diff --git a/sys/amd64/amd64/prof_machdep.c b/sys/amd64/amd64/prof_machdep.c
index 4c3a21e2135e..31b1c2a16059 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 */
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 __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__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 #error
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 
 #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.
  */
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 __asm("								\n\
 	.text							\n\
 #								\n\
@@ -168,9 +168,9 @@ __cyg_profile_func_exit:					\n\
 .mexitcount_exit:						\n\
 	ret							\n\
 ");
-#else /* !__GNUC__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 #error
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 
 /*
  * Return the time elapsed since the last call.  The units are machine-
@@ -346,7 +346,7 @@ stopguprof(gp)
 }
 
 #else /* !GUPROF */
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 __asm("								\n\
 	.text							\n\
 	.p2align 4,0x90						\n\
@@ -354,7 +354,7 @@ __asm("								\n\
 " __XSTRING(HIDENAME(mexitcount)) ":				\n\
 	ret							\n\
 ");
-#else /* !__GNUC__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 #error
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 #endif /* GUPROF */
diff --git a/sys/boot/arc/include/arcfuncs.h b/sys/boot/arc/include/arcfuncs.h
index 25c74465b3fa..e88ff03a1c10 100644
--- a/sys/boot/arc/include/arcfuncs.h
+++ b/sys/boot/arc/include/arcfuncs.h
@@ -27,7 +27,7 @@
  *
  */
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 #define INLINE inline
 #else
 #define INLINE /**/
diff --git a/sys/boot/i386/boot2/boot2.c b/sys/boot/i386/boot2/boot2.c
index bb583530ed1a..9c81d922a023 100644
--- a/sys/boot/i386/boot2/boot2.c
+++ b/sys/boot/i386/boot2/boot2.c
@@ -139,7 +139,17 @@ static int xputc(int);
 static int xgetc(int);
 static int getc(int);
 
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 #define memcpy __builtin_memcpy
+#else
+static void memcpy(char *, const char *, int);
+static void
+memcpy(char *dst, const char *src, int len)
+{
+    while (len--)
+        *dst++ = *src++;
+}
+#endif
 
 static inline int
 strcmp(const char *s1, const char *s2)
diff --git a/sys/boot/i386/gptboot/gptboot.c b/sys/boot/i386/gptboot/gptboot.c
index bb583530ed1a..9c81d922a023 100644
--- a/sys/boot/i386/gptboot/gptboot.c
+++ b/sys/boot/i386/gptboot/gptboot.c
@@ -139,7 +139,17 @@ static int xputc(int);
 static int xgetc(int);
 static int getc(int);
 
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 #define memcpy __builtin_memcpy
+#else
+static void memcpy(char *, const char *, int);
+static void
+memcpy(char *dst, const char *src, int len)
+{
+    while (len--)
+        *dst++ = *src++;
+}
+#endif
 
 static inline int
 strcmp(const char *s1, const char *s2)
diff --git a/sys/dev/aic7xxx/aicasm/aicasm.c b/sys/dev/aic7xxx/aicasm/aicasm.c
index cdf84e9ca244..0c780f9065be 100644
--- a/sys/dev/aic7xxx/aicasm/aicasm.c
+++ b/sys/dev/aic7xxx/aicasm/aicasm.c
@@ -143,7 +143,7 @@ main(int argc, char *argv[])
 	yydebug = 0;
 	mmdebug = 0;
 #endif
-	while ((ch = getopt(argc, argv, "d:i:l:n:o:p:r:I:")) != -1) {
+	while ((ch = getopt(argc, argv, "d:i:l:n:o:p:r:I:X")) != -1) {
 		switch(ch) {
 		case 'd':
 #if DEBUG
@@ -244,6 +244,9 @@ main(int argc, char *argv[])
 			}
 			break;
 		}
+		case 'X':
+			/* icc version of -nostdinc */
+			break;
 		case '?':
 		default:
 			usage();
@@ -309,7 +312,7 @@ usage()
 {
 
 	(void)fprintf(stderr,
-"usage: %-16s [-nostdinc] [-I-] [-I directory] [-o output_file]\n"
+"usage: %-16s [-nostdinc|-X] [-I-] [-I directory] [-o output_file]\n"
 "	[-r register_output_file [-p register_diag_file -i includefile]]\n"
 "	[-l program_list_file]\n"
 "	input_file\n", appname);
diff --git a/sys/dev/cx/machdep.h b/sys/dev/cx/machdep.h
index b88e9002e539..23469259bd15 100644
--- a/sys/dev/cx/machdep.h
+++ b/sys/dev/cx/machdep.h
@@ -84,7 +84,7 @@
 #endif
 
 #ifndef inline
-#   if __GNUC__ >= 2
+#   if __GNUC__ >= 2 || defined(__INTEL_COMPILER)
 #      define inline __inline__
 #   else
 #      define inline /**/
diff --git a/sys/dev/ichsmb/ichsmb.c b/sys/dev/ichsmb/ichsmb.c
index d92e23ea7d93..0d8dd59b07a3 100644
--- a/sys/dev/ichsmb/ichsmb.c
+++ b/sys/dev/ichsmb/ichsmb.c
@@ -69,7 +69,7 @@ __FBSDID("$FreeBSD$");
  * Enable debugging by defining ICHSMB_DEBUG to a non-zero value.
  */
 #define ICHSMB_DEBUG	0
-#if ICHSMB_DEBUG != 0 && defined(__GNUC__)
+#if ICHSMB_DEBUG != 0 && (defined(__GNUC__) || defined(__INTEL_COMPILER))
 #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 5ce705d10a3d..38c29bfd8b9c 100644
--- a/sys/dev/iir/iir.h
+++ b/sys/dev/iir/iir.h
@@ -697,7 +697,7 @@ void    iir_free(struct gdt_softc *);
 void    iir_attach(struct gdt_softc *);
 void    iir_intr(void *arg);
 
-#ifdef __GNUC__
+#if defined( __GNUC__) || defined(__INTEL_COMPILER)
 /* 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 f44c24abe0ee..6cd11a707c7e 100644
--- a/sys/dev/isp/ispvar.h
+++ b/sys/dev/isp/ispvar.h
@@ -753,7 +753,7 @@ int isp_async(struct ispsoftc *, ispasync_t, void *);
 /*
  * Platform Dependent Error and Debug Printout
  */
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 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 6d542af6a13c..cc8a3ab7163a 100644
--- a/sys/dev/mcd/mcdreg.h
+++ b/sys/dev/mcd/mcdreg.h
@@ -47,8 +47,8 @@
 #ifndef MCD_H
 #define	MCD_H
 
