C++ LLVMGetParam函数代码示例

int main(int argc, char const *argv[]) {
    LLVMModuleRef mod = LLVMModuleCreateWithName("sum");

    LLVMTypeRef param_types[] = { LLVMInt32Type(), LLVMInt32Type() };
    LLVMTypeRef ret_type = LLVMFunctionType(LLVMInt32Type(), /* ret type */
                                            param_types, /* arg types */
                                            2, /* arg count */
                                            0 /* is variadic */);
    LLVMValueRef sum = LLVMAddFunction(mod, "sum", ret_type);

    LLVMBasicBlockRef entry = LLVMAppendBasicBlock(sum, "entry");
    
    LLVMBuilderRef builder = LLVMCreateBuilder();
    LLVMPositionBuilderAtEnd(builder, entry);
    LLVMValueRef tmp = LLVMBuildAdd(builder, 
                            LLVMGetParam(sum, 0), 
                            LLVMGetParam(sum, 1), "tmp");
    LLVMBuildRet(builder, tmp);

    char *error = NULL;
    LLVMVerifyModule(mod, LLVMAbortProcessAction, &error);
    LLVMDisposeMessage(error);

    LLVMExecutionEngineRef engine;
    error = NULL;
    LLVMLinkInJIT();
    LLVMInitializeNativeTarget();
    if (LLVMCreateExecutionEngineForModule(&engine, mod, &error) != 0) {
        fprintf(stderr, "failed to create execution engine\n");
        abort();
    }
    if (error) {
        fprintf(stderr, "error: %s\n", error);
        LLVMDisposeMessage(error);
        exit(EXIT_FAILURE);
    }

    if (argc < 3) {
        fprintf(stderr, "usage: %s x y\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    long long x = strtoll(argv[1], NULL, 10);
    long long y = strtoll(argv[2], NULL, 10);

    LLVMGenericValueRef args[] = {
        LLVMCreateGenericValueOfInt(LLVMInt32Type(), x, 0),
        LLVMCreateGenericValueOfInt(LLVMInt32Type(), y, 0),
    };
    LLVMGenericValueRef res = LLVMRunFunction(engine, sum,  2, args);
    printf("%d\n", (int)LLVMGenericValueToInt(res, 0));

    // write bitcode to file
    if (LLVMWriteBitcodeToFile(mod, "sum.bc") != 0) {
        fprintf(stderr, "error writing bitcode to file\n");
    }

    LLVMDisposeBuilder(builder);
    LLVMDisposeExecutionEngine(engine);
}

int test_kal_codegen_function() {
    kal_named_value *val;
    unsigned int arg_count = 1;
    char **args = malloc(sizeof(char*) * arg_count);
    args[0] = "foo";
    
    LLVMModuleRef module = LLVMModuleCreateWithName("kal");
    LLVMBuilderRef builder = LLVMCreateBuilder();
    kal_ast_node *prototype = kal_ast_prototype_create("my_func", args, arg_count);
    kal_ast_node *lhs = kal_ast_variable_create("foo");
    kal_ast_node *rhs = kal_ast_number_create(20);
    kal_ast_node *body = kal_ast_binary_expr_create(KAL_BINOP_PLUS, lhs, rhs);
    kal_ast_node *node = kal_ast_function_create(prototype, body);

    kal_codegen_reset();
    LLVMValueRef value = kal_codegen(node, module, builder);

    mu_assert(value != NULL, "");
    mu_assert(LLVMGetNamedFunction(module, "my_func") == value, "");
    mu_assert(LLVMCountParams(value) == 1, "");

    val = kal_codegen_named_value("foo");
    mu_assert(val->value == LLVMGetParam(value, 0), "");
    mu_assert(LLVMGetTypeKind(LLVMTypeOf(LLVMGetParam(value, 0))) == LLVMDoubleTypeKind, "");

