llvm/test/Transforms/LoopVectorize/predicated-multiple-exits.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals none --version 6
; RUN: opt -S < %s -p loop-vectorize -force-vector-width=4 | FileCheck %s
;
@A = global [64 x i8] zeroinitializer
@B = global [64 x i8] zeroinitializer
@C = global [64 x i8] zeroinitializer
@D = global [64 x i8] zeroinitializer

define i64 @diamond_with_2_early_exits() {
; CHECK-LABEL: define i64 @diamond_with_2_early_exits() {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
; CHECK:       [[LOOP_HEADER]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ], [ 0, %[[ENTRY]] ]
; CHECK-NEXT:    [[GEP_A:%.*]] = getelementptr inbounds i8, ptr @A, i64 [[IV]]
; CHECK-NEXT:    [[L_A:%.*]] = load i8, ptr [[GEP_A]], align 1
; CHECK-NEXT:    [[BRANCH_COND:%.*]] = icmp slt i8 [[L_A]], 0
; CHECK-NEXT:    br i1 [[BRANCH_COND]], label %[[BLOCK_A:.*]], label %[[BLOCK_B:.*]]
; CHECK:       [[BLOCK_A]]:
; CHECK-NEXT:    [[GEP_B:%.*]] = getelementptr inbounds i8, ptr @B, i64 [[IV]]
; CHECK-NEXT:    [[L_B:%.*]] = load i8, ptr [[GEP_B]], align 1
; CHECK-NEXT:    [[EXT:%.*]] = zext i8 [[L_B]] to i64
; CHECK-NEXT:    [[CMP_A:%.*]] = icmp eq i8 [[L_A]], [[L_B]]
; CHECK-NEXT:    br i1 [[CMP_A]], label %[[LOOP_END:.*]], label %[[LOOP_LATCH]]
; CHECK:       [[BLOCK_B]]:
; CHECK-NEXT:    [[GEP_C:%.*]] = getelementptr inbounds i8, ptr @C, i64 [[IV]]
; CHECK-NEXT:    [[L_C:%.*]] = load i8, ptr [[GEP_C]], align 1
; CHECK-NEXT:    [[CMP_B:%.*]] = icmp eq i8 [[L_A]], [[L_C]]
; CHECK-NEXT:    br i1 [[CMP_B]], label %[[LOOP_END]], label %[[LOOP_LATCH]]
; CHECK:       [[LOOP_LATCH]]:
; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[IV_NEXT]], 64
; CHECK-NEXT:    br i1 [[EXITCOND]], label %[[LOOP_HEADER]], label %[[LOOP_END]]
; CHECK:       [[LOOP_END]]:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[EXT]], %[[BLOCK_A]] ], [ [[IV]], %[[BLOCK_B]] ], [ 0, %[[LOOP_LATCH]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  br label %loop.header

loop.header:
  %iv = phi i64 [ %iv.next, %loop.latch ], [ 0, %entry ]
  %gep.A = getelementptr inbounds i8, ptr @A, i64 %iv
  %l.A = load i8, ptr %gep.A, align 1
  %branch.cond = icmp slt i8 %l.A, 0
  br i1 %branch.cond, label %block.a, label %block.b

block.a:
  %gep.B = getelementptr inbounds i8, ptr @B, i64 %iv
  %l.B = load i8, ptr %gep.B, align 1
  %ext = zext i8 %l.B to i64
  %cmp.a = icmp eq i8 %l.A, %l.B
  br i1 %cmp.a, label %loop.end, label %loop.latch

block.b:
  %gep.C = getelementptr inbounds i8, ptr @C, i64 %iv
  %l.C = load i8, ptr %gep.C, align 1
  %cmp.b = icmp eq i8 %l.A, %l.C
  br i1 %cmp.b, label %loop.end, label %loop.latch

loop.latch:
  %iv.next = add i64 %iv, 1
  %exitcond = icmp ne i64 %iv.next, 64
  br i1 %exitcond, label %loop.header, label %loop.end

loop.end:
  %retval = phi i64 [ %ext, %block.a ], [ %iv, %block.b ], [ 0, %loop.latch ]
  ret i64 %retval
}

