GCC Middle and Back End API Reference

Data Fields  
gimple *  mul_stmt 
tree  mul_result 
tree  op1 
tree  op2 
Data necessary to perform the actual transformation from a multiplication and an addition to an FMA after decision is taken it should be done and to then delete the multiplication statement from the function IL.
tree fma_transformation_info::mul_result 
gimple* fma_transformation_info::mul_stmt 
tree fma_transformation_info::op1 
tree fma_transformation_info::op2 