Initial skeleton of Subzero.

Makefile

+# The following variables will likely need to be modified, depending on where
+# and how you built LLVM & Clang. They can be overridden in a command-line
+# invocation of make, like:
+#
+#   make LLVM_SRC_PATH=<path> LLVM_BIN_PATH=<path> ...
+#
+
+# LLVM_SRC_PATH is the path to the root of the checked out source code. This
+# directory should contain the configure script, the include/ and lib/
+# directories of LLVM, Clang in tools/clang/, etc.
+# Alternatively, if you're building vs. a binary download of LLVM, then
+# LLVM_SRC_PATH can point to the main untarred directory.
+LLVM_SRC_PATH ?= ../llvm
+
+# LLVM_BIN_PATH is the directory where binaries are placed by the LLVM build
+# process. It should contain the tools like opt, llc and clang. The default
+# reflects a debug build with autotools (configure & make).
+LLVM_BIN_PATH ?= $(shell readlink -e \
+        ../../out/llvm_i686_linux_work/Release+Asserts/bin)
+
+$(info -----------------------------------------------)
+$(info Using LLVM_SRC_PATH = $(LLVM_SRC_PATH))
+$(info Using LLVM_BIN_PATH = $(LLVM_BIN_PATH))
+$(info -----------------------------------------------)
+
+LLVM_CXXFLAGS := `$(LLVM_BIN_PATH)/llvm-config --cxxflags`
+LLVM_LDFLAGS := `$(LLVM_BIN_PATH)/llvm-config --ldflags --libs`
+
+# It's recommended that CXX matches the compiler you used to build LLVM itself.
+OPTLEVEL := -O0
+CXX := g++
+CXXFLAGS := -Wall -Werror -fno-rtti -fno-exceptions \
+        $(OPTLEVEL) -g $(LLVM_CXXFLAGS) -m32
+LDFLAGS := -m32
+
+SRCS= \
+        IceCfg.cpp \
+        IceCfgNode.cpp \
+        IceGlobalContext.cpp \
+        IceInst.cpp \
+        IceOperand.cpp \
+        IceTypes.cpp \
+        llvm2ice.cpp
+
+OBJS=$(patsubst %.cpp, build/%.o, $(SRCS))
+
+# Keep all the first target so it's the default.
+all: llvm2ice
+
+.PHONY: all
+
+llvm2ice: $(OBJS)
+        $(CXX) $(LDFLAGS) -o $@ $^ $(LLVM_LDFLAGS) -ldl
+
+# TODO: Be more precise than "*.h" here and elsewhere.
+$(OBJS): build/%.o: src/%.cpp src/*.h src/*.def
+        $(CXX) -c $(CXXFLAGS) $< -o $@
+
+$(OBJS): | build
+
+build:
+        @mkdir -p $@
+
+check: llvm2ice
+        LLVM_BIN_PATH=$(LLVM_BIN_PATH) \
+        $(LLVM_SRC_PATH)/utils/lit/lit.py -sv tests_lit
+
+# TODO: Fix the use of wildcards.
+format:
+        $(LLVM_BIN_PATH)/clang-format -style=LLVM -i \
+        src/Ice*.h src/Ice*.cpp src/llvm2ice.cpp
+
+clean:
+        rm -rf llvm2ice *.o build/