llvm/test/Transforms/SimpleLoopUnswitch/nontrivial-unswitch-trivial-select.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -passes='simple-loop-unswitch<nontrivial>' -S < %s | FileCheck %s

; If we try to replace uses of `true` outside of `@foo`, we'll see it here.
define i1 @bar() {
; CHECK-LABEL: @bar(
; CHECK-NEXT:    ret i1 true
;
  ret i1 true
}

; We shouldn't unswitch this loop.
define void @foo() {
; CHECK-LABEL: @foo(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[HEADER:%.*]]
; CHECK:       header:
; CHECK-NEXT:    [[VAL:%.*]] = select i1 true, i1 true, i1 false
; CHECK-NEXT:    br i1 [[VAL]], label [[EXIT:%.*]], label [[HEADER]]
; CHECK:       exit:
; CHECK-NEXT:    ret void
;
entry:
  br label %header

header:
  %val = select i1 true, i1 true, i1 false
  br i1 %val, label %exit, label %header

exit:
  ret void
}

define void @unswitch_trivial_select(i1 %c.1, i1 %c.2, i8 %a) {
; CHECK-LABEL: @unswitch_trivial_select(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br i1 [[C_1:%.*]], label [[PH_1:%.*]], label [[EXIT:%.*]]
; CHECK:       ph.1:
; CHECK-NEXT:    br i1 [[C_2:%.*]], label [[PH_2:%.*]], label [[EXIT]]
; CHECK:       ph.2:
; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[A:%.*]], 30
; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP]], i1 true, i1 false
; CHECK-NEXT:    [[CMP_FR:%.*]] = freeze i1 [[CMP]]
; CHECK-NEXT:    br i1 [[CMP_FR]], label [[PH_2_SPLIT_US:%.*]], label [[PH_2_SPLIT:%.*]]
; CHECK:       ph.2.split.us:
; CHECK-NEXT:    br label [[LOOP_US:%.*]]
; CHECK:       loop.us:
; CHECK-NEXT:    call void @foo()
; CHECK-NEXT:    br label [[EXIT_LOOPEXIT_SPLIT_US:%.*]]
; CHECK:       exit.loopexit.split.us:
; CHECK-NEXT:    br label [[EXIT_LOOPEXIT:%.*]]
; CHECK:       ph.2.split:
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    call void @foo()
; CHECK-NEXT:    br label [[LOOP_LATCH:%.*]]
; CHECK:       loop.latch:
; CHECK-NEXT:    br label [[LOOP]]
; CHECK:       exit.loopexit:
; CHECK-NEXT:    br label [[EXIT]]
; CHECK:       exit:
; CHECK-NEXT:    ret void
;
entry:
  br i1 %c.1, label %ph.1, label %exit

ph.1:
  br i1 %c.2, label %ph.2, label %exit

ph.2:
  %cmp = icmp eq i8 %a, 30
  %sel = select i1 %cmp, i1 true, i1 false
  br label %loop

loop:
  call void @foo()
  br i1 %sel, label %exit, label %loop.latch

loop.latch:
  br label %loop

exit:
  ret void
}

; Test case for PR55697.
define i32 @unswitch_trivial_select_cmp_outside(i32 %x) {
; CHECK-LABEL: @unswitch_trivial_select_cmp_outside(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[C:%.*]] = icmp ult i32 [[X:%.*]], 100
; CHECK-NEXT:    br i1 [[C]], label [[ENTRY_SPLIT_US:%.*]], label [[ENTRY_SPLIT:%.*]]
; CHECK:       entry.split.us:
; CHECK-NEXT:    br label [[LOOP_US:%.*]]
; CHECK:       loop.us:
; CHECK-NEXT:    [[P_US:%.*]] = phi i32 [ 0, [[ENTRY_SPLIT_US]] ], [ 35, [[LOOP_US]] ]
; CHECK-NEXT:    br label [[LOOP_US]]
; CHECK:       entry.split:
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[P:%.*]] = phi i32 [ 0, [[ENTRY_SPLIT]] ]
; CHECK-NEXT:    [[SPEC_SELECT:%.*]] = select i1 false, i1 true, i1 false
; CHECK-NEXT:    br label [[EXIT:%.*]]
; CHECK:       exit:
; CHECK-NEXT:    [[LCSSA:%.*]] = phi i32 [ [[P]], [[LOOP]] ]
; CHECK-NEXT:    ret i32 [[LCSSA]]
;
entry:
  %c = icmp ult i32 %x, 100
  br label %loop

loop:
  %p = phi i32 [ 0, %entry ], [ 35, %loop ]
  %spec.select = select i1 %c, i1 true, i1 false
  br i1 %spec.select, label %loop, label %exit

exit:
  %lcssa = phi i32 [ %p, %loop ]
  ret i32 %lcssa
}