define i64 @three_early_exits() {
; CHECK-LABEL: define i64 @three_early_exits() {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
; CHECK:       [[LOOP_HEADER]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ], [ 0, %[[ENTRY]] ]
; CHECK-NEXT:    [[GEP_A:%.*]] = getelementptr inbounds i8, ptr @A, i64 [[IV]]
; CHECK-NEXT:    [[L_A:%.*]] = load i8, ptr [[GEP_A]], align 1
; CHECK-NEXT:    [[COND_A:%.*]] = icmp slt i8 [[L_A]], -42
; CHECK-NEXT:    br i1 [[COND_A]], label %[[BLOCK_A:.*]], label %[[CHECK_B:.*]]
; CHECK:       [[CHECK_B]]:
; CHECK-NEXT:    [[COND_B:%.*]] = icmp slt i8 [[L_A]], 42
; CHECK-NEXT:    br i1 [[COND_B]], label %[[BLOCK_B:.*]], label %[[BLOCK_C:.*]]
; CHECK:       [[BLOCK_A]]:
; CHECK-NEXT:    [[GEP_B:%.*]] = getelementptr inbounds i8, ptr @B, i64 [[IV]]
; CHECK-NEXT:    [[L_B:%.*]] = load i8, ptr [[GEP_B]], align 1
; CHECK-NEXT:    [[CMP_A:%.*]] = icmp eq i8 [[L_A]], [[L_B]]
; CHECK-NEXT:    br i1 [[CMP_A]], label %[[LOOP_END:.*]], label %[[LOOP_LATCH]]
; CHECK:       [[BLOCK_B]]:
; CHECK-NEXT:    [[GEP_C:%.*]] = getelementptr inbounds i8, ptr @C, i64 [[IV]]
; CHECK-NEXT:    [[L_C:%.*]] = load i8, ptr [[GEP_C]], align 1
; CHECK-NEXT:    [[CMP_B:%.*]] = icmp eq i8 [[L_A]], [[L_C]]
; CHECK-NEXT:    br i1 [[CMP_B]], label %[[LOOP_END]], label %[[LOOP_LATCH]]
; CHECK:       [[BLOCK_C]]:
; CHECK-NEXT:    [[GEP_D:%.*]] = getelementptr inbounds i8, ptr @D, i64 [[IV]]
; CHECK-NEXT:    [[L_D:%.*]] = load i8, ptr [[GEP_D]], align 1
; CHECK-NEXT:    [[CMP_C:%.*]] = icmp eq i8 [[L_A]], [[L_D]]
; CHECK-NEXT:    br i1 [[CMP_C]], label %[[LOOP_END]], label %[[LOOP_LATCH]]
; CHECK:       [[LOOP_LATCH]]:
; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[IV_NEXT]], 64
; CHECK-NEXT:    br i1 [[EXITCOND]], label %[[LOOP_HEADER]], label %[[LOOP_END]]
; CHECK:       [[LOOP_END]]:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ 1, %[[BLOCK_A]] ], [ 2, %[[BLOCK_B]] ], [ 3, %[[BLOCK_C]] ], [ 0, %[[LOOP_LATCH]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  br label %loop.header

loop.header:
  %iv = phi i64 [ %iv.next, %loop.latch ], [ 0, %entry ]
  %gep.A = getelementptr inbounds i8, ptr @A, i64 %iv
  %l.A = load i8, ptr %gep.A, align 1
  %cond.a = icmp slt i8 %l.A, -42
  br i1 %cond.a, label %block.a, label %check.b

check.b:
  %cond.b = icmp slt i8 %l.A, 42
  br i1 %cond.b, label %block.b, label %block.c

block.a:
  %gep.B = getelementptr inbounds i8, ptr @B, i64 %iv
  %l.B = load i8, ptr %gep.B, align 1
  %cmp.a = icmp eq i8 %l.A, %l.B
  br i1 %cmp.a, label %loop.end, label %loop.latch

block.b:
  %gep.C = getelementptr inbounds i8, ptr @C, i64 %iv
  %l.C = load i8, ptr %gep.C, align 1
  %cmp.b = icmp eq i8 %l.A, %l.C
  br i1 %cmp.b, label %loop.end, label %loop.latch

block.c:
  %gep.D = getelementptr inbounds i8, ptr @D, i64 %iv
  %l.D = load i8, ptr %gep.D, align 1
  %cmp.c = icmp eq i8 %l.A, %l.D
  br i1 %cmp.c, label %loop.end, label %loop.latch

loop.latch:
  %iv.next = add i64 %iv, 1
  %exitcond = icmp ne i64 %iv.next, 64
  br i1 %exitcond, label %loop.header, label %loop.end

loop.end:
  %retval = phi i64 [ 1, %block.a ], [ 2, %block.b ], [ 3, %block.c ], [ 0, %loop.latch ]
  ret i64 %retval
}

