llvm/test/CodeGen/SystemZ/Large/branch-range-08.py

   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
  36 from __future__ import print_function
  37
  38 branch_blocks = 8
  39 main_size = 0xFFD8
  40
  41 print("define void @f1(i8 *%base, i64 *%counts) {")
  42 print("entry:")
  43
  44 for 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
  59 a, b = 1, 1
  60 for 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
  67 for 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
  74 print("  ret void")
  75 print("}")