llvm/test/Transforms/SimplifyCFG/switch-on-const.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s

; Test basic folding to a conditional branch.
define i32 @foo(i64 %x, i64 %y) nounwind {
; CHECK-LABEL: @foo(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[EQ:%.*]] = icmp eq i64 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT:    br i1 [[EQ]], label [[B:%.*]], label [[SWITCH:%.*]]
; CHECK:       switch:
; CHECK-NEXT:    [[LT:%.*]] = icmp slt i64 [[X]], [[Y]]
; CHECK-NEXT:    br i1 [[LT]], label [[A:%.*]], label [[B]]
; CHECK:       common.ret:
; CHECK-NEXT:    [[COMMON_RET_OP:%.*]] = phi i32 [ 1, [[A]] ], [ [[RETVAL:%.*]], [[B]] ]
; CHECK-NEXT:    ret i32 [[COMMON_RET_OP]]
; CHECK:       a:
; CHECK-NEXT:    tail call void @bees.a() #[[ATTR0:[0-9]+]]
; CHECK-NEXT:    br label [[COMMON_RET:%.*]]
; CHECK:       b:
; CHECK-NEXT:    [[RETVAL]] = phi i32 [ 2, [[ENTRY:%.*]] ], [ 0, [[SWITCH]] ]
; CHECK-NEXT:    tail call void @bees.b() #[[ATTR0]]
; CHECK-NEXT:    br label [[COMMON_RET]]
;
entry:
  %eq = icmp eq i64 %x, %y
  br i1 %eq, label %b, label %switch
switch:
  %lt = icmp slt i64 %x, %y
  %qux = select i1 %lt, i32 0, i32 2
  switch i32 %qux, label %bees [
  i32 0, label %a
  i32 1, label %b
  i32 2, label %b
  ]
a:
  tail call void @bees.a() nounwind
  ret i32 1
b:
  %retval = phi i32 [0, %switch], [0, %switch], [2, %entry]
  tail call void @bees.b() nounwind
  ret i32 %retval
bees:
  tail call void @llvm.trap() nounwind
  unreachable
}

; Test basic folding to an unconditional branch.
define i32 @bar(i64 %x, i64 %y) nounwind {
; CHECK-LABEL: @bar(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    tail call void @bees.a() #[[ATTR0]]
; CHECK-NEXT:    ret i32 0
;
entry:
  %lt = icmp slt i64 %x, %y
  %qux = select i1 %lt, i32 0, i32 2
  switch i32 %qux, label %bees [
  i32 0, label %a
  i32 1, label %b
  i32 2, label %a
  ]
a:
  %retval = phi i32 [0, %entry], [0, %entry], [1, %b]
  tail call void @bees.a() nounwind
  ret i32 0
b:
  tail call void @bees.b() nounwind
  br label %a
bees:
  tail call void @llvm.trap() nounwind
  unreachable
}

; Test the edge case where both values from the select are the default case.
define void @bazz(i64 %x, i64 %y) nounwind {
; CHECK-LABEL: @bazz(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    tail call void @bees.b() #[[ATTR0]]
; CHECK-NEXT:    ret void
;
entry:
  %lt = icmp slt i64 %x, %y
  %qux = select i1 %lt, i32 10, i32 12
  switch i32 %qux, label %b [
  i32 0, label %a
  i32 1, label %bees
  i32 2, label %bees
  ]
a:
  tail call void @bees.a() nounwind
  ret void
b:
  tail call void @bees.b() nounwind
  ret void
bees:
  tail call void @llvm.trap()
  unreachable
}

; Test the edge case where both values from the select are equal.
define void @quux(i64 %x, i64 %y) nounwind {
; CHECK-LABEL: @quux(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    tail call void @bees.a() #[[ATTR0]]
; CHECK-NEXT:    ret void
;
entry:
  %lt = icmp slt i64 %x, %y
  %qux = select i1 %lt, i32 0, i32 0
  switch i32 %qux, label %b [
  i32 0, label %a
  i32 1, label %bees
  i32 2, label %bees
  ]
a:
  tail call void @bees.a() nounwind
  ret void
b:
  tail call void @bees.b() nounwind
  ret void
bees:
  tail call void @llvm.trap()
  unreachable
}

