xref: /llvm-project/llvm/test/CodeGen/SystemZ/Large/branch-range-08.py (revision b71edfaa4ec3c998aadb35255ce2f60bba2940b0)
1# Test 64-bit BRANCH RELATIVE ON COUNT in cases where some branches are out
2# of range.
3# RUN: %python %s | llc -mtriple=s390x-linux-gnu | FileCheck %s
4
5# Construct:
6#
7# loopN:
8#   load of countN
9#   ...
10# loop0:
11#   0xffd8 bytes, from MVIY instructions
12#   conditional branch to main
13# after0:
14#   ...
15#   decrement of countN
16#   conditional branch to loopN
17# afterN:
18#
19# Each load occupies 6 bytes.  Each decrement and branch occupies 4
20# bytes if BRCTG can be used, otherwise it occupies 10 bytes (AGHI + BRCL).
21# This means that loop 5 contains 4 * 6 + 0xffd8 + 4 * 4 == 0x10000 bytes
22# and is therefore (just) in range.  Loop 6 is out of range.
23#
24# CHECK: brctg {{%r[0-9]+}}
25# CHECK: brctg {{%r[0-9]+}}
26# CHECK: brctg {{%r[0-9]+}}
27# CHECK: brctg {{%r[0-9]+}}
28# CHECK: brctg {{%r[0-9]+}}
29# CHECK: aghi {{%r[0-9]+}}, -1
30# CHECK: jglh
31# CHECK: aghi {{%r[0-9]+}}, -1
32# CHECK: jglh
33# CHECK: aghi {{%r[0-9]+}}, -1
34# CHECK: jglh
35
36from __future__ import print_function
37
38branch_blocks = 8
39main_size = 0xFFD8
40
41print("define void @f1(i8 *%base, i64 *%counts) {")
42print("entry:")
43
44for i in range(branch_blocks - 1, -1, -1):
45    print("  %%countptr%d = getelementptr i64, i64 *%%counts, i64 %d" % (i, i))
46    print("  %%initcount%d = load i64 , i64 *%%countptr%d" % (i, i))
47    print("  br label %%loop%d" % i)
48
49    print("loop%d:" % i)
50    block1 = "entry" if i == branch_blocks - 1 else "loop%d" % (i + 1)
51    block2 = "loop0" if i == 0 else "after%d" % (i - 1)
52    print(
53        (
54            "  %%count%d = phi i64 [ %%initcount%d, %%%s ],"
55            " [ %%nextcount%d, %%%s ]" % (i, i, block1, i, block2)
56        )
57    )
58
59a, b = 1, 1
60for i in range(0, main_size, 6):
61    a, b = b, a + b
62    offset = 4096 + b % 500000
63    value = a % 256
64    print("  %%ptr%d = getelementptr i8, i8 *%%base, i64 %d" % (i, offset))
65    print("  store volatile i8 %d, i8 *%%ptr%d" % (value, i))
66
67for i in range(branch_blocks):
68    print("  %%nextcount%d = add i64 %%count%d, -1" % (i, i))
69    print("  %%test%d = icmp ne i64 %%nextcount%d, 0" % (i, i))
70    print("  br i1 %%test%d, label %%loop%d, label %%after%d" % (i, i, i))
71    print("")
72    print("after%d:" % i)
73
74print("  ret void")
75print("}")
76