-#ifdef __GNUC__
-#if __GNUC__ >= 2
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#if __GNUC__ >= 2 || defined(__INTEL_COMPILER)
 #pragma pack(1)
 #endif
 #endif
@@ -222,8 +222,8 @@ struct mcd_rawsector {
 	u_char ecc_bits[280];
 };
 
-#ifdef __GNUC__
-#if __GNUC__ >= 2
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#if __GNUC__ >= 2 || defined(__INTEL_COMPILER)
 #pragma pack(4)
 #endif
 #endif
diff --git a/sys/dev/mpt/mpilib/mpi_type.h b/sys/dev/mpt/mpilib/mpi_type.h
index 040cf96b711d..becf1a0747c4 100644
--- a/sys/dev/mpt/mpilib/mpi_type.h
+++ b/sys/dev/mpt/mpilib/mpi_type.h
@@ -68,7 +68,7 @@ typedef unsigned char   U8;
 typedef signed   short  S16;
 typedef unsigned short  U16;
 
-#if defined(unix) || defined(__arm) || defined(ALPHA) || defined(__GNUC__)
+#if defined(unix) || defined(__arm) || defined(ALPHA) || defined(__GNUC__) || defined(__INTEL_COMPILER)
 
     typedef signed   int   S32;
     typedef unsigned int   U32;
diff --git a/sys/dev/scd/scdreg.h b/sys/dev/scd/scdreg.h
index bbfeefd7fce9..38e2293bc7d8 100644
--- a/sys/dev/scd/scdreg.h
+++ b/sys/dev/scd/scdreg.h
@@ -32,8 +32,8 @@
 #ifndef SCD_H
 #define	SCD_H
 
-#ifdef __GNUC__
-#if __GNUC__ >= 2
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#if __GNUC__ >= 2 || defined(__INTEL_COMPILER)
 #pragma pack(1)
 #endif
 #endif
diff --git a/sys/i386/acpica/acpi_wakeup.c b/sys/i386/acpica/acpi_wakeup.c
index 83e7c0106ee2..ae2bc0999c1d 100644
--- a/sys/i386/acpica/acpi_wakeup.c
+++ b/sys/i386/acpica/acpi_wakeup.c
@@ -81,7 +81,7 @@ static void		acpi_alloc_wakeup_handler(void);
 extern int		acpi_savecpu(void);
 extern int		acpi_restorecpu(void);
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 __asm__("				\n\
 	.text				\n\
 	.p2align 2, 0x90		\n\
@@ -148,7 +148,7 @@ acpi_savecpu:				\n\
 	movl	$1,%eax			\n\
 	ret				\n\
 ");
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 
 static void
 acpi_printcpu(void)
diff --git a/sys/i386/i386/db_interface.c b/sys/i386/i386/db_interface.c
index 79173c77428c..03d5453f0323 100644
--- a/sys/i386/i386/db_interface.c
+++ b/sys/i386/i386/db_interface.c
@@ -64,9 +64,10 @@ static __inline u_short
 rss(void)
 {
 	u_short ss;
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 	__asm __volatile("mov %%ss,%0" : "=r" (ss));
 #else
+#error Function rss() needs to get ported to this compiler.
 	ss = 0; /* XXXX Fix for other compilers. */
 #endif
 	return ss;
diff --git a/sys/i386/i386/identcpu.c b/sys/i386/i386/identcpu.c
index b5b1e9d88f25..23bb42bb06b7 100644
--- a/sys/i386/i386/identcpu.c
+++ b/sys/i386/i386/identcpu.c
@@ -768,7 +768,7 @@ static	volatile u_int trap_by_rdmsr;
  * be advanced.
  */
 inthand_t	bluetrap6;
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 __asm
 ("									\n\
 	.text								\n\
@@ -787,7 +787,7 @@ __asm
  * Accessing non-existent MSR generates general protection fault.
  */
 inthand_t	bluetrap13;
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 __asm
 ("									\n\
 	.text								\n\
diff --git a/sys/i386/i386/in_cksum.c b/sys/i386/i386/in_cksum.c
index 781c4f8b093b..a1b8e5f9b8b7 100644
--- a/sys/i386/i386/in_cksum.c
+++ b/sys/i386/i386/in_cksum.c
@@ -61,8 +61,195 @@ __FBSDID("$FreeBSD$");
 
 #undef	ADDCARRY
 #define ADDCARRY(x)     if ((x) > 0xffff) (x) -= 0xffff
+#if !defined(__GNUC__) || defined(__INTEL_COMPILER)
+/* non gcc parts stolen from sys/alpha/alpha/in_cksum.c */
+#define REDUCE32							  \
+    {									  \
+	q_util.q = sum;							  \
+	sum = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3];	  \
+    }
+#define REDUCE16							  \
+    {									  \
+	q_util.q = sum;							  \
+	l_util.l = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \
+	sum = l_util.s[0] + l_util.s[1];				  \
+	ADDCARRY(sum);							  \
+    }
+#endif
 #define REDUCE          {sum = (sum & 0xffff) + (sum >> 16); ADDCARRY(sum);}
 
