utils/testgen/mc-bundling-x86-gen.py

   1
   2 #!/usr/bin/python
   3
   4 # Auto-generates an exhaustive and repetitive test for correct bundle-locked
   5 # alignment on x86.
   6 # For every possible offset in an aligned bundle, a bundle-locked group of every
   7 # size in the inclusive range [1, bundle_size] is inserted. An appropriate CHECK
   8 # is added to verify that NOP padding occurred (or did not occur) as expected.
   9 # Run with --align-to-end to generate a similar test with align_to_end for each
  10 # .bundle_lock directive.
  11
  12 # This script runs with Python 2.7 and 3.2+
  13
  14 from __future__ import print_function
  15 import argparse
  16
  17 BUNDLE_SIZE_POW2 = 4
  18 BUNDLE_SIZE = 2 ** BUNDLE_SIZE_POW2
  19
  20 PREAMBLE = '''
  21 # RUN: llvm-mc -filetype=obj -triple i386-pc-linux-gnu %s -o - \\
  22 # RUN:   | llvm-objdump -triple i386 -disassemble -no-show-raw-insn - | FileCheck %s
  23
  24 # !!! This test is auto-generated from utils/testgen/mc-bundling-x86-gen.py !!!
  25 #     It tests that bundle-aligned grouping works correctly in MC. Read the
  26 #     source of the script for more details.
  27
  28   .text
  29   .bundle_align_mode {0}
  30 '''.format(BUNDLE_SIZE_POW2).lstrip()
  31
  32 ALIGNTO = '  .align {0}, 0x90'
  33 NOPFILL = '  .fill {0}, 1, 0x90'
  34
  35 def print_bundle_locked_sequence(len, align_to_end=False):
  36   print('  .bundle_lock{0}'.format(' align_to_end' if align_to_end else ''))
  37   print('  .rept {0}'.format(len))
  38   print('  inc %eax')
  39   print('  .endr')
  40   print('  .bundle_unlock')
  41
  42 def generate(align_to_end=False):
  43   print(PREAMBLE)
  44
  45   ntest = 0
  46   for instlen in range(1, BUNDLE_SIZE + 1):
  47     for offset in range(0, BUNDLE_SIZE):
  48       # Spread out all the instructions to not worry about cross-bundle
  49       # interference.
  50       print(ALIGNTO.format(2 * BUNDLE_SIZE))
  51       print('INSTRLEN_{0}_OFFSET_{1}:'.format(instlen, offset))
  52       if offset > 0:
  53         print(NOPFILL.format(offset))
  54       print_bundle_locked_sequence(instlen, align_to_end)
  55
  56       # Now generate an appropriate CHECK line
  57       base_offset = ntest * 2 * BUNDLE_SIZE
  58       inst_orig_offset = base_offset + offset  # had it not been padded...
  59
  60       def print_check(adjusted_offset=None, nop_split_offset=None):
  61         if adjusted_offset is not None:
  62           print('# CHECK: {0:x}: nop'.format(inst_orig_offset))
  63           if nop_split_offset is not None:
  64             print('# CHECK: {0:x}: nop'.format(nop_split_offset))
  65           print('# CHECK: {0:x}: incl'.format(adjusted_offset))
  66         else:
  67           print('# CHECK: {0:x}: incl'.format(inst_orig_offset))
  68
  69       if align_to_end:
  70         if offset + instlen == BUNDLE_SIZE:
  71           # No padding needed
  72           print_check()
  73         elif offset + instlen < BUNDLE_SIZE:
  74           # Pad to end at nearest bundle boundary
  75           offset_to_end = base_offset + (BUNDLE_SIZE - instlen)
  76           print_check(offset_to_end)
  77         else: # offset + instlen > BUNDLE_SIZE
  78           # Pad to end at next bundle boundary, splitting the nop sequence
  79           # at the nearest bundle boundary
  80           offset_to_nearest_bundle = base_offset + BUNDLE_SIZE
  81           offset_to_end = base_offset + (BUNDLE_SIZE * 2 - instlen)
  82           if offset_to_nearest_bundle == offset_to_end:
  83             offset_to_nearest_bundle = None
  84           print_check(offset_to_end, offset_to_nearest_bundle)
  85       else:
  86         if offset + instlen > BUNDLE_SIZE:
  87           # Padding needed
  88           aligned_offset = (inst_orig_offset + instlen) & ~(BUNDLE_SIZE - 1)
  89           print_check(aligned_offset)
  90         else:
  91           # No padding needed
  92           print_check()
  93
  94       print()
  95       ntest += 1
  96
  97 if __name__ == '__main__':
  98   argparser = argparse.ArgumentParser()
  99   argparser.add_argument('--align-to-end',
 100                          action='store_true',
 101                          help='generate .bundle_lock with align_to_end option')
 102   args = argparser.parse_args()
 103   generate(align_to_end=args.align_to_end)