On 19.09.2011, at 14:06, Xin Tong Utoronto wrote: > There are 2 files on helpers in target-ppc and target-i386 ( op-helper.c > helper.c), what are their differences ?
General rule: op_helper.c: Code snippets called from TCG generated code. Implement more complex operations that gcc gets better than TCG. helper.c: Helper functions specific to the CPU, but called from multiple places around QEMU. For example the MMU code belongs here. > also, what kind of functions are typically emulated using helpers ? IIRC the rule of thumb is anything containing branches or bigger than 10(?) TCG ops should be in a helper. But it's up to the target developer really. Alex