+#if !defined(__GNUC__) || defined(__INTEL_COMPILER)
+static const u_int32_t in_masks[] = {
+	/*0 bytes*/ /*1 byte*/	/*2 bytes*/ /*3 bytes*/
+	0x00000000, 0x000000FF, 0x0000FFFF, 0x00FFFFFF,	/* offset 0 */
+	0x00000000, 0x0000FF00, 0x00FFFF00, 0xFFFFFF00,	/* offset 1 */
+	0x00000000, 0x00FF0000, 0xFFFF0000, 0xFFFF0000,	/* offset 2 */
+	0x00000000, 0xFF000000, 0xFF000000, 0xFF000000,	/* offset 3 */
+};
+
+union l_util {
+	u_int16_t s[2];
+	u_int32_t l;
+};
+union q_util {
+	u_int16_t s[4];
+	u_int32_t l[2];
+	u_int64_t q;
+};
+
+static u_int64_t
+in_cksumdata(const u_int32_t *lw, int len)
+{
+	u_int64_t sum = 0;
+	u_int64_t prefilled;
+	int offset;
+	union q_util q_util;
+
+	if ((3 & (long) lw) == 0 && len == 20) {
+	     sum = (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3] + lw[4];
+	     REDUCE32;
+	     return sum;
+	}
+
+	if ((offset = 3 & (long) lw) != 0) {
+		const u_int32_t *masks = in_masks + (offset << 2);
+		lw = (u_int32_t *) (((long) lw) - offset);
+		sum = *lw++ & masks[len >= 3 ? 3 : len];
+		len -= 4 - offset;
+		if (len <= 0) {
+			REDUCE32;
+			return sum;
+		}
+	}
+#if 0
+	/*
+	 * Force to cache line boundary.
+	 */
+	offset = 32 - (0x1f & (long) lw);
+	if (offset < 32 && len > offset) {
+		len -= offset;
+		if (4 & offset) {
+			sum += (u_int64_t) lw[0];
+			lw += 1;
+		}
+		if (8 & offset) {
+			sum += (u_int64_t) lw[0] + lw[1];
+			lw += 2;
+		}
+		if (16 & offset) {
+			sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3];
+			lw += 4;
+		}
+	}
+#endif
+	/*
+	 * access prefilling to start load of next cache line.
+	 * then add current cache line
+	 * save result of prefilling for loop iteration.
+	 */
+	prefilled = lw[0];
+	while ((len -= 32) >= 4) {
+		u_int64_t prefilling = lw[8];
+		sum += prefilled + lw[1] + lw[2] + lw[3]
+			+ lw[4] + lw[5] + lw[6] + lw[7];
+		lw += 8;
+		prefilled = prefilling;
+	}
+	if (len >= 0) {
+		sum += prefilled + lw[1] + lw[2] + lw[3]
+			+ lw[4] + lw[5] + lw[6] + lw[7];
+		lw += 8;
+	} else {
+		len += 32;
+	}
+	while ((len -= 16) >= 0) {
+		sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3];
+		lw += 4;
+	}
+	len += 16;
+	while ((len -= 4) >= 0) {
+		sum += (u_int64_t) *lw++;
+	}
+	len += 4;
+	if (len > 0)
+		sum += (u_int64_t) (in_masks[len] & *lw);
+	REDUCE32;
+	return sum;
+}
+
+u_short
+in_addword(u_short a, u_short b)
+{
+	u_int64_t sum = a + b;
+
+	ADDCARRY(sum);
+	return (sum);
+}
+
+u_short
+in_pseudo(u_int32_t a, u_int32_t b, u_int32_t c)
+{
+	u_int64_t sum;
+	union q_util q_util;
+	union l_util l_util;
+		    
+	sum = (u_int64_t) a + b + c;
+	REDUCE16;
+	return (sum);
+}
+
+u_short
+in_cksum_skip(struct mbuf *m, int len, int skip)
+{
+	u_int64_t sum = 0;
+	int mlen = 0;
+	int clen = 0;
+	caddr_t addr;
+	union q_util q_util;
+	union l_util l_util;
+
+        len -= skip;
+        for (; skip && m; m = m->m_next) {
+                if (m->m_len > skip) {
+                        mlen = m->m_len - skip;
+			addr = mtod(m, caddr_t) + skip;
+                        goto skip_start;
+                } else {
+                        skip -= m->m_len;
+                }
+        }
+
+	for (; m && len; m = m->m_next) {
+		if (m->m_len == 0)
+			continue;
+		mlen = m->m_len;
+		addr = mtod(m, caddr_t);
+skip_start:
+		if (len < mlen)
+			mlen = len;
+		if ((clen ^ (long) addr) & 1)
+		    sum += in_cksumdata((const u_int32_t *)addr, mlen) << 8;
+		else
+		    sum += in_cksumdata((const u_int32_t *)addr, mlen);
+
+		clen += mlen;
+		len -= mlen;
+	}
+	REDUCE16;
+	return (~sum & 0xffff);
+}
+
+u_int in_cksum_hdr(const struct ip *ip)
+{
+    u_int64_t sum = in_cksumdata((const u_int32_t *)ip, sizeof(struct ip));
+    union q_util q_util;
+    union l_util l_util;
+
+    REDUCE16;
+    return (~sum & 0xffff);
+}
+#else
+
 /*
  * These asm statements require __volatile because they pass information
  * via the condition codes.  GCC does not currently provide a way to specify
@@ -270,3 +457,4 @@ in_cksum_skip(m, len, skip)
 	REDUCE;
 	return (~sum & 0xffff);
 }
+#endif
diff --git a/sys/i386/include/_types.h b/sys/i386/include/_types.h
index 93c2a36cc822..69f439d891c9 100644
--- a/sys/i386/include/_types.h
+++ b/sys/i386/include/_types.h
@@ -54,7 +54,7 @@ typedef	unsigned int		__uint32_t;
 typedef	long long		__int64_t;
 /* LONGLONG */
 typedef	unsigned long long	__uint64_t;
-#elif defined(__GNUC__)
+#elif defined(__GNUC__) || defined(__INTEL_COMPILER)
 typedef	int __attribute__((__mode__(__DI__)))		__int64_t;
 typedef	unsigned int __attribute__((__mode__(__DI__)))	__uint64_t;
 #else
@@ -113,12 +113,12 @@ typedef	__uint32_t	__vm_size_t;
 /*
  * Unusual type definitions.
  */
-#if defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3)
+#if (defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3) && !defined(__INTEL_COMPILER))
 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 /* ! (__GNUC__ post 2.95 || __INTEL_COMPILER) */
+#if defined(__GNUC__) && !defined(__INTEL_COMPILER) && !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 c05befafad35..feba60695a4e 100644
--- a/sys/i386/include/atomic.h
+++ b/sys/i386/include/atomic.h
@@ -75,7 +75,7 @@ void		atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
 #else /* !KLD_MODULE */
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 
 /*
  * For userland, assume the SMP case and use lock prefixes so that
@@ -101,12 +101,12 @@ atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 }							\
 struct __hack
 
-#else /* !__GNUC__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 
 #define ATOMIC_ASM(NAME, TYPE, OP, CONS, V)				\
 extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 
 /*
  * Atomic compare and set, used by the mutex functions
@@ -116,7 +116,7 @@ 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(__GNUC__) || defined(__INTEL_COMPILER)
 
