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basic questions about GCC (porting GCC to a new target)
- To: <gcc at gcc dot gnu dot org>
- Subject: basic questions about GCC (porting GCC to a new target)
- From: "Bernhard Schaffer" <b dot schaffer at evisioninc dot ch>
- Date: Thu, 1 Nov 2001 17:47:05 +0100
- Reply-To: <b dot schaffer at evisioninc dot ch>
hi all,
i recently started to port GCC to a new 16bit risc microcontroller target.
i have defined all needed files and the compiler starts producing
assembler code.
at the moment i have problems understanding argument passing:
1.) although i define the argument pointer as a fixed register
it is changed before function calls. the argument pointer
should be changed by a function prologue/epilogue only.
if i invoke the compiler with the option --fixed-ap
this behavior vanishes.
a) what could be the reason ?
b) what are the gcc files related to function calls ?
c) how to debug ?
2.) i see that the stack pointer is pushed to the stack although
this makes no sense at all since it should be changed by
function epilogues/prologues only.
a) possible reason ?
b) how to debug ?
for any answer to my question i would be very happy !
regards
bernhard schaffer
bernhard schaffer
zweiackerstrasse 31
8053 zurich / CH
<mailto:bschaffer@evisioninc.ch>