, used by the mutex functions
@@ -117,7 +121,7 @@ extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
  * Returns 0 on failure, non-zero on success
  */
 
-#if defined(__GNUC__)
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 static __inline int
 atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
@@ -158,9 +162,9 @@ atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src)
 
 	return (res);
 }
-#endif /* defined(__GNUC__) */
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
-#if defined(__GNUC__)
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP)		\
 static __inline u_##TYPE				\
@@ -189,7 +193,7 @@ atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 }							\
 struct __hack
 
-#else /* !defined(__GNUC__) */
+#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
 
 extern int atomic_cmpset_int(volatile u_int *, u_int, u_int);
 extern int atomic_cmpset_long(volatile u_long *, u_long, u_long);
@@ -198,7 +202,7 @@ extern int atomic_cmpset_long(volatile u_long *, u_long, u_long);
 extern u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p);		\
 extern void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
-#endif /* defined(__GNUC__) */
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
 #endif /* KLD_MODULE */
 
@@ -371,7 +375,7 @@ ATOMIC_PTR(subtract)
 
 #undef ATOMIC_PTR
 
-#if defined(__GNUC__)
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 static __inline u_int
 atomic_readandclear_int(volatile u_int *addr)
@@ -403,12 +407,12 @@ atomic_readandclear_long(volatile u_long *addr)
 	return (result);
 }
 
-#else /* !defined(__GNUC__) */
+#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
 
 extern u_long	atomic_readandclear_long(volatile u_long *);
 extern u_int	atomic_readandclear_int(volatile u_int *);
 
-#endif /* defined(__GNUC__) */
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
 #endif	/* !defined(WANT_FUNCTIONS) */
 #endif /* ! _MACHINE_ATOMIC_H_ */
diff --git a/sys/amd64/include/bus_amd64.h b/sys/amd64/include/bus_amd64.h
index 189816b..9e0bc45 100644
--- a/sys/amd64/include/bus_amd64.h
+++ b/sys/amd64/include/bus_amd64.h
@@ -74,6 +74,10 @@
 
 #include <machine/cpufunc.h>
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * To remain compatible with NetBSD's interface, default to both memio and
  * pio when neither of them is defined.
@@ -284,7 +288,7 @@ bus_space_read_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movb (%2),%%al				\n\
@@ -313,7 +317,7 @@ bus_space_read_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movw (%2),%%ax				\n\
@@ -342,7 +346,7 @@ bus_space_read_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movl (%2),%%eax				\n\
@@ -391,7 +395,7 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inb %w2,%%al				\n\
@@ -410,7 +414,7 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -433,7 +437,7 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inw %w2,%%ax				\n\
@@ -452,7 +456,7 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -475,7 +479,7 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inl %w2,%%eax				\n\
@@ -494,7 +498,7 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -623,7 +627,7 @@ bus_space_write_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsb					\n\
@@ -652,7 +656,7 @@ bus_space_write_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsw					\n\
@@ -681,7 +685,7 @@ bus_space_write_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsl					\n\
@@ -731,7 +735,7 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsb					\n\
@@ -750,7 +754,7 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -773,7 +777,7 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsw					\n\
@@ -792,7 +796,7 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -815,7 +819,7 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsl					\n\
@@ -834,7 +838,7 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		bus_space_handle_t _port_ = bsh + offset;
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -1213,7 +1217,7 @@ static __inline void
 bus_space_barrier(bus_space_tag_t tag __unused, bus_space_handle_t bsh __unused,
 		  bus_size_t offset __unused, bus_size_t len __unused, int flags)
 {
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 	if (flags & BUS_SPACE_BARRIER_READ)
 		__asm __volatile("lock; addl $0,0(%%rsp)" : : : "memory");
 	else
diff --git a/sys/amd64/include/cpufunc.h b/sys/amd64/include/cpufunc.h
index e558858..4c596a0 100644
--- a/sys/amd64/include/cpufunc.h
+++ b/sys/amd64/include/cpufunc.h
@@ -39,6 +39,10 @@
 #ifndef _MACHINE_CPUFUNC_H_
 #define	_MACHINE_CPUFUNC_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 struct region_descriptor;
 
 #define readb(va)	(*(volatile u_int8_t *) (va))
@@ -51,7 +55,7 @@ struct region_descriptor;
 #define writel(va, d)	(*(volatile u_int32_t *) (va) = (d))
 #define writeq(va, d)	(*(volatile u_int64_t *) (va) = (d))
 
-#ifdef	__GNUC__
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 static __inline void
 breakpoint(void)
@@ -152,12 +156,12 @@ halt(void)
 	__asm __volatile("hlt");
 }
 
-#if __GNUC__ < 2
+#if !defined(__GNUCLIKE_BUILTIN_CONSTANT_P) || __GNUCLIKE_ASM < 3
 
 #define	inb(port)		inbv(port)
 #define	outb(port, data)	outbv(port, data)
 
-#else /* __GNUC >= 2 */
+#else /* __GNUCLIKE_BUILTIN_CONSTANT_P  && __GNUCLIKE_ASM >= 3 */
 
 /*
  * The following complications are to get around gcc not having a
@@ -204,7 +208,7 @@ outbc(u_int port, u_char data)
 	__asm __volatile("outb %0,%1" : : "a" (data), "id" ((u_short)(port)));
 }
 
-#endif /* __GNUC <= 2 */
+#endif /* __GNUCLIKE_BUILTIN_CONSTANT_P */
 
 static __inline u_char
 inbv(u_int port)
@@ -696,7 +700,7 @@ intr_restore(register_t rflags)
 	write_rflags(rflags);
 }
 
-#else /* !__GNUC__ */
+#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
 
 int	breakpoint(void);
 u_int	bsfl(u_int mask);
@@ -761,7 +765,7 @@ void	wbinvd(void);
 void	write_rflags(u_int rf);
 void	wrmsr(u_int msr, u_int64_t newval);
 
-#endif	/* __GNUC__ */
+#endif	/* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
 void	reset_dbregs(void);
 
diff --git a/sys/amd64/include/critical.h b/sys/amd64/include/critical.h
index 0e02e1f..37ba264 100644
--- a/sys/amd64/include/critical.h
+++ b/sys/amd64/include/critical.h
@@ -46,7 +46,7 @@ __BEGIN_DECLS
  */
 void cpu_critical_fork_exit(void);
 
-#ifdef	__GNUC__
+#ifdef	__CC_SUPPORTS___INLINE
 
 /*
  *	cpu_critical_enter:
@@ -74,12 +74,12 @@ cpu_critical_exit(struct thread *td)
 	intr_restore(td->td_md.md_savecrit);
 }
 
-#else /* !__GNUC__ */
+#else /* !__CC_SUPPORTS___INLINE */
 
 void cpu_critical_enter(struct thread *td);
 void cpu_critical_exit(struct thread *td);
 
-#endif	/* __GNUC__ */
+#endif	/* __CC_SUPPORTS___INLINE */
 
 __END_DECLS
 
diff --git a/sys/amd64/include/endian.h b/sys/amd64/include/endian.h
index 459126b..6ed2118 100644
--- a/sys/amd64/include/endian.h
+++ b/sys/amd64/include/endian.h
@@ -63,7 +63,7 @@
 #define	BYTE_ORDER	_BYTE_ORDER
 #endif
 
-#ifdef __GNUC__
+#if defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE_BUILTIN_CONSTANT_P)
 
 #define __word_swap_int_var(x) \
 __extension__ ({ register __uint32_t __X = (x); \
@@ -177,7 +177,7 @@ __bswap16(__uint16_t _x)
 #define	__ntohl(x)	__bswap32(x)
 #define	__ntohs(x)	__bswap16(x)
 
-#else /* !__GNUC__ */
+#else /* !(__GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P) */
 
 /*
  * No optimizations are available for this compiler.  Fall back to
@@ -186,6 +186,6 @@ __bswap16(__uint16_t _x)
  */
 #define	_BYTEORDER_FUNC_DEFINED
 
-#endif /* __GNUC__ */
+#endif /* __GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P */
 
 #endif /* !_MACHINE_ENDIAN_H_ */
diff --git a/sys/amd64/include/ieeefp.h b/sys/amd64/include/ieeefp.h
index 214f3b5..bfa80aa 100644
--- a/sys/amd64/include/ieeefp.h
+++ b/sys/amd64/include/ieeefp.h
@@ -42,6 +42,10 @@
 #ifndef _MACHINE_IEEEFP_H_
 #define _MACHINE_IEEEFP_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * FP rounding modes
  */
@@ -117,7 +121,8 @@ typedef enum {
 #define	SSE_RND_OFF	13	/* rounding control offset */
 #define	SSE_FZ_OFF	15	/* flush to zero offset */
 
-#if defined(__GNUC__) && !defined(__cplusplus)
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE__) \
+    && !defined(__cplusplus)
 
 #define	__fldenv(addr)	__asm __volatile("fldenv %0" : : "m" (*(addr)))
 #define	__fnstenv(addr)	__asm __volatile("fnstenv %0" : "=m" (*(addr)))
@@ -263,9 +268,10 @@ __fpsetsticky(fp_except_t _m)
 	return (_p);
 }
 
-#endif /* __GNUC__ && !__cplusplus */
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE__ && !__cplusplus */
 
-#if !defined(__IEEEFP_NOINLINES__) && !defined(__cplusplus) && defined(__GNUC__)
+#if !defined(__IEEEFP_NOINLINES__) && !defined(__cplusplus) \
+    && defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE__)
 
 #define	fpgetround()	__fpgetround()
 #define	fpsetround(_m)	__fpsetround(_m)
@@ -279,7 +285,8 @@ __fpsetsticky(fp_except_t _m)
 /* Suppress prototypes in the MI header. */
 #define	_IEEEFP_INLINED_	1
 
-#else /* !__IEEEFP_NOINLINES__ && !__cplusplus && __GNUC__ */
+#else /* !__IEEEFP_NOINLINES__ && !__cplusplus && __GNUCLIKE_ASM
+         && __CC_SUPPORTS___INLINE__ */
 
 /* Augment the userland declarations */
 __BEGIN_DECLS
@@ -287,6 +294,7 @@ extern fp_prec_t fpgetprec(void);
 extern fp_prec_t fpsetprec(fp_prec_t);
 __END_DECLS
 
-#endif /* !__IEEEFP_NOINLINES__ && !__cplusplus && __GNUC__ */
+#endif /* !__IEEEFP_NOINLINES__ && !__cplusplus && __GNUCLIKE_ASM
+          && __CC_SUPPORTS___INLINE__ */
 
 #endif /* !_MACHINE_IEEEFP_H_ */
diff --git a/sys/amd64/include/in_cksum.h b/sys/amd64/include/in_cksum.h
index a899ef0..0992006 100644
--- a/sys/amd64/include/in_cksum.h
+++ b/sys/amd64/include/in_cksum.h
@@ -45,7 +45,7 @@
  * in the normal case (where there are no options and the header length is
  * therefore always exactly five 32-bit words.
  */
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS___INLINE
 
 static __inline void
 in_cksum_update(struct ip *ip)
diff --git a/sys/amd64/include/limits.h b/sys/amd64/include/limits.h
index 8e3bb11..35eea1f 100644
--- a/sys/amd64/include/limits.h
+++ b/sys/amd64/include/limits.h
@@ -33,7 +33,9 @@
 #ifndef _MACHINE_LIMITS_H_
 #define	_MACHINE_LIMITS_H_
 
