xref: /external/llvm/test/CodeGen/SystemZ/Large/spill-02.py

# Test cases where we spill from one frame index to another, both of which
# are out of range of MVC, and both of which need emergency spill slots.
# RUN: python %s | llc -mtriple=s390x-linux-gnu | FileCheck %s

# CHECK: f1:
# CHECK: %fallthru
# CHECK-DAG: stg [[REG1:%r[0-9]+]], 8168(%r15)
# CHECK-DAG: stg [[REG2:%r[0-9]+]], 8176(%r15)
# CHECK-DAG: lay [[REG3:%r[0-9]+]], 8192(%r15)
# CHECK-DAG: lay [[REG4:%r[0-9]+]], 4096(%r15)
# CHECK: mvc 0(8,[[REG3]]), 4088([[REG4]])
# CHECK-DAG: lg [[REG1]], 8168(%r15)
# CHECK-DAG: lg [[REG2]], 8176(%r15)
# CHECK: %skip
# CHECK: br %r14

# Arrange for %foo's spill slot to be at 8184(%r15) and the alloca area to be at
# 8192(%r15).  The two emergency spill slots live below that, so this requires
# the first 8168 bytes to be used for the call.  160 of these bytes are
# allocated for the ABI frame.  There are also 5 argument registers, one of
# which is used as a base pointer.
args = (8168 - 160) / 8 + (5 - 1)

print 'declare i64 *@foo(i64 *%s)' % (', i64' * args)
print 'declare void @bar(i64 *)'
print ''
print 'define i64 @f1(i64 %foo) {'
print 'entry:'

# Make the allocation big, so that it goes at the top of the frame.
print '  %array = alloca [1000 x i64]'
print '  %area = getelementptr [1000 x i64] *%array, i64 0, i64 0'
print '  %%base = call i64 *@foo(i64 *%%area%s)' % (', i64 0' * args)
print ''

# Make sure all GPRs are used.  One is needed for the stack pointer and
# another for %base, so we need 14 live values.
count = 14
for i in range(count):
    print '  %%ptr%d = getelementptr i64 *%%base, i64 %d' % (i, i / 2)
    print '  %%val%d = load volatile i64 *%%ptr%d' % (i, i)
    print ''

# Encourage the register allocator to give preference to these %vals
# by using them several times.
for j in range(4):
    for i in range(count):
        print '  store volatile i64 %%val%d, i64 *%%ptr%d' % (i, i)
    print ''

# Copy the incoming argument, which we expect to be spilled, to the frame
# index for the alloca area.  Also throw in a volatile store, so that this
# block cannot be reordered with the surrounding code.
print '  %cond = icmp eq i64 %val0, %val1'
print '  br i1 %cond, label %skip, label %fallthru'
print ''
print 'fallthru:'
print '  store i64 %foo, i64 *%area'
print '  store volatile i64 %val0, i64 *%ptr0'
print '  br label %skip'
print ''
print 'skip:'

# Use each %val a few more times to emphasise the point, and to make sure
# that they are live across the store of %foo.
for j in range(4):
    for i in range(count):
        print '  store volatile i64 %%val%d, i64 *%%ptr%d' % (i, i)
    print ''

print '  call void @bar(i64 *%area)'
print '  ret i64 0'
print '}'