Refactor how we define simple intrinsics

Intrinsics were hidden behind the GCC abstract. This removes it by keeping
all of this logic within rust-intrinsic.cc so that we can make mappings of
the rustc name to GCC ones. We have a big comment from the mappings used
over to LLVM builtins which we can use to help guide how we do this for
GCC.

1 files changed, 143 insertions, 54 deletions

diff --git a/gcc/rust/backend/rust-compile-intrinsic.cc b/gcc/rust/backend/rust-compile-intrinsic.cc
index 177c14e..c57943c 100644
--- a/gcc/rust/backend/rust-compile-intrinsic.cc
+++ b/gcc/rust/backend/rust-compile-intrinsic.cc
@@ -15,6 +15,7 @@
 // <http://www.gnu.org/licenses/>.
 
 #include "rust-compile-intrinsic.h"
+#include "langhooks.h"
 #include "rust-compile-type.h"
 #include "rust-compile-fnparam.h"
 #include "rust-tree.h"
@@ -22,6 +23,144 @@
 namespace Rust {
 namespace Compile {
 
+// https://github.com/rust-lang/rust/blob/master/library/core/src/intrinsics.rs
+// https://github.com/rust-lang/rust/blob/master/compiler/rustc_codegen_llvm/src/intrinsic.rs
+// https://github.com/Rust-GCC/gccrs/issues/658
+//
+//   let llvm_name = match name {
+//     sym::sqrtf32 => "llvm.sqrt.f32",
+//     sym::sqrtf64 => "llvm.sqrt.f64",
+//     sym::powif32 => "llvm.powi.f32",
+//     sym::powif64 => "llvm.powi.f64",
+//     sym::sinf32 => "llvm.sin.f32",
+//     sym::sinf64 => "llvm.sin.f64",
+//     sym::cosf32 => "llvm.cos.f32",
+//     sym::cosf64 => "llvm.cos.f64",
+//     sym::powf32 => "llvm.pow.f32",
+//     sym::powf64 => "llvm.pow.f64",
+//     sym::expf32 => "llvm.exp.f32",
+//     sym::expf64 => "llvm.exp.f64",
+//     sym::exp2f32 => "llvm.exp2.f32",
+//     sym::exp2f64 => "llvm.exp2.f64",
+//     sym::logf32 => "llvm.log.f32",
+//     sym::logf64 => "llvm.log.f64",
+//     sym::log10f32 => "llvm.log10.f32",
+//     sym::log10f64 => "llvm.log10.f64",
+//     sym::log2f32 => "llvm.log2.f32",
+//     sym::log2f64 => "llvm.log2.f64",
+//     sym::fmaf32 => "llvm.fma.f32",
+//     sym::fmaf64 => "llvm.fma.f64",
+//     sym::fabsf32 => "llvm.fabs.f32",
+//     sym::fabsf64 => "llvm.fabs.f64",
+//     sym::minnumf32 => "llvm.minnum.f32",
+//     sym::minnumf64 => "llvm.minnum.f64",
+//     sym::maxnumf32 => "llvm.maxnum.f32",
+//     sym::maxnumf64 => "llvm.maxnum.f64",
+//     sym::copysignf32 => "llvm.copysign.f32",
+//     sym::copysignf64 => "llvm.copysign.f64",
+//     sym::floorf32 => "llvm.floor.f32",
+//     sym::floorf64 => "llvm.floor.f64",
+//     sym::ceilf32 => "llvm.ceil.f32",
+//     sym::ceilf64 => "llvm.ceil.f64",
+//     sym::truncf32 => "llvm.trunc.f32",
+//     sym::truncf64 => "llvm.trunc.f64",
+//     sym::rintf32 => "llvm.rint.f32",
+//     sym::rintf64 => "llvm.rint.f64",
+//     sym::nearbyintf32 => "llvm.nearbyint.f32",
+//     sym::nearbyintf64 => "llvm.nearbyint.f64",
+//     sym::roundf32 => "llvm.round.f32",
+//     sym::roundf64 => "llvm.round.f64",
+//     _ => return None,
+// };
+// Some(cx.get_intrinsic(&llvm_name))
+class SimpleIntrinsics
+{
+public:
+  static SimpleIntrinsics &get ()
+  {
+    static SimpleIntrinsics instance;
+    return instance;
+  }
+
+  bool lookup_simple_builtin (const std::string &name, tree *builtin)
+  {
+    auto it = rust_intrinsic_to_gcc_builtin.find (name);
+    if (it == rust_intrinsic_to_gcc_builtin.end ())
+      return false;
+
+    return lookup_gcc_builtin (it->second, builtin);
+  }
+
+private:
+  static const int builtin_const = 1 << 0;
+  static const int builtin_noreturn = 1 << 1;
+  static const int builtin_novops = 1 << 2;
+
+  SimpleIntrinsics () { setup (); }
+
+  void setup ()
+  {
+    tree math_function_type_f32
+      = build_function_type_list (float_type_node, float_type_node, NULL_TREE);
+
+    define_builtin ("sinf32", BUILT_IN_SINF, "__builtin_sinf", "sinf",
+		    math_function_type_f32, builtin_const);
+
+    define_builtin ("sqrtf32", BUILT_IN_SQRTF, "__builtin_sqrtf", "sqrtf",
+		    math_function_type_f32, builtin_const);
+  }
+
+  // Define a builtin function.  BCODE is the builtin function code
+  // defined by builtins.def.  NAME is the name of the builtin function.
+  // LIBNAME is the name of the corresponding library function, and is
+  // NULL if there isn't one.  FNTYPE is the type of the function.
+  // CONST_P is true if the function has the const attribute.
+  // NORETURN_P is true if the function has the noreturn attribute.
+  void define_builtin (const std::string rust_name, built_in_function bcode,
+		       const char *name, const char *libname, tree fntype,
+		       int flags)
+  {
+    tree decl = add_builtin_function (name, fntype, bcode, BUILT_IN_NORMAL,
+				      libname, NULL_TREE);
+    if ((flags & builtin_const) != 0)
+      TREE_READONLY (decl) = 1;
+    if ((flags & builtin_noreturn) != 0)
+      TREE_THIS_VOLATILE (decl) = 1;
+    if ((flags & builtin_novops) != 0)
+      DECL_IS_NOVOPS (decl) = 1;
+    set_builtin_decl (bcode, decl, true);
+    this->builtin_functions_[name] = decl;
+    if (libname != NULL)
+      {
+	decl = add_builtin_function (libname, fntype, bcode, BUILT_IN_NORMAL,
+				     NULL, NULL_TREE);
+	if ((flags & builtin_const) != 0)
+	  TREE_READONLY (decl) = 1;
+	if ((flags & builtin_noreturn) != 0)
+	  TREE_THIS_VOLATILE (decl) = 1;
+	if ((flags & builtin_novops) != 0)
+	  DECL_IS_NOVOPS (decl) = 1;
+	this->builtin_functions_[libname] = decl;
+      }
+
+    rust_intrinsic_to_gcc_builtin[rust_name] = name;
+  }
+
+  bool lookup_gcc_builtin (const std::string &name, tree *builtin)
+  {
+    auto it = builtin_functions_.find (name);
+    if (it == builtin_functions_.end ())
+      return false;
+
+    *builtin = it->second;
+    return true;
+  }
+
+  // A mapping of the GCC built-ins exposed to GCC Rust.
+  std::map<std::string, tree> builtin_functions_;
+  std::map<std::string, std::string> rust_intrinsic_to_gcc_builtin;
+};
+
 static tree
 offset_intrinsic_handler (Context *ctx, TyTy::BaseType *fntype);
 