-#if __GNUC__
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning "machine/limits.h is deprecated.  Include sys/limits.h instead."
 #endif
 
diff --git a/sys/amd64/include/pcpu.h b/sys/amd64/include/pcpu.h
index 0694c76..b9d4a61 100644
--- a/sys/amd64/include/pcpu.h
+++ b/sys/amd64/include/pcpu.h
@@ -29,6 +29,10 @@
 #ifndef _MACHINE_PCPU_H_
 #define _MACHINE_PCPU_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 #ifdef _KERNEL
 
 /*
@@ -55,7 +59,8 @@ extern struct pcpu *pcpup;
 #define PCPU_PTR(member)        (&pcpup->pc_ ## member)
 #define PCPU_SET(member,value)  (pcpup->pc_ ## member = (value))
  
-#elif defined(__GNUC__)
+#elif defined(__GNUCLIKE___TYPEOF) && defined(__GNUCLIKE___OFFSETOF) \
+    && defined(__GNUCLIKE_ASM)
 
 /*
  * Evaluates to the byte offset of the per-cpu variable name.
@@ -170,7 +175,7 @@ __curthread(void)
 #define	curthread (__curthread())
 
 #else
-#error gcc or lint is required to use this file
+#error this file needs to be ported to your compiler
 #endif
 
 #endif	/* _KERNEL */
diff --git a/sys/amd64/include/profile.h b/sys/amd64/include/profile.h
index ecd3426..93e8614 100644
--- a/sys/amd64/include/profile.h
+++ b/sys/amd64/include/profile.h
@@ -33,6 +33,10 @@
 #ifndef _MACHINE_PROFILE_H_
 #define	_MACHINE_PROFILE_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 #ifdef _KERNEL
 
 /*
@@ -53,7 +57,7 @@
 #define	MCOUNT_DECL(s)
 #define	MCOUNT_ENTER(s)
 #define	MCOUNT_EXIT(s)
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 #define	MCOUNT_OVERHEAD(label)						\
 	__asm __volatile("pushq %0; call __mcount; popq %%rcx"		\
 			 :						\
@@ -70,8 +74,8 @@
 #define	MEXITCOUNT_OVERHEAD()
 #define	MEXITCOUNT_OVERHEAD_GETLABEL()
 #else
-#error
-#endif /* __GNUC */
+#error this file needs to be ported to your compiler
+#endif /* __GNUCLIKE_ASM */
 #else /* !GUPROF */
 #define	MCOUNT_DECL(s)	u_long s;
 #ifdef SMP
@@ -108,7 +112,7 @@ void user(void);
 static void _mcount(uintfptr_t frompc, uintfptr_t selfpc) __used; \
 static void _mcount
 
-#ifdef	__GNUC__
+#ifdef	__GNUCLIKE_ASM
 #define	MCOUNT __asm("			\n\
 	.globl	.mcount			\n\
 	.type	.mcount @function	\n\
@@ -166,13 +170,13 @@ mcount()								\
 	_mcount(frompc, selfpc);					\
 }
 #endif
-#else /* !__GNUC__ */
+#else /* !__GNUCLIKE_ASM */
 #define	MCOUNT								\
 void									\
 mcount()								\
 {									\
 }
-#endif /* __GNUC__ */
+#endif /* __GNUCLIKE_ASM */
 
 typedef	u_long	uintfptr_t;
 
@@ -193,7 +197,7 @@ void	mcount(uintfptr_t frompc, uintfptr_t selfpc);
 #include <sys/cdefs.h>
 
 __BEGIN_DECLS
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 void	mcount(void) __asm(".mcount");
 #endif
 __END_DECLS
diff --git a/sys/amd64/include/stdarg.h b/sys/amd64/include/stdarg.h
index 60a204a..d3612d2 100644
--- a/sys/amd64/include/stdarg.h
+++ b/sys/amd64/include/stdarg.h
@@ -39,7 +39,7 @@
 typedef	__va_list	va_list;
 #endif
 
-#if defined(__GNUC__)
+#if defined(__GNUCLIKE_BUILTIN_STDARG)
 #define	va_start(ap, last) \
 	__builtin_stdarg_start((ap), (last))
 
@@ -67,6 +67,8 @@ typedef	__va_list	va_list;
 	(*(type *)((ap) += __va_size(type), (ap) - __va_size(type)))
 #define	va_end(ap)
 
+#else
+#error this file needs to be ported to your compiler
 #endif
 
 #endif /* !_MACHINE_STDARG_H_ */
diff --git a/sys/amd64/include/varargs.h b/sys/amd64/include/varargs.h
index 1a58a47..3b9f542 100644
--- a/sys/amd64/include/varargs.h
+++ b/sys/amd64/include/varargs.h
@@ -43,7 +43,11 @@
 #ifndef _MACHINE_VARARGS_H_
 #define	_MACHINE_VARARGS_H_
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
+#ifdef __GNUCLIKE_BUILTIN_VARARGS
 
 #include <sys/_types.h>
 
@@ -60,21 +64,17 @@ typedef int __builtin_va_alist_t __attribute__((__mode__(__word__)));
 #define	va_arg(ap, type)	__builtin_va_arg((ap), type)
 #define	va_end(ap)		__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* !__GNUCLIKE_BUILTIN_VARARGS */
 
 typedef char *va_list;
 
 #define	__va_size(type) \
 	(((sizeof(type) + sizeof(int) - 1) / sizeof(int)) * sizeof(int))
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_BUILTIN_VAALIST
 #define	va_alist	__builtin_va_alist
 #endif
-#if __GNUC__ > 1
 #define	va_dcl	int va_alist; ...
-#else
-#define	va_dcl	int va_alist; 
-#endif
 
 #define	va_start(ap) \
 	((ap) = (va_list)&va_alist)
@@ -84,6 +84,6 @@ typedef char *va_list;
 
 #define	va_end(ap)
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_VARARGS */
 
 #endif /* !_MACHINE_VARARGS_H_ */
diff --git a/sys/arm/arm/busdma_machdep.c b/sys/arm/arm/busdma_machdep.c
index 6e296e9..a95163e 100644
--- a/sys/arm/arm/busdma_machdep.c
+++ b/sys/arm/arm/busdma_machdep.c
@@ -532,7 +532,7 @@ bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 {
      	vm_offset_t	lastaddr = 0;
 	int		error, nsegs = -1;
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
 	bus_dma_segment_t dm_segments[dmat->nsegments];
 #else
 	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
@@ -564,7 +564,7 @@ bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
 		     bus_dmamap_callback2_t *callback, void *callback_arg,
 		     int flags)
 {
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
 	bus_dma_segment_t dm_segments[dmat->nsegments];
 #else
 	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
@@ -650,7 +650,7 @@ bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
     int flags)
 {
 	vm_offset_t lastaddr;
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
 	bus_dma_segment_t dm_segments[dmat->nsegments];
 #else
 	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
diff --git a/sys/arm/include/_types.h b/sys/arm/include/_types.h
index 57b1c7c..c700f52 100644
--- a/sys/arm/include/_types.h
+++ b/sys/arm/include/_types.h
@@ -39,6 +39,10 @@
 #ifndef _MACHINE__TYPES_H_
 #define	_MACHINE__TYPES_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Basic types upon which most other types are built.
  */
@@ -49,7 +53,7 @@ typedef	unsigned short		__uint16_t;
 typedef	int			__int32_t;
 typedef	unsigned int		__uint32_t;
 
-#if defined(__GNUC__)
+#ifdef __GNUCLIKE_ATTRIBUTE_MODE_DI
 typedef	int __attribute__((__mode__(__DI__)))		__int64_t;
 typedef	unsigned int __attribute__((__mode__(__DI__)))	__uint64_t;
 #else
@@ -105,12 +109,13 @@ typedef	__uint32_t	__vm_size_t;
 /*
  * Unusual type definitions.
  */
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifdef __GNUCLIKE_BUILTIN_VARARGS
 typedef __builtin_va_list	__va_list;	/* internally known to gcc */
 #else
 typedef	char *			__va_list;
-#endif /* post GCC 2.95 */
-#if defined __GNUC__ && !defined(__GNUC_VA_LIST) && !defined(__NO_GNUC_VA_LIST)
+#endif /* __GNUCLIKE_BUILTIN_VARARGS */
+#if defined(__GNUCLIKE_BUILTIN_VAALIST) && !defined(__GNUC_VA_LIST) \
+    && !defined(__NO_GNUC_VA_LIST)
 #define __GNUC_VA_LIST
 typedef __va_list		__gnuc_va_list;	/* compatibility w/GNU headers*/
 #endif
diff --git a/sys/arm/include/limits.h b/sys/arm/include/limits.h
index 8e3bb11..35eea1f 100644
--- a/sys/arm/include/limits.h
+++ b/sys/arm/include/limits.h
@@ -33,7 +33,9 @@
 #ifndef _MACHINE_LIMITS_H_
 #define	_MACHINE_LIMITS_H_
 
-#if __GNUC__
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning "machine/limits.h is deprecated.  Include sys/limits.h instead."
 #endif
 
diff --git a/sys/arm/include/stdarg.h b/sys/arm/include/stdarg.h
index cf8aef5..a8b0ff0 100644
--- a/sys/arm/include/stdarg.h
+++ b/sys/arm/include/stdarg.h
@@ -42,7 +42,7 @@
 typedef	__va_list	va_list;
 #endif
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifdef __GNUCLIKE_BUILTIN_STDARG
 
 #define	va_start(ap, last) \
 	__builtin_stdarg_start((ap), (last))
@@ -58,24 +58,24 @@ typedef	__va_list	va_list;
 #define	va_end(ap) \
 	__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* !__GNUCLIKE_BUILTIN_STDARG */
 
 #define	__va_size(type) \
 	(((sizeof(type) + sizeof(int) - 1) / sizeof(int)) * sizeof(int))
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_BUILTIN_NEXT_ARG
 #define va_start(ap, last) \
 	((ap) = (va_list)__builtin_next_arg(last))
-#else	/* non-GNU compiler */
+#else	/* !__GNUCLIKE_BUILTIN_NEXT_ARG */
 #define	va_start(ap, last) \
 	((ap) = (va_list)&(last) + __va_size(last))
-#endif	/* __GNUC__ */
+#endif	/* __GNUCLIKE_BUILTIN_NEXT_ARG */
 
 #define	va_arg(ap, type) \
 	(*(type *)((ap) += __va_size(type), (ap) - __va_size(type)))
 
 #define	va_end(ap)
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_STDARG */
 
 #endif /* !_MACHINE_STDARG_H_ */
diff --git a/sys/boot/arc/include/arcfuncs.h b/sys/boot/arc/include/arcfuncs.h
index e88ff03..13e4792 100644
--- a/sys/boot/arc/include/arcfuncs.h
+++ b/sys/boot/arc/include/arcfuncs.h
@@ -27,7 +27,14 @@
  *
  */
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifndef _ARCFUNCS_H
+#define _ARCFUNCS_H
+
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
+#ifdef __CC_SUPPORTS_INLINE
 #define INLINE inline
 #else
 #define INLINE /**/
@@ -197,3 +204,6 @@ VND_FN(3, u_int32_t, Print,
 VND_FN(4, void, ReturnExtendedSystemInformation, 
        (EXTENDED_SYSTEM_INFORMATION *SystemInfo),
        (SystemInfo))
+
+#endif /* _ARGFUNCS_H */
+
diff --git a/sys/boot/efi/include/ia64/efibind.h b/sys/boot/efi/include/ia64/efibind.h
index 73f3469..07883b8 100644
--- a/sys/boot/efi/include/ia64/efibind.h
+++ b/sys/boot/efi/include/ia64/efibind.h
@@ -18,8 +18,6 @@ Revision History
 
