[RISCV] Add support for llvm parameter -mabi (-target-abi) (#8860)

python/tvm/target/__init__.py

@@ -43,6 +43,10 @@
    such as whether SIMD operations are enabled or not. The
    default set of attributes is set by the current CPU.
 
+- **-mabi=<abi>**
+
+   Generate code for the specified ABI, for example "lp64d".
+
 - **-system-lib**
 
    Build TVM system library module. System lib is a global module that contains
@@ -55,7 +59,18 @@
 We can also use other specific function in this module to create specific targets.
 """
 from .target import Target, create
-from .target import cuda, rocm, mali, intel_graphics, arm_cpu, rasp, vta, bifrost, hexagon
+from .target import (
+    cuda,
+    rocm,
+    mali,
+    intel_graphics,
+    arm_cpu,
+    rasp,
+    vta,
+    bifrost,
+    riscv_cpu,
+    hexagon,
+)
 from .tag import list_tags
 from .generic_func import GenericFunc
 from .generic_func import generic_func, get_native_generic_func, override_native_generic_func

python/tvm/target/target.py

@@ -87,6 +87,8 @@ def __init__(self, target, host=None):
             mfloat-abi : str (optional)
                 An llvm setting that is one of 'hard' or 'soft' indicating whether to use
                 hardware or software floating-point operations.
+            mabi : str (optional)
+                An llvm setting. Generate code for the specified ABI, for example "lp64d".
             host : Union[str, Dict[str, Any]] (optional)
                 Description for target host. Can be recursive. Similar to target.
         host : Optional[Union[str, Dict[str, Any]]]
@@ -413,6 +415,54 @@ def bifrost(model="unknown", options=None):
     return Target(" ".join(["opencl"] + opts))
 
 
+def riscv_cpu(model="sifive-u54", options=None):
+    """Returns a RISC-V CPU target.
+    Default: sifive-u54 rv64gc
+
+    Parameters
+    ----------
+    model: str
+        CPU name.
+    options : str or list of str
+        Additional options
+    """
+    trans_table = {
+        "sifive-e31": [
+            "-model=sifive-e31",
+            "-mtriple=riscv32-unknown-linux-gnu",
+            "-mcpu=sifive-e31",
+            "-mabi=ilp32",
+            # cc: riscv64-unknown-linux-gnu-g++ -march=rv32imac -mabi=ilp32 -mcpu=sifive-e31
+        ],
+        "sifive-e76": [
+            "-model=sifive-e76",
+            "-mtriple=riscv32-unknown-linux-gnu",
+            "-mcpu=sifive-e76",
+            "-mabi=ilp32",
+            # cc: riscv64-unknown-linux-gnu-g++ -march=rv32imafc -mabi=ilp32 -mcpu=sifive-e76
+        ],
+        "sifive-u54": [
+            "-model=sifive-u54",
+            "-mtriple=riscv64-unknown-linux-gnu",
+            "-mcpu=sifive-u54",
+            "-mabi=lp64d",
+            # cc: riscv64-unknown-linux-gnu-g++ -march=rv64gc -mabi=lp64d -mcpu=sifive-u54
+        ],
+        "sifive-u74": [
+            "-model=sifive-u74",
+            "-mtriple=riscv64-unknown-linux-gnu",
+            "-mcpu=sifive-u74",
+            "-mabi=lp64d",
+            # cc: riscv64-unknown-linux-gnu-g++ -march=rv64gc -mabi=lp64d -mcpu=sifive-u74
+        ],
+    }
+    pre_defined_opt = trans_table.get(model, ["-model=%s" % model])
+
+    opts = ["-device=arm_cpu"] + pre_defined_opt
+    opts = _merge_opts(opts, options)
+    return Target(" ".join(["llvm"] + opts))
+
+
 def hexagon(cpu_ver="v66", **kwargs):
     """Returns a Hexagon target.
 

src/target/llvm/llvm_common.cc

@@ -115,6 +115,9 @@ void ParseLLVMTargetOptions(const Target& target, std::string* triple, std::stri
   } else {
     opt.FloatABIType = llvm::FloatABI::Hard;
   }
+  if (const Optional<String>& v = target->GetAttr<String>("mabi")) {
+    opt.MCOptions.ABIName = v.value();
+  }
 }
 
 std::unique_ptr<llvm::TargetMachine> GetLLVMTargetMachine(const Target& target, bool allow_null) {
@@ -164,6 +167,9 @@ std::string LLVMTargetToString(const Target& target) {
   if (Optional<String> mfloat_abo = target->GetAttr<String>("mfloat-abi")) {
     os << " -mfloat-abi=" << mfloat_abo.value();
   }
+  if (Optional<String> mabi = target->GetAttr<String>("mabi")) {
+    os << " -mabi=" << mabi.value();
+  }
   return os.str();
 }
 

src/target/llvm/llvm_module.cc

@@ -69,12 +69,22 @@ class LLVMModuleNode final : public runtime::ModuleNode {
     } else if (name == "get_const_vars") {
       return PackedFunc(nullptr);
     } else if (name == "_get_target_triple") {
-      std::string target_triple = tm_->getTargetTriple().str();
+      std::ostringstream target_triple_ss;
+      target_triple_ss << tm_->getTargetTriple().str();
       // getTargetTriple() doesn't include other flags besides the triple. Add back flags which are
       // important for ModulePackImportsToLLVM.
       if (tm_->Options.FloatABIType == llvm::FloatABI::ABIType::Soft) {
-        target_triple += " -mfloat-abi=soft";
+        target_triple_ss << " -mfloat-abi=soft";
       }
+      std::string mabi = tm_->Options.MCOptions.ABIName;
+      if (!mabi.empty()) {
+        target_triple_ss << " -mabi=" << mabi;
+      }
+      llvm::StringRef mcpu = tm_->getTargetCPU();
+      if (!mcpu.empty() && mcpu != "generic") {
+        target_triple_ss << " -mcpu=" << mcpu.str();
+      }
+      std::string target_triple = target_triple_ss.str();
       return PackedFunc([target_triple](TVMArgs args, TVMRetValue* rv) { *rv = target_triple; });
     }
     if (ee_ == nullptr) LazyInitJIT();

src/target/target_kind.cc

@@ -216,6 +216,7 @@ TVM_REGISTER_TARGET_KIND("llvm", kDLCPU)
     .add_attr_option<String>("mcpu")
     .add_attr_option<String>("mtriple")
     .add_attr_option<String>("mfloat-abi")
+    .add_attr_option<String>("mabi")
     .add_attr_option<Bool>("system-lib")
     .add_attr_option<String>("runtime")
     .add_attr_option<Bool>("link-params", Bool(false))