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

1 files changed, 14 insertions, 1 deletions

diff --git a/sys/conf/kmod.mk b/sys/conf/kmod.mk
index 0766b71..c303061 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}