define i64 @nested_diamond_inner_exits() {
; CHECK-LABEL: define i64 @nested_diamond_inner_exits() {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
; CHECK:       [[LOOP_HEADER]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ], [ 0, %[[ENTRY]] ]
; CHECK-NEXT:    [[GEP_A:%.*]] = getelementptr inbounds i8, ptr @A, i64 [[IV]]
; CHECK-NEXT:    [[L_A:%.*]] = load i8, ptr [[GEP_A]], align 1
; CHECK-NEXT:    [[OUTER_COND:%.*]] = icmp slt i8 [[L_A]], 0
; CHECK-NEXT:    br i1 [[OUTER_COND]], label %[[BLOCK_A:.*]], label %[[BLOCK_B:.*]]
; CHECK:       [[BLOCK_A]]:
; CHECK-NEXT:    [[GEP_B:%.*]] = getelementptr inbounds i8, ptr @B, i64 [[IV]]
; CHECK-NEXT:    [[L_B:%.*]] = load i8, ptr [[GEP_B]], align 1
; CHECK-NEXT:    [[INNER_COND:%.*]] = icmp slt i8 [[L_B]], 0
; CHECK-NEXT:    br i1 [[INNER_COND]], label %[[BLOCK_A1:.*]], label %[[BLOCK_A2:.*]]
; CHECK:       [[BLOCK_A1]]:
; CHECK-NEXT:    [[CMP_A1:%.*]] = icmp eq i8 [[L_A]], [[L_B]]
; CHECK-NEXT:    br i1 [[CMP_A1]], label %[[LOOP_END:.*]], label %[[JOIN_A:.*]]
; CHECK:       [[BLOCK_A2]]:
; CHECK-NEXT:    [[GEP_C:%.*]] = getelementptr inbounds i8, ptr @C, i64 [[IV]]
; CHECK-NEXT:    [[L_C:%.*]] = load i8, ptr [[GEP_C]], align 1
; CHECK-NEXT:    [[CMP_A2:%.*]] = icmp eq i8 [[L_A]], [[L_C]]
; CHECK-NEXT:    br i1 [[CMP_A2]], label %[[LOOP_END]], label %[[JOIN_A]]
; CHECK:       [[JOIN_A]]:
; CHECK-NEXT:    br label %[[LOOP_LATCH]]
; CHECK:       [[BLOCK_B]]:
; CHECK-NEXT:    [[GEP_D:%.*]] = getelementptr inbounds i8, ptr @D, i64 [[IV]]
; CHECK-NEXT:    [[L_D:%.*]] = load i8, ptr [[GEP_D]], align 1
; CHECK-NEXT:    [[CMP_B:%.*]] = icmp eq i8 [[L_A]], [[L_D]]
; CHECK-NEXT:    br i1 [[CMP_B]], label %[[LOOP_END]], label %[[LOOP_LATCH]]
; CHECK:       [[LOOP_LATCH]]:
; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[IV_NEXT]], 64
; CHECK-NEXT:    br i1 [[EXITCOND]], label %[[LOOP_HEADER]], label %[[LOOP_END]]
; CHECK:       [[LOOP_END]]:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ 1, %[[BLOCK_A1]] ], [ 2, %[[BLOCK_A2]] ], [ 3, %[[BLOCK_B]] ], [ 0, %[[LOOP_LATCH]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  br label %loop.header

loop.header:
  %iv = phi i64 [ %iv.next, %loop.latch ], [ 0, %entry ]
  %gep.A = getelementptr inbounds i8, ptr @A, i64 %iv
  %l.A = load i8, ptr %gep.A, align 1
  %outer.cond = icmp slt i8 %l.A, 0
  br i1 %outer.cond, label %block.a, label %block.b

block.a:
  %gep.B = getelementptr inbounds i8, ptr @B, i64 %iv
  %l.B = load i8, ptr %gep.B, align 1
  %inner.cond = icmp slt i8 %l.B, 0
  br i1 %inner.cond, label %block.a1, label %block.a2

block.a1:
  %cmp.a1 = icmp eq i8 %l.A, %l.B
  br i1 %cmp.a1, label %loop.end, label %join.a

block.a2:
  %gep.C = getelementptr inbounds i8, ptr @C, i64 %iv
  %l.C = load i8, ptr %gep.C, align 1
  %cmp.a2 = icmp eq i8 %l.A, %l.C
  br i1 %cmp.a2, label %loop.end, label %join.a

join.a:
  br label %loop.latch

block.b:
  %gep.D = getelementptr inbounds i8, ptr @D, i64 %iv
  %l.D = load i8, ptr %gep.D, align 1
  %cmp.b = icmp eq i8 %l.A, %l.D
  br i1 %cmp.b, label %loop.end, label %loop.latch