 --*/
 
-#pragma pack()
-
 #include <sys/stdint.h>
 
 /* Basic EFI types of various widths. */
@@ -142,7 +140,7 @@ void __mf (void);
 #ifdef NO_INTERFACE_DECL
 #define INTERFACE_DECL(x)
 #else
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS_FORWARD_REFERENCE_CONSTRUCT
 #define INTERFACE_DECL(x) struct x
 #else
 #define INTERFACE_DECL(x) typedef struct x
diff --git a/sys/dev/cx/machdep.h b/sys/dev/cx/machdep.h
index c4affc4..a425af5 100644
--- a/sys/dev/cx/machdep.h
+++ b/sys/dev/cx/machdep.h
@@ -75,6 +75,10 @@
 #   include <sys/systm.h>
 #   define memset(a,b,c)	bzero (a,c)
 #   define port_t int
+
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
 #endif
 
 #endif
@@ -82,7 +86,7 @@
 #endif
 
 #ifndef inline
-#   if __GNUC__ >= 2 || defined(__INTEL_COMPILER)
+#   ifdef __CC_SUPPORTS___INLINE__
 #      define inline __inline__
 #   else
 #      define inline /**/
diff --git a/sys/dev/ichsmb/ichsmb.c b/sys/dev/ichsmb/ichsmb.c
index 2d92a65..8896745 100644
--- a/sys/dev/ichsmb/ichsmb.c
+++ b/sys/dev/ichsmb/ichsmb.c
@@ -68,7 +68,7 @@ __FBSDID("$FreeBSD$");
  * Enable debugging by defining ICHSMB_DEBUG to a non-zero value.
  */
 #define ICHSMB_DEBUG	0
-#if ICHSMB_DEBUG != 0 && (defined(__GNUC__) || defined(__INTEL_COMPILER))
+#if ICHSMB_DEBUG != 0 && defined(__CC_SUPPORTS___FUNC__)
 #define DBG(fmt, args...)	\
 	do { log(LOG_DEBUG, "%s: " fmt, __func__ , ## args); } while (0)
 #else
diff --git a/sys/dev/iir/iir.h b/sys/dev/iir/iir.h
index 667a8d2..ad5528d 100644
--- a/sys/dev/iir/iir.h
+++ b/sys/dev/iir/iir.h
@@ -47,6 +47,10 @@
 #ifndef _IIR_H
 #define _IIR_H
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 #define IIR_DRIVER_VERSION      1
 #define IIR_DRIVER_SUBVERSION   5
 
@@ -699,7 +703,7 @@ void    iir_free(struct gdt_softc *);
 void    iir_attach(struct gdt_softc *);
 void    iir_intr(void *arg);
 
-#if defined( __GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __CC_SUPPORTS___INLINE__
 /* These all require correctly aligned buffers */
 static __inline__ void gdt_enc16(u_int8_t *, u_int16_t);
 static __inline__ void gdt_enc32(u_int8_t *, u_int32_t);
diff --git a/sys/dev/isp/ispvar.h b/sys/dev/isp/ispvar.h
index b5aa8de..b3e7911 100644
--- a/sys/dev/isp/ispvar.h
+++ b/sys/dev/isp/ispvar.h
@@ -44,6 +44,9 @@
 #include <dev/isp/isp_target.h>
 #include <dev/isp/isp_tpublic.h>
 #endif
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
 #endif
 #ifdef	__linux__
 #include "ispmbox.h"
@@ -760,7 +763,7 @@ int isp_async(struct ispsoftc *, ispasync_t, void *);
 /*
  * Platform Dependent Error and Debug Printout
  */
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ATTRIBUTE_PRINTF
 void isp_prt(struct ispsoftc *, int level, const char *, ...)
 	__attribute__((__format__(__printf__,3,4)));
 #else
diff --git a/sys/dev/mcd/mcdreg.h b/sys/dev/mcd/mcdreg.h
index 7a255af..451fc5d 100644
--- a/sys/dev/mcd/mcdreg.h
+++ b/sys/dev/mcd/mcdreg.h
@@ -47,12 +47,6 @@
 #ifndef MCD_H
 #define	MCD_H
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
-#if __GNUC__ >= 2 || defined(__INTEL_COMPILER)
-#pragma pack(1)
-#endif
-#endif
-
 /* toc */
 #define MCD_MAXTOCS	104	/* from the Linux driver */
 #define MCD_LASTPLUS1	170	/* special toc entry */
@@ -172,14 +166,14 @@ struct mcd_dma_mode {
 	u_char	dma_mode;
 	u_char	data0;		/* If dma_mode & 0x10: Use IRQ settings	*/
 	u_char	data1;		/* Used	if dma_mode & 0x01 */
-};
+} __packed;
 
 struct mcd_volinfo {
 	bcd_t	trk_low;
 	bcd_t	trk_high;
 	bcd_t	vol_msf[3];
 	bcd_t	trk1_msf[3];
-};
+} __packed;
 
 struct mcd_qchninfo {
 	u_char  addr_type:4;
@@ -189,29 +183,29 @@ struct mcd_qchninfo {
 	bcd_t	trk_size_msf[3];
 	u_char	:8;
 	bcd_t	hd_pos_msf[3];
-};
+} __packed;
 
 struct mcd_volume {
 	u_char	v0l;
 	u_char	v0rs;
 	u_char	v0r;
 	u_char	v0ls;
-};
+} __packed;
 
 struct mcd_holdtime {
 	u_char	units_of_ten_seconds;
 			/* If this is 0, the default (12) is used */
-};
+} __packed;
 
 struct mcd_read1 {
 	bcd_t	start_msf[3];
 	u_char	nsec[3];
-};
+} __packed;
 
 struct mcd_read2 {
 	bcd_t	start_msf[3];
 	bcd_t	end_msf[3];
-};
+} __packed;
 
 struct mcd_rawsector {
 	u_char sync1[12];
@@ -220,11 +214,6 @@ struct mcd_rawsector {
 	u_char subheader2[4];
 	u_char data[MCDBLK];
 	u_char ecc_bits[280];
-};
+} __packed;
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
-#if __GNUC__ >= 2 || defined(__INTEL_COMPILER)
-#pragma pack(4)
-#endif
-#endif
 #endif /* MCD_H */
diff --git a/sys/dev/mpt/mpilib/mpi_type.h b/sys/dev/mpt/mpilib/mpi_type.h
index c10cb92..2fc4832 100644
--- a/sys/dev/mpt/mpilib/mpi_type.h
+++ b/sys/dev/mpt/mpilib/mpi_type.h
@@ -46,6 +46,9 @@
 #ifndef MPI_TYPE_H
 #define MPI_TYPE_H
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
 
 /*******************************************************************************
  * Define MPI_POINTER if it hasn't already been defined. By default MPI_POINTER
@@ -68,7 +71,8 @@ typedef unsigned char   U8;
 typedef signed   short  S16;
 typedef unsigned short  U16;
 
-#if defined(unix) || defined(__arm) || defined(ALPHA) || defined(__GNUC__) || defined(__INTEL_COMPILER)
+#if defined(unix) || defined(__arm) || defined(ALPHA) \
+    || defined(__CC_INT_IS_32BIT)
 
     typedef signed   int   S32;
     typedef unsigned int   U32;
diff --git a/sys/dev/random/nehemiah.c b/sys/dev/random/nehemiah.c
index c0dba9e..9780dbd 100644
--- a/sys/dev/random/nehemiah.c
+++ b/sys/dev/random/nehemiah.c
@@ -85,7 +85,7 @@ static union VIA_ACE_CW acw		__aligned(16);
 static __inline size_t
 VIA_RNG_store(void *buf)
 {
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 	uint32_t retval = 0;
 	uint32_t rate = 0;
 
@@ -107,7 +107,7 @@ VIA_RNG_store(void *buf)
 static __inline void
 VIA_ACE_cbc(void *in, void *out, size_t count, void *key, union VIA_ACE_CW *cw, void *iv)
 {
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 	/* The .byte line is really VIA C3 "xcrypt-cbc" instruction */
 	__asm __volatile(
 		"pushf				\n\t"
diff --git a/sys/dev/scd/scdreg.h b/sys/dev/scd/scdreg.h
index 38e2293..c98c6ca 100644
--- a/sys/dev/scd/scdreg.h
+++ b/sys/dev/scd/scdreg.h
@@ -32,12 +32,6 @@
 #ifndef SCD_H
 #define	SCD_H
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
-#if __GNUC__ >= 2 || defined(__INTEL_COMPILER)
-#pragma pack(1)
-#endif
-#endif
-
 typedef unsigned char	bcd_t;
 #define	M_msf(msf)	msf[0]
 #define	S_msf(msf)	msf[1]
@@ -94,7 +88,7 @@ struct sony_drive_configuration {
 	char product[16];
 	char revision[8];
 	u_short config;
-};
+} __packed;
 
 /* Almost same as cd_sub_channel_position_data */
 struct sony_subchannel_position_data {
@@ -105,14 +99,14 @@ struct sony_subchannel_position_data {
 	u_char	rel_msf[3];
 	u_char	dummy;
 	u_char	abs_msf[3];
-};
+} __packed;
 
 struct sony_tracklist {
 	u_char adr :4; /* xcdplayer needs these two values */
 	u_char ctl :4;
 	u_char track;
 	u_char start_msf[3];
-};
+} __packed;
 
 #define MAX_TRACKS 100
 
@@ -140,6 +134,6 @@ struct sony_toc {
 	/* The rest is just to take space in case all data is returned */
 
 	u_char dummy[6*9];
-};
+} __packed;
 
 #endif /* SCD_H */
diff --git a/sys/i386/acpica/acpi_wakeup.c b/sys/i386/acpica/acpi_wakeup.c
index 400d9f1..fa5e784 100644
--- a/sys/i386/acpica/acpi_wakeup.c
+++ b/sys/i386/acpica/acpi_wakeup.c
@@ -52,6 +52,10 @@ __FBSDID("$FreeBSD$");
 
 #include "acpi_wakecode.h"
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 extern uint32_t	acpi_reset_video;
 extern void	initializecpu(void);
 
@@ -73,7 +77,7 @@ static void		acpi_alloc_wakeup_handler(void);
 extern int		acpi_savecpu(void);
 extern int		acpi_restorecpu(void);
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 __asm__("				\n\
 	.text				\n\
 	.p2align 2, 0x90		\n\
@@ -140,7 +144,7 @@ acpi_savecpu:				\n\
 	movl	$1,%eax			\n\
 	ret				\n\
 ");
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#endif /* __GNUCLIKE_ASM */
 
 static void
 acpi_printcpu(void)
diff --git a/sys/i386/i386/identcpu.c b/sys/i386/i386/identcpu.c
index 8b9d989..8c8e121 100644
--- a/sys/i386/i386/identcpu.c
+++ b/sys/i386/i386/identcpu.c
@@ -776,7 +776,7 @@ static	volatile u_int trap_by_rdmsr;
  * be advanced.
  */
 inthand_t	bluetrap6;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 __asm
 ("									\n\
 	.text								\n\
@@ -795,7 +795,7 @@ __asm
  * Accessing non-existent MSR generates general protection fault.
  */
 inthand_t	bluetrap13;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 __asm
 ("									\n\
 	.text								\n\
diff --git a/sys/i386/i386/in_cksum.c b/sys/i386/i386/in_cksum.c
index a236245..412a93b 100644
--- a/sys/i386/i386/in_cksum.c
+++ b/sys/i386/i386/in_cksum.c
@@ -57,7 +57,11 @@ __FBSDID("$FreeBSD$");
 