    LLVMDisposeBuilder(builder);
    LLVMDisposeModule(module);
    kal_ast_node_free(node);
    return 0;
}

static void pointer_realloc(compile_t* c, reach_type_t* t,
  reach_type_t* t_elem)
{
  FIND_METHOD("_realloc");

  LLVMTypeRef params[2];
  params[0] = t->use_type;
  params[1] = c->intptr;
  start_function(c, m, t->use_type, params, 2);

  // Set up a constant integer for the allocation size.
  size_t size = (size_t)LLVMABISizeOfType(c->target_data, t_elem->use_type);
  LLVMValueRef l_size = LLVMConstInt(c->intptr, size, false);

  LLVMValueRef args[3];
  args[0] = codegen_ctx(c);
  args[1] = LLVMGetParam(m->func, 0);

  LLVMValueRef len = LLVMGetParam(m->func, 1);
  args[2] = LLVMBuildMul(c->builder, len, l_size, "");

  LLVMValueRef result = gencall_runtime(c, "pony_realloc", args, 3, "");
  result = LLVMBuildBitCast(c->builder, result, t->use_type, "");

  LLVMBuildRet(c->builder, result);
  codegen_finishfun(c);
}

static void make_serialise(compile_t* c, reach_type_t* t)
{
  // Use the trace function as the serialise_trace function.
  t->serialise_trace_fn = t->trace_fn;

  // Generate the serialise function.
  t->serialise_fn = codegen_addfun(c, genname_serialise(t->name),
    c->serialise_type);

  codegen_startfun(c, t->serialise_fn, NULL, NULL);
  LLVMSetFunctionCallConv(t->serialise_fn, LLVMCCallConv);
  LLVMSetLinkage(t->serialise_fn, LLVMExternalLinkage);

  LLVMValueRef ctx = LLVMGetParam(t->serialise_fn, 0);
  LLVMValueRef arg = LLVMGetParam(t->serialise_fn, 1);
  LLVMValueRef addr = LLVMGetParam(t->serialise_fn, 2);
  LLVMValueRef offset = LLVMGetParam(t->serialise_fn, 3);

  LLVMValueRef object = LLVMBuildBitCast(c->builder, arg, t->structure_ptr,
    "");
  LLVMValueRef offset_addr = LLVMBuildInBoundsGEP(c->builder, addr, &offset, 1,
    "");

  serialise(c, t, ctx, object, offset_addr);

  LLVMBuildRetVoid(c->builder);
  codegen_finishfun(c);
}

void genprim_string_deserialise(compile_t* c, reach_type_t* t)
{
  // Generate the deserisalise function.
  t->deserialise_fn = codegen_addfun(c, genname_serialise(t->name),
    c->trace_type);

  codegen_startfun(c, t->deserialise_fn, NULL, NULL);
  LLVMSetFunctionCallConv(t->deserialise_fn, LLVMCCallConv);

  LLVMValueRef ctx = LLVMGetParam(t->deserialise_fn, 0);
  LLVMValueRef arg = LLVMGetParam(t->deserialise_fn, 1);

  LLVMValueRef object = LLVMBuildBitCast(c->builder, arg, t->structure_ptr,
    "");
  gendeserialise_typeid(c, t, object);

  // Deserialise the string contents.
  LLVMValueRef alloc = field_value(c, object, 2);
  LLVMValueRef ptr_offset = field_value(c, object, 3);
  ptr_offset = LLVMBuildPtrToInt(c->builder, ptr_offset, c->intptr, "");

  LLVMValueRef args[3];
  args[0] = ctx;
  args[1] = ptr_offset;
  args[2] = alloc;
  LLVMValueRef ptr_addr = gencall_runtime(c, "pony_deserialise_block", args, 3,
    "");

  LLVMValueRef ptr = LLVMBuildStructGEP(c->builder, object, 3, "");
  LLVMBuildStore(c->builder, ptr_addr, ptr);