; A final test, for phi node munging.
define i32 @xyzzy(i64 %x, i64 %y) {
; CHECK-LABEL: @xyzzy(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[EQ:%.*]] = icmp eq i64 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT:    [[LT:%.*]] = icmp slt i64 [[X]], [[Y]]
; CHECK-NEXT:    [[SPEC_SELECT:%.*]] = select i1 [[LT]], i32 -1, i32 1
; CHECK-NEXT:    [[COMMON_RET_OP:%.*]] = select i1 [[EQ]], i32 0, i32 [[SPEC_SELECT]]
; CHECK-NEXT:    ret i32 [[COMMON_RET_OP]]
;
entry:
  %eq = icmp eq i64 %x, %y
  br i1 %eq, label %r, label %cont
cont:
  %lt = icmp slt i64 %x, %y
  %qux = select i1 %lt, i32 0, i32 2
  switch i32 %qux, label %bees [
  i32 0, label %a
  i32 1, label %r
  i32 2, label %r
  ]
r:
  %val = phi i32 [0, %entry], [1, %cont], [1, %cont]
  ret i32 %val
a:
  ret i32 -1
bees:
  tail call void @llvm.trap()
  unreachable
}

define void @pr165179(i1 %cond) {
; CHECK-LABEL: @pr165179(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br i1 [[COND:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
; CHECK:       if.then:
; CHECK-NEXT:    tail call void @bees.a() #[[ATTR0]]
; CHECK-NEXT:    br label [[SWITCHBB:%.*]]
; CHECK:       if.else:
; CHECK-NEXT:    tail call void @bees.b() #[[ATTR0]]
; CHECK-NEXT:    br label [[SWITCHBB]]
; CHECK:       exit:
; CHECK-NEXT:    tail call void @bees.a() #[[ATTR0]]
; CHECK-NEXT:    ret void
;
entry:
  br i1 %cond, label %if.then, label %if.else

if.then:
  tail call void @bees.a() nounwind
  br label %switchbb

if.else:
  tail call void @bees.b() nounwind
  br label %switchbb

switchbb:
  %cond1 = phi i32 [ 1, %if.else ], [ -1, %if.then ]
  switch i32 %cond1, label %default [
  i32 1, label %exit
  i32 -1, label %exit
  ]

exit:
  tail call void @bees.a() nounwind
  ret void

default:
  tail call void @bees.b() nounwind
  ret void
}

define void @switch_remove_dead_case_phi(i1 %cond1, i1 %cond2) {
; CHECK-LABEL: @switch_remove_dead_case_phi(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br i1 [[COND1:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
; CHECK:       if.then:
; CHECK-NEXT:    tail call void @bees.a() #[[ATTR0]]
; CHECK-NEXT:    br i1 [[COND2:%.*]], label [[SWITCHBB:%.*]], label [[IF_ELSE]]
; CHECK:       if.else:
; CHECK-NEXT:    [[PHI:%.*]] = phi i32 [ 3, [[ENTRY:%.*]] ], [ -1, [[IF_THEN]] ]
; CHECK-NEXT:    tail call void @bees.b() #[[ATTR0]]
; CHECK-NEXT:    br label [[SWITCHBB]]
; CHECK:       switchbb:
; CHECK-NEXT:    [[COND:%.*]] = phi i32 [ [[PHI]], [[IF_ELSE]] ], [ 5, [[IF_THEN]] ]
; CHECK-NEXT:    [[COND3:%.*]] = icmp eq i32 [[COND]], -1
; CHECK-NEXT:    br i1 [[COND3]], label [[EXIT:%.*]], label [[DEFAULT:%.*]]
; CHECK:       common.ret:
; CHECK-NEXT:    ret void
; CHECK:       exit:
; CHECK-NEXT:    tail call void @bees.a() #[[ATTR0]]
; CHECK-NEXT:    br label [[COMMON_RET:%.*]]
; CHECK:       default:
; CHECK-NEXT:    tail call void @bees.b() #[[ATTR0]]
; CHECK-NEXT:    br label [[COMMON_RET]]
;
entry:
  br i1 %cond1, label %if.then, label %if.else