 #if defined(I386_CPU) || defined(CPU_DISABLE_CMPXCHG)
 
@@ -168,9 +168,9 @@ atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
 
 #endif /* defined(I386_CPU) */
 
-#endif /* defined(__GNUC__) */
+#endif /* defined(__GNUC__) || defined(__INTEL_COMPILER) */
 
-#if defined(__GNUC__)
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 
 #if defined(I386_CPU)
 
@@ -226,7 +226,7 @@ struct __hack
 
 #endif	/* defined(I386_CPU) */
 
-#else /* !defined(__GNUC__) */
+#else /* !(defined(__GNUC__) || defined(__INTEL_COMPILER)) */
 
 extern int atomic_cmpset_int(volatile u_int *, u_int, u_int);
 
@@ -234,7 +234,7 @@ 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__) */
+#endif /* defined(__GNUC__) || defined(__INTEL_COMPILER) */
 
 #endif /* KLD_MODULE */
 
@@ -410,7 +410,7 @@ ATOMIC_PTR(subtract)
 
 #undef ATOMIC_PTR
 
-#if defined(__GNUC__)
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 
 static __inline u_int
 atomic_readandclear_int(volatile u_int *addr)
@@ -442,12 +442,12 @@ atomic_readandclear_long(volatile u_long *addr)
 	return (result);
 }
 
-#else /* !defined(__GNUC__) */
+#else /* !(defined(__GNUC__) || defined(__INTEL_COMPILER)) */
 
 extern u_long	atomic_readandclear_long(volatile u_long *);
 extern u_int	atomic_readandclear_int(volatile u_int *);
 
-#endif /* defined(__GNUC__) */
+#endif /* defined(__GNUC__) || defined(__INTEL_COMPILER) */
 
 #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 277badd0400b..38c71bac3968 100644
--- a/sys/i386/include/bus_at386.h
+++ b/sys/i386/include/bus_at386.h
@@ -292,7 +292,7 @@ bus_space_read_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movb (%2),%%al				\n\
@@ -301,6 +301,10 @@ bus_space_read_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (addr), "=c" (count)			:
 		    "r" (bsh + offset), "0" (addr), "1" (count)	:
 		    "%eax", "memory");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -321,7 +325,7 @@ bus_space_read_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movw (%2),%%ax				\n\
@@ -330,6 +334,10 @@ bus_space_read_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (addr), "=c" (count)			:
 		    "r" (bsh + offset), "0" (addr), "1" (count)	:
 		    "%eax", "memory");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -350,7 +358,7 @@ bus_space_read_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	movl (%2),%%eax				\n\
@@ -359,6 +367,10 @@ bus_space_read_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (addr), "=c" (count)			:
 		    "r" (bsh + offset), "0" (addr), "1" (count)	:
 		    "%eax", "memory");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -399,7 +411,7 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inb %w2,%%al				\n\
@@ -409,6 +421,10 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (addr), "=c" (count), "=d" (_port_)	:
 		    "0" (addr), "1" (count), "2" (_port_)	:
 		    "%eax", "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -418,7 +434,7 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -426,6 +442,10 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (addr), "=c" (count), "=S" (_port_)	:
 		    "0" (addr), "1" (count), "2" (_port_)	:
 		    "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -441,7 +461,7 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inw %w2,%%ax				\n\
@@ -451,6 +471,10 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (addr), "=c" (count), "=d" (_port_)	:
 		    "0" (addr), "1" (count), "2" (_port_)	:
 		    "%eax", "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -460,7 +484,7 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -468,6 +492,10 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (addr), "=c" (count), "=S" (_port_)	:
 		    "0" (addr), "1" (count), "2" (_port_)	:
 		    "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -483,7 +511,7 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	inl %w2,%%eax				\n\
@@ -493,6 +521,10 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (addr), "=c" (count), "=d" (_port_)	:
 		    "0" (addr), "1" (count), "2" (_port_)	:
 		    "%eax", "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -502,7 +534,7 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -510,6 +542,10 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (addr), "=c" (count), "=S" (_port_)	:
 		    "0" (addr), "1" (count), "2" (_port_)	:
 		    "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -631,7 +667,7 @@ bus_space_write_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsb					\n\
@@ -640,6 +676,10 @@ bus_space_write_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=S" (addr), "=c" (count)			:
 		    "r" (bsh + offset), "0" (addr), "1" (count)	:
 		    "%eax", "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -660,7 +700,7 @@ bus_space_write_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsw					\n\
@@ -669,6 +709,10 @@ bus_space_write_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=S" (addr), "=c" (count)			:
 		    "r" (bsh + offset), "0" (addr), "1" (count)	:
 		    "%eax", "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -689,7 +733,7 @@ bus_space_write_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsl					\n\
@@ -698,6 +742,10 @@ bus_space_write_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=S" (addr), "=c" (count)			:
 		    "r" (bsh + offset), "0" (addr), "1" (count)	:
 		    "%eax", "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -739,7 +787,7 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsb					\n\
@@ -749,6 +797,10 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=d" (_port_), "=S" (addr), "=c" (count)	:
 		    "0" (_port_), "1" (addr), "2" (count)	:
 		    "%eax", "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -758,7 +810,7 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -766,6 +818,10 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (_port_), "=S" (addr), "=c" (count)	:
 		    "0" (_port_), "1" (addr), "2" (count)	:
 		    "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -781,7 +837,7 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsw					\n\
@@ -791,6 +847,10 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=d" (_port_), "=S" (addr), "=c" (count)	:
 		    "0" (_port_), "1" (addr), "2" (count)	:
 		    "%eax", "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -800,7 +860,7 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -808,6 +868,10 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (_port_), "=S" (addr), "=c" (count)	:
 		    "0" (_port_), "1" (addr), "2" (count)	:
 		    "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -823,7 +887,7 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsl					\n\
@@ -833,6 +897,10 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=d" (_port_), "=S" (addr), "=c" (count)	:
 		    "0" (_port_), "1" (addr), "2" (count)	:
 		    "%eax", "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -842,7 +910,7 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 #endif
 	{
 		int _port_ = bsh + offset;
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
@@ -850,6 +918,10 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 		    "=D" (_port_), "=S" (addr), "=c" (count)	:
 		    "0" (_port_), "1" (addr), "2" (count)	:
 		    "memory", "cc");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 	}
 #endif
@@ -1221,11 +1293,15 @@ 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__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 	if (flags & BUS_SPACE_BARRIER_READ)
 		__asm __volatile("lock; addl $0,0(%%esp)" : : : "memory");
 	else
 		__asm __volatile("" : : : "memory");
+#else
+# ifndef lint
+#  error "no assembler code for your compiler"
+# endif
 #endif
 }
 
diff --git a/sys/i386/include/cpufunc.h b/sys/i386/include/cpufunc.h
index 6d00fff30409..5b092f01d5af 100644
--- a/sys/i386/include/cpufunc.h
+++ b/sys/i386/include/cpufunc.h
@@ -52,7 +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))
 