  LLVMBuildRetVoid(c->builder);
  codegen_finishfun(c);
}

static void make_dispatch(compile_t* c, gentype_t* g)
{
  // Do nothing if we're not an actor.
  if(g->underlying != TK_ACTOR)
    return;

  // Create a dispatch function.
  const char* dispatch_name = genname_dispatch(g->type_name);
  g->dispatch_fn = codegen_addfun(c, dispatch_name, c->dispatch_type);
  codegen_startfun(c, g->dispatch_fn, false);

  LLVMBasicBlockRef unreachable = codegen_block(c, "unreachable");
  LLVMValueRef this_ptr = LLVMGetParam(g->dispatch_fn, 0);
  LLVMSetValueName(this_ptr, "this");

  g->dispatch_msg = LLVMGetParam(g->dispatch_fn, 1);
  LLVMSetValueName(g->dispatch_msg, "msg");

  // Read the message ID.
  LLVMValueRef id_ptr = LLVMBuildStructGEP(c->builder, g->dispatch_msg, 1, "");
  LLVMValueRef id = LLVMBuildLoad(c->builder, id_ptr, "id");

  // Store a reference to the dispatch switch. When we build behaviours, we
  // will add cases to this switch statement based on message ID.
  g->dispatch_switch = LLVMBuildSwitch(c->builder, id, unreachable, 0);

  // Mark the default case as unreachable.
  LLVMPositionBuilderAtEnd(c->builder, unreachable);
  LLVMBuildUnreachable(c->builder);
  codegen_finishfun(c);
}

void genprim_string_serialise_trace(compile_t* c, reach_type_t* t)
{
  // Generate the serialise_trace function.
  t->serialise_trace_fn = codegen_addfun(c, genname_serialise_trace(t->name),
    c->serialise_type);

  codegen_startfun(c, t->serialise_trace_fn, NULL, NULL);
  LLVMSetFunctionCallConv(t->serialise_trace_fn, LLVMCCallConv);

  LLVMValueRef ctx = LLVMGetParam(t->serialise_trace_fn, 0);
  LLVMValueRef arg = LLVMGetParam(t->serialise_trace_fn, 1);
  LLVMValueRef object = LLVMBuildBitCast(c->builder, arg, t->use_type, "");

  // Read the size.
  LLVMValueRef size = field_value(c, object, 1);
  LLVMValueRef alloc = LLVMBuildAdd(c->builder, size,
    LLVMConstInt(c->intptr, 1, false), "");

  // Reserve space for the contents.
  LLVMValueRef ptr = field_value(c, object, 3);

  LLVMValueRef args[3];
  args[0] = ctx;
  args[1] = ptr;
  args[2] = alloc;
  gencall_runtime(c, "pony_serialise_reserve", args, 3, "");

  LLVMBuildRetVoid(c->builder);
  codegen_finishfun(c);
}

static void pointer_offset(compile_t* c, reach_type_t* t, reach_type_t* t_elem)
{
  FIND_METHOD("_offset");

  LLVMTypeRef params[3];
  params[0] = t->use_type;
  params[1] = c->intptr;
  start_function(c, m, t->use_type, params, 2);

  // Set up a constant integer for the allocation size.
  size_t size = (size_t)LLVMABISizeOfType(c->target_data, t_elem->use_type);
  LLVMValueRef l_size = LLVMConstInt(c->intptr, size, false);

  LLVMValueRef ptr = LLVMGetParam(m->func, 0);
  LLVMValueRef n = LLVMGetParam(m->func, 1);

  // Return ptr + (n * sizeof(len)).
  LLVMValueRef src = LLVMBuildPtrToInt(c->builder, ptr, c->intptr, "");
  LLVMValueRef offset = LLVMBuildMul(c->builder, n, l_size, "");
  LLVMValueRef result = LLVMBuildAdd(c->builder, src, offset, "");
  result = LLVMBuildIntToPtr(c->builder, result, t->use_type, "");

  LLVMBuildRet(c->builder, result);
  codegen_finishfun(c);

