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      1 # Test 32-bit COMPARE LOGICAL IMMEDIATE AND BRANCH in cases where the sheer
      2 # number of instructions causes some branches to be out of range.
      3 # RUN: python %s | llc -mtriple=s390x-linux-gnu | FileCheck %s
      4 
      5 # Construct:
      6 #
      7 # before0:
      8 #   conditional branch to after0
      9 #   ...
     10 # beforeN:
     11 #   conditional branch to after0
     12 # main:
     13 #   0xffc6 bytes, from MVIY instructions
     14 #   conditional branch to main
     15 # after0:
     16 #   ...
     17 #   conditional branch to main
     18 # afterN:
     19 #
     20 # Each conditional branch sequence occupies 14 bytes if it uses a short
     21 # branch and 20 if it uses a long one.  The ones before "main:" have to
     22 # take the branch length into account, which is 6 for short branches,
     23 # so the final (0x3a - 6) / 14 == 3 blocks can use short branches.
     24 # The ones after "main:" do not, so the first 0x3a / 14 == 4 blocks
     25 # can use short branches.  The conservative algorithm we use makes
     26 # one of the forward branches unnecessarily long, as noted in the
     27 # check output below.
     28 #
     29 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     30 # CHECK: s [[REG]], 0(%r4)
     31 # CHECK: clfi [[REG]], 50
     32 # CHECK: jgl [[LABEL:\.L[^ ]*]]
     33 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     34 # CHECK: s [[REG]], 0(%r4)
     35 # CHECK: clfi [[REG]], 51
     36 # CHECK: jgl [[LABEL]]
     37 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     38 # CHECK: s [[REG]], 0(%r4)
     39 # CHECK: clfi [[REG]], 52
     40 # CHECK: jgl [[LABEL]]
     41 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     42 # CHECK: s [[REG]], 0(%r4)
     43 # CHECK: clfi [[REG]], 53
     44 # CHECK: jgl [[LABEL]]
     45 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     46 # CHECK: s [[REG]], 0(%r4)
     47 # CHECK: clfi [[REG]], 54
     48 # CHECK: jgl [[LABEL]]
     49 # ...as mentioned above, the next one could be a CLIJL instead...
     50 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     51 # CHECK: s [[REG]], 0(%r4)
     52 # CHECK: clfi [[REG]], 55
     53 # CHECK: jgl [[LABEL]]
     54 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     55 # CHECK: s [[REG]], 0(%r4)
     56 # CHECK: clijl [[REG]], 56, [[LABEL]]
     57 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     58 # CHECK: s [[REG]], 0(%r4)
     59 # CHECK: clijl [[REG]], 57, [[LABEL]]
     60 # ...main goes here...
     61 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     62 # CHECK: s [[REG]], 0(%r4)
     63 # CHECK: clijl [[REG]], 100, [[LABEL:\.L[^ ]*]]
     64 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     65 # CHECK: s [[REG]], 0(%r4)
     66 # CHECK: clijl [[REG]], 101, [[LABEL]]
     67 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     68 # CHECK: s [[REG]], 0(%r4)
     69 # CHECK: clijl [[REG]], 102, [[LABEL]]
     70 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     71 # CHECK: s [[REG]], 0(%r4)
     72 # CHECK: clijl [[REG]], 103, [[LABEL]]
     73 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     74 # CHECK: s [[REG]], 0(%r4)
     75 # CHECK: clfi [[REG]], 104
     76 # CHECK: jgl [[LABEL]]
     77 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     78 # CHECK: s [[REG]], 0(%r4)
     79 # CHECK: clfi [[REG]], 105
     80 # CHECK: jgl [[LABEL]]
     81 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     82 # CHECK: s [[REG]], 0(%r4)
     83 # CHECK: clfi [[REG]], 106
     84 # CHECK: jgl [[LABEL]]
     85 # CHECK: l [[REG:%r[0-5]]], 0(%r3)
     86 # CHECK: s [[REG]], 0(%r4)
     87 # CHECK: clfi [[REG]], 107
     88 # CHECK: jgl [[LABEL]]
     89 
     90 branch_blocks = 8
     91 main_size = 0xffc6
     92 
     93 print 'define void @f1(i8 *%base, i32 *%stopa, i32 *%stopb) {'
     94 print 'entry:'
     95 print '  br label %before0'
     96 print ''
     97 
     98 for i in xrange(branch_blocks):
     99     next = 'before%d' % (i + 1) if i + 1 < branch_blocks else 'main'
    100     print 'before%d:' % i
    101     print '  %%bcur%da = load i32 *%%stopa' % i
    102     print '  %%bcur%db = load i32 *%%stopb' % i
    103     print '  %%bsub%d = sub i32 %%bcur%da, %%bcur%db' % (i, i, i)
    104     print '  %%btest%d = icmp ult i32 %%bsub%d, %d' % (i, i, i + 50)
    105     print '  br i1 %%btest%d, label %%after0, label %%%s' % (i, next)
    106     print ''
    107 
    108 print '%s:' % next
    109 a, b = 1, 1
    110 for i in xrange(0, main_size, 6):
    111     a, b = b, a + b
    112     offset = 4096 + b % 500000
    113     value = a % 256
    114     print '  %%ptr%d = getelementptr i8 *%%base, i64 %d' % (i, offset)
    115     print '  store volatile i8 %d, i8 *%%ptr%d' % (value, i)
    116 
    117 for i in xrange(branch_blocks):
    118     print '  %%acur%da = load i32 *%%stopa' % i
    119     print '  %%acur%db = load i32 *%%stopb' % i
    120     print '  %%asub%d = sub i32 %%acur%da, %%acur%db' % (i, i, i)
    121     print '  %%atest%d = icmp ult i32 %%asub%d, %d' % (i, i, i + 100)
    122     print '  br i1 %%atest%d, label %%main, label %%after%d' % (i, i)
    123     print ''
    124     print 'after%d:' % i
    125 
    126 print '  ret void'
    127 print '}'
    128