Klaus Friedrich <klaus-fried@xxxxxxx> writes: > For my diploma thesis, i will work with the gcc4.1 internals. I would > like to extract information about the RTL > language. I search for a description of the virtual machine/virtual > processor on the RTL instruction set and for example the register > management/alignment. > > I can't find exakt information about the meaning for the RTL > constructs. For Example the meaning for this reg expression [D.1281] in > (reg:SI 58 [D.1281]) or the meaning for virtual-stack-vars in > (reg/f:SI 54 virtual-stack-vars). The [D.1281] refers to the variable associated with that register. In this case I can tell by the name that it is a GIMPLE temporary register. If you use -fdump-tree-final_cleanup and look in the dump file you will see the last GIMPLE code before the expansion into RTL. You should see D.1281 in that code. virtual-stack-vars is a pseudo register which points to the first local variable on the stack frame. It is only used for a little while, and is eliminated by pass_instantiate_virtual_regs. > I also information about the (clobber (reg:CC 17 flags)) expr. What do > the clobber function with the reg 17 ? What can I say: it clobbers it. See the RTL documentation. Ian