  BOX_FUNCTION();
}

static LLVMValueRef
add_blend_test(struct gallivm_state *gallivm,
               const struct pipe_blend_state *blend,
               struct lp_type type)
{
   LLVMModuleRef module = gallivm->module;
   LLVMContextRef context = gallivm->context;
   LLVMTypeRef vec_type;
   LLVMTypeRef args[5];
   LLVMValueRef func;
   LLVMValueRef src_ptr;
   LLVMValueRef src1_ptr;
   LLVMValueRef dst_ptr;
   LLVMValueRef const_ptr;
   LLVMValueRef res_ptr;
   LLVMBasicBlockRef block;
   LLVMBuilderRef builder;
   const enum pipe_format format = PIPE_FORMAT_R8G8B8A8_UNORM;
   const unsigned rt = 0;
   const unsigned char swizzle[4] = { 0, 1, 2, 3 };
   LLVMValueRef src;
   LLVMValueRef src1;
   LLVMValueRef dst;
   LLVMValueRef con;
   LLVMValueRef res;

   vec_type = lp_build_vec_type(gallivm, type);

   args[4] = args[3] = args[2] = args[1] = args[0] = LLVMPointerType(vec_type, 0);
   func = LLVMAddFunction(module, "test", LLVMFunctionType(LLVMVoidTypeInContext(context), args, 5, 0));
   LLVMSetFunctionCallConv(func, LLVMCCallConv);
   src_ptr = LLVMGetParam(func, 0);
   src1_ptr = LLVMGetParam(func, 1);
   dst_ptr = LLVMGetParam(func, 2);
   const_ptr = LLVMGetParam(func, 3);
   res_ptr = LLVMGetParam(func, 4);

   block = LLVMAppendBasicBlockInContext(context, func, "entry");
   builder = gallivm->builder;
   LLVMPositionBuilderAtEnd(builder, block);

   src = LLVMBuildLoad(builder, src_ptr, "src");
   src1 = LLVMBuildLoad(builder, src1_ptr, "src1");
   dst = LLVMBuildLoad(builder, dst_ptr, "dst");
   con = LLVMBuildLoad(builder, const_ptr, "const");

   res = lp_build_blend_aos(gallivm, blend, format, type, rt, src, NULL,
                            src1, NULL, dst, NULL, con, NULL, swizzle, 4);

   lp_build_name(res, "res");

   LLVMBuildStore(builder, res, res_ptr);

   LLVMBuildRetVoid(builder);;

   gallivm_verify_function(gallivm, func);

   return func;
}

static void declare_input_vs(
	struct si_shader_context * si_shader_ctx,
	unsigned input_index,
	const struct tgsi_full_declaration *decl)
{
	struct lp_build_context * base = &si_shader_ctx->radeon_bld.soa.bld_base.base;
	unsigned divisor = si_shader_ctx->shader->key.vs.instance_divisors[input_index];

	unsigned chan;

	LLVMValueRef t_list_ptr;
	LLVMValueRef t_offset;
	LLVMValueRef t_list;
	LLVMValueRef attribute_offset;
	LLVMValueRef buffer_index;
	LLVMValueRef args[3];
	LLVMTypeRef vec4_type;
	LLVMValueRef input;

	/* Load the T list */
	t_list_ptr = LLVMGetParam(si_shader_ctx->radeon_bld.main_fn, SI_PARAM_VERTEX_BUFFER);

	t_offset = lp_build_const_int32(base->gallivm, input_index);

	t_list = build_indexed_load(si_shader_ctx, t_list_ptr, t_offset);

