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Re: Question about long jump implementation
Hi Ian, thanks for the response.
I did manage to fix it. The problem was in my call_internal
implementation. I went back and looked again at the arm implementation
and spotted what I'd done wrong.
Sorry for the bother.
On 17 December 2010 01:21, Ian Lance Taylor <iant@google.com> wrote:
> Neil Hickey <neil@petapath.com> writes:
>
>> I'm trying to implement long jump and I'm using the call instruction
>> in the arm implementation as a reference.
>>
>> The code looks like this:
>>
>> ? ? rtx callee, pat;
>>
>> ? ? callee = XEXP(operands[0], 0);
>> ? ? if (GET_CODE (callee) == SYMBOL_REF
>> ? ? ? ? atdsp_is_long_call_p (SYMBOL_REF_DECL (callee))
>> ? ? ? : !REG_P (callee)) {
>> ? ? ? XEXP(operands[0], 0) = force_reg (SImode, callee);
>> ? ? }
>> ? ? pat = gen_call_internal (operands[0], operands[1]);
>> ? ? emit_call_insn(pat);
>> ? ? DONE;
>>
>> What I want to happen is for the function name to be copied to a
>> register and then the compiler emit the instruction to call the
>> function, by jumping to the address held in that register.
>>
>> The compiler emits instructions that copy the function name to a
>> register, then it loads from the value of this register, before
>> jumping to the loaded value. What I want it to do is copy the function
>> name to the register, then jump to the address held in this register.
>>
>> Does anyone know what it is I've done wrong and how I can get this to work?
>
> I think it's impossible for us to say without more information.
>
> Does the RTL look correct? ?If not, then you need to fix the RTL
> generation, which will look more or less like the code above. ?If the
> RTL does look correct, then you need to fix your MD file to generate
> instructions which correctly represent the RTL.
>
> Ian
>