# Test normal conditional branches in cases where the sheer number of # instructions causes some branches to be out of range. # RUN: python %s | llc -mtriple=s390x-linux-gnu | FileCheck %s # Construct: # # before0: # conditional branch to after0 # ... # beforeN: # conditional branch to after0 # main: # 0xffd8 bytes, from MVIY instructions # conditional branch to main # after0: # ... # conditional branch to main # afterN: # # Each conditional branch sequence occupies 8 bytes if it uses a short branch # and 10 if it uses a long one. The ones before "main:" have to take the branch # length into account -- which is 4 bytes for short branches -- so the final # (0x28 - 4) / 8 == 4 blocks can use short branches. The ones after "main:" # do not, so the first 0x28 / 8 == 5 can use short branches. However, # the conservative algorithm we use makes one branch unnecessarily long # on each side. # # CHECK: c %r4, 0(%r3) # CHECK: jge [[LABEL:\.L[^ ]*]] # CHECK: c %r4, 4(%r3) # CHECK: jge [[LABEL]] # CHECK: c %r4, 8(%r3) # CHECK: jge [[LABEL]] # CHECK: c %r4, 12(%r3) # CHECK: jge [[LABEL]] # CHECK: c %r4, 16(%r3) # CHECK: jge [[LABEL]] # CHECK: c %r4, 20(%r3) # CHECK: jge [[LABEL]] # CHECK: c %r4, 24(%r3) # CHECK: j{{g?}}e [[LABEL]] # CHECK: c %r4, 28(%r3) # CHECK: je [[LABEL]] # CHECK: c %r4, 32(%r3) # CHECK: je [[LABEL]] # CHECK: c %r4, 36(%r3) # CHECK: je [[LABEL]] # ...main goes here... # CHECK: c %r4, 100(%r3) # CHECK: je [[LABEL:\.L[^ ]*]] # CHECK: c %r4, 104(%r3) # CHECK: je [[LABEL]] # CHECK: c %r4, 108(%r3) # CHECK: je [[LABEL]] # CHECK: c %r4, 112(%r3) # CHECK: je [[LABEL]] # CHECK: c %r4, 116(%r3) # CHECK: j{{g?}}e [[LABEL]] # CHECK: c %r4, 120(%r3) # CHECK: jge [[LABEL]] # CHECK: c %r4, 124(%r3) # CHECK: jge [[LABEL]] # CHECK: c %r4, 128(%r3) # CHECK: jge [[LABEL]] # CHECK: c %r4, 132(%r3) # CHECK: jge [[LABEL]] # CHECK: c %r4, 136(%r3) # CHECK: jge [[LABEL]] branch_blocks = 10 main_size = 0xffd8 print '@global = global i32 0' print 'define void @f1(i8 *%base, i32 *%stop, i32 %limit) {' print 'entry:' print ' br label %before0' print '' for i in xrange(branch_blocks): next = 'before%d' % (i + 1) if i + 1 < branch_blocks else 'main' print 'before%d:' % i print ' %%bstop%d = getelementptr i32, i32 *%%stop, i64 %d' % (i, i) print ' %%bcur%d = load i32 , i32 *%%bstop%d' % (i, i) print ' %%btest%d = icmp eq i32 %%limit, %%bcur%d' % (i, i) print ' br i1 %%btest%d, label %%after0, label %%%s' % (i, next) print '' print '%s:' % next a, b = 1, 1 for i in xrange(0, main_size, 6): a, b = b, a + b offset = 4096 + b % 500000 value = a % 256 print ' %%ptr%d = getelementptr i8, i8 *%%base, i64 %d' % (i, offset) print ' store volatile i8 %d, i8 *%%ptr%d' % (value, i) for i in xrange(branch_blocks): print ' %%astop%d = getelementptr i32, i32 *%%stop, i64 %d' % (i, i + 25) print ' %%acur%d = load i32 , i32 *%%astop%d' % (i, i) print ' %%atest%d = icmp eq i32 %%limit, %%acur%d' % (i, i) print ' br i1 %%atest%d, label %%main, label %%after%d' % (i, i) print '' print 'after%d:' % i print ' %dummy = load volatile i32, i32 *@global' print ' ret void' print '}'