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 
 static __inline void
 breakpoint(void)
@@ -614,7 +614,7 @@ intr_restore(register_t eflags)
 	write_eflags(eflags);
 }
 
-#else /* !__GNUC__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 
 int	breakpoint(void);
 u_int	bsfl(u_int mask);
@@ -679,7 +679,7 @@ void	wbinvd(void);
 void	write_eflags(u_int ef);
 void	wrmsr(u_int msr, u_int64_t newval);
 
-#endif	/* __GNUC__ */
+#endif	/* __GNUC__ || __INTEL_COMPILER */
 
 void    reset_dbregs(void);
 
diff --git a/sys/i386/include/critical.h b/sys/i386/include/critical.h
index 17f75ebd9c58..8ddc7ef1576d 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);
 
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 
 /*
  *	cpu_critical_enter:
@@ -81,12 +81,12 @@ cpu_critical_exit(void)
 	intr_restore(curthread->td_md.md_savecrit);
 }
 
-#else /* !__GNUC__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 
 void cpu_critical_enter(void);
 void cpu_critical_exit(void);
 
-#endif	/* __GNUC__ */
+#endif        /* __GNUC__ || __INTEL_COMPILER */
 
 __END_DECLS
 
diff --git a/sys/i386/include/endian.h b/sys/i386/include/endian.h
index dc924b1d3046..1bdea69d8a84 100644
--- a/sys/i386/include/endian.h
+++ b/sys/i386/include/endian.h
@@ -40,6 +40,10 @@
 #include <sys/cdefs.h>
 #include <sys/_types.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  * Define the order of 32-bit words in 64-bit words.
  */
@@ -67,7 +71,17 @@
 #define	BYTE_ORDER	_BYTE_ORDER
 #endif
 
-#ifdef __GNUC__
+#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)
 
 #define __word_swap_int_var(x) \
 __extension__ ({ register __uint32_t __X = (x); \
@@ -168,7 +182,7 @@ __bswap16(__uint16_t _x)
 #define	__ntohl(x)	__bswap32(x)
 #define	__ntohs(x)	__bswap16(x)
 
-#else /* !__GNUC__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER_with_FreeBSD_endian) */
 
 /*
  * No optimizations are available for this compiler.  Fall back to
@@ -177,6 +191,10 @@ __bswap16(__uint16_t _x)
  */
 #define	_BYTEORDER_FUNC_DEFINED
 
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER_with_FreeBSD_endian */
+
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* !_MACHINE_ENDIAN_H_ */
diff --git a/sys/i386/include/ieeefp.h b/sys/i386/include/ieeefp.h
index ac67be183eb1..48011f71aea1 100644
--- a/sys/i386/include/ieeefp.h
+++ b/sys/i386/include/ieeefp.h
@@ -98,7 +98,7 @@ typedef enum {
 #define FP_RND_OFF	10	/* round control offset */
 #define FP_STKY_OFF	0	/* sticky flags offset */
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 
 #define	__fldenv(addr)	__asm __volatile("fldenv %0" : : "m" (*(addr)))
 #define	__fnstenv(addr)	__asm __volatile("fnstenv %0" : "=m" (*(addr)))
@@ -151,7 +151,7 @@ __fpsetreg(int _m, int _reg, int _fld, int _off)
 	return _p;
 }
 
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 
 /*
  * SysV/386 FP control interface
diff --git a/sys/i386/include/in_cksum.h b/sys/i386/include/in_cksum.h
index b1cb3f8d98a4..69eb509967ec 100644
--- a/sys/i386/include/in_cksum.h
+++ b/sys/i386/include/in_cksum.h
@@ -53,7 +53,7 @@
  * in the normal case (where there are no options and the header length is
  * therefore always exactly five 32-bit words.
  */
-#ifdef __GNUC__
+#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
 static __inline u_int
 in_cksum_hdr(const struct ip *ip)
 {
@@ -115,7 +115,6 @@ in_pseudo(u_int sum, u_int b, u_int c)
 }
 
 #else
-u_int in_cksum_hdr(const struct ip *);
 #define	in_cksum_update(ip) \
 	do { \
 		int __tmpsum; \
@@ -126,7 +125,12 @@ u_int in_cksum_hdr(const struct ip *);
 #endif
 
 #ifdef _KERNEL
-u_short	in_cksum_skip(struct mbuf *m, int len, int skip); 
+#if !defined(__GNUC__) || 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);
+#endif
+u_short in_cksum_skip(struct mbuf *m, int len, int skip);
 #endif /* _KERNEL */
 
 #endif /* _MACHINE_IN_CKSUM_H_ */
diff --git a/sys/i386/include/ioctl_bt848.h b/sys/i386/include/ioctl_bt848.h
index 7ef237b00e2f..c87c4b9320a4 100644
--- a/sys/i386/include/ioctl_bt848.h
+++ b/sys/i386/include/ioctl_bt848.h
@@ -29,7 +29,7 @@
 #ifndef	_MACHINE_IOCTL_BT848_H_
 #define	_MACHINE_IOCTL_BT848_H_
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 #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 69d033e6573e..c9595ded5bb1 100644
--- a/sys/i386/include/ioctl_meteor.h
+++ b/sys/i386/include/ioctl_meteor.h
@@ -29,7 +29,7 @@
 #ifndef	_MACHINE_IOCTL_METEOR_H_
 #define	_MACHINE_IOCTL_METEOR_H_
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 #warning Include dev/bktr/ioctl_meteor.h instead of this header.
 #endif
 
diff --git a/sys/i386/include/pcpu.h b/sys/i386/include/pcpu.h
index 357f52e4e600..6552ea9fa449 100644
--- a/sys/i386/include/pcpu.h
+++ b/sys/i386/include/pcpu.h
@@ -59,7 +59,7 @@ 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(__GNUC__) || defined (__INTEL_COMPILER)
 
