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

   1 #!/usr/bin/env python
   2
   3 # Auto-generates an exhaustive and repetitive test for correct bundle-locked
   4 # alignment on x86.
   5 # For every possible offset in an aligned bundle, a bundle-locked group of every
   6 # size in the inclusive range [1, bundle_size] is inserted. An appropriate CHECK
   7 # is added to verify that NOP padding occurred (or did not occur) as expected.
   8 # Run with --align-to-end to generate a similar test with align_to_end for each
   9 # .bundle_lock directive.
  10
  11 # This script runs with Python 2.7 and 3.2+
  12
  13 from __future__ import print_function
  14 import argparse
  15
  16 BUNDLE_SIZE_POW2 = 4
  17 BUNDLE_SIZE = 2**BUNDLE_SIZE_POW2
  18
  19 PREAMBLE = """
  20 # RUN: llvm-mc -filetype=obj -triple i386-pc-linux-gnu %s -o - \\
  21 # RUN:   | llvm-objdump -triple i386 -disassemble -no-show-raw-insn - | FileCheck %s
  22
  23 # !!! This test is auto-generated from utils/testgen/mc-bundling-x86-gen.py !!!
  24 #     It tests that bundle-aligned grouping works correctly in MC. Read the
  25 #     source of the script for more details.
  26
  27   .text
  28   .bundle_align_mode {0}
  29 """.format(
  30     BUNDLE_SIZE_POW2
  31 ).lstrip()
  32
  33 ALIGNTO = "  .align {0}, 0x90"
  34 NOPFILL = "  .fill {0}, 1, 0x90"
  35
  36
  37 def print_bundle_locked_sequence(len, align_to_end=False):
  38     print("  .bundle_lock{0}".format(" align_to_end" if align_to_end else ""))
  39     print("  .rept {0}".format(len))
  40     print("  inc %eax")
  41     print("  .endr")
  42     print("  .bundle_unlock")
  43
  44
  45 def generate(align_to_end=False):
  46     print(PREAMBLE)
  47
  48     ntest = 0
  49     for instlen in range(1, BUNDLE_SIZE + 1):
  50         for offset in range(0, BUNDLE_SIZE):
  51             # Spread out all the instructions to not worry about cross-bundle
  52             # interference.
  53             print(ALIGNTO.format(2 * BUNDLE_SIZE))
  54             print("INSTRLEN_{0}_OFFSET_{1}:".format(instlen, offset))
  55             if offset > 0:
  56                 print(NOPFILL.format(offset))
  57             print_bundle_locked_sequence(instlen, align_to_end)
  58
  59             # Now generate an appropriate CHECK line
  60             base_offset = ntest * 2 * BUNDLE_SIZE
  61             inst_orig_offset = base_offset + offset  # had it not been padded...
  62
  63             def print_check(adjusted_offset=None, nop_split_offset=None):
  64                 if adjusted_offset is not None:
  65                     print("# CHECK: {0:x}: nop".format(inst_orig_offset))
  66                     if nop_split_offset is not None:
  67                         print("# CHECK: {0:x}: nop".format(nop_split_offset))
  68                     print("# CHECK: {0:x}: incl".format(adjusted_offset))
  69                 else:
  70                     print("# CHECK: {0:x}: incl".format(inst_orig_offset))
  71
  72             if align_to_end:
  73                 if offset + instlen == BUNDLE_SIZE:
  74                     # No padding needed
  75                     print_check()
  76                 elif offset + instlen < BUNDLE_SIZE:
  77                     # Pad to end at nearest bundle boundary
  78                     offset_to_end = base_offset + (BUNDLE_SIZE - instlen)
  79                     print_check(offset_to_end)
  80                 else:  # offset + instlen > BUNDLE_SIZE
  81                     # Pad to end at next bundle boundary, splitting the nop sequence
  82                     # at the nearest bundle boundary
  83                     offset_to_nearest_bundle = base_offset + BUNDLE_SIZE
  84                     offset_to_end = base_offset + (BUNDLE_SIZE * 2 - instlen)
  85                     if offset_to_nearest_bundle == offset_to_end:
  86                         offset_to_nearest_bundle = None
  87                     print_check(offset_to_end, offset_to_nearest_bundle)
  88             else:
  89                 if offset + instlen > BUNDLE_SIZE:
  90                     # Padding needed
  91                     aligned_offset = (inst_orig_offset + instlen) & ~(BUNDLE_SIZE - 1)
  92                     print_check(aligned_offset)
  93                 else:
  94                     # No padding needed
  95                     print_check()
  96
  97             print()
  98             ntest += 1
  99
 100
 101 if __name__ == "__main__":
 102     argparser = argparse.ArgumentParser()
 103     argparser.add_argument(
 104         "--align-to-end",
 105         action="store_true",
 106         help="generate .bundle_lock with align_to_end option",
 107     )
 108     args = argparser.parse_args()
 109     generate(align_to_end=args.align_to_end)