This are the build infrastructure changes to allow to use the

Intel C/C++ compiler (lang/icc) to build the kernel.

The icc CPUTYPE CFLAGS use icc v7 syntax, icc v8 moans about them, but
doesn't abort. They also produce CPU specific code (new instructions
of the CPU, not only CPU specific scheduling), so if you get coredumps
with signal 4 (SIGILL, illegal instruction) you've used the wrong
CPUTYPE.

Incarnations of this patch survive gcc compiles and my make universe.
I use it on my desktop.

To use it update share/mk, add
	/usr/local/intel/compiler70/ia32/bin	(icc v7, works)
or
	/usr/local/intel_cc_80/bin		(icc v8, doesn't work)
to your PATH, make sure you have a new kernel compile directory
(e.g. MYKERNEL_icc) and run
	CFLAGS="-O2 -ip" CC=icc make depend
	CFLAGS="-O2 -ip" CC=icc make
in it.

Don't compile with -ipo, the build infrastructure uses ld directly to
link the kernel and the modules, but -ipo needs the link step to be
performed with Intel's linker.

Problems with icc v8:
 - panic: npx0 cannot be emulated on an SMP system
 - UP: first start of /bin/sh results in a FP exception

Parts of this commit contains suggestions or submissions from
Marius Strobl <marius@alchemy.franken.de>.

Reviewed by:	silence on -arch
Submitted by:	netchild

4 files changed, 61 insertions, 6 deletions

diff --git a/sys/conf/files b/sys/conf/files
index 73d1df7e14fb..339f7db1b620 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -6,12 +6,12 @@
 #
 aicasm				optional ahc				   \
 	dependency 	"$S/dev/aic7xxx/aicasm/*.[chyl]"		   \
-	compile-with	"${MAKE} -f $S/dev/aic7xxx/aicasm/Makefile MAKESRCPATH=$S/dev/aic7xxx/aicasm" \
+	compile-with	"CC=${CC} ${MAKE} -f $S/dev/aic7xxx/aicasm/Makefile MAKESRCPATH=$S/dev/aic7xxx/aicasm" \
 	no-obj no-implicit-rule						   \
 	clean		"aicasm* y.tab.h"
 aicasm				optional ahd				   \
 	dependency 	"$S/dev/aic7xxx/aicasm/*.[chyl]"		   \
-	compile-with	"${MAKE} -f $S/dev/aic7xxx/aicasm/Makefile MAKESRCPATH=$S/dev/aic7xxx/aicasm" \
+	compile-with	"CC=${CC} ${MAKE} -f $S/dev/aic7xxx/aicasm/Makefile MAKESRCPATH=$S/dev/aic7xxx/aicasm" \
 	no-obj no-implicit-rule						   \
 	clean		"aicasm* y.tab.h"
 aic7xxx_{seq.h,reg.h,reg_print.c}       optional ahc                       \
diff --git a/sys/conf/kern.mk b/sys/conf/kern.mk
index dc369df738b7..133f1cf4a66c 100644
--- a/sys/conf/kern.mk
+++ b/sys/conf/kern.mk
@@ -6,9 +6,14 @@
 # Note that the newly added -Wcast-qual is responsible for generating 
 # most of the remaining warnings.  Warnings introduced with -Wall will
 # also pop up, but are easier to fix.
+.if ${CC} == "icc"
+#CWARNFLAGS=	-w2	# use this if you are terribly bored
+CWARNFLAGS=
+.else
 CWARNFLAGS?=	-Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \
 		-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \
 		-fformat-extensions -std=c99
+.endif
 #
 # The following flags are next up for working on:
 #	-W
@@ -22,7 +27,7 @@ CWARNFLAGS?=	-Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \
 # use of code cache tag lines) and uses more stack (less efficient use of data
 # cache tag lines)
 #
-.if ${MACHINE_ARCH} == "i386"
+.if ${MACHINE_ARCH} == "i386" && ${CC} != "icc"
 CFLAGS+=	-mno-align-long-strings -mpreferred-stack-boundary=2
 INLINE_LIMIT?=	8000
 .endif
@@ -80,4 +85,12 @@ INLINE_LIMIT?=	15000
 # GCC 3.0 and above like to do certain optimizations based on the
 # assumption that the program is linked against libc.  Stop this.
 #
+.if ${CC} == "icc"
+CFLAGS+=	-nolib_inline
+.else
 CFLAGS+=	-ffreestanding
+.endif
+
+.if ${CC} == "icc"
+CFLAGS+=	-restrict
+.endif
diff --git a/sys/conf/kern.pre.mk b/sys/conf/kern.pre.mk
index 9732ffb94089..4a786a54c807 100644
--- a/sys/conf/kern.pre.mk
+++ b/sys/conf/kern.pre.mk
@@ -16,14 +16,28 @@ NM?=		nm
 OBJCOPY?=	objcopy
 SIZE?=		size
 
