------- Comment #2 from bonzini at gnu dot org 2010-01-05 11:43 ------- Combine is doing what it knows best (forming complicated instructions, addressing modes in this case); to do this it is already damaging the nice shape of the code after the tree optimizers, and synthesizing things like x+2.
I wonder more about what the RTL looks like before auto-inc-dec, and whether it is missing something because it must be taught some trick... Is this a regression from pre-DF (that would be 4.2)? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42612
