[RISCV] Add stub backend
This contains just enough for lib/Target/RISCV to compile. Notably a basic
RISCVTargetMachine and RISCVTargetInfo. At this point you can attempt llc
-march=riscv32 myinput.ll and will find it fails due to the lack of
MCAsmInfo.
See http://lists.llvm.org/pipermail/llvm-dev/2016-August/103748.html for
further discussion
Differential Revision: https://reviews.llvm.org/D23560
llvm-svn: 285712
diff --git a/llvm/lib/Target/RISCV/TargetInfo/RISCVTargetInfo.cpp b/llvm/lib/Target/RISCV/TargetInfo/RISCVTargetInfo.cpp
new file mode 100644
index 0000000..3cb657a
--- /dev/null
+++ b/llvm/lib/Target/RISCV/TargetInfo/RISCVTargetInfo.cpp
@@ -0,0 +1,35 @@
+//===-- RISCVTargetInfo.cpp - RISCV Target Implementation -----------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/TargetRegistry.h"
+using namespace llvm;
+
+namespace llvm {
+Target &getTheRISCV32Target() {
+ static Target TheRISCV32Target;
+ return TheRISCV32Target;
+}
+
+Target &getTheRISCV64Target() {
+ static Target TheRISCV64Target;
+ return TheRISCV64Target;
+}
+}
+
+extern "C" void LLVMInitializeRISCVTargetInfo() {
+ RegisterTarget<Triple::riscv32> X(getTheRISCV32Target(), "riscv32",
+ "32-bit RISC-V");
+ RegisterTarget<Triple::riscv64> Y(getTheRISCV64Target(), "riscv64",
+ "64-bit RISC-V");
+}
+
+// FIXME: Temporary stub - this function must be defined for linking
+// to succeed and will be called unconditionally by llc, so must be a no-op.
+// Remove once this function is properly implemented.
+extern "C" void LLVMInitializeRISCVTargetMC() {}