+.if ${CC} == "icc"
+COPTFLAGS?=-O
+.else
 COPTFLAGS?=-O -pipe
-.if ${COPTFLAGS:M-O[23s]} != ""
+. if ${COPTFLAGS:M-O[23s]} != ""
 COPTFLAGS+= -fno-strict-aliasing
+. endif
 .endif
 .if !defined(NO_CPU_COPTFLAGS)
+. if ${CC} == "icc"
+COPTFLAGS+= ${_ICC_CPUCFLAGS:C/(-x[^M^K^W]+)[MKW]+|-x[MKW]+/\1/}
+. else
 COPTFLAGS+= ${_CPUCFLAGS}
+. endif
+.endif
+.if ${CC} == "icc"
+NOSTDINC= -X
+.else
+NOSTDINC= -nostdinc
 .endif
-INCLUDES= -nostdinc -I- ${INCLMAGIC} -I. -I$S
+
+INCLUDES= ${NOSTDINC} -I- ${INCLMAGIC} -I. -I$S
 
 # This hack lets us use the Intel ACPICA code without spamming a new 
 # include path into 100+ source files.
@@ -43,19 +57,34 @@ INCLUDES+= -I$S/contrib/ngatm
 
 COPTS=	${INCLUDES} -D_KERNEL -include opt_global.h
 CFLAGS=	${COPTFLAGS} ${CWARNFLAGS} ${DEBUG} ${COPTS}
+.if ${CC} != "icc"
 CFLAGS+= -fno-common -finline-limit=${INLINE_LIMIT}
 WERROR?= -Werror
+.endif
 
 # XXX LOCORE means "don't declare C stuff" not "for locore.s".
 ASM_CFLAGS= -x assembler-with-cpp -DLOCORE ${CFLAGS}
 
 .if defined(PROFLEVEL) && ${PROFLEVEL} >= 1
+. if ${CC} == "icc"
+CFLAGS+=	-DGPROF
+. else
 CFLAGS+=	-DGPROF -falign-functions=16
+. endif
 .if ${PROFLEVEL} >= 2
 CFLAGS+=	-DGPROF4 -DGUPROF
+. if ${CC} == "icc"
+# XXX doesn't work yet
+#PROF=	-prof_gen
+. else
 PROF=	-finstrument-functions
+. endif
 .else
+. if ${CC} == "icc"
+PROF=	-p
+. else
 PROF=	-pg
+. endif
 .endif
 .endif
 DEFINED_PROF=	${PROF}
diff --git a/sys/conf/kmod.mk b/sys/conf/kmod.mk
index 0766b71540aa..c3030619064d 100644
--- a/sys/conf/kmod.mk
+++ b/sys/conf/kmod.mk
@@ -70,6 +70,10 @@ OBJCOPY?=	objcopy
 
 .SUFFIXES: .out .o .c .cc .cxx .C .y .l .s .S
 
+.if ${CC} == "icc"
+_ICC_CFLAGS:=	${CFLAGS:C/(-x[^M^K^W]+)[MKW]+|-x[MKW]+/\1/}
+CFLAGS=		${_ICC_CFLAGS}
+.endif
 CFLAGS+=	${COPTS} -D_KERNEL
 CFLAGS+=	-DKLD_MODULE
 
@@ -78,7 +82,12 @@ CFLAGS+=	-DKLD_MODULE
 # such paths after -nostdinc.  It doesn't seem to be possible to
 # add to the front of `make' variable.
 _ICFLAGS:=	${CFLAGS:M-I*}
-CFLAGS+=	-nostdinc -I- ${INCLMAGIC} ${_ICFLAGS}
+.if ${CC} == "icc"
+NOSTDINC=	-X
+.else
+NOSTDINC=	-nostdinc
+.endif
+CFLAGS+=	${NOSTDINC} -I- ${INCLMAGIC} ${_ICFLAGS}
 .if defined(KERNBUILDDIR)
 CFLAGS+=       -include ${KERNBUILDDIR}/opt_global.h
 .endif
@@ -102,11 +111,15 @@ CFLAGS+=	-I${DESTDIR}/usr/include
 CFLAGS+=	-I@/../include -I${DESTDIR}/usr/include
 .endif # @
 
+.if ${CC} != "icc"
 CFLAGS+=	-finline-limit=${INLINE_LIMIT}
+.endif
 
 # Disallow common variables, and if we end up with commons from
 # somewhere unexpected, allocate storage for them in the module itself.
+.if ${CC} != "icc"
 CFLAGS+=	-fno-common
+.endif
 LDFLAGS+=	-d -warn-common
 
 CFLAGS+=	${DEBUG_FLAGS}