llvm/test/CodeGen/SystemZ/Large/branch-range-07.py

   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
  35 from __future__ import print_function
  36
  37 branch_blocks = 8
  38 main_size = 0xFFD8
  39
  40 print("define void @f1(i8 *%base, i32 *%counts) {")
  41 print("entry:")
  42
  43 for 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
  58 a, b = 1, 1
  59 for 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
  66 for 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
  73 print("  ret void")
  74 print("}")