xref: /llvm-project/llvm/test/CodeGen/SystemZ/Large/branch-range-06.py (revision b71edfaa4ec3c998aadb35255ce2f60bba2940b0)
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