How to compile Xeon phi patched gcc from source? - linux

Question

I downloaded the MPSS software stack version 3.5.2 source code from the intel website. I am trying to compile the xeon phi ported GCC (ported from GCC 4.7.0) from source and install it in a local subdirectory. However, I am getting the following error-
k1om-mpss-linux-gcc -dumpspecs > tmp-specs
/bin/sh: k1om-mpss-linux-gcc: command not found
My configuration is as follows-
# The below directory contains the cross compiled libs
# like assembler and linker
export PATH=$HOME/xeon-phi-gcc/bin
# The configure command
../xeon-phi-gcc/configure \
--build=x86_64-linux \
--host=x86_64-mpsssdk-linux \
--target=k1om-mpss-linux \
--prefix=$HOME/cross-gcc \
--enable-languages=c,c++ \
--with-sysroot=/opt/mpss/3.5.1/sysroots/k1om-mpss-linux \
--disable-multilib
# Compiling
make
Why is the Makefile calling k1om-mpss-linux-gcc ? Shouldn't this be the cross compiled gcc binary after make completes ? How can I fix this or what am I missing ?
EDIT 1: I changed the config parameters to --build=x86_64-mpsssdk-linux --host=x86_64-mpsssdk-linux. I get the following errors now-
In file included from gtype-desc.c:30:0:
../../gcc-4.7.0+mpss3.5.2/gcc/tree.h:3179:11: warning: identifier ‘thread_local’ conflicts with C++ keyword [-Wc++-compat]
unsigned thread_local : 1;
^
gtype-desc.c:8696:18: error: subscripted value is neither array nor pointer nor vector
sizeof (x_rtl[0]),
^
gtype-desc.c:8815:36: error: subscripted value is neither array nor pointer nor vector
sizeof (default_target_libfuncs[0]),
^
gtype-desc.c:8899:31: error: subscripted value is neither array nor pointer nor vector
sizeof (default_target_rtl[0]),
^
gtype-desc.c:8920:31: error: subscripted value is neither array nor pointer nor vector
sizeof (default_target_rtl[0]),
^
gtype-desc.c:8927:31: error: subscripted value is neither array nor pointer nor vector
sizeof (default_target_rtl[0]),
^
gtype-desc.c:8934:31: error: subscripted value is neither array nor pointer nor vector
sizeof (default_target_rtl[0]),
^
gtype-desc.c is a machine generated file.
EDIT 2: I am now getting the error-
/tmp/cc4aDvmI.s: Assembler messages:
/tmp/cc4aDvmI.s:94: Error: no such instruction: `kmov %esi,%k2'
/tmp/cc4aDvmI.s:147: Error: no such instruction: `kmov %edi,%k2'
/tmp/cc4aDvmI.s:255: Error: no such instruction: `kmov %r8d,%k2'
/tmp/cc4aDvmI.s:258: Error: no such instruction: `vpackstorelq %zmm0,(%rsp){%k2}'
How can I fix this ? These seem to be vector instructions but I thought that the gcc cross compiler didn't support vector instructions.

Answer 1

Your --build, --host and --target machine are all different (this is referenced as canadian compile, which is slightly different from cross compile, where --build and --host are the same). This means that an additional compiler is needed to build target libraries.
From GCC docs (6.1):
If build and host are different, you must have already built and installed a cross compiler that will be used to build the target libraries (if you configured with --target=foo-bar, this compiler will be called foo-bar-gcc).
So, as your --target is k1om-mpss-linux, you need that version of compiler in order to build GCC.
The result will be a GCC compiled on a --build machine that will run on a --host machine and that will produce code that can run on a --target machine.