# Test 64-bit COMPARE AND BRANCH 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:
# 0xffcc bytes, from MVIY instructions
# conditional branch to main
# after0:
# ...
# conditional branch to main
# afterN:
#
# Each conditional branch sequence occupies 12 bytes if it uses a short
# branch and 16 if it uses a long one. The ones before "main:" have to
# take the branch length into account, which is 6 for short branches,
# so the final (0x34 - 6) / 12 == 3 blocks can use short branches.
# The ones after "main:" do not, so the first 0x34 / 12 == 4 blocks
# can use short branches. The conservative algorithm we use makes
# one of the forward branches unnecessarily long, as noted in the
# check output below.
#
# CHECK: lgb [[REG:%r[0-5]]], 0(%r3)
# CHECK: cgr %r4, [[REG]]
# CHECK: jge [[LABEL:\.L[^ ]*]]
# CHECK: lgb [[REG:%r[0-5]]], 1(%r3)
# CHECK: cgr %r4, [[REG]]
# CHECK: jge [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 2(%r3)
# CHECK: cgr %r4, [[REG]]
# CHECK: jge [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 3(%r3)
# CHECK: cgr %r4, [[REG]]
# CHECK: jge [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 4(%r3)
# CHECK: cgr %r4, [[REG]]
# CHECK: jge [[LABEL]]
# ...as mentioned above, the next one could be a CGRJE instead...
# CHECK: lgb [[REG:%r[0-5]]], 5(%r3)
# CHECK: cgr %r4, [[REG]]
# CHECK: jge [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 6(%r3)
# CHECK: cgrje %r4, [[REG]], [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 7(%r3)
# CHECK: cgrje %r4, [[REG]], [[LABEL]]
# ...main goes here...
# CHECK: lgb [[REG:%r[0-5]]], 25(%r3)
# CHECK: cgrje %r4, [[REG]], [[LABEL:\.L[^ ]*]]
# CHECK: lgb [[REG:%r[0-5]]], 26(%r3)
# CHECK: cgrje %r4, [[REG]], [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 27(%r3)
# CHECK: cgrje %r4, [[REG]], [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 28(%r3)
# CHECK: cgrje %r4, [[REG]], [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 29(%r3)
# CHECK: cgr %r4, [[REG]]
# CHECK: jge [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 30(%r3)
# CHECK: cgr %r4, [[REG]]
# CHECK: jge [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 31(%r3)
# CHECK: cgr %r4, [[REG]]
# CHECK: jge [[LABEL]]
# CHECK: lgb [[REG:%r[0-5]]], 32(%r3)
# CHECK: cgr %r4, [[REG]]
# CHECK: jge [[LABEL]]
from __future__ import print_function
branch_blocks = 8
main_size = 0xFFCC
print("@global = global i32 0")
print("define void @f1(i8 *%base, i8 *%stop, i64 %limit) {")
print("entry:")
print(" br label %before0")
print("")
for i in range(branch_blocks):
next = "before%d" % (i + 1) if i + 1 < branch_blocks else "main"
print("before%d:" % i)
print(" %%bstop%d = getelementptr i8, i8 *%%stop, i64 %d" % (i, i))
print(" %%bcur%d = load i8 , i8 *%%bstop%d" % (i, i))
print(" %%bext%d = sext i8 %%bcur%d to i64" % (i, i))
print(" %%btest%d = icmp eq i64 %%limit, %%bext%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 range(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 range(branch_blocks):
print(" %%astop%d = getelementptr i8, i8 *%%stop, i64 %d" % (i, i + 25))
print(" %%acur%d = load i8 , i8 *%%astop%d" % (i, i))
print(" %%aext%d = sext i8 %%acur%d to i64" % (i, i))
print(" %%atest%d = icmp eq i64 %%limit, %%aext%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("}")
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