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riscv-gcc-1
Commit 8ba2bda8 by Ian Lance Taylor
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compiler: generate memmove for non-pointer slice copy 

    
    The builtin copy function is lowered to runtime functions
    slicecopy, stringslicecopy, or typedslicecopy. The first two are
    basically thin wrappers of memmove. Instead of making a runtime
    call, we can just use __builtin_memmove. This gives the compiler
    backend opportunities for further optimizations.
    
    Move the lowering of builtin copy function to flatten phase for
    the ease of rewriting.
    
    Also do this optimization for the copy part of append(s1, s2...).
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/170005

From-SVN: r271017
parent fbe4e644
Showing with 134 additions and 56 deletions
gcc/go/gofrontend/MERGE
3a9bccfbf4af1c756978c40967838d9f6a4e7a62
859e8ed3d632d9fe43d03fb81f6abefecf5fe3a6
The first line of this file holds the git revision number of the last
merge done from the gofrontend repository.
gcc/go/gofrontend/expressions.cc
......@@ -7743,8 +7743,9 @@ Builtin_call_expression::do_lower(Gogo*, Named_object* function,
return this;
}
// Flatten a builtin call expression. This turns the arguments of copy and
// append into temporary expressions.
// Flatten a builtin call expression. This turns the arguments of some
// builtin calls into temporary expressions. Also expand copy and append
// to runtime calls.
Expression*
Builtin_call_expression::do_flatten(Gogo* gogo, Named_object* function,
......@@ -7781,6 +7782,85 @@ Builtin_call_expression::do_flatten(Gogo* gogo, Named_object* function,
*pa = Expression::make_temporary_reference(temp, loc);
}
}
// Lower to runtime call.
const Expression_list* args = this->args();
go_assert(args != NULL && args->size() == 2);
Expression* arg1 = args->front();
Expression* arg2 = args->back();
go_assert(arg1->is_variable());
go_assert(arg2->is_variable());
bool arg2_is_string = arg2->type()->is_string_type();
Expression* ret;
Type* et = at->array_type()->element_type();
if (et->has_pointer())
{
Expression* td = Expression::make_type_descriptor(et, loc);
ret = Runtime::make_call(Runtime::TYPEDSLICECOPY, loc,
3, td, arg1, arg2);
}
else
{
Type* int_type = Type::lookup_integer_type("int");
Type* uintptr_type = Type::lookup_integer_type("uintptr");
// l1 = len(arg1)
Named_object* lenfn = gogo->lookup_global("len");
Expression* lenref = Expression::make_func_reference(lenfn, NULL, loc);
Expression_list* len_args = new Expression_list();
len_args->push_back(arg1->copy());
Expression* len1 = Expression::make_call(lenref, len_args, false, loc);
gogo->lower_expression(function, inserter, &len1);
gogo->flatten_expression(function, inserter, &len1);
Temporary_statement* l1tmp = Statement::make_temporary(int_type, len1, loc);
inserter->insert(l1tmp);
// l2 = len(arg2)
len_args = new Expression_list();
len_args->push_back(arg2->copy());
Expression* len2 = Expression::make_call(lenref, len_args, false, loc);
gogo->lower_expression(function, inserter, &len2);
gogo->flatten_expression(function, inserter, &len2);
Temporary_statement* l2tmp = Statement::make_temporary(int_type, len2, loc);
inserter->insert(l2tmp);
// n = (l1 < l2 ? l1 : l2)
Expression* l1ref = Expression::make_temporary_reference(l1tmp, loc);
Expression* l2ref = Expression::make_temporary_reference(l2tmp, loc);
Expression* cond = Expression::make_binary(OPERATOR_LT, l1ref, l2ref, loc);
Expression* n = Expression::make_conditional(cond,
l1ref->copy(),
l2ref->copy(),
loc);
Temporary_statement* ntmp = Statement::make_temporary(NULL, n, loc);
inserter->insert(ntmp);
// sz = n * sizeof(elem_type)
Expression* nref = Expression::make_temporary_reference(ntmp, loc);
nref = Expression::make_cast(uintptr_type, nref, loc);
Expression* sz = Expression::make_type_info(et, TYPE_INFO_SIZE);
sz = Expression::make_binary(OPERATOR_MULT, sz, nref, loc);
// memmove(arg1.ptr, arg2.ptr, sz)
Expression* p1 = Expression::make_slice_info(arg1,
SLICE_INFO_VALUE_POINTER,
loc);
Expression* p2 = (arg2_is_string
? Expression::make_string_info(arg2,
STRING_INFO_DATA,
loc)
: Expression::make_slice_info(arg2,
SLICE_INFO_VALUE_POINTER,
loc));
Expression* call = Runtime::make_call(Runtime::BUILTIN_MEMMOVE, loc, 3,
