GCC Middle and Back End API Reference
tree-ssa-coalesce.h File Reference

Go to the source code of this file.


var_map coalesce_ssa_name (void)

Function Documentation

var_map coalesce_ssa_name ( void  )
   Reduce the number of copies by coalescing variables in the function.  Return
   a partition map with the resulting coalesces.  
     We need to coalesce all names originating same SSA_NAME_VAR
     so debug info remains undisturbed.  
     Don't calculate live ranges for variables not in the coalesce list.  
     Build a conflict graph.  
     First, coalesce all live on entry variables to their base variable.
     This will ensure the first use is coming from the correct location.  
     Now coalesce everything in the list.