 #undef	ADDCARRY
 #define ADDCARRY(x)     if ((x) > 0xffff) (x) -= 0xffff
-#if !defined(__GNUC__) || defined(__INTEL_COMPILER)
+/*
+ * icc needs to be special cased here, as the asm code below results
+ * in broken code if compiled with icc.
+ */
+#if !defined(__GNUCLIKE_ASM) || defined(__INTEL_COMPILER)
 /* non gcc parts stolen from sys/alpha/alpha/in_cksum.c */
 #define REDUCE32							  \
     {									  \
@@ -74,7 +78,7 @@ __FBSDID("$FreeBSD$");
 #endif
 #define REDUCE          {sum = (sum & 0xffff) + (sum >> 16); ADDCARRY(sum);}
 
-#if !defined(__GNUC__) || defined(__INTEL_COMPILER)
+#if !defined(__GNUCLIKE_ASM) || defined(__INTEL_COMPILER)
 static const u_int32_t in_masks[] = {
 	/*0 bytes*/ /*1 byte*/	/*2 bytes*/ /*3 bytes*/
 	0x00000000, 0x000000FF, 0x0000FFFF, 0x00FFFFFF,	/* offset 0 */
diff --git a/sys/i386/include/_types.h b/sys/i386/include/_types.h
index 9884c83..7df734d 100644
--- a/sys/i386/include/_types.h
+++ b/sys/i386/include/_types.h
@@ -39,6 +39,10 @@
 #ifndef _MACHINE__TYPES_H_
 #define	_MACHINE__TYPES_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Basic types upon which most other types are built.
  */
@@ -54,7 +58,7 @@ typedef	unsigned int		__uint32_t;
 typedef	long long		__int64_t;
 /* LONGLONG */
 typedef	unsigned long long	__uint64_t;
-#elif defined(__GNUC__) || defined(__INTEL_COMPILER)
+#elif defined(__GNUCLIKE_ATTRIBUTE_MODE_DI)
 typedef	int __attribute__((__mode__(__DI__)))		__int64_t;
 typedef	unsigned int __attribute__((__mode__(__DI__)))	__uint64_t;
 #else
@@ -114,12 +118,13 @@ typedef	__uint32_t	__vm_size_t;
 /*
  * Unusual type definitions.
  */
-#if (defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3) && !defined(__INTEL_COMPILER))
+#ifdef __GNUCLIKE_BUILTIN_VARARGS
 typedef __builtin_va_list	__va_list;	/* internally known to gcc */
 #else
 typedef	char *			__va_list;
-#endif /* ! (__GNUC__ post 2.95 || __INTEL_COMPILER) */
-#if defined(__GNUC__) && !defined(__GNUC_VA_LIST) && !defined(__NO_GNUC_VA_LIST)
+#endif /* __GNUCLIKE_BUILTIN_VARARGS */
+#if defined(__GNUC_VA_LIST_COMPATIBILITY) && !defined(__GNUC_VA_LIST) \
+    && !defined(__NO_GNUC_VA_LIST)
 #define __GNUC_VA_LIST
 typedef __va_list		__gnuc_va_list;	/* compatibility w/GNU headers*/
 #endif
diff --git a/sys/i386/include/atomic.h b/sys/i386/include/atomic.h
index 5b9ef42..219a33b 100644
--- a/sys/i386/include/atomic.h
+++ b/sys/i386/include/atomic.h
@@ -28,6 +28,10 @@
 #ifndef _MACHINE_ATOMIC_H_
 #define _MACHINE_ATOMIC_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Various simple arithmetic on memory which is atomic in the presence
  * of interrupts and multiple processors.
@@ -75,7 +79,7 @@ void		atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
 #else /* !KLD_MODULE */
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 
 /*
  * For userland, assume the SMP case and use lock prefixes so that
@@ -101,12 +105,12 @@ atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 }							\
 struct __hack
 
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
+#else /* !__GNUCLIKE_ASM */
 
 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V)				\
 extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#endif /* __GNUCLIKE_ASM */
 
 /*
  * Atomic compare and set, used by the mutex functions
@@ -116,7 +120,7 @@ extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
  * Returns 0 on failure, non-zero on success
  */
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 
 #if defined(CPU_DISABLE_CMPXCHG)
 
@@ -168,9 +172,9 @@ atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
 
 #endif /* defined(CPU_DISABLE_CMPXCHG) */
 
-#endif /* defined(__GNUC__) || defined(__INTEL_COMPILER) */
+#endif /* __GNUCLIKE_ASM */
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 
 #if defined(_KERNEL) && !defined(SMP)
 
@@ -226,7 +230,7 @@ struct __hack
 
 #endif	/* !defined(SMP) */
 
-#else /* !(defined(__GNUC__) || defined(__INTEL_COMPILER)) */
+#else /* !__GNUCLIKE_ASM */
 
 extern int atomic_cmpset_int(volatile u_int *, u_int, u_int);
 
@@ -234,7 +238,7 @@ extern int atomic_cmpset_int(volatile u_int *, u_int, u_int);
 extern u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p);		\
 extern void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
-#endif /* defined(__GNUC__) || defined(__INTEL_COMPILER) */
+#endif /* __GNUCLIKE_ASM */
 
 #endif /* KLD_MODULE */
 
@@ -410,7 +414,7 @@ ATOMIC_PTR(subtract)
 
 #undef ATOMIC_PTR
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 
 static __inline u_int
 atomic_readandclear_int(volatile u_int *addr)
@@ -442,12 +446,12 @@ atomic_readandclear_long(volatile u_long *addr)
 	return (result);
 }
 
-#else /* !(defined(__GNUC__) || defined(__INTEL_COMPILER)) */
+#else /* !__GNUCLIKE_ASM */
 
 extern u_long	atomic_readandclear_long(volatile u_long *);
 extern u_int	atomic_readandclear_int(volatile u_int *);
 
-#endif /* defined(__GNUC__) || defined(__INTEL_COMPILER) */
+#endif /* __GNUCLIKE_ASM */
 
 #endif	/* !defined(WANT_FUNCTIONS) */
 #endif /* ! _MACHINE_ATOMIC_H_ */
diff --git a/sys/i386/include/bus_at386.h b/sys/i386/include/bus_at386.h
index 4600e35..83302b9 100644
--- a/sys/i386/include/bus_at386.h
+++ b/sys/i386/include/bus_at386.h
@@ -72,6 +72,10 @@
 #ifndef _I386_BUS_AT386_H_
 #define _I386_BUS_AT386_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 #include <machine/cpufunc.h>
 
 /*
@@ -292,7 +296,7 @@ bus_space_read_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movb (%2),%%al				\n\
@@ -325,7 +329,7 @@ bus_space_read_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movw (%2),%%ax				\n\
@@ -358,7 +362,7 @@ bus_space_read_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movl (%2),%%eax				\n\
@@ -411,7 +415,7 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inb %w2,%%al				\n\
@@ -434,7 +438,7 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -461,7 +465,7 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inw %w2,%%ax				\n\
@@ -484,7 +488,7 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -511,7 +515,7 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inl %w2,%%eax				\n\
@@ -534,7 +538,7 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -667,7 +671,7 @@ bus_space_write_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsb					\n\
@@ -700,7 +704,7 @@ bus_space_write_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsw					\n\
@@ -733,7 +737,7 @@ bus_space_write_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsl					\n\
@@ -787,7 +791,7 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsb					\n\
@@ -810,7 +814,7 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -837,7 +841,7 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsw					\n\
@@ -860,7 +864,7 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -887,7 +891,7 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsl					\n\
@@ -910,7 +914,7 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -1293,7 +1297,7 @@ static __inline void
 bus_space_barrier(bus_space_tag_t tag __unused, bus_space_handle_t bsh __unused,
 		  bus_size_t offset __unused, bus_size_t len __unused, int flags)
 {
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 	if (flags & BUS_SPACE_BARRIER_READ)
 		__asm __volatile("lock; addl $0,0(%%esp)" : : : "memory");
 	else
diff --git a/sys/i386/include/cpufunc.h b/sys/i386/include/cpufunc.h
index 01f5c56..ecb84cd 100644
--- a/sys/i386/include/cpufunc.h
+++ b/sys/i386/include/cpufunc.h
@@ -38,6 +38,10 @@
 #ifndef _MACHINE_CPUFUNC_H_
 #define	_MACHINE_CPUFUNC_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 struct region_descriptor;
 
 #define readb(va)	(*(volatile u_int8_t *) (va))
@@ -48,7 +52,7 @@ struct region_descriptor;
 #define writew(va, d)	(*(volatile u_int16_t *) (va) = (d))
 #define writel(va, d)	(*(volatile u_int32_t *) (va) = (d))
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
 static __inline void
 breakpoint(void)
@@ -126,12 +130,12 @@ halt(void)
 	__asm __volatile("hlt");
 }
 
-#if __GNUC__ < 2
+#if !defined(__GNUCLIKE_BUILTIN_CONSTANT_P) || __GNUCLIKE_ASM < 3
 
 #define	inb(port)		inbv(port)
 #define	outb(port, data)	outbv(port, data)
 
-#else /* __GNUC >= 2 */
+#else /* __GNUCLIKE_BUILTIN_CONSTANT_P && __GNUCLIKE_ASM >= 3 */
 
 /*
  * The following complications are to get around gcc not having a
@@ -178,7 +182,7 @@ outbc(u_int port, u_char data)
 	__asm __volatile("outb %0,%1" : : "a" (data), "id" ((u_short)(port)));
 }
 
-#endif /* __GNUC <= 2 */
+#endif /* __GNUCLIKE_BUILTIN_CONSTANT_P  && __GNUCLIKE_ASM >= 3*/
 
 static __inline u_char
 inbv(u_int port)
@@ -618,7 +622,7 @@ intr_restore(register_t eflags)
 	write_eflags(eflags);
 }
 
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
+#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
 
 int	breakpoint(void);
 u_int	bsfl(u_int mask);
@@ -683,7 +687,7 @@ void	wbinvd(void);
 void	write_eflags(u_int ef);
 void	wrmsr(u_int msr, u_int64_t newval);
 
-#endif	/* __GNUC__ || __INTEL_COMPILER */
+#endif	/* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
 void    reset_dbregs(void);
 
diff --git a/sys/i386/include/critical.h b/sys/i386/include/critical.h
index 9826988..58af490 100644
--- a/sys/i386/include/critical.h
+++ b/sys/i386/include/critical.h
@@ -46,7 +46,7 @@ __BEGIN_DECLS
  */
 void cpu_critical_fork_exit(void);
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __CC_SUPPORTS___INLINE
 
 /*
  *	cpu_critical_enter:
@@ -81,12 +81,12 @@ cpu_critical_exit(struct thread *td)
 	intr_restore(td->td_md.md_savecrit);
 }
 
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
+#else /* !__CC_SUPPORTS___INLINE */
 
 void cpu_critical_enter(struct thread *td);
 void cpu_critical_exit(struct thread *td);
 
-#endif        /* __GNUC__ || __INTEL_COMPILER */
+#endif        /* __CC_SUPPORTS___INLINE */
 
 __END_DECLS
 
diff --git a/sys/i386/include/endian.h b/sys/i386/include/endian.h
index 13d596a..59fa4a5 100644
--- a/sys/i386/include/endian.h
+++ b/sys/i386/include/endian.h
@@ -67,17 +67,7 @@ extern "C" {
 #define	BYTE_ORDER	_BYTE_ORDER
 #endif
 
-#if defined(__INTEL_COMPILER)
-#if defined(__cplusplus)
-#if __INTEL_COMPILER >= 800
-#define __INTEL_COMPILER_with_FreeBSD_endian 1
-#endif
-#else
-#define __INTEL_COMPILER_with_FreeBSD_endian 1
-#endif
-#endif
-
-#if defined(__GNUC__) || defined(__INTEL_COMPILER_with_FreeBSD_endian)
+#if defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE_BUILTIN_CONSTANT_P)
 
