llvm/test/Transforms/IndVarSimplify/outer_phi.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -indvars -S | FileCheck %s
; RUN: opt < %s -passes=indvars -S | FileCheck %s

declare i1 @cond()
declare i32 @llvm.smax.i32(i32, i32)

; FIXME: In all tests in this file, signed_cond is equivalent to unsigned_cond, and therefore
; one of the checks in the inner loop can be removed. The key to proving it is to prove that
; %iv starts from something that is non-negative and only goes up. The positivity of its start
; follows from the fact that %outer.iv also starts from somethign non-negative and only goes
; up or remains same between iterations.
define i32 @test_01(i32 %a, i32 %b) {
; CHECK-LABEL: @test_01(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B_IS_NON_NEGATIVE:%.*]] = icmp sge i32 [[B:%.*]], 0
; CHECK-NEXT:    br i1 [[B_IS_NON_NEGATIVE]], label [[OUTER_PREHEADER:%.*]], label [[FAILURE:%.*]]
; CHECK:       outer.preheader:
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ], [ 0, [[OUTER_PREHEADER]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       failure:
; CHECK-NEXT:    unreachable
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b_is_non_negative = icmp sge i32 %b, 0
  br i1 %b_is_non_negative, label %outer, label %failure

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

failure:
  unreachable

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; FIXME: iv <u b, b >=s 0 --> iv <s b. We should be able to remove the 2nd check.
define i32 @test_01a(i32 %a, i32 %b) {
; CHECK-LABEL: @test_01a(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B_IS_NON_NEGATIVE:%.*]] = icmp sge i32 [[B:%.*]], 0
; CHECK-NEXT:    br i1 [[B_IS_NON_NEGATIVE]], label [[OUTER_PREHEADER:%.*]], label [[FAILURE:%.*]]
; CHECK:       outer.preheader:
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ], [ 0, [[OUTER_PREHEADER]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       failure:
; CHECK-NEXT:    unreachable
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b_is_non_negative = icmp sge i32 %b, 0
  br i1 %b_is_non_negative, label %outer, label %failure

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp ult i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp slt i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

failure:
  unreachable

side.exit:
  ret i32 0

exit:
  ret i32 1
}

define i32 @test_02(i32 %a, i32 %b) {
; CHECK-LABEL: @test_02(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B_IS_NON_NEGATIVE:%.*]] = icmp sge i32 [[B:%.*]], 0
; CHECK-NEXT:    br i1 [[B_IS_NON_NEGATIVE]], label [[OUTER_PREHEADER:%.*]], label [[FAILURE:%.*]]
; CHECK:       outer.preheader:
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ [[OUTER_MERGE:%.*]], [[OUTER_BACKEDGE:%.*]] ], [ 0, [[OUTER_PREHEADER]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[OUTER_MERGE]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       failure:
; CHECK-NEXT:    unreachable
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b_is_non_negative = icmp sge i32 %b, 0
  br i1 %b_is_non_negative, label %outer, label %failure

outer:
  %outer.iv = phi i32 [0, %entry], [%outer.merge, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.merge = phi i32 [%iv.next, %inner.backedge]
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