	/* Build the attribute offset */
	attribute_offset = lp_build_const_int32(base->gallivm, 0);

	if (divisor) {
		/* Build index from instance ID, start instance and divisor */
		si_shader_ctx->shader->shader.uses_instanceid = true;
		buffer_index = get_instance_index(&si_shader_ctx->radeon_bld, divisor);
	} else {
		/* Load the buffer index, which is always stored in VGPR0
		 * for Vertex Shaders */
		buffer_index = LLVMGetParam(si_shader_ctx->radeon_bld.main_fn, SI_PARAM_VERTEX_ID);
	}

	vec4_type = LLVMVectorType(base->elem_type, 4);
	args[0] = t_list;
	args[1] = attribute_offset;
	args[2] = buffer_index;
	input = build_intrinsic(base->gallivm->builder,
		"llvm.SI.vs.load.input", vec4_type, args, 3,
		LLVMReadNoneAttribute | LLVMNoUnwindAttribute);

	/* Break up the vec4 into individual components */
	for (chan = 0; chan < 4; chan++) {
		LLVMValueRef llvm_chan = lp_build_const_int32(base->gallivm, chan);
		/* XXX: Use a helper function for this.  There is one in
 		 * tgsi_llvm.c. */
		si_shader_ctx->radeon_bld.inputs[radeon_llvm_reg_index_soa(input_index, chan)] =
				LLVMBuildExtractElement(base->gallivm->builder,
				input, llvm_chan, "");
	}
}

static bool make_trace(compile_t* c, gentype_t* g)
{
  // Do nothing if we have no fields.
  if(g->field_count == 0)
    return true;

  if(g->underlying == TK_CLASS)
  {
    // Special case the array trace function.
    AST_GET_CHILDREN(g->ast, pkg, id);
    const char* package = ast_name(pkg);
    const char* name = ast_name(id);

    if((package == c->str_builtin) && (name == c->str_Array))
    {
      genprim_array_trace(c, g);
      return true;
    }
  }

  // Create a trace function.
  const char* trace_name = genname_trace(g->type_name);
  LLVMValueRef trace_fn = codegen_addfun(c, trace_name, c->trace_type);

  codegen_startfun(c, trace_fn, false);
  LLVMSetFunctionCallConv(trace_fn, LLVMCCallConv);

  LLVMValueRef ctx = LLVMGetParam(trace_fn, 0);
  LLVMValueRef arg = LLVMGetParam(trace_fn, 1);
  LLVMValueRef object = LLVMBuildBitCast(c->builder, arg, g->structure_ptr,
    "object");

  // If we don't ever trace anything, delete this function.
  int extra = 0;

  // Non-structs have a type descriptor.
  if(g->underlying != TK_STRUCT)
    extra++;

  // Actors have a pad.
  if(g->underlying == TK_ACTOR)
    extra++;

  bool need_trace = trace_fields(c, g, ctx, object, extra);

  LLVMBuildRetVoid(c->builder);
  codegen_finishfun(c);

  if(!need_trace)
    LLVMDeleteFunction(trace_fn);

  return true;
}

static LLVMValueRef
add_conv_test(struct gallivm_state *gallivm,
              struct lp_type src_type, unsigned num_srcs,
              struct lp_type dst_type, unsigned num_dsts)
{
   LLVMModuleRef module = gallivm->module;
   LLVMContextRef context = gallivm->context;
   LLVMBuilderRef builder = gallivm->builder;
   LLVMTypeRef args[2];
   LLVMValueRef func;
   LLVMValueRef src_ptr;
   LLVMValueRef dst_ptr;
   LLVMBasicBlockRef block;
   LLVMValueRef src[LP_MAX_VECTOR_LENGTH];
   LLVMValueRef dst[LP_MAX_VECTOR_LENGTH];
   unsigned i;

   args[0] = LLVMPointerType(lp_build_vec_type(gallivm, src_type), 0);
   args[1] = LLVMPointerType(lp_build_vec_type(gallivm, dst_type), 0);

   func = LLVMAddFunction(module, "test",
                          LLVMFunctionType(LLVMVoidTypeInContext(context),
                                           args, 2, 0));
   LLVMSetFunctionCallConv(func, LLVMCCallConv);
   src_ptr = LLVMGetParam(func, 0);
   dst_ptr = LLVMGetParam(func, 1);