loop.latch:
  %iv.next = add i64 %iv, 1
  %exitcond = icmp ne i64 %iv.next, 64
  br i1 %exitcond, label %loop.header, label %loop.end

loop.end:
  %retval = phi i64 [ 1, %block.a1 ], [ 2, %block.a2 ], [ 3, %block.b ], [ 0, %loop.latch ]
  ret i64 %retval
}

define i64 @chain_of_3_exits() {
; CHECK-LABEL: define i64 @chain_of_3_exits() {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
; CHECK:       [[LOOP_HEADER]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ], [ 0, %[[ENTRY]] ]
; CHECK-NEXT:    [[GEP_A:%.*]] = getelementptr inbounds i8, ptr @A, i64 [[IV]]
; CHECK-NEXT:    [[L_A:%.*]] = load i8, ptr [[GEP_A]], align 1
; CHECK-NEXT:    [[COND_A:%.*]] = icmp slt i8 [[L_A]], 0
; CHECK-NEXT:    br i1 [[COND_A]], label %[[BLOCK_A:.*]], label %[[LOOP_LATCH]]
; CHECK:       [[BLOCK_A]]:
; CHECK-NEXT:    [[GEP_B:%.*]] = getelementptr inbounds i8, ptr @B, i64 [[IV]]
; CHECK-NEXT:    [[L_B:%.*]] = load i8, ptr [[GEP_B]], align 1
; CHECK-NEXT:    [[CMP_A:%.*]] = icmp eq i8 [[L_A]], [[L_B]]
; CHECK-NEXT:    br i1 [[CMP_A]], label %[[LOOP_END:.*]], label %[[BLOCK_B:.*]]
; CHECK:       [[BLOCK_B]]:
; CHECK-NEXT:    [[GEP_C:%.*]] = getelementptr inbounds i8, ptr @C, i64 [[IV]]
; CHECK-NEXT:    [[L_C:%.*]] = load i8, ptr [[GEP_C]], align 1
; CHECK-NEXT:    [[CMP_B:%.*]] = icmp eq i8 [[L_A]], [[L_C]]
; CHECK-NEXT:    br i1 [[CMP_B]], label %[[LOOP_END]], label %[[BLOCK_C:.*]]
; CHECK:       [[BLOCK_C]]:
; CHECK-NEXT:    [[GEP_D:%.*]] = getelementptr inbounds i8, ptr @D, i64 [[IV]]
; CHECK-NEXT:    [[L_D:%.*]] = load i8, ptr [[GEP_D]], align 1
; CHECK-NEXT:    [[CMP_C:%.*]] = icmp eq i8 [[L_A]], [[L_D]]
; CHECK-NEXT:    br i1 [[CMP_C]], label %[[LOOP_END]], label %[[LOOP_LATCH]]
; CHECK:       [[LOOP_LATCH]]:
; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[IV_NEXT]], 64
; CHECK-NEXT:    br i1 [[EXITCOND]], label %[[LOOP_HEADER]], label %[[LOOP_END]]
; CHECK:       [[LOOP_END]]:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ 1, %[[BLOCK_A]] ], [ 2, %[[BLOCK_B]] ], [ 3, %[[BLOCK_C]] ], [ 0, %[[LOOP_LATCH]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  br label %loop.header

loop.header:
  %iv = phi i64 [ %iv.next, %loop.latch ], [ 0, %entry ]
  %gep.A = getelementptr inbounds i8, ptr @A, i64 %iv
  %l.A = load i8, ptr %gep.A, align 1
  %cond.a = icmp slt i8 %l.A, 0
  br i1 %cond.a, label %block.a, label %loop.latch

block.a:
  %gep.B = getelementptr inbounds i8, ptr @B, i64 %iv
  %l.B = load i8, ptr %gep.B, align 1
  %cmp.a = icmp eq i8 %l.A, %l.B
  br i1 %cmp.a, label %loop.end, label %block.b

block.b:
  %gep.C = getelementptr inbounds i8, ptr @C, i64 %iv
  %l.C = load i8, ptr %gep.C, align 1
  %cmp.b = icmp eq i8 %l.A, %l.C
  br i1 %cmp.b, label %loop.end, label %block.c

block.c:
  %gep.D = getelementptr inbounds i8, ptr @D, i64 %iv
  %l.D = load i8, ptr %gep.D, align 1
  %cmp.c = icmp eq i8 %l.A, %l.D
  br i1 %cmp.c, label %loop.end, label %loop.latch

loop.latch:
  %iv.next = add i64 %iv, 1
  %exitcond = icmp ne i64 %iv.next, 64
  br i1 %exitcond, label %loop.header, label %loop.end