 /*
  * Evaluates to the byte offset of the per-cpu variable name.
diff --git a/sys/i386/include/profile.h b/sys/i386/include/profile.h
index 4af818429894..ecad115f012d 100644
--- a/sys/i386/include/profile.h
+++ b/sys/i386/include/profile.h
@@ -82,7 +82,7 @@ extern int	mcount_lock;
 
 #define	_MCOUNT_DECL static __inline void _mcount
 
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 #define	MCOUNT								\
 void									\
 mcount()								\
@@ -105,13 +105,13 @@ mcount()								\
 	frompc = ((uintfptr_t *)frompc)[1];				\
 	_mcount(frompc, selfpc);					\
 }
-#else	/* __GNUC__ */
+#else	/* !(__GNUC__ || __INTEL_COMPILER) */
 #define	MCOUNT		\
 void			\
 mcount()		\
 {			\
 }
-#endif	/* __GNUC__ */
+#endif	/* __GNUC__ || __INTEL_COMPILER */
 
 typedef	unsigned int	uintfptr_t;
 
@@ -145,7 +145,7 @@ void	stopguprof(struct gmonparam *p);
 #include <sys/cdefs.h>
 
 __BEGIN_DECLS
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 void	mcount(void) __asm(".mcount");
 #endif
 __END_DECLS
diff --git a/sys/i386/include/stdarg.h b/sys/i386/include/stdarg.h
index 128fb33e5c79..ce59c7f4813a 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)
+#if (defined(__GNUC__) && (__GNUC__ == 2 && __GNUC_MINOR__ > 95 || __GNUC__ >= 3) && !defined(__INTEL_COMPILER))
 
 #define	va_start(ap, last) \
 	__builtin_stdarg_start((ap), (last))
@@ -62,12 +62,12 @@ typedef	__va_list	va_list;
 #define	va_end(ap) \
 	__builtin_va_end(ap)
 
-#else	/* ! __GNUC__ post GCC 2.95 */
+#else	/* ! (__GNUC__ post GCC 2.95 || __INTEL_COMPILER) */
 
 #define	__va_size(type) \
 	(((sizeof(type) + sizeof(int) - 1) / sizeof(int)) * sizeof(int))
 
-#ifdef __GNUC__
+#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
 #define va_start(ap, last) \
 	((ap) = (va_list)__builtin_next_arg(last))
 #else	/* non-GNU compiler */
@@ -78,6 +78,11 @@ typedef	__va_list	va_list;
 #define	va_arg(ap, type) \
 	(*(type *)((ap) += __va_size(type), (ap) - __va_size(type)))
 
+#if __ISO_C_VISIBLE >= 1999
+#define	va_copy(dest, src) \
+	((dest) = (src))
+#endif
+
 #define	va_end(ap)
 
 #endif /* __GNUC__ post GCC 2.95 */
diff --git a/sys/i386/isa/npx.c b/sys/i386/isa/npx.c
index 76919fe94870..731733acaec6 100644
--- a/sys/i386/isa/npx.c
+++ b/sys/i386/isa/npx.c
@@ -101,7 +101,7 @@ __FBSDID("$FreeBSD$");
 #define	NPX_DISABLE_I586_OPTIMIZED_BZERO	(1 << 1)
 #define	NPX_DISABLE_I586_OPTIMIZED_COPYIO	(1 << 2)
 
-#if defined(__GNUC__) && !defined(lint)
+#if (defined(__GNUC__) && !defined(lint)) || defined(__INTEL_COMPILER)
 
 #define	fldcw(addr)		__asm("fldcw %0" : : "m" (*(addr)))
 #define	fnclex()		__asm("fnclex")
@@ -119,7 +119,7 @@ __FBSDID("$FreeBSD$");
 				      : : "n" (CR0_TS) : "ax")
 #define	stop_emulating()	__asm("clts")
 
-#else	/* not __GNUC__ */
+#else	/* !((__GNUC__ && !lint ) || __INTEL_COMPILER) */
 
 void	fldcw(caddr_t addr);
 void	fnclex(void);
@@ -136,7 +136,7 @@ void	fxrstor(caddr_t addr);
 void	start_emulating(void);
 void	stop_emulating(void);
 
-#endif	/* __GNUC__ */
+#endif	/* (__GNUC__ && !lint ) || __INTEL_COMPILER */
 
 #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 4c3a21e2135e..31b1c2a16059 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 */
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 __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__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 #error
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 
 #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.
  */
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 __asm("								\n\
 	.text							\n\
 #								\n\
@@ -168,9 +168,9 @@ __cyg_profile_func_exit:					\n\
 .mexitcount_exit:						\n\
 	ret							\n\
 ");
-#else /* !__GNUC__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 #error
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 
 /*
  * Return the time elapsed since the last call.  The units are machine-
@@ -346,7 +346,7 @@ stopguprof(gp)
 }
 
 #else /* !GUPROF */
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 __asm("								\n\
 	.text							\n\
 	.p2align 4,0x90						\n\
@@ -354,7 +354,7 @@ __asm("								\n\
 " __XSTRING(HIDENAME(mexitcount)) ":				\n\
 	ret							\n\
 ");
-#else /* !__GNUC__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 #error
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 #endif /* GUPROF */
diff --git a/sys/kern/subr_prof.c b/sys/kern/subr_prof.c
index b31e516bcc86..7fed7e9b71d6 100644
--- a/sys/kern/subr_prof.c
+++ b/sys/kern/subr_prof.c
@@ -225,7 +225,7 @@ kmstartup(dummy)
 
 	startguprof(p);
 	for (i = 0; i < CALIB_SCALE; i++)
-#if defined(__i386__) && __GNUC__ >= 2
+#if defined(__i386__) && (__GNUC__ >= 2 || defined(__INTEL_COMPILER))
 		__asm("pushl %0; call __mcount; popl %%ecx"
 		      :
 		      : "i" (profil)
@@ -238,7 +238,7 @@ kmstartup(dummy)
 
 	startguprof(p);
 	for (i = 0; i < CALIB_SCALE; i++)
-#if defined(__i386__) && __GNUC__ >= 2
+#if defined(__i386__) && (__GNUC__ >= 2 || defined(__INTEL_COMPILER))
 		    __asm("call " __XSTRING(HIDENAME(mexitcount)) "; 1:"
 			  : : : "ax", "bx", "cx", "dx", "memory");
 	__asm("movl $1b,%0" : "=rm" (tmp_addr));
@@ -550,7 +550,7 @@ addupc_task(struct thread *td, uintptr_t pc, u_int ticks)
 	PROC_UNLOCK(p);
 }
 
