[x86] Tweak my update script to use test case function names starting

with 'stress' to indicate that the specific output isn't interesting and
relax them to only check the last instruction (a ret).

I've updated the one test case that really uses this to name the one
'stress_test' which was actually producing output we can directly check.
With this, the script doesn't introduce noise when run over the v16 test
file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228033 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/X86/vector-shuffle-128-v16.ll

@@ -429,12 +429,12 @@ entry:
   ret <16 x i8> %s.16.0
 }
 
-define <16 x i8> @stress_test1(<16 x i8> %s.0.5, <16 x i8> %s.0.8, <16 x i8> %s.0.9) noinline nounwind {
+define <16 x i8> @undef_test1(<16 x i8> %s.0.5, <16 x i8> %s.0.8, <16 x i8> %s.0.9) noinline nounwind {
 ; There is nothing interesting to check about these instructions other than
 ; that they survive codegen. However, we actually do better and delete all of
 ; them because the result is 'undef'.
 ;
-; ALL-LABEL: stress_test1:
+; ALL-LABEL: undef_test1:
 ; ALL:       # BB#0: # %entry
 ; ALL-NEXT:    retq
 entry:

utils/update_llc_test_checks.py

@@ -122,6 +122,9 @@ def main():
           continue
         f = m.group('f')
         f_asm = scrub_asm(m.group('body'))
+        if f.startswith('stress'):
+          # We only use the last line of the asm for stress tests.
+          f_asm = '\n'.join(f_asm.splitlines()[-1:])
         if args.verbose:
           print >>sys.stderr, 'Processing asm for function: ' + f
           for l in f_asm.splitlines():