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