loop.end:
  %retval = phi i64 [ 1, %block.a ], [ 2, %block.b ], [ 3, %block.c ], [ 0, %loop.latch ]
  ret i64 %retval
}

define i64 @four_exits_2x2_diamond() {
; CHECK-LABEL: define i64 @four_exits_2x2_diamond() {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
; CHECK:       [[LOOP_HEADER]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ], [ 0, %[[ENTRY]] ]
; CHECK-NEXT:    [[GEP_A:%.*]] = getelementptr inbounds i8, ptr @A, i64 [[IV]]
; CHECK-NEXT:    [[L_A:%.*]] = load i8, ptr [[GEP_A]], align 1
; CHECK-NEXT:    [[COND1:%.*]] = icmp slt i8 [[L_A]], 0
; CHECK-NEXT:    br i1 [[COND1]], label %[[BRANCH1_A:.*]], label %[[BRANCH1_B:.*]]
; CHECK:       [[BRANCH1_A]]:
; CHECK-NEXT:    [[GEP_B:%.*]] = getelementptr inbounds i8, ptr @B, i64 [[IV]]
; CHECK-NEXT:    [[L_B:%.*]] = load i8, ptr [[GEP_B]], align 1
; CHECK-NEXT:    [[CMP1A:%.*]] = icmp eq i8 [[L_A]], [[L_B]]
; CHECK-NEXT:    br i1 [[CMP1A]], label %[[LOOP_END:.*]], label %[[BRANCH2:.*]]
; CHECK:       [[BRANCH1_B]]:
; CHECK-NEXT:    [[GEP_C:%.*]] = getelementptr inbounds i8, ptr @C, i64 [[IV]]
; CHECK-NEXT:    [[L_C:%.*]] = load i8, ptr [[GEP_C]], align 1
; CHECK-NEXT:    [[CMP1B:%.*]] = icmp eq i8 [[L_A]], [[L_C]]
; CHECK-NEXT:    br i1 [[CMP1B]], label %[[LOOP_END]], label %[[BRANCH2]]
; CHECK:       [[BRANCH2]]:
; CHECK-NEXT:    [[GEP_D:%.*]] = getelementptr inbounds i8, ptr @D, i64 [[IV]]
; CHECK-NEXT:    [[L_D:%.*]] = load i8, ptr [[GEP_D]], align 1
; CHECK-NEXT:    [[COND2:%.*]] = icmp slt i8 [[L_D]], 0
; CHECK-NEXT:    br i1 [[COND2]], label %[[BRANCH2_A:.*]], label %[[BRANCH2_B:.*]]
; CHECK:       [[BRANCH2_A]]:
; CHECK-NEXT:    [[CMP2A:%.*]] = icmp eq i8 [[L_A]], [[L_D]]
; CHECK-NEXT:    br i1 [[CMP2A]], label %[[LOOP_END]], label %[[LOOP_LATCH]]
; CHECK:       [[BRANCH2_B]]:
; CHECK-NEXT:    [[CMP2B:%.*]] = icmp ne i8 [[L_A]], [[L_D]]
; CHECK-NEXT:    br i1 [[CMP2B]], label %[[LOOP_END]], label %[[LOOP_LATCH]]
; CHECK:       [[LOOP_LATCH]]:
; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[IV_NEXT]], 64
; CHECK-NEXT:    br i1 [[EXITCOND]], label %[[LOOP_HEADER]], label %[[LOOP_END]]
; CHECK:       [[LOOP_END]]:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ 1, %[[BRANCH1_A]] ], [ 2, %[[BRANCH1_B]] ], [ 3, %[[BRANCH2_A]] ], [ 4, %[[BRANCH2_B]] ], [ 0, %[[LOOP_LATCH]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  br label %loop.header

loop.header:
  %iv = phi i64 [ %iv.next, %loop.latch ], [ 0, %entry ]
  %gep.A = getelementptr inbounds i8, ptr @A, i64 %iv
  %l.A = load i8, ptr %gep.A, align 1
  %cond1 = icmp slt i8 %l.A, 0
  br i1 %cond1, label %branch1.a, label %branch1.b

branch1.a:
  %gep.B = getelementptr inbounds i8, ptr @B, i64 %iv
  %l.B = load i8, ptr %gep.B, align 1
  %cmp1a = icmp eq i8 %l.A, %l.B
  br i1 %cmp1a, label %loop.end, label %branch2