-#if defined(__i386__) && __GNUC__ >= 2
+#if defined(__i386__) && __GNUC__ >= 2 && !defined(__INTEL_COMPILER)
 /*
  * Support for "--test-coverage --profile-arcs" in GCC.
  *
diff --git a/sys/libkern/quad.h b/sys/libkern/quad.h
index 0e48e1232db8..6f636a57310d 100644
--- a/sys/libkern/quad.h
+++ b/sys/libkern/quad.h
@@ -108,15 +108,5 @@ u_quad_t	__udivdi3(u_quad_t a, u_quad_t b);
 u_quad_t	__umoddi3(u_quad_t a, u_quad_t b);
 int		__ucmpdi2(u_quad_t a, u_quad_t b);
 
-/*
- * XXX
- * Compensate for gcc 1 vs gcc 2.  Gcc 1 defines ?sh?di3's second argument
- * as u_quad_t, while gcc 2 correctly uses int.  Unfortunately, we still use
- * both compilers.
- */
-#if __GNUC__ >= 2
 typedef unsigned int	qshift_t;
-#else
-typedef u_quad_t	qshift_t;
-#endif
 #endif /* _LIBKERN_QUAD_H */
diff --git a/sys/netatm/atm_ioctl.h b/sys/netatm/atm_ioctl.h
index 43bc86f39e5d..1dc14b52c544 100644
--- a/sys/netatm/atm_ioctl.h
+++ b/sys/netatm/atm_ioctl.h
@@ -421,7 +421,7 @@ struct air_phy_stat_rsp {
 /*
  * PF_ATM ioctls
  */
-#if !defined(__GNUC__)
+#if !(defined(__GNUC__) || defined(__INTEL_COMPILER))
 #define	AIOCCFG		_IOW(A, 128, struct atmcfgreq)	/* Configure i/f */
 #define	AIOCADD		_IOW(A, 129, struct atmaddreq)	/* Add (e.g. PVC) */
 #define	AIOCDEL		_IOW(A, 130, struct atmdelreq)	/* Delete */
diff --git a/sys/sys/assym.h b/sys/sys/assym.h
index d3c8291e2d2b..9316a4e4996c 100644
--- a/sys/sys/assym.h
+++ b/sys/sys/assym.h
@@ -31,13 +31,14 @@
 #ifndef _SYS_ASSYM_H_
 #define	_SYS_ASSYM_H_
 
+#define	ASSYM_BIAS		0x10000	/* avoid zero-length arrays */
 #define	ASSYM_ABS(value)	((value) < 0 ? -((value) + 1) + 1ULL : (value))
 
-#define	ASSYM(name, value)					\
-char name ## sign[(value) < 0 ? 1 : 0];				\
-char name ## w0[ASSYM_ABS(value) & 0xFFFFU];			\
-char name ## w1[(ASSYM_ABS(value) & 0xFFFF0000UL) >> 16];	\
-char name ## w2[(ASSYM_ABS(value) & 0xFFFF00000000ULL) >> 32];	\
-char name ## w3[(ASSYM_ABS(value) & 0xFFFF000000000000ULL) >> 48]
+#define	ASSYM(name, value)						      \
+char name ## sign[((value) < 0 ? 1 : 0) + ASSYM_BIAS];			      \
+char name ## w0[(ASSYM_ABS(value) & 0xFFFFU) + ASSYM_BIAS];		      \
+char name ## w1[((ASSYM_ABS(value) & 0xFFFF0000UL) >> 16) + ASSYM_BIAS];      \
+char name ## w2[((ASSYM_ABS(value) & 0xFFFF00000000ULL) >> 32) + ASSYM_BIAS]; \
+char name ## w3[((ASSYM_ABS(value) & 0xFFFF000000000000ULL) >> 48) + ASSYM_BIAS]
 
 #endif /* !_SYS_ASSYM_H_ */
diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h
index f8eae841b38c..dd4acd903d72 100644
--- a/sys/sys/cdefs.h
+++ b/sys/sys/cdefs.h
@@ -51,7 +51,7 @@
 /*
  * Macro to test if we're using a specific version of gcc or later.
  */
-#ifdef __GNUC__
+#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
 #define	__GNUC_PREREQ__(ma, mi)	\
 	(__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi))
 #else
@@ -83,9 +83,9 @@
 #if defined(__cplusplus)
 #define	__inline	inline		/* convert to C++ keyword */
 #else
-#ifndef __GNUC__
+#if !(defined(__GNUC__) || defined(__INTEL_COMPILER))
 #define	__inline			/* delete GCC keyword */
-#endif /* !__GNUC__ */
+#endif /* !(__GNUC__ || __INTEL_COMPILER) */
 #endif /* !__cplusplus */
 
 #else	/* !(__STDC__ || __cplusplus) */
@@ -93,7 +93,7 @@
 #define	__CONCAT(x,y)	x/**/y
 #define	__STRING(x)	"x"
 
-#ifndef __GNUC__
+#if !(defined(__GNUC__) || defined(__INTEL_COMPILER))
 #define	__const				/* delete pseudo-ANSI C keywords */
 #define	__inline
 #define	__signed
@@ -112,7 +112,7 @@
 #define	signed
 #define	volatile
 #endif	/* !NO_ANSI_KEYWORDS */
-#endif	/* !__GNUC__ */
+#endif	/* !(__GNUC__ || __INTEL_COMPILER) */
 #endif	/* !(__STDC__ || __cplusplus) */
 
