Prepare to commit to gollvm

CMakeLists.txt

@@ -18,6 +18,10 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")
 set(GOLLVM_USE_SPLIT_STACK ON CACHE BOOL "use split stack by default")
 set(GOLLVM_DEFAULT_LINKER gold CACHE STRING "default linker for Go links")
 
+string(REGEX REPLACE "-" " " lht_components ${LLVM_DEFAULT_TARGET_TRIPLE})
+separate_arguments(lht_components)
+list(GET lht_components 0 llarch)
+
 include(CmakeUtils)
 include(AddGollvm)
 
@@ -39,13 +43,25 @@ set(EXTCC "CC=${CMAKE_C_COMPILER}" "CXX=${CMAKE_CXX_COMPILER}")
 
 set(gollvm_binroot "${CMAKE_CURRENT_BINARY_DIR}")
 
+# Set MPN path according to the target processor
+
+if( ${llarch} STREQUAL "x86_64" )
+  set(MPN_PATH "x86_64 generic")
+elseif( ${llarch} STREQUAL "aarch64" )
+  set(MPN_PATH "arm64 generic")
+elseif( ${llarch} STREQUAL "riscv64" )
+  set(MPN_PATH "riscv generic")
+else()
+  message(SEND_ERROR "Arch ${llarch} not yet supported")
+endif()
+
 externalproject_add(libgmp
   URL https://gmplib.org/download/gmp/gmp-6.2.0.tar.bz2 https://mirrors.kernel.org/gnu/gmp/gmp-6.2.0.tar.bz2
   URL_MD5 c24161e0dd44cae78cd5f67193492a21
   DOWNLOAD_DIR ${CMAKE_CURRENT_BINARY_DIR}/external-downloads
   BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/external/gmp-build
   SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/external/gmp
-  CONFIGURE_COMMAND <SOURCE_DIR>/configure --prefix=${EXTINSTALLDIR} ${EXTCPPFLAGS} ${EXTLDFLAGS} ${EXTCC}
+  CONFIGURE_COMMAND <SOURCE_DIR>/configure --prefix=${EXTINSTALLDIR} ${EXTCPPFLAGS} ${EXTLDFLAGS} ${EXTCC} --build=${LLVM_HOST_TRIPLE} --host=${LLVM_DEFAULT_TARGET_TRIPLE} MPN_PATH=${MPN_PATH}
   BUILD_COMMAND make -j${PROCESSOR_COUNT} install
   LOG_CONFIGURE 1
   LOG_BUILD 1
@@ -59,7 +75,7 @@ externalproject_add(libmpfr
   DOWNLOAD_DIR ${CMAKE_CURRENT_BINARY_DIR}/external-downloads
   BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/external/mpfr
   SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/external/mpfr
-  CONFIGURE_COMMAND <SOURCE_DIR>/configure --with-gmp=${CMAKE_CURRENT_BINARY_DIR}/external/gmp --prefix=${EXTINSTALLDIR} ${EXTCPPFLAGS} ${EXTLDFLAGS} ${EXTCC}
+  CONFIGURE_COMMAND <SOURCE_DIR>/configure --with-gmp=${CMAKE_CURRENT_BINARY_DIR}/external/gmp --prefix=${EXTINSTALLDIR} ${EXTCPPFLAGS} ${EXTLDFLAGS} ${EXTCC} -build=${LLVM_HOST_TRIPLE} --host=${LLVM_DEFAULT_TARGET_TRIPLE}
   BUILD_COMMAND make -j${PROCESSOR_COUNT} install
   LOG_CONFIGURE 1
   LOG_BUILD 1
@@ -74,7 +90,7 @@ externalproject_add(libmpc
   BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/external/mpc
   SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/external/mpc
   PREFIX ${EXTINSTALLDIR}
-  CONFIGURE_COMMAND <SOURCE_DIR>/configure --with-gmp=${CMAKE_CURRENT_BINARY_DIR}/external/gmp --with-mpfr=${CMAKE_CURRENT_BINARY_DIR}/external/mpfr --prefix=${EXTINSTALLDIR} ${EXTCPPFLAGS} ${EXTLDFLAGS} ${EXTCC}
+  CONFIGURE_COMMAND <SOURCE_DIR>/configure --with-gmp=${CMAKE_CURRENT_BINARY_DIR}/external/gmp --with-mpfr=${CMAKE_CURRENT_BINARY_DIR}/external/mpfr --prefix=${EXTINSTALLDIR} ${EXTCPPFLAGS} ${EXTLDFLAGS} ${EXTCC} -build=${LLVM_HOST_TRIPLE} --host=${LLVM_DEFAULT_TARGET_TRIPLE}
   BUILD_COMMAND make -j${PROCESSOR_COUNT} install
   LOG_CONFIGURE 1
   LOG_BUILD 1