branch1.b:
  %gep.C = getelementptr inbounds i8, ptr @C, i64 %iv
  %l.C = load i8, ptr %gep.C, align 1
  %cmp1b = icmp eq i8 %l.A, %l.C
  br i1 %cmp1b, label %loop.end, label %branch2

branch2:
  %gep.D = getelementptr inbounds i8, ptr @D, i64 %iv
  %l.D = load i8, ptr %gep.D, align 1
  %cond2 = icmp slt i8 %l.D, 0
  br i1 %cond2, label %branch2.a, label %branch2.b

branch2.a:
  %cmp2a = icmp eq i8 %l.A, %l.D
  br i1 %cmp2a, label %loop.end, label %loop.latch

branch2.b:
  %cmp2b = icmp ne i8 %l.A, %l.D
  br i1 %cmp2b, label %loop.end, label %loop.latch

loop.latch:
  %iv.next = add i64 %iv, 1
  %exitcond = icmp ne i64 %iv.next, 64
  br i1 %exitcond, label %loop.header, label %loop.end

loop.end:
  %retval = phi i64 [ 1, %branch1.a ], [ 2, %branch1.b ], [ 3, %branch2.a ], [ 4, %branch2.b ], [ 0, %loop.latch ]
  ret i64 %retval
}

; Diamond where neither branch exits directly. Both sides of the diamond
; merge to a block that then has an exit with a phi-dependent live-out value.
define i64 @diamond_merge_then_exit_with_phi_liveout() {
; CHECK-LABEL: define i64 @diamond_merge_then_exit_with_phi_liveout() {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    br label %[[VECTOR_PH:.*]]
; CHECK:       [[VECTOR_PH]]:
; CHECK-NEXT:    br label %[[VECTOR_BODY:.*]]
; CHECK:       [[VECTOR_BODY]]:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY_INTERIM:.*]] ]
; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds i8, ptr @A, i64 [[INDEX]]
; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <4 x i8>, ptr [[TMP0]], align 1
; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <4 x i8> [[WIDE_LOAD]], zeroinitializer
; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds i8, ptr @C, i64 [[INDEX]]
; CHECK-NEXT:    [[WIDE_LOAD1:%.*]] = load <4 x i8>, ptr [[TMP2]], align 1
; CHECK-NEXT:    [[TMP3:%.*]] = getelementptr inbounds i8, ptr @B, i64 [[INDEX]]
; CHECK-NEXT:    [[WIDE_LOAD2:%.*]] = load <4 x i8>, ptr [[TMP3]], align 1
; CHECK-NEXT:    [[PREDPHI:%.*]] = select <4 x i1> [[TMP1]], <4 x i8> [[WIDE_LOAD2]], <4 x i8> [[WIDE_LOAD1]]
; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq <4 x i8> [[WIDE_LOAD]], [[PREDPHI]]
; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
; CHECK-NEXT:    [[TMP5:%.*]] = freeze <4 x i1> [[TMP4]]
; CHECK-NEXT:    [[TMP6:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[TMP5]])
; CHECK-NEXT:    [[TMP7:%.*]] = icmp eq i64 [[INDEX_NEXT]], 64
; CHECK-NEXT:    br i1 [[TMP6]], label %[[VECTOR_EARLY_EXIT:.*]], label %[[VECTOR_BODY_INTERIM]]
; CHECK:       [[VECTOR_BODY_INTERIM]]:
; CHECK-NEXT:    br i1 [[TMP7]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
; CHECK:       [[MIDDLE_BLOCK]]:
; CHECK-NEXT:    br label %[[LOOP_END:.*]]
; CHECK:       [[VECTOR_EARLY_EXIT]]:
; CHECK-NEXT:    [[TMP8:%.*]] = zext <4 x i8> [[WIDE_LOAD1]] to <4 x i64>
; CHECK-NEXT:    [[TMP9:%.*]] = zext <4 x i8> [[WIDE_LOAD2]] to <4 x i64>
; CHECK-NEXT:    [[PREDPHI3:%.*]] = select <4 x i1> [[TMP1]], <4 x i64> [[TMP9]], <4 x i64> [[TMP8]]
; CHECK-NEXT:    [[FIRST_ACTIVE_LANE:%.*]] = call i64 @llvm.experimental.cttz.elts.i64.v4i1(<4 x i1> [[TMP4]], i1 false)
; CHECK-NEXT:    [[TMP10:%.*]] = extractelement <4 x i64> [[PREDPHI3]], i64 [[FIRST_ACTIVE_LANE]]
; CHECK-NEXT:    br label %[[LOOP_END]]
; CHECK:       [[LOOP_END]]:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[TMP10]], %[[VECTOR_EARLY_EXIT]] ], [ 0, %[[MIDDLE_BLOCK]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  br label %loop.header