   block = LLVMAppendBasicBlockInContext(context, func, "entry");
   LLVMPositionBuilderAtEnd(builder, block);

   for(i = 0; i < num_srcs; ++i) {
      LLVMValueRef index = LLVMConstInt(LLVMInt32TypeInContext(context), i, 0);
      LLVMValueRef ptr = LLVMBuildGEP(builder, src_ptr, &index, 1, "");
      src[i] = LLVMBuildLoad(builder, ptr, "");
   }

   lp_build_conv(gallivm, src_type, dst_type, src, num_srcs, dst, num_dsts);

   for(i = 0; i < num_dsts; ++i) {
      LLVMValueRef index = LLVMConstInt(LLVMInt32TypeInContext(context), i, 0);
      LLVMValueRef ptr = LLVMBuildGEP(builder, dst_ptr, &index, 1, "");
      LLVMBuildStore(builder, dst[i], ptr);
   }

   LLVMBuildRetVoid(builder);;

   gallivm_verify_function(gallivm, func);

   return func;
}

static LLVMValueRef make_unbox_function(compile_t* c, gentype_t* g,
  const char* name)
{
  LLVMValueRef fun = LLVMGetNamedFunction(c->module, name);

  if(fun == NULL)
    return LLVMConstNull(c->void_ptr);

  // Create a new unboxing function that forwards to the real function.
  LLVMTypeRef f_type = LLVMGetElementType(LLVMTypeOf(fun));
  int count = LLVMCountParamTypes(f_type);

  // If it takes no arguments, it's a special number constructor. Don't put it
  // in the vtable.
  if(count == 0)
    return LLVMConstNull(c->void_ptr);

  size_t buf_size = count *sizeof(LLVMTypeRef);
  LLVMTypeRef* params = (LLVMTypeRef*)pool_alloc_size(buf_size);
  LLVMGetParamTypes(f_type, params);
  LLVMTypeRef ret_type = LLVMGetReturnType(f_type);

  // It's the same type, but it takes the boxed type instead of the primitive
  // type as the receiver.
  params[0] = g->structure_ptr;

  const char* unbox_name = genname_unbox(name);
  LLVMTypeRef unbox_type = LLVMFunctionType(ret_type, params, count, false);
  LLVMValueRef unbox_fun = codegen_addfun(c, unbox_name, unbox_type);
  codegen_startfun(c, unbox_fun, false);

  // Extract the primitive type from element 1 and call the real function.
  LLVMValueRef this_ptr = LLVMGetParam(unbox_fun, 0);
  LLVMValueRef primitive_ptr = LLVMBuildStructGEP(c->builder, this_ptr, 1, "");
  LLVMValueRef primitive = LLVMBuildLoad(c->builder, primitive_ptr, "");

  LLVMValueRef* args = (LLVMValueRef*)pool_alloc_size(buf_size);
  args[0] = primitive;

  for(int i = 1; i < count; i++)
    args[i] = LLVMGetParam(unbox_fun, i);

  LLVMValueRef result = codegen_call(c, fun, args, count);
  LLVMBuildRet(c->builder, result);
  codegen_finishfun(c);

  pool_free_size(buf_size, params);
  pool_free_size(buf_size, args);
  return LLVMConstBitCast(unbox_fun, c->void_ptr);
}

static void add_dispatch_case(compile_t* c, gentype_t* g, ast_t* fun,
  uint32_t index, LLVMValueRef handler, LLVMTypeRef type)
{
  // Add a case to the dispatch function to handle this message.
  codegen_startfun(c, g->dispatch_fn, false);
  LLVMBasicBlockRef block = codegen_block(c, "handler");
  LLVMValueRef id = LLVMConstInt(c->i32, index, false);
  LLVMAddCase(g->dispatch_switch, id, block);

