# Test 64-bit COMPARE IMMEDIATE 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: cghi [[REG]], 50 # CHECK: jgl [[LABEL:\.L[^ ]*]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cghi [[REG]], 51 # CHECK: jgl [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cghi [[REG]], 52 # CHECK: jgl [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cghi [[REG]], 53 # CHECK: jgl [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cghi [[REG]], 54 # CHECK: jgl [[LABEL]] # ...as mentioned above, the next one could be a CGIJL instead... # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cghi [[REG]], 55 # CHECK: jgl [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cgijl [[REG]], 56, [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cgijl [[REG]], 57, [[LABEL]] # ...main goes here... # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cgijl [[REG]], 100, [[LABEL:\.L[^ ]*]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cgijl [[REG]], 101, [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cgijl [[REG]], 102, [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cgijl [[REG]], 103, [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cghi [[REG]], 104 # CHECK: jgl [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cghi [[REG]], 105 # CHECK: jgl [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cghi [[REG]], 106 # CHECK: jgl [[LABEL]] # CHECK: lgb [[REG:%r[0-5]]], 0(%r3) # CHECK: cghi [[REG]], 107 # CHECK: jgl [[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) {") 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(" %%bcur%d = load i8 , i8 *%%stop" % i) print(" %%bext%d = sext i8 %%bcur%d to i64" % (i, i)) print(" %%btest%d = icmp slt i64 %%bext%d, %d" % (i, i, i + 50)) 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(" %%acur%d = load i8 , i8 *%%stop" % i) print(" %%aext%d = sext i8 %%acur%d to i64" % (i, i)) print(" %%atest%d = icmp slt i64 %%aext%d, %d" % (i, i, i + 100)) 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("}")