loop.header:
  %iv = phi i64 [ %iv.next, %loop.latch ], [ 0, %entry ]
  %gep.A = getelementptr inbounds i8, ptr @A, i64 %iv
  %l.A = load i8, ptr %gep.A, align 1
  %cond = icmp slt i8 %l.A, 0
  br i1 %cond, label %left, label %right

left:
  %gep.B = getelementptr inbounds i8, ptr @B, i64 %iv
  %l.B = load i8, ptr %gep.B, align 1
  %val.left = zext i8 %l.B to i64
  br label %merge

right:
  %gep.C = getelementptr inbounds i8, ptr @C, i64 %iv
  %l.C = load i8, ptr %gep.C, align 1
  %val.right = zext i8 %l.C to i64
  br label %merge

merge:
  %val = phi i64 [ %val.left, %left ], [ %val.right, %right ]
  %ld.for.cmp = phi i8 [ %l.B, %left ], [ %l.C, %right ]
  %cmp = icmp eq i8 %l.A, %ld.for.cmp
  br i1 %cmp, label %loop.end, label %loop.latch

loop.latch:
  %iv.next = add i64 %iv, 1
  %exitcond = icmp ne i64 %iv.next, 64
  br i1 %exitcond, label %loop.header, label %loop.end

loop.end:
  %retval = phi i64 [ %val, %merge ], [ 0, %loop.latch ]
  ret i64 %retval
}

; Diamond where both exit conditions compare l.A against l.B and l.C
; respectively. If l.B == l.C at runtime, both conditions could be true
; for the same lane, but the masking with cond/NOT cond prevents both
; from firing simultaneously. Tests that the predication correctly
; disambiguates the exits.
define i64 @diamond_exits_overlapping_conditions() {
; CHECK-LABEL: define i64 @diamond_exits_overlapping_conditions() {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
; CHECK:       [[LOOP_HEADER]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ], [ 0, %[[ENTRY]] ]
; CHECK-NEXT:    [[GEP_A:%.*]] = getelementptr inbounds i8, ptr @A, i64 [[IV]]
; CHECK-NEXT:    [[L_A:%.*]] = load i8, ptr [[GEP_A]], align 1
; CHECK-NEXT:    [[GEP_B:%.*]] = getelementptr inbounds i8, ptr @B, i64 [[IV]]
; CHECK-NEXT:    [[L_B:%.*]] = load i8, ptr [[GEP_B]], align 1
; CHECK-NEXT:    [[GEP_C:%.*]] = getelementptr inbounds i8, ptr @C, i64 [[IV]]
; CHECK-NEXT:    [[L_C:%.*]] = load i8, ptr [[GEP_C]], align 1
; CHECK-NEXT:    [[COND:%.*]] = icmp slt i8 [[L_A]], 0
; CHECK-NEXT:    br i1 [[COND]], label %[[BLOCK_A:.*]], label %[[BLOCK_B:.*]]
; CHECK:       [[BLOCK_A]]:
; CHECK-NEXT:    [[CMP_A:%.*]] = icmp eq i8 [[L_A]], [[L_B]]
; CHECK-NEXT:    br i1 [[CMP_A]], label %[[LOOP_END:.*]], label %[[LOOP_LATCH]]
; CHECK:       [[BLOCK_B]]:
; CHECK-NEXT:    [[CMP_B:%.*]] = icmp eq i8 [[L_A]], [[L_C]]
; CHECK-NEXT:    br i1 [[CMP_B]], label %[[LOOP_END]], label %[[LOOP_LATCH]]
; CHECK:       [[LOOP_LATCH]]:
; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[IV_NEXT]], 64
; CHECK-NEXT:    br i1 [[EXITCOND]], label %[[LOOP_HEADER]], label %[[LOOP_END]]
; CHECK:       [[LOOP_END]]:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[IV]], %[[BLOCK_A]] ], [ [[IV]], %[[BLOCK_B]] ], [ 0, %[[LOOP_LATCH]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  br label %loop.header

loop.header:
  %iv = phi i64 [ %iv.next, %loop.latch ], [ 0, %entry ]
  %gep.A = getelementptr inbounds i8, ptr @A, i64 %iv
  %l.A = load i8, ptr %gep.A, align 1
  %gep.B = getelementptr inbounds i8, ptr @B, i64 %iv
  %l.B = load i8, ptr %gep.B, align 1
  %gep.C = getelementptr inbounds i8, ptr @C, i64 %iv
  %l.C = load i8, ptr %gep.C, align 1
  %cond = icmp slt i8 %l.A, 0
  br i1 %cond, label %block.a, label %block.b

