Richard Tew writes: > Hi, > > I am using the inline assembly functionality of gcc (gcc 4.1.0 > compiled as part of the devkitpro/devkitarm package which > uses mingw/msys on Windows). What I am trying to do is > port Stackless Python, which copies portions of the stack > off and back on, as it switches between microthreads. > > The problem is, gcc preserves the stack pointer on entry to the > function and restores it at the end, so while I may copy around > portions of the stack with the presumption my modified stack > pointer will be used on exit of the function, what I actually get > is the modified stack, but the old stack pointer restored over > my modified one. > > I can hack a solution. Looking at the disassembly in the > debugger I am using, I see that sp is preserved in r7, so if I > modify my inline assembler to modify r7 instead of sp, > Stackless Python works fine. Why don't you just write the stack-exchanging routine in pure asm? It seems to me that inline asm is just the wrong tool for the job. Andrew.
