diff options
Diffstat (limited to 'gcc/go/gofrontend/wb.cc')
| -rw-r--r-- | gcc/go/gofrontend/wb.cc | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/gcc/go/gofrontend/wb.cc b/gcc/go/gofrontend/wb.cc index c672bf3..a3f71a4 100644 --- a/gcc/go/gofrontend/wb.cc +++ b/gcc/go/gofrontend/wb.cc @@ -64,6 +64,47 @@ Mark_address_taken::expression(Expression** pexpr) } aie->array()->address_taken(escapes); } + + // Rewrite non-escaping makeslice with constant size to stack allocation. + Unsafe_type_conversion_expression* uce = + expr->unsafe_conversion_expression(); + if (uce != NULL + && uce->type()->is_slice_type() + && Node::make_node(uce->expr())->encoding() == Node::ESCAPE_NONE + && uce->expr()->call_expression() != NULL) + { + Call_expression* call = uce->expr()->call_expression(); + if (call->fn()->func_expression() != NULL + && call->fn()->func_expression()->runtime_code() == Runtime::MAKESLICE) + { + Expression* len_arg = call->args()->at(1); + Expression* cap_arg = call->args()->at(2); + Numeric_constant nclen; + Numeric_constant nccap; + unsigned long vlen; + unsigned long vcap; + if (len_arg->numeric_constant_value(&nclen) + && cap_arg->numeric_constant_value(&nccap) + && nclen.to_unsigned_long(&vlen) == Numeric_constant::NC_UL_VALID + && nccap.to_unsigned_long(&vcap) == Numeric_constant::NC_UL_VALID) + { + // Turn it into a slice expression of an addressable array, + // which is allocated on stack. + Location loc = expr->location(); + Type* elmt_type = expr->type()->array_type()->element_type(); + Expression* len_expr = + Expression::make_integer_ul(vcap, cap_arg->type(), loc); + Type* array_type = Type::make_array_type(elmt_type, len_expr); + Expression* alloc = Expression::make_allocation(array_type, loc); + alloc->allocation_expression()->set_allocate_on_stack(); + Expression* array = Expression::make_unary(OPERATOR_MULT, alloc, loc); + Expression* zero = Expression::make_integer_ul(0, len_arg->type(), loc); + Expression* slice = + Expression::make_array_index(array, zero, len_arg, cap_arg, loc); + *pexpr = slice; + } + } + } return TRAVERSE_CONTINUE; } |