src/llvm/test/CodeGen/SystemZ/Large/branch-range-08.py

   1 # Test 64-bit BRANCH RELATIVE ON COUNT in cases where some branches are out
   2 # of range.
   3 # RUN: python %s | llc -mtriple=s390x-linux-gnu | FileCheck %s
   4
   5 # Construct:
   6 #
   7 # loopN:
   8 #   load of countN
   9 #   ...
  10 # loop0:
  11 #   0xffd8 bytes, from MVIY instructions
  12 #   conditional branch to main
  13 # after0:
  14 #   ...
  15 #   decrement of countN
  16 #   conditional branch to loopN
  17 # afterN:
  18 #
  19 # Each load occupies 6 bytes.  Each decrement and branch occupies 4
  20 # bytes if BRCTG can be used, otherwise it occupies 10 bytes (AGHI + BRCL).
  21 # This means that loop 5 contains 4 * 6 + 0xffd8 + 4 * 4 == 0x10000 bytes
  22 # and is therefore (just) in range.  Loop 6 is out of range.
  23 #
  24 # CHECK: brctg {{%r[0-9]+}}
  25 # CHECK: brctg {{%r[0-9]+}}
  26 # CHECK: brctg {{%r[0-9]+}}
  27 # CHECK: brctg {{%r[0-9]+}}
  28 # CHECK: brctg {{%r[0-9]+}}
  29 # CHECK: aghi {{%r[0-9]+}}, -1
  30 # CHECK: jglh
  31 # CHECK: aghi {{%r[0-9]+}}, -1
  32 # CHECK: jglh
  33 # CHECK: aghi {{%r[0-9]+}}, -1
  34 # CHECK: jglh
  35
  36 branch_blocks = 8
  37 main_size = 0xffd8
  38
  39 print 'define void @f1(i8 *%base, i64 *%counts) {'
  40 print 'entry:'
  41
  42 for i in xrange(branch_blocks - 1, -1, -1):
  43     print '  %%countptr%d = getelementptr i64 *%%counts, i64 %d' % (i, i)
  44     print '  %%initcount%d = load i64 *%%countptr%d' % (i, i)
  45     print '  br label %%loop%d' % i
  46
  47     print 'loop%d:' % i
  48     block1 = 'entry' if i == branch_blocks - 1 else 'loop%d' % (i + 1)
  49     block2 = 'loop0' if i == 0 else 'after%d' % (i - 1)
  50     print ('  %%count%d = phi i64 [ %%initcount%d, %%%s ],'
  51            ' [ %%nextcount%d, %%%s ]' % (i, i, block1, i, block2))
  52
  53 a, b = 1, 1
  54 for i in xrange(0, main_size, 6):
  55     a, b = b, a + b
  56     offset = 4096 + b % 500000
  57     value = a % 256
  58     print '  %%ptr%d = getelementptr i8 *%%base, i64 %d' % (i, offset)
  59     print '  store volatile i8 %d, i8 *%%ptr%d' % (value, i)
  60
  61 for i in xrange(branch_blocks):
  62     print '  %%nextcount%d = add i64 %%count%d, -1' % (i, i)
  63     print '  %%test%d = icmp ne i64 %%nextcount%d, 0' % (i, i)
  64     print '  br i1 %%test%d, label %%loop%d, label %%after%d' % (i, i, i)
  65     print ''
  66     print 'after%d:' % i
  67
  68 print '  ret void'
  69 print '}'