README.md

@@ -16,6 +16,7 @@ source tree, then within the LLVM tree you check out additional git repos.
  * [Invoking cmake and ninja](#cmakeninja)
  * [Installing gollvm](#installing)
  * [Using an installed copy of gollvm](#using)
+ * [Crosscompiling gollvm](#crosscompiling)
  * [Information for gollvm developers](#developers)
 
 [FAQ](#FAQ)
@@ -120,6 +121,58 @@ hi mom!
 %
 ```
 
+## Crosscompiling gollvm  <a name="crosscompiling"></a>
+You need a working version of gollvm on host system to cross compile. The following script will build and install gollvm on a cross compile system.
+
+```
+#!/bin/bash
+set -e
+mkdir -p build
+cd build
+
+RISCV=$HOME/toolchain
+SOURCE=$HOME/llvm-project/llvm
+TRIPLE=riscv64-unknown-linux-gnu
+INSTALL=/tmp/gollvm-install
+
+# host
+cmake -G Ninja -S $SOURCE -B build-x86 \
+    -DCMAKE_INSTALL_PREFIX=install-x86 \
+    -DCMAKE_BUILD_TYPE=Debug \
+    -DLLVM_USE_LINKER=bfd \
+    -DGOLLVM_DEFAULT_LINKER=bfd \
+    -DLLVM_TARGET_ARCH="X86-64,RISCV64" \
+    -DLLVM_TARGETS_TO_BUILD="X86;RISCV"
+
+# crosscompile
+cmake -G Ninja -S $SOURCE -B build-riscv \
+    -DCMAKE_INSTALL_PREFIX=$INSTALL \
+    -DCMAKE_BUILD_TYPE=Debug \
+    -DLLVM_USE_LINKER=bfd \
+    -DGOLLVM_DEFAULT_LINKER=bfd \
+    -DCMAKE_CROSSCOMPILING=True \
+    -DLLVM_TARGET_ARCH=RISCV64 \
+    -DLLVM_DEFAULT_TARGET_TRIPLE=$TRIPLE \
+    -DLLVM_TARGETS_TO_BUILD=RISCV \
+    -DCMAKE_C_COMPILER=$RISCV/bin/$TRIPLE-gcc \
+    -DCMAKE_CXX_COMPILER=$RISCV/bin/$TRIPLE-g++ \
+    -DLLVM_TABLEGEN=$PWD/build-x86/bin/llvm-tblgen \
+    -DGOLLVM_DRIVER_DIR=$PWD/build-x86/bin \
+    -DGOLLVM_EXTRA_GOCFLAGS="--target=$TRIPLE \
+                             --gcc-toolchain=$RISCV/ \
+                             --sysroot=$RISCV/sysroot" \
+    -DGOLLVM_USE_SPLIT_STACK=OFF \
+    -DCMAKE_C_FLAGS=-latomic \
+    -DCMAKE_CXX_FLAGS=-latomic
+
+
+# build gollvm crosscompiler
+ninja -C build-x86 llvm-goc llvm-goc-token llvm-godumpspec
+
+# cross compile gollvm, go tools and install
+ninja -C build-riscv install-gollvm
+```
+
 # Information for gollvm developers <a name="developers"></a>
 
 ## Source code structure
@@ -269,7 +322,7 @@ inlining, vectorization, register allocation, etc.
 
 ## Which architectures and operating systems are supported for gollvm? <a name="supported"></a>
 
-Gollvm is currently supported only for x86_64 and aarch64 Linux.
+Gollvm is currently supported only for x86_64, aarch64 and riscv64 Linux.
 
 ## How does the gollvm runtime differ from the main Go runtime?  <a name="runtimediffs"></a>