 /*
@@ -132,12 +132,12 @@
 #define	__aligned(x)
 #define	__section(x)
 #else
-#if !__GNUC_PREREQ__(2, 5)
+#if !__GNUC_PREREQ__(2, 5) && !defined(__INTEL_COMPILER)
 #define	__dead2
 #define	__pure2
 #define	__unused
 #endif
-#if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7
+#if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7 && !defined(__INTEL_COMPILER)
 #define	__dead2		__attribute__((__noreturn__))
 #define	__pure2		__attribute__((__const__))
 #define	__unused
@@ -151,9 +151,17 @@
 #define	__aligned(x)	__attribute__((__aligned__(x)))
 #define	__section(x)	__attribute__((__section__(x)))
 #endif
+#if defined(__INTEL_COMPILER)
+#define __dead2		__attribute__((__noreturn__))
+#define __pure2		__attribute__((__const__))
+#define __unused	__attribute__((__unused__))
+#define __packed	__attribute__((__packed__))
+#define __aligned(x)	__attribute__((__aligned__(x)))
+#define __section(x)	__attribute__((__section__(x)))
+#endif
 #endif
 
-#if __GNUC_PREREQ__(3, 1)
+#if __GNUC_PREREQ__(3, 1) || (defined(__INTEL_COMPILER) && __INTEL_COMPILER >= 800)
 #define	__always_inline	__attribute__((__always_inline__))
 #else
 #define	__always_inline
@@ -166,11 +174,11 @@
 #endif
 
 /* XXX: should use `#if __STDC_VERSION__ < 199901'. */
-#if !__GNUC_PREREQ__(2, 7)
+#if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
 #define	__func__	NULL
 #endif
 
-#if __GNUC__ >= 2 && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
+#if (defined(__INTEL_COMPILER) || (defined(__GNUC__) && __GNUC__ >= 2)) && !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901
 #define	__LONG_LONG_SUPPORTED
 #endif
 
@@ -236,7 +244,7 @@
  * that are known to support the features properly (old versions of gcc-2
  * didn't permit keeping the keywords out of the application namespace).
  */
-#if !__GNUC_PREREQ__(2, 7)
+#if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
 #define	__printflike(fmtarg, firstvararg)
 #define	__scanflike(fmtarg, firstvararg)
 #else
@@ -247,16 +255,18 @@
 #endif
 
 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
-#if __FreeBSD_cc_version >= 300001
+#if __FreeBSD_cc_version >= 300001 && defined(__GNUC__) && !defined(__INTEL_COMPILER)
 #define	__printf0like(fmtarg, firstvararg) \
 	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
 #else
 #define	__printf0like(fmtarg, firstvararg)
 #endif
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifndef __INTEL_COMPILER
 #define	__strong_reference(sym,aliassym)	\
 	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
+#endif
 #ifdef __STDC__
 #define	__weak_reference(sym,alias)	\
 	__asm__(".weak " #alias);	\
@@ -274,9 +284,9 @@
 	__asm__(".asciz \"msg\"");	\
 	__asm__(".previous")
 #endif	/* __STDC__ */
-#endif	/* __GNUC__ */
+#endif	/* __GNUC__ || __INTEL_COMPILER */
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 #define	__IDSTRING(name,string)	__asm__(".ident\t\"" string "\"")
 #else
 /*
diff --git a/sys/sys/dir.h b/sys/sys/dir.h
index 670850ac37ef..1f74c60b6d1c 100644
--- a/sys/sys/dir.h
+++ b/sys/sys/dir.h
@@ -37,7 +37,7 @@
 #ifndef _SYS_DIR_H_
 #define	_SYS_DIR_H_
 
-#if __GNUC__
+#if defined(__GNUC__) || defined (__INTEL_COMPILER)
 #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 c18b22dda7ba..6666b22ed384 100644
--- a/sys/sys/ioctl.h
+++ b/sys/sys/ioctl.h
@@ -43,7 +43,7 @@
 #define	_SYS_IOCTL_H_
 
 #ifdef _KERNEL
-#if __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 #warning "Don't #include ioctl.h in the kernel.  Include xxxio.h instead."
 #endif
 #endif
diff --git a/sys/sys/linker_set.h b/sys/sys/linker_set.h
index f025e18db14d..5550ed1d714e 100644
--- a/sys/sys/linker_set.h
+++ b/sys/sys/linker_set.h
@@ -39,16 +39,16 @@
 /*
  * Private macros, not to be used outside this header file.
  */
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 #define __MAKE_SET(set, sym)						\
 	static void const * const __set_##set##_sym_##sym 		\
 	__section("set_" #set) __unused = &sym
-#else /* !__GNUC__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 #ifndef lint
-#error "This file needs to be compiled by GCC or lint"
+#error "This file needs to be compiled by GCC, an Intel compiler or lint"
 #endif /* lint */
 #define __MAKE_SET(set, sym)	extern void const * const (__set_##set##_sym_##sym)
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 
 /*
  * Public macros.
diff --git a/sys/sys/param.h b/sys/sys/param.h
index 85b0b07e3087..a403f8db8bba 100644
--- a/sys/sys/param.h
+++ b/sys/sys/param.h
@@ -59,7 +59,7 @@
  * scheme is:  <major><two digit minor><0 if release branch, otherwise 1>xx
  */
 #undef __FreeBSD_version
-#define __FreeBSD_version 502107	/* Master, propagated to newvers */
+#define __FreeBSD_version 502108	/* Master, propagated to newvers */
 
 #ifndef LOCORE
 #include <sys/types.h>
diff --git a/sys/sys/queue.h b/sys/sys/queue.h
index b8758472bffa..ae79a21f89fa 100644
--- a/sys/sys/queue.h
+++ b/sys/sys/queue.h
@@ -521,7 +521,7 @@ struct quehead {
 	struct quehead *qh_rlink;
 };
 
-#ifdef	__GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 
 static __inline void
 insque(void *a, void *b)
@@ -545,12 +545,12 @@ remque(void *a)
 	element->qh_rlink = 0;
 }
 
-#else /* !__GNUC__ */
+#else /* !(__GNUC__ || __INTEL_COMPILER) */
 
 void	insque(void *a, void *b);
 void	remque(void *a);
 
-#endif /* __GNUC__ */
+#endif /* __GNUC__ || __INTEL_COMPILER */
 
 #endif /* _KERNEL */
 
diff --git a/sys/sys/syslimits.h b/sys/sys/syslimits.h
index 7f14ae92c156..ed14be74a79a 100644
--- a/sys/sys/syslimits.h
+++ b/sys/sys/syslimits.h
@@ -38,7 +38,7 @@
 #define _SYS_SYSLIMITS_H_
 
 #if !defined(_KERNEL) && !defined(_LIMITS_H_) && !defined(_SYS_PARAM_H_)
-#if __GNUC__
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
 #warning "No user-serviceable parts inside."
 #endif
 #endif