1 # Test normal conditional branches in cases where the sheer number of 2 # 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 # 0xffd8 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 8 bytes if it uses a short branch 21 # and 10 if it uses a long one. The ones before "main:" have to take the branch 22 # length into account -- which is 4 bytes for short branches -- so the final 23 # (0x28 - 4) / 8 == 4 blocks can use short branches. The ones after "main:" 24 # do not, so the first 0x28 / 8 == 5 can use short branches. However, 25 # the conservative algorithm we use makes one branch unnecessarily long 26 # on each side. 27 # 28 # CHECK: c %r4, 0(%r3) 29 # CHECK: jge [[LABEL:\.L[^ ]*]] 30 # CHECK: c %r4, 4(%r3) 31 # CHECK: jge [[LABEL]] 32 # CHECK: c %r4, 8(%r3) 33 # CHECK: jge [[LABEL]] 34 # CHECK: c %r4, 12(%r3) 35 # CHECK: jge [[LABEL]] 36 # CHECK: c %r4, 16(%r3) 37 # CHECK: jge [[LABEL]] 38 # CHECK: c %r4, 20(%r3) 39 # CHECK: jge [[LABEL]] 40 # CHECK: c %r4, 24(%r3) 41 # CHECK: j{{g?}}e [[LABEL]] 42 # CHECK: c %r4, 28(%r3) 43 # CHECK: je [[LABEL]] 44 # CHECK: c %r4, 32(%r3) 45 # CHECK: je [[LABEL]] 46 # CHECK: c %r4, 36(%r3) 47 # CHECK: je [[LABEL]] 48 # ...main goes here... 49 # CHECK: c %r4, 100(%r3) 50 # CHECK: je [[LABEL:\.L[^ ]*]] 51 # CHECK: c %r4, 104(%r3) 52 # CHECK: je [[LABEL]] 53 # CHECK: c %r4, 108(%r3) 54 # CHECK: je [[LABEL]] 55 # CHECK: c %r4, 112(%r3) 56 # CHECK: je [[LABEL]] 57 # CHECK: c %r4, 116(%r3) 58 # CHECK: j{{g?}}e [[LABEL]] 59 # CHECK: c %r4, 120(%r3) 60 # CHECK: jge [[LABEL]] 61 # CHECK: c %r4, 124(%r3) 62 # CHECK: jge [[LABEL]] 63 # CHECK: c %r4, 128(%r3) 64 # CHECK: jge [[LABEL]] 65 # CHECK: c %r4, 132(%r3) 66 # CHECK: jge [[LABEL]] 67 # CHECK: c %r4, 136(%r3) 68 # CHECK: jge [[LABEL]] 69 70 branch_blocks = 10 71 main_size = 0xffd8 72 73 print 'define void @f1(i8 *%base, i32 *%stop, i32 %limit) {' 74 print 'entry:' 75 print ' br label %before0' 76 print '' 77 78 for i in xrange(branch_blocks): 79 next = 'before%d' % (i + 1) if i + 1 < branch_blocks else 'main' 80 print 'before%d:' % i 81 print ' %%bstop%d = getelementptr i32, i32 *%%stop, i64 %d' % (i, i) 82 print ' %%bcur%d = load i32 , i32 *%%bstop%d' % (i, i) 83 print ' %%btest%d = icmp eq i32 %%limit, %%bcur%d' % (i, i) 84 print ' br i1 %%btest%d, label %%after0, label %%%s' % (i, next) 85 print '' 86 87 print '%s:' % next 88 a, b = 1, 1 89 for i in xrange(0, main_size, 6): 90 a, b = b, a + b 91 offset = 4096 + b % 500000 92 value = a % 256 93 print ' %%ptr%d = getelementptr i8, i8 *%%base, i64 %d' % (i, offset) 94 print ' store volatile i8 %d, i8 *%%ptr%d' % (value, i) 95 96 for i in xrange(branch_blocks): 97 print ' %%astop%d = getelementptr i32, i32 *%%stop, i64 %d' % (i, i + 25) 98 print ' %%acur%d = load i32 , i32 *%%astop%d' % (i, i) 99 print ' %%atest%d = icmp eq i32 %%limit, %%acur%d' % (i, i) 100 print ' br i1 %%atest%d, label %%main, label %%after%d' % (i, i) 101 print '' 102 print 'after%d:' % i 103 104 print ' ret void' 105 print '}' 106
