fanqifei <fanqi...@gmail.com> writes: > I am using gcc4.3.2. > In our microcontroller, move instruction(mov reg, imm) can accept > 16bits and 32bits immediate operand. > The data memory size is less than 64KB, however, code memory size is > larger than 64KB. > The immediate operand may be addresses of variables in data sections > and function pointers. The address of variables can be represented by > 16bits. However, function pointers may be larger than 16bits. > I'd like to use "mov reg, imm16" for addresses of variables and "mov > reg, imm32" for function pointers. So that the code size can be a > little bit smaller. > Another way to understand the requirement is the size of pointers to > data and text have to be different. > > How can I select appropriate mov for them? I tried to use LABEL_REF > and SYMBOL_REL to distinguish between them, but it didn't help. It > seems that function pointers are treated as symbols too. > Are there any other cases that references to functions in text > sections are used in data sections?
SYMBOL_REF_FUNCTION_P. (A LABEL_REF refers to a goto label.) Ian