  // Destructure the message.
  LLVMPositionBuilderAtEnd(c->builder, block);
  LLVMValueRef ctx = LLVMGetParam(g->dispatch_fn, 0);
  LLVMValueRef this_ptr = LLVMGetParam(g->dispatch_fn, 1);
  LLVMValueRef msg = LLVMBuildBitCast(c->builder,
    LLVMGetParam(g->dispatch_fn, 2), type, "");

  int count = LLVMCountParams(handler);
  size_t buf_size = count * sizeof(LLVMValueRef);
  LLVMValueRef* args = (LLVMValueRef*)pool_alloc_size(buf_size);
  args[0] = LLVMBuildBitCast(c->builder, this_ptr, g->use_type, "");

  // Trace the message.
  LLVMValueRef start_trace = gencall_runtime(c, "pony_gc_recv", &ctx, 1, "");
  ast_t* params = ast_childidx(fun, 3);
  ast_t* param = ast_child(params);
  bool need_trace = false;

  for(int i = 1; i < count; i++)
  {
    LLVMValueRef field = LLVMBuildStructGEP(c->builder, msg, i + 2, "");
    args[i] = LLVMBuildLoad(c->builder, field, "");

    need_trace |= gentrace(c, ctx, args[i], ast_type(param));
    param = ast_sibling(param);
  }

  if(need_trace)
  {
    gencall_runtime(c, "pony_recv_done", &ctx, 1, "");
  } else {
    LLVMInstructionEraseFromParent(start_trace);
  }

  // Call the handler.
  codegen_call(c, handler, args, count);
  LLVMBuildRetVoid(c->builder);
  codegen_finishfun(c);
  pool_free_size(buf_size, args);
}

static void llvm_load_input(
	struct radeon_llvm_context * ctx,
	unsigned input_index,
	const struct tgsi_full_declaration *decl)
{
	const struct r600_shader_io * input = &ctx->r600_inputs[input_index];
	unsigned chan;
	int two_side = (ctx->two_side && input->name == TGSI_SEMANTIC_COLOR);
	LLVMValueRef v;
	boolean require_interp_intrinsic = ctx->chip_class >= EVERGREEN &&
		ctx->type == TGSI_PROCESSOR_FRAGMENT;

	if (require_interp_intrinsic && input->spi_sid) {
		v = llvm_load_input_vector(ctx, input->lds_pos, input->ij_index,
			(input->interpolate > 0));
	} else
		v = LLVMGetParam(ctx->main_fn, input->gpr);

	if (two_side) {
		struct r600_shader_io * back_input =
			&ctx->r600_inputs[input->back_color_input];
		LLVMValueRef v2;
		LLVMValueRef face = LLVMGetParam(ctx->main_fn, ctx->face_gpr);
		face = LLVMBuildExtractElement(ctx->gallivm.builder, face,
			lp_build_const_int32(&(ctx->gallivm), 0), "");

		if (require_interp_intrinsic && back_input->spi_sid)
			v2 = llvm_load_input_vector(ctx, back_input->lds_pos,
				back_input->ij_index, (back_input->interpolate > 0));
		else
			v2 = LLVMGetParam(ctx->main_fn, back_input->gpr);
		v = llvm_face_select_helper(ctx, face, v, v2);
	}

	for (chan = 0; chan < 4; chan++) {
		unsigned soa_index = radeon_llvm_reg_index_soa(input_index, chan);

		ctx->inputs[soa_index] = LLVMBuildExtractElement(ctx->gallivm.builder, v,
			lp_build_const_int32(&(ctx->gallivm), chan), "");

		if (input->name == TGSI_SEMANTIC_POSITION &&
				ctx->type == TGSI_PROCESSOR_FRAGMENT && chan == 3) {
		/* RCP for fragcoord.w */
		ctx->inputs[soa_index] = LLVMBuildFDiv(ctx->gallivm.builder,
				lp_build_const_float(&(ctx->gallivm), 1.0f),
				ctx->inputs[soa_index], "");
	}
	}
}