p1, p2, sz);
// n is the return value of copy
nref = Expression::make_temporary_reference(ntmp, loc);
ret = Expression::make_compound(call, nref, loc);
}
return ret;
}
break;
......@@ -8209,21 +8289,51 @@ Builtin_call_expression::flatten_append(Gogo* gogo, Named_object* function,
if (this->is_varargs())
{
// copy(s1tmp[l1tmp:], s2tmp)
a1 = Expression::make_temporary_reference(s1tmp, loc);
ref = Expression::make_temporary_reference(l1tmp, loc);
Expression* nil = Expression::make_nil(loc);
a1 = Expression::make_array_index(a1, ref, nil, NULL, loc);
a1->array_index_expression()->set_needs_bounds_check(false);
a2 = Expression::make_temporary_reference(s2tmp, loc);
Named_object* copyfn = gogo->lookup_global("copy");
Expression* copyref = Expression::make_func_reference(copyfn, NULL, loc);
call_args = new Expression_list();
call_args->push_back(a1);
call_args->push_back(a2);
call = Expression::make_call(copyref, call_args, false, loc);
if (element_type->has_pointer())
{
// copy(s1tmp[l1tmp:], s2tmp)
a1 = Expression::make_temporary_reference(s1tmp, loc);
ref = Expression::make_temporary_reference(l1tmp, loc);
Expression* nil = Expression::make_nil(loc);
a1 = Expression::make_array_index(a1, ref, nil, NULL, loc);
a1->array_index_expression()->set_needs_bounds_check(false);
a2 = Expression::make_temporary_reference(s2tmp, loc);
Named_object* copyfn = gogo->lookup_global("copy");
Expression* copyref = Expression::make_func_reference(copyfn, NULL, loc);
call_args = new Expression_list();
call_args->push_back(a1);
call_args->push_back(a2);
call = Expression::make_call(copyref, call_args, false, loc);
}
else
{
// memmove(&s1tmp[l1tmp], s2tmp.ptr, l2tmp*sizeof(elem))
a1 = Expression::make_temporary_reference(s1tmp, loc);
ref = Expression::make_temporary_reference(l1tmp, loc);
a1 = Expression::make_array_index(a1, ref, NULL, NULL, loc);
a1->array_index_expression()->set_needs_bounds_check(false);
a1 = Expression::make_unary(OPERATOR_AND, a1, loc);
a2 = Expression::make_temporary_reference(s2tmp, loc);
a2 = (a2->type()->is_string_type()
? Expression::make_string_info(a2,
STRING_INFO_DATA,
loc)
: Expression::make_slice_info(a2,
SLICE_INFO_VALUE_POINTER,
loc));
Type* uintptr_type = Type::lookup_integer_type("uintptr");
ref = Expression::make_temporary_reference(l2tmp, loc);
ref = Expression::make_cast(uintptr_type, ref, loc);
a3 = Expression::make_type_info(element_type, TYPE_INFO_SIZE);
a3 = Expression::make_binary(OPERATOR_MULT, a3, ref, loc);
call = Runtime::make_call(Runtime::BUILTIN_MEMMOVE, loc, 3,
a1, a2, a3);
}
gogo->lower_expression(function, inserter, &call);
gogo->flatten_expression(function, inserter, &call);
inserter->insert(Statement::make_statement(call, false));
......@@ -9666,44 +9776,8 @@ Builtin_call_expression::do_get_backend(Translate_context* context)
}
case BUILTIN_COPY:
{
const Expression_list* args = this->args();
go_assert(args != NULL && args->size() == 2);
Expression* arg1 = args->front();
Expression* arg2 = args->back();
Type* arg1_type = arg1->type();
Array_type* at = arg1_type->array_type();
go_assert(arg1->is_variable());
Expression* call;
Type* arg2_type = arg2->type();
go_assert(arg2->is_variable());
if (arg2_type->is_string_type())
call = Runtime::make_call(Runtime::SLICESTRINGCOPY, location,
2, arg1, arg2);
else
{
Type* et = at->element_type();
if (et->has_pointer())
{
Expression* td = Expression::make_type_descriptor(et,
location);
call = Runtime::make_call(Runtime::TYPEDSLICECOPY, location,
3, td, arg1, arg2);
}
else
{
Expression* sz = Expression::make_type_info(et,
TYPE_INFO_SIZE);
call = Runtime::make_call(Runtime::SLICECOPY, location, 3,
arg1, arg2, sz);
}
}
return call->get_backend(context);
}
// Handled in Builtin_call_expression::do_flatten.
go_unreachable();
case BUILTIN_APPEND:
// Handled in Builtin_call_expression::flatten_append.
......
gcc/go/gofrontend/runtime.def
......@@ -372,6 +372,10 @@ DEF_GO_RUNTIME(FIELDTRACK, "__go_fieldtrack", P1(POINTER), R0())
// Unreachable code.
DEF_GO_RUNTIME(UNREACHABLE, "__builtin_unreachable", P0(), R0())
// Memmove.
DEF_GO_RUNTIME(BUILTIN_MEMMOVE, "__builtin_memmove",
P3(POINTER, POINTER, UINTPTR), R0())
// Remove helper macros.
#undef ABFT6
#undef ABFT2
......
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