 #define __word_swap_int_var(x) \
 __extension__ ({ register __uint32_t __X = (x); \
@@ -168,7 +158,7 @@ __bswap16(__uint16_t _x)
 #define	__ntohl(x)	__bswap32(x)
 #define	__ntohs(x)	__bswap16(x)
 
-#else /* !(__GNUC__ || __INTEL_COMPILER_with_FreeBSD_endian) */
+#else /* !(__GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P) */
 
 /*
  * No optimizations are available for this compiler.  Fall back to
@@ -177,7 +167,7 @@ __bswap16(__uint16_t _x)
  */
 #define	_BYTEORDER_FUNC_DEFINED
 
-#endif /* __GNUC__ || __INTEL_COMPILER_with_FreeBSD_endian */
+#endif /* __GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P */
 
 #ifdef __cplusplus
 }
diff --git a/sys/i386/include/ieeefp.h b/sys/i386/include/ieeefp.h
index 48011f71..17dbc88 100644
--- a/sys/i386/include/ieeefp.h
+++ b/sys/i386/include/ieeefp.h
@@ -41,6 +41,10 @@
 #ifndef _MACHINE_IEEEFP_H_
 #define _MACHINE_IEEEFP_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * FP rounding modes
  */
@@ -98,7 +102,7 @@ typedef enum {
 #define FP_RND_OFF	10	/* round control offset */
 #define FP_STKY_OFF	0	/* sticky flags offset */
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 
 #define	__fldenv(addr)	__asm __volatile("fldenv %0" : : "m" (*(addr)))
 #define	__fnstenv(addr)	__asm __volatile("fnstenv %0" : "=m" (*(addr)))
@@ -151,7 +155,7 @@ __fpsetreg(int _m, int _reg, int _fld, int _off)
 	return _p;
 }
 
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#endif /* __GNUCLIKE_ASM */
 
 /*
  * SysV/386 FP control interface
diff --git a/sys/i386/include/in_cksum.h b/sys/i386/include/in_cksum.h
index 27d1195..062c675 100644
--- a/sys/i386/include/in_cksum.h
+++ b/sys/i386/include/in_cksum.h
@@ -35,6 +35,10 @@
 #ifndef _MACHINE_IN_CKSUM_H_
 #define	_MACHINE_IN_CKSUM_H_	1
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * MP safe (alfred)
  */
@@ -49,7 +53,7 @@
  * in the normal case (where there are no options and the header length is
  * therefore always exactly five 32-bit words.
  */
-#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
+#if defined(__GNUCLIKE_ASM) && !defined(__INTEL_COMPILER)
 static __inline u_int
 in_cksum_hdr(const struct ip *ip)
 {
@@ -119,7 +123,7 @@ in_pseudo(u_int sum, u_int b, u_int c)
 #endif
 
 #ifdef _KERNEL
-#if !defined(__GNUC__) || defined(__INTEL_COMPILER)
+#if !defined(__GNUCLIKE_ASM) || defined(__INTEL_COMPILER)
 u_int in_cksum_hdr(const struct ip *ip);
 u_short in_addword(u_short sum, u_short b);
 u_short in_pseudo(u_int sum, u_int b, u_int c);
diff --git a/sys/i386/include/ioctl_bt848.h b/sys/i386/include/ioctl_bt848.h
index c87c4b9..ca83a36 100644
--- a/sys/i386/include/ioctl_bt848.h
+++ b/sys/i386/include/ioctl_bt848.h
@@ -29,7 +29,9 @@
 #ifndef	_MACHINE_IOCTL_BT848_H_
 #define	_MACHINE_IOCTL_BT848_H_
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning Include dev/bktr/ioctl_bt848.h instead of this header.
 #endif
 
diff --git a/sys/i386/include/ioctl_meteor.h b/sys/i386/include/ioctl_meteor.h
index c9595de..0322f1e 100644
--- a/sys/i386/include/ioctl_meteor.h
+++ b/sys/i386/include/ioctl_meteor.h
@@ -29,7 +29,9 @@
 #ifndef	_MACHINE_IOCTL_METEOR_H_
 #define	_MACHINE_IOCTL_METEOR_H_
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning Include dev/bktr/ioctl_meteor.h instead of this header.
 #endif
 
diff --git a/sys/i386/include/limits.h b/sys/i386/include/limits.h
index 8e3bb11..35eea1f 100644
--- a/sys/i386/include/limits.h
+++ b/sys/i386/include/limits.h
@@ -33,7 +33,9 @@
 #ifndef _MACHINE_LIMITS_H_
 #define	_MACHINE_LIMITS_H_
 
-#if __GNUC__
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning "machine/limits.h is deprecated.  Include sys/limits.h instead."
 #endif
 
diff --git a/sys/i386/include/pcpu.h b/sys/i386/include/pcpu.h
index 6552ea9..f371e39 100644
--- a/sys/i386/include/pcpu.h
+++ b/sys/i386/include/pcpu.h
@@ -29,6 +29,10 @@
 #ifndef _MACHINE_PCPU_H_
 #define _MACHINE_PCPU_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 #ifdef _KERNEL
 
 #include <machine/segments.h>
@@ -59,7 +63,8 @@ extern struct pcpu *pcpup;
 #define PCPU_PTR(member)        (&pcpup->pc_ ## member)
 #define PCPU_SET(member,value)  (pcpup->pc_ ## member = (value))
  
-#elif defined(__GNUC__) || defined (__INTEL_COMPILER)
+#elif defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE___TYPEOF) \
+    && defined(__GNUCLIKE___OFFSETOF)
 
 /*
  * Evaluates to the byte offset of the per-cpu variable name.
@@ -162,7 +167,7 @@ __curthread(void)
 #define	curthread (__curthread())
 
 #else
-#error gcc or lint is required to use this file
+#error this file needs to be ported to your compiler
 #endif
 
 #endif	/* _KERNEL */
diff --git a/sys/i386/include/profile.h b/sys/i386/include/profile.h
index 79dd308..06418eb 100644
--- a/sys/i386/include/profile.h
+++ b/sys/i386/include/profile.h
@@ -33,6 +33,10 @@
 #ifndef _MACHINE_PROFILE_H_
 #define	_MACHINE_PROFILE_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 #ifdef _KERNEL
 
 /*
@@ -53,7 +57,7 @@
 #define	MCOUNT_DECL(s)
 #define	MCOUNT_ENTER(s)
 #define	MCOUNT_EXIT(s)
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 #define	MCOUNT_OVERHEAD(label)						\
 	__asm __volatile("pushl %0; call __mcount; popl %%ecx"		\
 			 :						\
@@ -71,7 +75,7 @@
 #define	MEXITCOUNT_OVERHEAD_GETLABEL()
 #else
 #error
-#endif /* !(__GNUC__ || __INTEL_COMPILER) */
+#endif /* !__GNUCLIKE_ASM */
 #else /* !GUPROF */
 #define	MCOUNT_DECL(s)	u_long s;
 #ifdef SMP
@@ -106,7 +110,7 @@ void user(void);
 
 #define	_MCOUNT_DECL static __inline void _mcount
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 #define	MCOUNT								\
 void									\
 mcount()								\
@@ -129,13 +133,13 @@ mcount()								\
 	frompc = ((uintfptr_t *)frompc)[1];				\
 	_mcount(frompc, selfpc);					\
 }
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
+#else /* !__GNUCLIKE_ASM */
 void									\
 #define	MCOUNT								\
 mcount()								\
 {									\
 }
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#endif /* __GNUCLIKE_ASM */
 
 typedef	u_int	uintfptr_t;
 
@@ -156,7 +160,7 @@ void	mcount(uintfptr_t frompc, uintfptr_t selfpc);
 #include <sys/cdefs.h>
 
 __BEGIN_DECLS
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 void	mcount(void) __asm(".mcount");
 #endif
 __END_DECLS
diff --git a/sys/i386/include/stdarg.h b/sys/i386/include/stdarg.h
index ce59c7f..a8ef25e 100644
--- a/sys/i386/include/stdarg.h
+++ b/sys/i386/include/stdarg.h
@@ -46,7 +46,7 @@
 typedef	__va_list	va_list;
 #endif
 
-#if (defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3) && !defined(__INTEL_COMPILER))
+#ifdef __GNUCLIKE_BUILTIN_STDARG
 
 #define	va_start(ap, last) \
 	__builtin_stdarg_start((ap), (last))
@@ -62,18 +62,18 @@ typedef	__va_list	va_list;
 #define	va_end(ap) \
 	__builtin_va_end(ap)
 
-#else	/* ! (__GNUC__ post GCC 2.95 || __INTEL_COMPILER) */
+#else	/* !__GNUCLIKE_BUILTIN_STDARG */
 
 #define	__va_size(type) \
 	(((sizeof(type) + sizeof(int) - 1) / sizeof(int)) * sizeof(int))
 
-#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_BUILTIN_NEXT_ARG
 #define va_start(ap, last) \
 	((ap) = (va_list)__builtin_next_arg(last))
-#else	/* non-GNU compiler */
+#else	/* !__GNUCLIKE_BUILTIN_NEXT_ARG */
 #define	va_start(ap, last) \
 	((ap) = (va_list)&(last) + __va_size(last))
-#endif	/* __GNUC__ */
+#endif	/* __GNUCLIKE_BUILTIN_NEXT_ARG */
 
 #define	va_arg(ap, type) \
 	(*(type *)((ap) += __va_size(type), (ap) - __va_size(type)))
@@ -85,6 +85,6 @@ typedef	__va_list	va_list;
 
 #define	va_end(ap)
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_STDARG */
 
 #endif /* !_MACHINE_STDARG_H_ */
diff --git a/sys/i386/include/varargs.h b/sys/i386/include/varargs.h
index 4d05f87..a71b2ff 100644
--- a/sys/i386/include/varargs.h
+++ b/sys/i386/include/varargs.h
@@ -39,7 +39,11 @@
 #ifndef _MACHINE_VARARGS_H_
 #define	_MACHINE_VARARGS_H_
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
+#ifdef __GNUCLIKE_BUILTIN_VARARGS
 
 #include <sys/_types.h>
 
@@ -56,17 +60,17 @@ typedef int __builtin_va_alist_t __attribute__((__mode__(__word__)));
 #define	va_arg(ap, type)	__builtin_va_arg((ap), type)
 #define	va_end(ap)		__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* !__GNUCLIKE_BUILTIN_VARARGS */
 
 typedef char *va_list;
 
 #define	__va_size(type) \
 	(((sizeof(type) + sizeof(int) - 1) / sizeof(int)) * sizeof(int))
 
-#ifdef __GNUC__
+#if defined(__GNUCLIKE_BUILTIN_VAALIST)
 #define	va_alist	__builtin_va_alist
 #endif
-#if __GNUC__ > 1
+#ifdef __CC_SUPPORTS_VARADIC_XXX
 #define	va_dcl	int va_alist; ...
 #else
 #define	va_dcl	int va_alist; 
@@ -80,6 +84,6 @@ typedef char *va_list;
 
 #define	va_end(ap)
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_VARARGS */
 
 #endif /* !_MACHINE_VARARGS_H_ */
diff --git a/sys/i386/isa/npx.c b/sys/i386/isa/npx.c
index 4a80533d..6db8970 100644
--- a/sys/i386/isa/npx.c
+++ b/sys/i386/isa/npx.c
@@ -95,7 +95,7 @@ __FBSDID("$FreeBSD$");
 #define	NPX_DISABLE_I586_OPTIMIZED_BZERO	(1 << 1)
 #define	NPX_DISABLE_I586_OPTIMIZED_COPYIO	(1 << 2)
 
-#if (defined(__GNUC__) && !defined(lint)) || defined(__INTEL_COMPILER)
+#if defined(__GNUCLIKE_ASM) && !defined(lint)
 