block.a:
  %cmp.a = icmp eq i8 %l.A, %l.B
  br i1 %cmp.a, label %loop.end, label %loop.latch

block.b:
  %cmp.b = icmp eq i8 %l.A, %l.C
  br i1 %cmp.b, label %loop.end, label %loop.latch

loop.latch:
  %iv.next = add i64 %iv, 1
  %exitcond = icmp ne i64 %iv.next, 64
  br i1 %exitcond, label %loop.header, label %loop.end

loop.end:
  %retval = phi i64 [ %iv, %block.a ], [ %iv, %block.b ], [ 0, %loop.latch ]
  ret i64 %retval
}

; Block C is reachable from both an exit-fallthrough path and a direct branch.
; block.a has an exit; if it doesn't exit, it falls through to block.c.
; The header's false branch goes directly to block.c.
; block.c then has its own exit.
define i64 @exit_from_merge_of_exit_fallthrough_and_bypass() {
; CHECK-LABEL: define i64 @exit_from_merge_of_exit_fallthrough_and_bypass() {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
; CHECK:       [[LOOP_HEADER]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ], [ 0, %[[ENTRY]] ]
; CHECK-NEXT:    [[GEP_A:%.*]] = getelementptr inbounds i8, ptr @A, i64 [[IV]]
; CHECK-NEXT:    [[L_A:%.*]] = load i8, ptr [[GEP_A]], align 1
; CHECK-NEXT:    [[COND:%.*]] = icmp slt i8 [[L_A]], 0
; CHECK-NEXT:    br i1 [[COND]], label %[[BLOCK_A:.*]], label %[[BLOCK_C:.*]]
; CHECK:       [[BLOCK_A]]:
; CHECK-NEXT:    [[GEP_B:%.*]] = getelementptr inbounds i8, ptr @B, i64 [[IV]]
; CHECK-NEXT:    [[L_B:%.*]] = load i8, ptr [[GEP_B]], align 1
; CHECK-NEXT:    [[CMP_A:%.*]] = icmp eq i8 [[L_A]], [[L_B]]
; CHECK-NEXT:    br i1 [[CMP_A]], label %[[LOOP_END:.*]], label %[[BLOCK_C]]
; CHECK:       [[BLOCK_C]]:
; CHECK-NEXT:    [[GEP_C:%.*]] = getelementptr inbounds i8, ptr @C, i64 [[IV]]
; CHECK-NEXT:    [[L_C:%.*]] = load i8, ptr [[GEP_C]], align 1
; CHECK-NEXT:    [[CMP_C:%.*]] = icmp eq i8 [[L_A]], [[L_C]]
; CHECK-NEXT:    br i1 [[CMP_C]], label %[[LOOP_END]], label %[[LOOP_LATCH]]
; CHECK:       [[LOOP_LATCH]]:
; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[IV_NEXT]], 64
; CHECK-NEXT:    br i1 [[EXITCOND]], label %[[LOOP_HEADER]], label %[[LOOP_END]]
; CHECK:       [[LOOP_END]]:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ 1, %[[BLOCK_A]] ], [ 2, %[[BLOCK_C]] ], [ 0, %[[LOOP_LATCH]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  br label %loop.header

loop.header:
  %iv = phi i64 [ %iv.next, %loop.latch ], [ 0, %entry ]
  %gep.A = getelementptr inbounds i8, ptr @A, i64 %iv
  %l.A = load i8, ptr %gep.A, align 1
  %cond = icmp slt i8 %l.A, 0
  br i1 %cond, label %block.a, label %block.c

block.a:
  %gep.B = getelementptr inbounds i8, ptr @B, i64 %iv
  %l.B = load i8, ptr %gep.B, align 1
  %cmp.a = icmp eq i8 %l.A, %l.B
  br i1 %cmp.a, label %loop.end, label %block.c

block.c:
  %gep.C = getelementptr inbounds i8, ptr @C, i64 %iv
  %l.C = load i8, ptr %gep.C, align 1
  %cmp.c = icmp eq i8 %l.A, %l.C
  br i1 %cmp.c, label %loop.end, label %loop.latch

loop.latch:
  %iv.next = add i64 %iv, 1
  %exitcond = icmp ne i64 %iv.next, 64
  br i1 %exitcond, label %loop.header, label %loop.end

loop.end:
  %retval = phi i64 [ 1, %block.a ], [ 2, %block.c ], [ 0, %loop.latch ]
  ret i64 %retval
}