llvm-6502/test/CodeGen/SystemZ/Large/branch-range-02.py
Richard Sandiford 086791eca2 Add TargetLowering::prepareVolatileOrAtomicLoad
One unusual feature of the z architecture is that the result of a
previous load can be reused indefinitely for subsequent loads, even if
a cache-coherent store to that location is performed by another CPU.
A special serializing instruction must be used if you want to force
a load to be reattempted.

Since volatile loads are not supposed to be omitted in this way,
we should insert a serializing instruction before each such load.
The same goes for atomic loads.

The patch implements this at the IR->DAG boundary, in a similar way
to atomic fences.  It is a no-op for targets other than SystemZ.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196905 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-10 10:36:34 +00:00

83 lines
2.1 KiB
Python

# Test normal conditional branches in cases where block alignments cause
# some branches to be out of range.
# RUN: python %s | llc -mtriple=s390x-linux-gnu -align-all-blocks=8 | FileCheck %s
# Construct:
#
# b0:
# conditional branch to end
# ...
# b<N>:
# conditional branch to end
# b<N+1>:
# conditional branch to b0
# ...
# b<2*N>:
# conditional branch to b0
# end:
#
# with N == 256 + 4. The -align-all-blocks=8 option ensures that all blocks
# are 256 bytes in size. The first 4 blocks and the last 4 blocks are then
# out of range.
#
# CHECK: c %r4, 0(%r3)
# CHECK: jge [[LABEL:\.L[^ ]*]]
# CHECK: c %r4, 4(%r3)
# CHECK: jge [[LABEL]]
# CHECK: c %r4, 8(%r3)
# CHECK: jge [[LABEL]]
# CHECK: c %r4, 12(%r3)
# CHECK: jge [[LABEL]]
# CHECK: c %r4, 16(%r3)
# CHECK: je [[LABEL]]
# CHECK: c %r4, 20(%r3)
# CHECK: je [[LABEL]]
# CHECK: c %r4, 24(%r3)
# CHECK: je [[LABEL]]
# CHECK: c %r4, 28(%r3)
# CHECK: je [[LABEL]]
# ...lots of other blocks...
# CHECK: c %r4, 1004(%r3)
# CHECK: je [[LABEL:\.L[^ ]*]]
# CHECK: c %r4, 1008(%r3)
# CHECK: je [[LABEL]]
# CHECK: c %r4, 1012(%r3)
# CHECK: je [[LABEL]]
# CHECK: c %r4, 1016(%r3)
# CHECK: je [[LABEL]]
# CHECK: c %r4, 1020(%r3)
# CHECK: je [[LABEL]]
# CHECK: c %r4, 1024(%r3)
# CHECK: jge [[LABEL]]
# CHECK: c %r4, 1028(%r3)
# CHECK: jge [[LABEL]]
# CHECK: c %r4, 1032(%r3)
# CHECK: jge [[LABEL]]
# CHECK: c %r4, 1036(%r3)
# CHECK: jge [[LABEL]]
blocks = 256 + 4
print 'define void @f1(i8 *%base, i32 *%stop, i32 %limit) {'
print 'entry:'
print ' br label %b0'
print ''
a, b = 1, 1
for i in xrange(blocks):
a, b = b, a + b
value = a % 256
next = 'b%d' % (i + 1) if i + 1 < blocks else 'end'
other = 'end' if 2 * i < blocks else 'b0'
print 'b%d:' % i
print ' store volatile i8 %d, i8 *%%base' % value
print ' %%astop%d = getelementptr i32 *%%stop, i64 %d' % (i, i)
print ' %%acur%d = load i32 *%%astop%d' % (i, i)
print ' %%atest%d = icmp eq i32 %%limit, %%acur%d' % (i, i)
print ' br i1 %%atest%d, label %%%s, label %%%s' % (i, other, next)
print ''
print '%s:' % next
print ' ret void'
print '}'