 #define	fldcw(addr)		__asm("fldcw %0" : : "m" (*(addr)))
 #define	fnclex()		__asm("fnclex")
@@ -113,7 +113,7 @@ __FBSDID("$FreeBSD$");
 				      : : "n" (CR0_TS) : "ax")
 #define	stop_emulating()	__asm("clts")
 
-#else	/* !((__GNUC__ && !lint ) || __INTEL_COMPILER) */
+#else	/* !(__GNUCLIKE_ASM && !lint) */
 
 void	fldcw(caddr_t addr);
 void	fnclex(void);
@@ -130,7 +130,7 @@ void	fxrstor(caddr_t addr);
 void	start_emulating(void);
 void	stop_emulating(void);
 
-#endif	/* (__GNUC__ && !lint ) || __INTEL_COMPILER */
+#endif	/* __GNUCLIKE_ASM && !lint */
 
 #ifdef CPU_ENABLE_SSE
 #define GET_FPU_CW(thread) \
diff --git a/sys/i386/isa/prof_machdep.c b/sys/i386/isa/prof_machdep.c
index 57d2342..616be3e 100644
--- a/sys/i386/isa/prof_machdep.c
+++ b/sys/i386/isa/prof_machdep.c
@@ -69,7 +69,7 @@ static struct gmonparam saved_gmp;
 #endif
 #endif /* GUPROF */
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 __asm("								\n\
 GM_STATE	=	0					\n\
 GMON_PROF_OFF	=	3					\n\
@@ -122,9 +122,9 @@ __cyg_profile_func_enter:					\n\
 .mcount_exit:							\n\
 	ret							\n\
 ");
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
-#error
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#else /* !__GNUCLIKE_ASM */
+#error this file needs to be ported to your compiler
+#endif /* __GNUCLIKE_ASM */
 
 #ifdef GUPROF
 /*
@@ -133,7 +133,7 @@ __cyg_profile_func_enter:					\n\
  * dependent file together with cputime(), __mcount and [.]mcount.  cputime()
  * can't just be put in machdep.c because it has to be compiled without -pg.
  */
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 __asm("								\n\
 	.text							\n\
 #								\n\
@@ -168,9 +168,7 @@ __cyg_profile_func_exit:					\n\
 .mexitcount_exit:						\n\
 	ret							\n\
 ");
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
-#error
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#endif /* __GNUCLIKE_ASM */
 
 /*
  * Return the time elapsed since the last call.  The units are machine-
@@ -353,7 +351,7 @@ stopguprof(gp)
 }
 
 #else /* !GUPROF */
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE_ASM
 __asm("								\n\
 	.text							\n\
 	.p2align 4,0x90						\n\
@@ -361,7 +359,5 @@ __asm("								\n\
 " __XSTRING(HIDENAME(mexitcount)) ":				\n\
 	ret							\n\
 ");
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
-#error
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#endif /* __GNUCLIKE_ASM */
 #endif /* GUPROF */
diff --git a/sys/ia64/include/_types.h b/sys/ia64/include/_types.h
index 5809f63..8fc1be2 100644
--- a/sys/ia64/include/_types.h
+++ b/sys/ia64/include/_types.h
@@ -39,6 +39,10 @@
 #ifndef _MACHINE__TYPES_H_
 #define	_MACHINE__TYPES_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Basic types upon which most other types are built.
  */
@@ -97,9 +101,10 @@ typedef	__uint64_t	__vm_size_t;
 /*
  * Unusual type definitions.
  */
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_BUILTIN_VARARGS
 typedef __builtin_va_list	__va_list;	/* internally known to gcc */
-#if !defined(__GNUC_VA_LIST) && !defined(__NO_GNUC_VA_LIST)
+#if defined(__GNUC_VA_LIST_COMPATIBILITY) && !defined(__GNUC_VA_LIST) \
+    && !defined(__NO_GNUC_VA_LIST)
 #define	__GNUC_VA_LIST
 typedef	__va_list	__gnuc_va_list;		/* compat. with GNU headers */
 #endif
@@ -109,6 +114,6 @@ typedef char *			__va_list;	/* non-functional */
 #else
 #error Must add va_list support for this non-GCC compiler.   
 #endif /* lint */
-#endif /* __GNUC__ */
+#endif /* __GNUCLIKE_BUILTIN_VARARGS */
 
 #endif /* !_MACHINE__TYPES_H_ */
diff --git a/sys/ia64/include/cpufunc.h b/sys/ia64/include/cpufunc.h
index 29563fe..27d66ef 100644
--- a/sys/ia64/include/cpufunc.h
+++ b/sys/ia64/include/cpufunc.h
@@ -35,11 +35,15 @@
 #include <machine/ia64_cpu.h>
 #include <machine/vmparam.h>
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 struct thread;
 
 #define	IA64_FIXED_BREAK	0x84B5D
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 
 static __inline void
 breakpoint(void)
@@ -50,8 +54,6 @@ breakpoint(void)
 #define	HAVE_INLINE_FFS
 #define	ffs(x)	__builtin_ffs(x)
 
-#endif
-
 extern uint64_t ia64_port_base;
 #define	__MEMIO_ADDR(x)		(__volatile void*)(IA64_PHYS_TO_RR6(x))
 #define	__PIO_ADDR(x)		(__volatile void*)(ia64_port_base |	\
@@ -208,6 +210,8 @@ intr_restore(register_t ie)
 		enable_intr();
 }
 
+#endif /* __GNUCLIKE_ASM */
+
 #endif /* _KERNEL */
 
 #endif /* !_MACHINE_CPUFUNC_H_ */
diff --git a/sys/ia64/include/critical.h b/sys/ia64/include/critical.h
index 08c7d61..26f2edd 100644
--- a/sys/ia64/include/critical.h
+++ b/sys/ia64/include/critical.h
@@ -46,7 +46,7 @@ __BEGIN_DECLS
  */
 void cpu_critical_fork_exit(void);
 
-#ifdef	__GNUC__
+#ifdef	__CC_SUPPORTS___INLINE
 
 /*
  *	cpu_critical_enter:
@@ -76,12 +76,12 @@ cpu_critical_exit(struct thread *td)
 }
 
 
-#else /* !__GNUC__ */
+#else /* !__CC_SUPPORTS___INLINE */
 
 void cpu_critical_enter(struct thread *td)
 void cpu_critical_exit(struct thread *td)
 
-#endif	/* __GNUC__ */
+#endif	/* __CC_SUPPORTS___INLINE */
 
 __END_DECLS
 
diff --git a/sys/ia64/include/endian.h b/sys/ia64/include/endian.h
index 2293dde..5b3d978 100644
--- a/sys/ia64/include/endian.h
+++ b/sys/ia64/include/endian.h
@@ -64,7 +64,7 @@
 #define	BYTE_ORDER	_BYTE_ORDER
 #endif
 
-#ifdef __GNUC__
+#if defined(__CC_SUPPORTS___INLINE) && defined(__GNUCLIKE_ASM)
 
 static __inline __uint64_t
 __bswap64(__uint64_t _x)
@@ -95,7 +95,7 @@ __bswap16(__uint16_t _x)
 #define	__ntohl(x)	__bswap32(x)
 #define	__ntohs(x)	__bswap16(x)
 
-#else /* !__GNUC__ */
+#else /* !(__CC_SUPPORTS___INLINE && __GNUCLIKE_ASM) */
 
 /*
  * No optimizations are available for this compiler.  Fall back to
@@ -104,6 +104,6 @@ __bswap16(__uint16_t _x)
  */
 #define	_BYTEORDER_FUNC_DEFINED
 
-#endif /* __GNUC__ */
+#endif /* __CC_SUPPORTS___INLINE && __GNUCLIKE_ASM */
 
 #endif /* !_MACHINE_ENDIAN_H_ */
diff --git a/sys/ia64/include/in_cksum.h b/sys/ia64/include/in_cksum.h
index a899ef0..0992006 100644
--- a/sys/ia64/include/in_cksum.h
+++ b/sys/ia64/include/in_cksum.h
@@ -45,7 +45,7 @@
  * in the normal case (where there are no options and the header length is
  * therefore always exactly five 32-bit words.
  */
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS___INLINE
 
 static __inline void
 in_cksum_update(struct ip *ip)
diff --git a/sys/ia64/include/limits.h b/sys/ia64/include/limits.h
index c26df92..62772bc 100644
--- a/sys/ia64/include/limits.h
+++ b/sys/ia64/include/limits.h
@@ -35,7 +35,9 @@
 #ifndef _MACHINE_LIMITS_H_
 #define	_MACHINE_LIMITS_H_
 
-#if __GNUC__
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning "machine/limits.h is deprecated.  Include sys/limits.h instead."
 #endif
 
diff --git a/sys/ia64/include/stdarg.h b/sys/ia64/include/stdarg.h
index 51dde80..9ab18b8 100644
--- a/sys/ia64/include/stdarg.h
+++ b/sys/ia64/include/stdarg.h
@@ -46,7 +46,7 @@
 typedef	__va_list	va_list;
 #endif
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#if defined(__GNUCLIKE_BUILTIN_STDARG)
 
 #define	va_start(ap, last) \
 	__builtin_stdarg_start((ap), (last))
diff --git a/sys/kern/subr_prof.c b/sys/kern/subr_prof.c
index ba36093..0e2379d 100644
--- a/sys/kern/subr_prof.c
+++ b/sys/kern/subr_prof.c
@@ -543,8 +543,8 @@ out:
 	PROC_UNLOCK(p);
 }
 
-#if (defined(__amd64__) || defined(__i386__)) && __GNUC__ >= 2 && \
-	!defined(__INTEL_COMPILER)
+#if (defined(__amd64__) || defined(__i386__)) && \
+	defined(__GNUCLIKE_CTOR_SECTION_HANDLING)
 /*
  * Support for "--test-coverage --profile-arcs" in GCC.
  *
diff --git a/sys/powerpc/include/_types.h b/sys/powerpc/include/_types.h
index 32fe2e3..c6babcf 100644
--- a/sys/powerpc/include/_types.h
+++ b/sys/powerpc/include/_types.h
@@ -39,6 +39,10 @@
 #ifndef _MACHINE__TYPES_H_
 #define	_MACHINE__TYPES_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Basic types upon which most other types are built.
  */
@@ -54,7 +58,7 @@ typedef	unsigned int		__uint32_t;
 typedef long long		__int64_t;
 /* LONGLONG */
 typedef unsigned long long	__uint64_t;
-#elif defined(__GNUC__)
+#elif defined(__GNUCLIKE_ATTRIBUTE_MODE_DI)
 typedef int __attribute__((__mode__(__DI__)))		__int64_t;
 typedef unsigned int __attribute__((__mode__(__DI__)))	__uint64_t;
 #else
@@ -110,7 +114,7 @@ typedef	__uint32_t	__vm_size_t;
 /*
  * Unusual type definitions.
  */
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#if defined(__GNUCLIKE_BUILTIN_VARARGS)
 typedef __builtin_va_list	__va_list;	/* internally known to gcc */
 #else
 typedef	struct {
@@ -121,7 +125,8 @@ typedef	struct {
 	char	*__base;
 } __va_list;
 #endif /* post GCC 2.95 */
-#if defined __GNUC__ && !defined(__GNUC_VA_LIST) && !defined(__NO_GNUC_VA_LIST)
+#if defined(__GNUC_VA_LIST_COMPATIBILITY) && !defined(__GNUC_VA_LIST) \
+    && !defined(__NO_GNUC_VA_LIST)
 #define __GNUC_VA_LIST
 typedef __va_list		__gnuc_va_list;	/* compatibility w/GNU headers*/
 #endif
diff --git a/sys/powerpc/include/atomic.h b/sys/powerpc/include/atomic.h
index dee4c84..ad23a3f 100644
--- a/sys/powerpc/include/atomic.h
+++ b/sys/powerpc/include/atomic.h
@@ -33,6 +33,10 @@
 
