vax optimization breakage?

[Jeffrey A Law]

  In message < 20000719004847.A12@pobox.com >you write:
  > The code that is generated looks like this:
  > 
  > #NO_APP
  > gcc2_compiled.:
  > ___gnu_compiled_c:
  > .text
  >         .align 1
  > .globl _func
  >         .type   _func , @function
  > _func:
  >         .word 0x0
  >         clrl _cnt
  >         clrl r0
  > L5:
  >         incl r0
  >         cmpl r0,$4
  >         jleq L5
  >         ret
  >         .size   _func , . - _func
  > .comm _cnt,4 
  > 
  > 
  > _cnt is ending up unchanged.  
  > 
  > (speculation begins here, please don't flame too badly)
  > I've looked through rtl dumps, and it looks like the "set" insn which 
  > sets cnt to what it should be (after the loop) gets trapped with 
  > a code_label with 0 uses:  > 

What we really need to see are the .gcse and .loop dump files so that we
can determine if things look OK before the loop optimizer or after the
loop optimizer.  One we have that information we can guide you towards
the offending code.

jeff