1# Test 64-bit COMPARE IMMEDIATE AND BRANCH 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# 0xffcc 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 12 bytes if it uses a short 21# branch and 16 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 (0x34 - 6) / 12 == 3 blocks can use short branches. 24# The ones after "main:" do not, so the first 0x34 / 12 == 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: lgb [[REG:%r[0-5]]], 0(%r3) 30# CHECK: cghi [[REG]], 50 31# CHECK: jgl [[LABEL:\.L[^ ]*]] 32# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 33# CHECK: cghi [[REG]], 51 34# CHECK: jgl [[LABEL]] 35# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 36# CHECK: cghi [[REG]], 52 37# CHECK: jgl [[LABEL]] 38# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 39# CHECK: cghi [[REG]], 53 40# CHECK: jgl [[LABEL]] 41# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 42# CHECK: cghi [[REG]], 54 43# CHECK: jgl [[LABEL]] 44# ...as mentioned above, the next one could be a CGIJL instead... 45# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 46# CHECK: cghi [[REG]], 55 47# CHECK: jgl [[LABEL]] 48# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 49# CHECK: cgijl [[REG]], 56, [[LABEL]] 50# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 51# CHECK: cgijl [[REG]], 57, [[LABEL]] 52# ...main goes here... 53# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 54# CHECK: cgijl [[REG]], 100, [[LABEL:\.L[^ ]*]] 55# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 56# CHECK: cgijl [[REG]], 101, [[LABEL]] 57# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 58# CHECK: cgijl [[REG]], 102, [[LABEL]] 59# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 60# CHECK: cgijl [[REG]], 103, [[LABEL]] 61# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 62# CHECK: cghi [[REG]], 104 63# CHECK: jgl [[LABEL]] 64# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 65# CHECK: cghi [[REG]], 105 66# CHECK: jgl [[LABEL]] 67# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 68# CHECK: cghi [[REG]], 106 69# CHECK: jgl [[LABEL]] 70# CHECK: lgb [[REG:%r[0-5]]], 0(%r3) 71# CHECK: cghi [[REG]], 107 72# CHECK: jgl [[LABEL]] 73 74from __future__ import print_function 75 76branch_blocks = 8 77main_size = 0xffcc 78 79print('@global = global i32 0') 80 81print('define void @f1(i8 *%base, i8 *%stop) {') 82print('entry:') 83print(' br label %before0') 84print('') 85 86for i in range(branch_blocks): 87 next = 'before%d' % (i + 1) if i + 1 < branch_blocks else 'main' 88 print('before%d:' % i) 89 print(' %%bcur%d = load i8 , i8 *%%stop' % i) 90 print(' %%bext%d = sext i8 %%bcur%d to i64' % (i, i)) 91 print(' %%btest%d = icmp slt i64 %%bext%d, %d' % (i, i, i + 50)) 92 print(' br i1 %%btest%d, label %%after0, label %%%s' % (i, next)) 93 print('') 94 95print('%s:' % next) 96a, b = 1, 1 97for i in range(0, main_size, 6): 98 a, b = b, a + b 99 offset = 4096 + b % 500000 100 value = a % 256 101 print(' %%ptr%d = getelementptr i8, i8 *%%base, i64 %d' % (i, offset)) 102 print(' store volatile i8 %d, i8 *%%ptr%d' % (value, i)) 103 104for i in range(branch_blocks): 105 print(' %%acur%d = load i8 , i8 *%%stop' % i) 106 print(' %%aext%d = sext i8 %%acur%d to i64' % (i, i)) 107 print(' %%atest%d = icmp slt i64 %%aext%d, %d' % (i, i, i + 100)) 108 print(' br i1 %%atest%d, label %%main, label %%after%d' % (i, i)) 109 print('') 110 print('after%d:' % i) 111 112print(' %dummy = load volatile i32, i32 *@global') 113print(' ret void') 114print('}') 115