 #include <machine/cpufunc.h>
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Various simple arithmetic on memory which is atomic in the presence
  * of interrupts and SMP safe.
@@ -53,7 +57,7 @@ atomic_set_32(volatile uint32_t *p, uint32_t v)
 {
 	uint32_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tlwarx %0, 0, %2\n\t"	/* load old value */
 		"or %0, %3, %0\n\t"		/* calculate new value */
@@ -70,7 +74,7 @@ atomic_clear_32(volatile uint32_t *p, uint32_t v)
 {
 	uint32_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tlwarx %0, 0, %2\n\t"	/* load old value */
 		"andc %0, %0, %3\n\t"		/* calculate new value */
@@ -87,7 +91,7 @@ atomic_add_32(volatile uint32_t *p, uint32_t v)
 {
 	uint32_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tlwarx %0, 0, %2\n\t"	/* load old value */
 		"add %0, %3, %0\n\t"		/* calculate new value */
@@ -104,7 +108,7 @@ atomic_subtract_32(volatile uint32_t *p, uint32_t v)
 {
 	uint32_t temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tlwarx %0, 0, %2\n\t"	/* load old value */
 		"subf %0, %3, %0\n\t"		/* calculate new value */
@@ -121,7 +125,7 @@ atomic_readandclear_32(volatile uint32_t *addr)
 {
 	uint32_t result,temp;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"\tsync\n"			/* drain writes */
 		"1:\tlwarx %0, 0, %3\n\t"	/* load old value */
@@ -348,7 +352,7 @@ atomic_cmpset_32(volatile uint32_t* p, uint32_t cmpval, uint32_t newval)
 {
 	uint32_t	ret;
 
-#ifdef __GNUC__
+#ifdef __GNUCLIKE_ASM
 	__asm __volatile (
 		"1:\tlwarx %0, 0, %2\n\t"	/* load old value */
 		"cmplw %3, %0\n\t"		/* compare */
diff --git a/sys/powerpc/include/critical.h b/sys/powerpc/include/critical.h
index cc0768a..405bc57 100644
--- a/sys/powerpc/include/critical.h
+++ b/sys/powerpc/include/critical.h
@@ -46,7 +46,7 @@ __BEGIN_DECLS
  */
 void cpu_critical_fork_exit(void);
 
-#ifdef	__GNUC__
+#ifdef	__CC_SUPPORTS___INLINE
 
 /*
  *	cpu_critical_enter:
@@ -77,12 +77,12 @@ cpu_critical_exit(struct thread *td)
 }
 
 
-#else /* !__GNUC__ */
+#else /* !__CC_SUPPORTS___INLINE */
 
 void cpu_critical_enter(struct thread *td);
 void cpu_critical_exit(struct thread *td);
 
-#endif	/* __GNUC__ */
+#endif	/* __CC_SUPPORTS___INLINE */
 
 __END_DECLS
 
diff --git a/sys/powerpc/include/endian.h b/sys/powerpc/include/endian.h
index af8f030..bc96b9e 100644
--- a/sys/powerpc/include/endian.h
+++ b/sys/powerpc/include/endian.h
@@ -65,7 +65,7 @@
 #define	BYTE_ORDER	_BYTE_ORDER
 #endif
 
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS___INLINE
 
 static __inline __uint16_t
 __bswap16(__uint16_t _x)
@@ -97,7 +97,7 @@ __bswap64(__uint64_t _x)
 #define	__ntohl(x)	((__uint32_t)(x))
 #define	__ntohs(x)	((__uint16_t)(x))
 
-#else /* !__GNUC__ */
+#else /* !__CC_SUPPORTS___INLINE */
 
 /*
  * No optimizations are available for this compiler.  Fall back to
@@ -106,6 +106,6 @@ __bswap64(__uint64_t _x)
  */
 #define	_BYTEORDER_FUNC_DEFINED
 
-#endif /* __GNUC__ */
+#endif /* __CC_SUPPORTS___INLINE */
 
 #endif /* !_MACHINE_ENDIAN_H_ */
diff --git a/sys/powerpc/include/in_cksum.h b/sys/powerpc/include/in_cksum.h
index a899ef0..0992006 100644
--- a/sys/powerpc/include/in_cksum.h
+++ b/sys/powerpc/include/in_cksum.h
@@ -45,7 +45,7 @@
  * in the normal case (where there are no options and the header length is
  * therefore always exactly five 32-bit words.
  */
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS___INLINE
 
 static __inline void
 in_cksum_update(struct ip *ip)
diff --git a/sys/powerpc/include/limits.h b/sys/powerpc/include/limits.h
index 8e3bb11..35eea1f 100644
--- a/sys/powerpc/include/limits.h
+++ b/sys/powerpc/include/limits.h
@@ -33,7 +33,9 @@
 #ifndef _MACHINE_LIMITS_H_
 #define	_MACHINE_LIMITS_H_
 
-#if __GNUC__
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning "machine/limits.h is deprecated.  Include sys/limits.h instead."
 #endif
 
diff --git a/sys/powerpc/include/stdarg.h b/sys/powerpc/include/stdarg.h
index 973da78..d0af5bb 100644
--- a/sys/powerpc/include/stdarg.h
+++ b/sys/powerpc/include/stdarg.h
@@ -39,7 +39,7 @@
 typedef	__va_list	va_list;
 #endif
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#if defined(__GNUCLIKE_BUILTIN_STDARG)
 
 #define	va_start(ap, last) \
 	__builtin_stdarg_start((ap), (last))
@@ -58,7 +58,7 @@ typedef	__va_list	va_list;
 #define	va_end(ap) \
 	__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* !__GNUCLIKE_BUILTIN_STDARG */
 
 #ifdef __lint__
 
@@ -67,7 +67,7 @@ typedef	__va_list	va_list;
 
 #else
 
-#if defined(__GNUC__) && (__GNUC__ > 2 || __GNUC__ == 2 && __GNUC_MINOR__ >= 95)
+#if defined(__GNUC_VA_LIST_COMPATIBILITY)
 #define	va_start(ap, last)						\
 	(__builtin_next_arg(last),					\
 	 __builtin_memcpy((void *)&(ap), __builtin_saveregs (),		\
@@ -145,6 +145,6 @@ typedef	__va_list	va_list;
 #endif
 #endif
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_STDARG */
 
 #endif /* _MACHINE_STDARG_H_ */
diff --git a/sys/powerpc/include/varargs.h b/sys/powerpc/include/varargs.h
index 8bbf2ca..fed04c9 100644
--- a/sys/powerpc/include/varargs.h
+++ b/sys/powerpc/include/varargs.h
@@ -31,7 +31,11 @@
 #ifndef _MACHINE_VARARGS_H_
 #define	_MACHINE_VARARGS_H_
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
+#if defined(__GNUCLIKE_BUILTIN_VARARGS)
 
 #include <sys/_types.h>
 
@@ -48,12 +52,16 @@ typedef int __builtin_va_alist_t __attribute__((__mode__(__word__)));
 #define	va_arg(ap, type)	__builtin_va_arg((ap), type)
 #define	va_end(ap)		__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* !  __GNUCLIKE_BUILTIN_VARARGS */
 
 #include <machine/stdarg.h>
 
+#ifdef __GNUCLIKE_BUILTIN_VAALIST
 #define	va_alist	__builtin_va_alist
 #define	va_dcl		int __builtin_va_alist; ...
+#else
+#error this file needs to be ported to your compiler
+#endif
 
 #undef va_start
 
@@ -67,6 +75,6 @@ typedef int __builtin_va_alist_t __attribute__((__mode__(__word__)));
 	 (ap).__fpr = __va_first_fpr)
 #endif
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_VARARGS */
 
 #endif /* _MACHINE_VARARGS_H_ */
diff --git a/sys/powerpc/powerpc/busdma_machdep.c b/sys/powerpc/powerpc/busdma_machdep.c
index 7493980..f2efafe 100644
--- a/sys/powerpc/powerpc/busdma_machdep.c
+++ b/sys/powerpc/powerpc/busdma_machdep.c
@@ -309,7 +309,7 @@ bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 {
         vm_offset_t             vaddr;
         vm_offset_t             paddr;
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
         bus_dma_segment_t       dm_segments[dmat->nsegments];
 #else
         bus_dma_segment_t       dm_segments[BUS_DMAMAP_NSEGS];
@@ -462,7 +462,7 @@ bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
 		     bus_dmamap_callback2_t *callback, void *callback_arg,
 		     int flags)
 {
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
 	bus_dma_segment_t dm_segments[dmat->nsegments];
 #else
 	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
@@ -538,7 +538,7 @@ bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
     int flags)
 {
 	vm_offset_t lastaddr;
-#ifdef __GNUC__
+#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
 	bus_dma_segment_t dm_segments[dmat->nsegments];
 #else
 	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
diff --git a/sys/sparc64/include/_types.h b/sys/sparc64/include/_types.h
index f014b54..f810c15 100644
--- a/sys/sparc64/include/_types.h
+++ b/sys/sparc64/include/_types.h
@@ -35,6 +35,10 @@
 #ifndef _MACHINE__TYPES_H_
 #define	_MACHINE__TYPES_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * Basic types upon which most other types are built.
  */
@@ -93,12 +97,13 @@ typedef	__uint64_t	__vm_size_t;
 /*
  * Unusual type definitions.
  */
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifdef __GNUCLIKE_BUILTIN_VARARGS
 typedef __builtin_va_list	__va_list;	/* internally known to gcc */
 #else
 typedef	char *			__va_list;
-#endif /* post GCC 2.95 */
-#if defined __GNUC__ && !defined(__GNUC_VA_LIST) && !defined(__NO_GNUC_VA_LIST)
+#endif /* __GNUCLIKE_BUILTIN_VARARGS */
+#if defined(__GNUCLIKE_BUILTIN_VAALIST) && !defined(__GNUC_VA_LIST) \
+    && !defined(__NO_GNUC_VA_LIST)
 #define __GNUC_VA_LIST
 typedef __va_list		__gnuc_va_list;	/* compatibility w/GNU headers*/
 #endif
diff --git a/sys/sparc64/include/critical.h b/sys/sparc64/include/critical.h
index 381ec45..999a5fd 100644
--- a/sys/sparc64/include/critical.h
+++ b/sys/sparc64/include/critical.h
@@ -46,7 +46,7 @@ __BEGIN_DECLS
  */
 void cpu_critical_fork_exit(void);
 
-#ifdef	__GNUC__
+#ifdef	__CC_SUPPORTS___INLINE
 
 /*
  *	cpu_critical_enter:
@@ -79,12 +79,12 @@ cpu_critical_exit(struct thread *td)
 	wrpr(pil, td->td_md.md_savecrit, 0);
 }
 
-#else /* !__GNUC__ */
+#else /* !__CC_SUPPORTS___INLINE */
 
 void cpu_critical_enter(struct thread *td);
 void cpu_critical_exit(struct thread *td);
 
-#endif	/* __GNUC__ */
+#endif	/* __CC_SUPPORTS___INLINE */
 
 __END_DECLS
 
diff --git a/sys/sparc64/include/endian.h b/sys/sparc64/include/endian.h
index a3b9c2d..a643dd3 100644
--- a/sys/sparc64/include/endian.h
+++ b/sys/sparc64/include/endian.h
@@ -63,7 +63,7 @@
 #define	BYTE_ORDER	_BYTE_ORDER
 #endif
 
