[committed] Fix recent msp430-elf regressions

I didn't actually bisect this, but I strongly suspect this relates to 
the recent set INSN_CODE before calling insn_cost.

An obscure corner case I didn't even know existed.  Inside combine we 
can create nop moves which look something like (set (pc) (pc)).  That 
would have triggered an early out in msp430_insn_cost.  After the 
combine change those insns use NOOP_MOVE_INSN_CODE via special hackery 
in combine rather than the -1 for an unrecognized insn.

So rather than early exit from msp430_insn_code, we try to call 
get_attr_length of that noop move which of course fails and triggers all 
kinds of testsuite regressions.


While I considered checking earlier in the call stack, msp430 seems to 
be the only port affected, so I put it down in there. Built and 
regression tested where it fixes the recent regressions and causes no 
new regressions.  Pushing to the trunk.

jeff

diff --git a/gcc/config/msp430/msp430.cc b/gcc/config/msp430/msp430.cc
index 671b95029d21..5b3e447881af 100644
--- a/gcc/config/msp430/msp430.cc
+++ b/gcc/config/msp430/msp430.cc
@@ -1657,6 +1657,9 @@ msp430_insn_cost (rtx_insn *insn, bool speed ATTRIBUTE_UNUSED)
   if (recog_memoized (insn) < 0)
     return 0;
 
+  if (INSN_CODE (insn) == NOOP_MOVE_INSN_CODE)
+    return 0;
+
   /* The returned cost must be relative to COSTS_N_INSNS (1). An insn with a
      length of 2 bytes is the smallest possible size and so must be equivalent
      to COSTS_N_INSNS (1).  */