if.then:
  tail call void @bees.a() nounwind
  br i1 %cond2, label %switchbb, label %if.else

if.else:
  %phi = phi i32 [ 3, %entry ], [ -1, %if.then ]
  tail call void @bees.b() nounwind
  br label %switchbb

switchbb:
  %cond = phi i32 [ %phi, %if.else ], [ 5, %if.then ]
  switch i32 %cond, label %default [
  i32 1, label %exit
  i32 -1, label %exit
  ]

exit:
  tail call void @bees.a() nounwind
  ret void

default:
  tail call void @bees.b() nounwind
  ret void
}

define void @switch_remove_dead_case_select(i1 %cond1, i1 %cond2) {
; CHECK-LABEL: @switch_remove_dead_case_select(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[X:%.*]] = select i1 [[COND1:%.*]], i32 -1, i32 3
; CHECK-NEXT:    [[Y:%.*]] = select i1 [[COND2:%.*]], i32 [[X]], i32 5
; CHECK-NEXT:    [[COND:%.*]] = icmp eq i32 [[Y]], -1
; CHECK-NEXT:    br i1 [[COND]], label [[EXIT:%.*]], label [[DEFAULT:%.*]]
; CHECK:       common.ret:
; CHECK-NEXT:    ret void
; CHECK:       exit:
; CHECK-NEXT:    tail call void @bees.a() #[[ATTR0]]
; CHECK-NEXT:    br label [[COMMON_RET:%.*]]
; CHECK:       default:
; CHECK-NEXT:    tail call void @bees.b() #[[ATTR0]]
; CHECK-NEXT:    br label [[COMMON_RET]]
;
entry:
  %x = select i1 %cond1, i32 -1, i32 3
  %y = select i1 %cond2, i32 %x, i32 5
  switch i32 %y, label %default [
  i32 1, label %exit
  i32 -1, label %exit
  ]

exit:
  tail call void @bees.a() nounwind
  ret void

default:
  tail call void @bees.b() nounwind
  ret void
}

@G = constant i16 zeroinitializer, align 1

; Make sure we don't remove edges when the condition is a unresolved constant expression.

define i16 @switch_on_nonimmediate_constant_expr() {
; CHECK-LABEL: @switch_on_nonimmediate_constant_expr(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[SWITCH_SELECTCMP:%.*]] = icmp eq i32 ptrtoint (ptr @G to i32), 2
; CHECK-NEXT:    [[SWITCH_SELECT:%.*]] = select i1 [[SWITCH_SELECTCMP]], i16 456, i16 789
; CHECK-NEXT:    [[SWITCH_SELECTCMP1:%.*]] = icmp eq i32 ptrtoint (ptr @G to i32), 1
; CHECK-NEXT:    [[SWITCH_SELECT2:%.*]] = select i1 [[SWITCH_SELECTCMP1]], i16 123, i16 [[SWITCH_SELECT]]
; CHECK-NEXT:    ret i16 [[SWITCH_SELECT2]]
;
entry:
  switch i32 ptrtoint (ptr @G to i32), label %sw.default [
  i32 1, label %sw.bb
  i32 2, label %sw.bb1
  ]

sw.bb:
  ret i16 123

sw.bb1:
  ret i16 456

sw.default:
  ret i16 789
}


declare void @llvm.trap() nounwind noreturn
declare void @bees.a() nounwind
declare void @bees.b() nounwind

; CHECK: attributes #1 = { cold noreturn nounwind memory(inaccessiblemem: write) }