-#if defined(__GNUC__) && defined(__OPTIMIZE__)
+#if defined(__GNUCLIKE_BUILTIN_CONSTANT_P) && defined(__OPTIMIZE__)
 #define	__is_constant(x)	__builtin_constant_p(x)
 #else
 #define	__is_constant(x)	0
diff --git a/sys/sparc64/include/stdarg.h b/sys/sparc64/include/stdarg.h
index bd4e9dd..a7ff284 100644
--- a/sys/sparc64/include/stdarg.h
+++ b/sys/sparc64/include/stdarg.h
@@ -49,7 +49,7 @@
 typedef	__va_list	va_list;
 #endif
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifdef __GNUCLIKE_BUILTIN_STDARG
 
 #define	va_start(ap, last) \
 	__builtin_stdarg_start((ap), (last))
@@ -65,7 +65,11 @@ typedef	__va_list	va_list;
 #define	va_end(ap) \
 	__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* ! __GNUCLIKE_BUILTIN_STDARG */
+
+#if !defined(__GNUCLIKE_BUILTIN_NEXT_ARG) && !defined(lint)
+#error no support for your compiler
+#endif
 
 #define	va_start(ap, last) \
 	(__builtin_next_arg(last), (ap) = (va_list)__builtin_saveregs())
@@ -92,6 +96,6 @@ typedef	__va_list	va_list;
 	   (sizeof(type) <= 16 ? __va_arg16(ap, type) :			\
 	    *__va_arg8(ap, type *)))))
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_STDARG */
 
 #endif /* !_MACHINE_STDARG_H_ */
diff --git a/sys/sparc64/include/varargs.h b/sys/sparc64/include/varargs.h
index 165e807..a168c6e 100644
--- a/sys/sparc64/include/varargs.h
+++ b/sys/sparc64/include/varargs.h
@@ -52,7 +52,11 @@
 #ifndef _MACHINE_VARARGS_H_
 #define	_MACHINE_VARARGS_H_
 
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
+#ifdef __GNUCLIKE_BUILTIN_VARARGS
 
 #include <sys/_types.h>
 
@@ -69,15 +73,11 @@ typedef int __builtin_va_alist_t __attribute__((__mode__(__word__)));
 #define	va_arg(ap, type)	__builtin_va_arg((ap), type)
 #define	va_end(ap)		__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* !__GNUCLIKE_BUILTIN_VARARGS */
 
 #include <machine/stdarg.h>
 
-#if __GNUC__ == 1
-#define	__va_ellipsis
-#else
 #define	__va_ellipsis	...
-#endif
 
 #define	va_alist	__builtin_va_alist
 #define	va_dcl		long __builtin_va_alist; __va_ellipsis
@@ -86,6 +86,6 @@ typedef int __builtin_va_alist_t __attribute__((__mode__(__word__)));
 #define	va_start(ap) \
 	((ap) = (va_list)__builtin_saveregs())
 
-#endif /* __GNUC__ post GCC 2.95 */
+#endif /* __GNUCLIKE_BUILTIN_VARARGS */
 
 #endif /* !_MACHINE_VARARGS_H_ */
diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h
index a3f0025..a4b11c4 100644
--- a/sys/sys/cdefs.h
+++ b/sys/sys/cdefs.h
@@ -45,6 +45,76 @@
 #endif
 
 /*
+ * This code has been put in place to help reduce the addition of
+ * compiler specific defines in FreeBSD code.  It helps to aid in
+ * having a compiler-agnostic source tree.
+ */
+
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+
+#if __GNUC__ >= 3 || defined(__INTEL_COMPILER)
+#define __GNUCLIKE_ASM 3
+#define __GNUCLIKE_MATH_BUILTIN_CONSTANTS
+#else
+#define __GNUCLIKE_ASM 2
+#endif
+#define __GNUCLIKE___TYPEOF 1
+#define __GNUCLIKE___OFFSETOF 1
+#define __GNUCLIKE___SECTION 1
+
+#define __GNUCLIKE_ATTRIBUTE_PRINTF 1
+#define __GNUCLIKE_ATTRIBUTE_MODE_DI 1
+
+#ifndef __INTEL_COMPILER
+# define __GNUCLIKE_CTOR_SECTION_HANDLING 1
+#endif
+
+#define __GNUCLIKE_BUILTIN_CONSTANT_P 1
+# if defined(__INTEL_COMPILER) && defined(__cplusplus) \
+    && __INTEL_COMPILER < 800
+#  undef __GNUCLIKE_BUILTIN_CONSTANT_P
+# endif
+
+#if __GNUC_MINOR__ > 95 || __GNUC__ >= 3 || defined(__INTEL_COMPILER)
+# define __GNUCLIKE_BUILTIN_VARARGS 1
+#endif
+#define __GNUCLIKE_BUILTIN_VAALIST 1
+
+#if defined(__GNUC__)
+# define __GNUC_VA_LIST_COMPATIBILITY 1
+#endif
+
+#if (__GNUC_MINOR__ > 95 || __GNUC__ >= 3) && !defined(__INTEL_COMPILER)
+# define __GNUCLIKE_BUILTIN_STDARG 1
+#endif
+
+#ifndef __INTEL_COMPILER
+# define __GNUCLIKE_BUILTIN_NEXT_ARG 1
+# define __GNUCLIKE_MATH_BUILTIN_RELOPS
+#endif
+
+#define __GNUCLIKE_BUILTIN_MEMCPY 1
+
+/* XXX: if __GNUC__ >= 2: not tested everywhere originally, where replaced */
+#define __CC_SUPPORTS_INLINE 1
+#define __CC_SUPPORTS___INLINE 1
+#define __CC_SUPPORTS___INLINE__ 1
+
+#define __CC_SUPPORTS___FUNC__ 1
+#define __CC_SUPPORTS_WARNING 1
+
+#define __CC_SUPPORTS_FORWARD_REFERENCE_CONSTRUCT 1
+
+#define __CC_SUPPORTS_VARADIC_XXX 1 /* see varargs.h */
+
+#define __CC_SUPPORTS_DYNAMIC_ARRAY_INIT 1
+
+/* XXX: sys/dev/mpt/mpilib/mpi_type.h uses it, someone should review it */
+#define __CC_INT_IS_32BIT 1
+
+#endif /* __GNUC__ || __INTEL_COMPILER */
+
+/*
  * Macro to test if we're using a specific version of gcc or later.
  */
 #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
@@ -79,9 +149,9 @@
 #if defined(__cplusplus)
 #define	__inline	inline		/* convert to C++ keyword */
 #else
-#if !(defined(__GNUC__) || defined(__INTEL_COMPILER))
+#if !(defined(__CC_SUPPORTS___INLINE))
 #define	__inline			/* delete GCC keyword */
-#endif /* !(__GNUC__ || __INTEL_COMPILER) */
+#endif /* ! __CC_SUPPORTS___INLINE */
 #endif /* !__cplusplus */
 
 #else	/* !(__STDC__ || __cplusplus) */
@@ -89,7 +159,7 @@
 #define	__CONCAT(x,y)	x/**/y
 #define	__STRING(x)	"x"
 
-#if !(defined(__GNUC__) || defined(__INTEL_COMPILER))
+#if !defined(__CC_SUPPORTS___INLINE)
 #define	__const				/* delete pseudo-ANSI C keywords */
 #define	__inline
 #define	__signed
@@ -108,7 +178,7 @@
 #define	signed
 #define	volatile
 #endif	/* !NO_ANSI_KEYWORDS */
-#endif	/* !(__GNUC__ || __INTEL_COMPILER) */
+#endif	/* !__CC_SUPPORTS___INLINE */
 #endif	/* !(__STDC__ || __cplusplus) */
 
 /*
diff --git a/sys/sys/dir.h b/sys/sys/dir.h
index 48c98d2..799ad9e 100644
--- a/sys/sys/dir.h
+++ b/sys/sys/dir.h
@@ -33,7 +33,9 @@
 #ifndef _SYS_DIR_H_
 #define	_SYS_DIR_H_
 
-#if defined(__GNUC__) || defined (__INTEL_COMPILER)
+#include <sys/cdefs.h>
+
+#ifdef __CC_SUPPORTS_WARNING
 #warning "The information in this file should be obtained from <dirent.h>"
 #warning "and is provided solely (and temporarily) for backward compatibility."
 #endif
diff --git a/sys/sys/ioctl.h b/sys/sys/ioctl.h
index 530e2d4..fd54f6d 100644
--- a/sys/sys/ioctl.h
+++ b/sys/sys/ioctl.h
@@ -39,10 +39,13 @@
 #define	_SYS_IOCTL_H_
 
 #ifdef _KERNEL
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
-#warning "Don't #include ioctl.h in the kernel.  Include xxxio.h instead."
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
 #endif
+#ifdef __CC_SUPPORTS_WARNING
+#warning "Don't #include ioctl.h in the kernel.  Include xxxio.h instead."
 #endif
+#endif /* _KERNEL */
 
 #include <sys/ttycom.h>
 
diff --git a/sys/sys/linker_set.h b/sys/sys/linker_set.h
index 0c4a246..5f55beb 100644
--- a/sys/sys/linker_set.h
+++ b/sys/sys/linker_set.h
@@ -30,6 +30,10 @@
 #ifndef _SYS_LINKER_SET_H_
 #define _SYS_LINKER_SET_H_
 
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+
 /*
  * The following macros are used to declare global sets of objects, which
  * are collected by the linker into a `linker_set' as defined below.
@@ -39,16 +43,16 @@
 /*
  * Private macros, not to be used outside this header file.
  */
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __GNUCLIKE___SECTION
 #define __MAKE_SET(set, sym)						\
 	static void const * const __set_##set##_sym_##sym 		\
 	__section("set_" #set) __used = &sym
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
+#else /* !__GNUCLIKE___SECTION */
 #ifndef lint
-#error "This file needs to be compiled by GCC, an Intel compiler or lint"
+#error this file needs to be ported to your compiler
 #endif /* lint */
 #define __MAKE_SET(set, sym)	extern void const * const (__set_##set##_sym_##sym)
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#endif /* __GNUCLIKE___SECTION */
 
 /*
  * Public macros.
diff --git a/sys/sys/queue.h b/sys/sys/queue.h
index 23c03c8..c9a3230 100644
--- a/sys/sys/queue.h
+++ b/sys/sys/queue.h
@@ -517,7 +517,7 @@ struct quehead {
 	struct quehead *qh_rlink;
 };
 
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifdef __CC_SUPPORTS___INLINE
 
 static __inline void
 insque(void *a, void *b)
@@ -541,12 +541,12 @@ remque(void *a)
 	element->qh_rlink = 0;
 }
 
-#else /* !(__GNUC__ || __INTEL_COMPILER) */
+#else /* !__CC_SUPPORTS___INLINE */
 
 void	insque(void *a, void *b);
 void	remque(void *a);
 
-#endif /* __GNUC__ || __INTEL_COMPILER */
+#endif /* __CC_SUPPORTS___INLINE */
 
 #endif /* _KERNEL */
 
diff --git a/sys/sys/syslimits.h b/sys/sys/syslimits.h
index 974e173..0d477be 100644
--- a/sys/sys/syslimits.h
+++ b/sys/sys/syslimits.h
@@ -34,7 +34,10 @@
 #define _SYS_SYSLIMITS_H_
 
 #if !defined(_KERNEL) && !defined(_LIMITS_H_) && !defined(_SYS_PARAM_H_)
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifndef _SYS_CDEFS_H_
+#error this file needs sys/cdefs.h as a prerequisite
+#endif
+#ifdef __CC_SUPPORTS_WARNING
 #warning "No user-serviceable parts inside."
 #endif
 #endif