[clang] fcce256 - [Clang][LoongArch] Pass "f" and "d" features to cc1 to enable hard float

[Weining Lu via cfe-commits]

Author: Weining Lu
Date: 2022-10-13T20:00:29+08:00
New Revision: fcce2562c177f0ad2aa03620be8675bef5c631d1

URL: https://github.com/llvm/llvm-project/commit/fcce2562c177f0ad2aa03620be8675bef5c631d1
DIFF: https://github.com/llvm/llvm-project/commit/fcce2562c177f0ad2aa03620be8675bef5c631d1.diff

LOG: [Clang][LoongArch] Pass "f" and "d" features to cc1 to enable hard float

On LoongArch, currently neither of "f" and "d" feature is passed from
clang driver to cc1 by default. This means the backend generates code
for soft float.

In order to run programs in current LoongArch machines (hard float
environment) this patch temporarily enables "f" and "d" features.

In future, we should conditionally turn on these features depend on
various clang options, e.g. -mdouble-float, -msingle-float,
-msoft-float and -mfpu.

Added: 
    clang/test/Driver/loongarch-default-features.c

Modified: 
    clang/lib/Driver/ToolChains/Arch/LoongArch.cpp
    clang/lib/Driver/ToolChains/Arch/LoongArch.h
    clang/lib/Driver/ToolChains/Clang.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Driver/ToolChains/Arch/LoongArch.cpp b/clang/lib/Driver/ToolChains/Arch/LoongArch.cpp
index f8cda26ad3f8e..d364a2e8f7a8e 100644
--- a/clang/lib/Driver/ToolChains/Arch/LoongArch.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/LoongArch.cpp
@@ -26,3 +26,14 @@ StringRef loongarch::getLoongArchABI(const ArgList &Args,
   // TODO: select appropiate ABI.
   return Triple.getArch() == llvm::Triple::loongarch32 ? "ilp32d" : "lp64d";
 }
+
+void loongarch::getLoongArchTargetFeatures(const Driver &D,
+                                           const llvm::Triple &Triple,
+                                           const ArgList &Args,
+                                           std::vector<StringRef> &Features) {
+  // FIXME: hornor various clang options that may affect target features, e.g.
+  // -march/-mtune/-mdouble-float/-msingle-float/-msoft-float/-mfpu. See:
+  // https://loongson.github.io/LoongArch-Documentation/LoongArch-toolchain-conventions-EN.html
+  Features.push_back("+f");
+  Features.push_back("+d");
+}

diff  --git a/clang/lib/Driver/ToolChains/Arch/LoongArch.h b/clang/lib/Driver/ToolChains/Arch/LoongArch.h
index a128e611f8c3c..eb09419c2c1ba 100644
--- a/clang/lib/Driver/ToolChains/Arch/LoongArch.h
+++ b/clang/lib/Driver/ToolChains/Arch/LoongArch.h
@@ -19,6 +19,10 @@ namespace tools {
 namespace loongarch {
 StringRef getLoongArchABI(const llvm::opt::ArgList &Args,
                           const llvm::Triple &Triple);
+
+void getLoongArchTargetFeatures(const Driver &D, const llvm::Triple &Triple,
+                                const llvm::opt::ArgList &Args,
+                                std::vector<llvm::StringRef> &Features);
 } // end namespace loongarch
 } // end namespace tools
 } // end namespace driver

diff  --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 83023a155dee9..15f45275b76ab 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -372,6 +372,10 @@ static void getTargetFeatures(const Driver &D, const llvm::Triple &Triple,
   case llvm::Triple::csky:
     csky::getCSKYTargetFeatures(D, Triple, Args, CmdArgs, Features);
     break;
+  case llvm::Triple::loongarch32:
+  case llvm::Triple::loongarch64:
+    loongarch::getLoongArchTargetFeatures(D, Triple, Args, Features);
+    break;
   }
 
   for (auto Feature : unifyTargetFeatures(Features)) {

diff  --git a/clang/test/Driver/loongarch-default-features.c b/clang/test/Driver/loongarch-default-features.c
new file mode 100644
index 0000000000000..833ee4fd3fafa
--- /dev/null
+++ b/clang/test/Driver/loongarch-default-features.c
@@ -0,0 +1,10 @@
+// RUN: %clang --target=loongarch32 -S -emit-llvm %s -o - | FileCheck %s --check-prefix=LA32
+// RUN: %clang --target=loongarch64 -S -emit-llvm %s -o - | FileCheck %s --check-prefix=LA64
+
+// LA32: "target-features"="+d,+f"
+// LA64: "target-features"="+d,+f"
+
+/// Dummy function
+int foo(void) {
+  return  3;
+}