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      1 ; RUN: opt %s -simplifycfg -S | FileCheck %s
      2 
      3 declare i32 @f(i32)
      4 
      5 define i32 @basic(i32 %x) {
      6 ; CHECK-LABEL: @basic
      7 ; CHECK: x.off = add i32 %x, -5
      8 ; CHECK: %switch = icmp ult i32 %x.off, 3
      9 ; CHECK: br i1 %switch, label %a, label %default
     10 
     11 entry:
     12   switch i32 %x, label %default [
     13     i32 5, label %a
     14     i32 6, label %a
     15     i32 7, label %a
     16   ]
     17 default:
     18   %0 = call i32 @f(i32 0)
     19   ret i32 %0
     20 a:
     21   %1 = call i32 @f(i32 1)
     22   ret i32 %1
     23 }
     24 
     25 
     26 define i32 @unreachable(i32 %x) {
     27 ; CHECK-LABEL: @unreachable
     28 ; CHECK: x.off = add i32 %x, -5
     29 ; CHECK: %switch = icmp ult i32 %x.off, 3
     30 ; CHECK: br i1 %switch, label %a, label %b
     31 
     32 entry:
     33   switch i32 %x, label %unreachable [
     34     i32 5, label %a
     35     i32 6, label %a
     36     i32 7, label %a
     37     i32 10, label %b
     38     i32 20, label %b
     39     i32 30, label %b
     40     i32 40, label %b
     41   ]
     42 unreachable:
     43   unreachable
     44 a:
     45   %0 = call i32 @f(i32 0)
     46   ret i32 %0
     47 b:
     48   %1 = call i32 @f(i32 1)
     49   ret i32 %1
     50 }
     51 
     52 
     53 define i32 @unreachable2(i32 %x) {
     54 ; CHECK-LABEL: @unreachable2
     55 ; CHECK: x.off = add i32 %x, -5
     56 ; CHECK: %switch = icmp ult i32 %x.off, 3
     57 ; CHECK: br i1 %switch, label %a, label %b
     58 
     59 entry:
     60   ; Note: folding the most popular case destination into the default
     61   ; would prevent switch-to-icmp here.
     62   switch i32 %x, label %unreachable [
     63     i32 5, label %a
     64     i32 6, label %a
     65     i32 7, label %a
     66     i32 10, label %b
     67     i32 20, label %b
     68   ]
     69 unreachable:
     70   unreachable
     71 a:
     72   %0 = call i32 @f(i32 0)
     73   ret i32 %0
     74 b:
     75   %1 = call i32 @f(i32 1)
     76   ret i32 %1
     77 }
     78