@@ -36,60 +175,10 @@ Intrinsics::compile (TyTy::FnType *fntype)
 {
   rust_assert (fntype->get_abi () == ABI::INTRINSIC);
 
-  // https://github.com/rust-lang/rust/blob/master/library/core/src/intrinsics.rs
-  // https://github.com/rust-lang/rust/blob/master/compiler/rustc_codegen_llvm/src/intrinsic.rs
-  // https://github.com/Rust-GCC/gccrs/issues/658
-
-  //   let llvm_name = match name {
-  //     sym::sqrtf32 => "llvm.sqrt.f32",
-  //     sym::sqrtf64 => "llvm.sqrt.f64",
-  //     sym::powif32 => "llvm.powi.f32",
-  //     sym::powif64 => "llvm.powi.f64",
-  //     sym::sinf32 => "llvm.sin.f32",
-  //     sym::sinf64 => "llvm.sin.f64",
-  //     sym::cosf32 => "llvm.cos.f32",
-  //     sym::cosf64 => "llvm.cos.f64",
-  //     sym::powf32 => "llvm.pow.f32",
-  //     sym::powf64 => "llvm.pow.f64",
-  //     sym::expf32 => "llvm.exp.f32",
-  //     sym::expf64 => "llvm.exp.f64",
-  //     sym::exp2f32 => "llvm.exp2.f32",
-  //     sym::exp2f64 => "llvm.exp2.f64",
-  //     sym::logf32 => "llvm.log.f32",
-  //     sym::logf64 => "llvm.log.f64",
-  //     sym::log10f32 => "llvm.log10.f32",
-  //     sym::log10f64 => "llvm.log10.f64",
-  //     sym::log2f32 => "llvm.log2.f32",
-  //     sym::log2f64 => "llvm.log2.f64",
-  //     sym::fmaf32 => "llvm.fma.f32",
-  //     sym::fmaf64 => "llvm.fma.f64",
-  //     sym::fabsf32 => "llvm.fabs.f32",
-  //     sym::fabsf64 => "llvm.fabs.f64",
-  //     sym::minnumf32 => "llvm.minnum.f32",
-  //     sym::minnumf64 => "llvm.minnum.f64",
-  //     sym::maxnumf32 => "llvm.maxnum.f32",
-  //     sym::maxnumf64 => "llvm.maxnum.f64",
-  //     sym::copysignf32 => "llvm.copysign.f32",
-  //     sym::copysignf64 => "llvm.copysign.f64",
-  //     sym::floorf32 => "llvm.floor.f32",
-  //     sym::floorf64 => "llvm.floor.f64",
-  //     sym::ceilf32 => "llvm.ceil.f32",
-  //     sym::ceilf64 => "llvm.ceil.f64",
-  //     sym::truncf32 => "llvm.trunc.f32",
-  //     sym::truncf64 => "llvm.trunc.f64",
-  //     sym::rintf32 => "llvm.rint.f32",
-  //     sym::rintf64 => "llvm.rint.f64",
-  //     sym::nearbyintf32 => "llvm.nearbyint.f32",
-  //     sym::nearbyintf64 => "llvm.nearbyint.f64",
-  //     sym::roundf32 => "llvm.round.f32",
-  //     sym::roundf64 => "llvm.round.f64",
-  //     _ => return None,
-  // };
-  // Some(cx.get_intrinsic(&llvm_name))
-
-  tree builtin = ctx->get_backend ()->lookup_builtin_by_rust_name (
-    fntype->get_identifier ());
-  if (builtin != nullptr)
+  tree builtin = error_mark_node;
+  SimpleIntrinsics &simple_intrinsics = SimpleIntrinsics::get ();
+  if (simple_intrinsics.lookup_simple_builtin (fntype->get_identifier (),
+					       &builtin))
     return builtin;
 
   // is it an generic builtin?