[ixp1200] How to generate asm code from SDK

HI, I try to generate the assembly code from Micro C code using SDK 2.0, In the Build->setting, I check the "Produce assembly code file". When I compile , I got the following warning: (0): warning : IPO enabled; -Fa and -FA produce dummy .asm files It seems it did not produce asm file, and I cannot find asm file anywhere. How can I get the assembly code? Thanks, Yan