[LLVM-C] Improve Intrinsics Bindings

Summary:
Improve the intrinsic bindings with operations for

- Retrieving and automatically inserting the declaration of an intrinsic by ID
- Retrieving the name of a non-overloaded intrinsic by ID
- Retrieving the name of an overloaded intrinsic by ID and overloaded parameter types

Improve the echo test to copy non-overloaded intrinsics by ID.

Reviewers: whitequark, deadalnix

Reviewed By: whitequark

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D53626

llvm-svn: 346195

llvm/include/llvm-c/Core.h

@@ -2381,6 +2381,54 @@ void LLVMSetPersonalityFn(LLVMValueRef Fn, LLVMValueRef PersonalityFn);
  */
 unsigned LLVMGetIntrinsicID(LLVMValueRef Fn);
 
+/**
+ * Create or insert the declaration of an intrinsic.  For overloaded intrinsics,
+ * parameter types must be provided to uniquely identify an overload.
+ *
+ * @see llvm::Intrinsic::getDeclaration()
+ */
+LLVMValueRef LLVMGetIntrinsicDeclaration(LLVMModuleRef Mod,
+                                         unsigned ID,
+                                         LLVMTypeRef *ParamTypes,
+                                         size_t ParamCount);
+
+/**
+ * Retrieves the type of an intrinsic.  For overloaded intrinsics, parameter
+ * types must be provided to uniquely identify an overload.
+ *
+ * @see llvm::Intrinsic::getType()
+ */
+LLVMTypeRef LLVMIntrinsicGetType(LLVMContextRef Ctx, unsigned ID,
+                                 LLVMTypeRef *ParamTypes, size_t ParamCount);
+
+/**
+ * Retrieves the name of an intrinsic.
+ *
+ * @see llvm::Intrinsic::getName()
+ */
+const char *LLVMIntrinsicGetName(unsigned ID, size_t *NameLength);
+
+/**
+ * Copies the name of an overloaded intrinsic identified by a given list of
+ * parameter types.
+ *
+ * Unlike LLVMIntrinsicGetName, the caller is responsible for freeing the
+ * returned string.
+ *
+ * @see llvm::Intrinsic::getName()
+ */
+const char *LLVMIntrinsicCopyOverloadedName(unsigned ID,
+                                            LLVMTypeRef *ParamTypes,
+                                            size_t ParamCount,
+                                            size_t *NameLength);
+
+/**
+ * Obtain if the intrinsic identified by the given ID is overloaded.
+ *
+ * @see llvm::Intrinsic::isOverloaded()
+ */
+LLVMBool LLVMIntrinsicIsOverloaded(unsigned ID);
+
 /**
  * Obtain the calling function of a function.
  *

llvm/lib/IR/Core.cpp

@@ -2280,6 +2280,50 @@ unsigned LLVMGetIntrinsicID(LLVMValueRef Fn) {
   return 0;
 }
 
+static Intrinsic::ID llvm_map_to_intrinsic_id(unsigned ID) {
+  assert(ID < llvm::Intrinsic::num_intrinsics && "Intrinsic ID out of range");
+  return llvm::Intrinsic::ID(ID);
+}
+
+LLVMValueRef LLVMGetIntrinsicDeclaration(LLVMModuleRef Mod,
+                                         unsigned ID,
+                                         LLVMTypeRef *ParamTypes,
+                                         size_t ParamCount) {
+  ArrayRef<Type*> Tys(unwrap(ParamTypes), ParamCount);
+  auto IID = llvm_map_to_intrinsic_id(ID);
+  return wrap(llvm::Intrinsic::getDeclaration(unwrap(Mod), IID, Tys));
+}
+
+const char *LLVMIntrinsicGetName(unsigned ID, size_t *NameLength) {
+  auto IID = llvm_map_to_intrinsic_id(ID);
+  auto Str = llvm::Intrinsic::getName(IID);
+  *NameLength = Str.size();
+  return Str.data();
+}
+
+LLVMTypeRef LLVMIntrinsicGetType(LLVMContextRef Ctx, unsigned ID,
+                                 LLVMTypeRef *ParamTypes, size_t ParamCount) {
+  auto IID = llvm_map_to_intrinsic_id(ID);
+  ArrayRef<Type*> Tys(unwrap(ParamTypes), ParamCount);
+  return wrap(llvm::Intrinsic::getType(*unwrap(Ctx), IID, Tys));
+}
+
+const char *LLVMIntrinsicCopyOverloadedName(unsigned ID,
+                                            LLVMTypeRef *ParamTypes,
+                                            size_t ParamCount,
+                                            size_t *NameLength) {
+  auto IID = llvm_map_to_intrinsic_id(ID);
+  ArrayRef<Type*> Tys(unwrap(ParamTypes), ParamCount);
+  auto Str = llvm::Intrinsic::getName(IID, Tys);
+  *NameLength = Str.length();
+  return strndup(Str.c_str(), Str.length());
+}
+
+LLVMBool LLVMIntrinsicIsOverloaded(unsigned ID) {
+  auto IID = llvm_map_to_intrinsic_id(ID);
+  return llvm::Intrinsic::isOverloaded(IID);
+}
+
 unsigned LLVMGetFunctionCallConv(LLVMValueRef Fn) {
   return unwrap<Function>(Fn)->getCallingConv();
 }

llvm/test/Bindings/llvm-c/echo.ll

@@ -170,6 +170,22 @@ define void @with_debuginfo() !dbg !4 {
   ret void, !dbg !7
 }
 
+declare i8* @llvm.stacksave()
+declare void @llvm.stackrestore(i8*)
+declare void @llvm.lifetime.start.p0i8(i64, i8*)
+declare void @llvm.lifetime.end.p0i8(i64, i8*)
+
+define void @test_intrinsics() {
+entry:
+  %sp = call i8* @llvm.stacksave()
+  %x = alloca i32
+  %0 = bitcast i32* %x to i8*
+  call void @llvm.lifetime.start.p0i8(i64 4, i8* %0)
+  call void @llvm.lifetime.end.p0i8(i64 4, i8* %0)
+  call void @llvm.stackrestore(i8* %sp)
+  ret void
+}
+
 !llvm.dbg.cu = !{!0, !2}
 !llvm.module.flags = !{!3}
 

llvm/tools/llvm-c-test/echo.cpp

@@ -240,7 +240,17 @@ static LLVMValueRef clone_constant_impl(LLVMValueRef Cst, LLVMModuleRef M) {
     // Try function
     if (LLVMIsAFunction(Cst)) {
       check_value_kind(Cst, LLVMFunctionValueKind);
-      LLVMValueRef Dst = LLVMGetNamedFunction(M, Name);
+
+      LLVMValueRef Dst = nullptr;
+      // Try an intrinsic
+      unsigned ID = LLVMGetIntrinsicID(Cst);
+      if (ID > 0 && !LLVMIntrinsicIsOverloaded(ID)) {
+        Dst = LLVMGetIntrinsicDeclaration(M, ID, nullptr, 0);
+      } else {
+        // Try a normal function
+        Dst = LLVMGetNamedFunction(M, Name);
+      }
+
       if (Dst)
         return Dst;
       report_fatal_error("Could not find function");