Dear SDCC users, for a while there has been work on moving to a more efficient calling convention. In particular, the following changes can substantially improve the code geenerated for stm8:
* Pass some parameters in registers. * Have the callee instead of the caller clean up stack parameters for some functions (medium memory model only). For a while, this has been implemented in the breaktheworld branch, as the new default. As of today, the new calling convention is also available in trunk (and thus the snapshots); it can be make the default by compiling with --sdcccall 1. Independent of the default, individual functions can be marked as using the old convention via __sdcccall(0) or the new one via __sdcccall(1). The details are documented in the manual. As of today (revision 12615), only two differences remain between trunk and the breaktheworld branch: * When the --sdcccall option is not used: in trunk, the old convention is the default, in the branch the new convention is the default. * In trunk, the standard library is compiled for the old convnetion, in the branch it is compiled for the new convention. If users are happy with the new ABI, these two differences will be merged from the branch to trunk in the future. THIS WOULD BE A BREAKING CHANGE, as hand-written asm code written for the old calling convention would stop to work. Users of such code would have to either rewrite it for the new convention, or add __sdcccall(0) to the function declarations to continue using the old convnetion. Philipp _______________________________________________ Sdcc-user mailing list Sdcc-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sdcc-user
