xref: /llvm-project/llvm/test/CodeGen/SystemZ/Large/branch-range-07.py (revision b71edfaa4ec3c998aadb35255ce2f60bba2940b0)
1# Test 32-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 4 bytes.  Each decrement and branch occupies 4
20# bytes if BRCT can be used, otherwise it occupies 10 bytes (AHI + BRCL).
21# This means that loop 6 contains 5 * 4 + 0xffd8 + 5 * 4 == 0x10000 bytes
22# and is therefore (just) in range.  Loop 7 is out of range.
23#
24# CHECK: brct {{%r[0-9]+}}
25# CHECK: brct {{%r[0-9]+}}
26# CHECK: brct {{%r[0-9]+}}
27# CHECK: brct {{%r[0-9]+}}
28# CHECK: brct {{%r[0-9]+}}
29# CHECK: brct {{%r[0-9]+}}
30# CHECK: ahi {{%r[0-9]+}}, -1
31# CHECK: jglh
32# CHECK: ahi {{%r[0-9]+}}, -1
33# CHECK: jglh
34
35from __future__ import print_function
36
37branch_blocks = 8
38main_size = 0xFFD8
39
40print("define void @f1(i8 *%base, i32 *%counts) {")
41print("entry:")
42
43for i in range(branch_blocks - 1, -1, -1):
44    print("  %%countptr%d = getelementptr i32, i32 *%%counts, i64 %d" % (i, i))
45    print("  %%initcount%d = load i32 , i32 *%%countptr%d" % (i, i))
46    print("  br label %%loop%d" % i)
47
48    print("loop%d:" % i)
49    block1 = "entry" if i == branch_blocks - 1 else "loop%d" % (i + 1)
50    block2 = "loop0" if i == 0 else "after%d" % (i - 1)
51    print(
52        (
53            "  %%count%d = phi i32 [ %%initcount%d, %%%s ],"
54            " [ %%nextcount%d, %%%s ]" % (i, i, block1, i, block2)
55        )
56    )
57
58a, b = 1, 1
59for i in range(0, main_size, 6):
60    a, b = b, a + b
61    offset = 4096 + b % 500000
62    value = a % 256
63    print("  %%ptr%d = getelementptr i8, i8 *%%base, i64 %d" % (i, offset))
64    print("  store volatile i8 %d, i8 *%%ptr%d" % (value, i))
65
66for i in range(branch_blocks):
67    print("  %%nextcount%d = add i32 %%count%d, -1" % (i, i))
68    print("  %%test%d = icmp ne i32 %%nextcount%d, 0" % (i, i))
69    print("  br i1 %%test%d, label %%loop%d, label %%after%d" % (i, i, i))
70    print("")
71    print("after%d:" % i)
72
73print("  ret void")
74print("}")
75