failure:
  unreachable

side.exit:
  ret i32 0

exit:
  ret i32 1
}

define i32 @test_03(i32 %a, i32 %b) {
; CHECK-LABEL: @test_03(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B_IS_NON_NEGATIVE:%.*]] = icmp sge i32 [[B:%.*]], 0
; CHECK-NEXT:    br i1 [[B_IS_NON_NEGATIVE]], label [[OUTER_PREHEADER:%.*]], label [[FAILURE:%.*]]
; CHECK:       outer.preheader:
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ [[OUTER_MERGE:%.*]], [[OUTER_BACKEDGE:%.*]] ], [ 0, [[OUTER_PREHEADER]] ]
; CHECK-NEXT:    [[OUTER_COND_1:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_COND_1]], label [[INNER_PREHEADER:%.*]], label [[NO_INNER:%.*]]
; CHECK:       inner.preheader:
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       no_inner:
; CHECK-NEXT:    [[OUTER_COND_2:%.*]] = call i1 @cond()
; CHECK-NEXT:    br label [[OUTER_BACKEDGE]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ], [ [[OUTER_IV]], [[INNER_PREHEADER]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE_LOOPEXIT:%.*]]
; CHECK:       outer.backedge.loopexit:
; CHECK-NEXT:    [[IV_NEXT_LCSSA:%.*]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    br label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[OUTER_MERGE]] = phi i32 [ [[OUTER_IV]], [[NO_INNER]] ], [ [[IV_NEXT_LCSSA]], [[OUTER_BACKEDGE_LOOPEXIT]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       failure:
; CHECK-NEXT:    unreachable
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b_is_non_negative = icmp sge i32 %b, 0
  br i1 %b_is_non_negative, label %outer, label %failure

outer:
  %outer.iv = phi i32 [0, %entry], [%outer.merge, %outer.backedge]
  %outer_cond_1 = call i1 @cond()
  br i1 %outer_cond_1, label %inner, label %no_inner

no_inner:
  %outer_cond_2 = call i1 @cond()
  br label %outer.backedge

inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.merge = phi i32 [%outer.iv, %no_inner], [%iv.next, %inner.backedge]
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

failure:
  unreachable

side.exit:
  ret i32 0

exit:
  ret i32 1
}

define i32 @test_04(i32 %a, i32 %b) {
; CHECK-LABEL: @test_04(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B_IS_NON_NEGATIVE:%.*]] = icmp sge i32 [[B:%.*]], 0
; CHECK-NEXT:    br i1 [[B_IS_NON_NEGATIVE]], label [[OUTER_PREHEADER:%.*]], label [[FAILURE:%.*]]
; CHECK:       outer.preheader:
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ [[OUTER_MERGE:%.*]], [[OUTER_BACKEDGE:%.*]] ], [ 0, [[OUTER_PREHEADER]] ]
; CHECK-NEXT:    [[OUTER_COND_1:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_COND_1]], label [[INNER_PREHEADER:%.*]], label [[NO_INNER:%.*]]
; CHECK:       inner.preheader:
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       no_inner:
; CHECK-NEXT:    [[OUTER_COND_2:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_COND_2]], label [[IF_TRUE:%.*]], label [[IF_FALSE:%.*]]
; CHECK:       if.true:
; CHECK-NEXT:    [[SMAX:%.*]] = call i32 @llvm.smax.i32(i32 [[A:%.*]], i32 [[OUTER_IV]])
; CHECK-NEXT:    br label [[OUTER_BACKEDGE]]
; CHECK:       if.false:
; CHECK-NEXT:    br label [[OUTER_BACKEDGE]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ], [ [[OUTER_IV]], [[INNER_PREHEADER]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE_LOOPEXIT:%.*]]
; CHECK:       outer.backedge.loopexit:
; CHECK-NEXT:    [[IV_NEXT_LCSSA:%.*]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    br label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[OUTER_MERGE]] = phi i32 [ [[SMAX]], [[IF_TRUE]] ], [ [[OUTER_IV]], [[IF_FALSE]] ], [ [[IV_NEXT_LCSSA]], [[OUTER_BACKEDGE_LOOPEXIT]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       failure:
; CHECK-NEXT:    unreachable
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b_is_non_negative = icmp sge i32 %b, 0
  br i1 %b_is_non_negative, label %outer, label %failure

outer:
  %outer.iv = phi i32 [0, %entry], [%outer.merge, %outer.backedge]
  %outer_cond_1 = call i1 @cond()
  br i1 %outer_cond_1, label %inner, label %no_inner

no_inner:
  %outer_cond_2 = call i1 @cond()
  br i1 %outer_cond_2, label %if.true, label %if.false

if.true:
  %smax = call i32 @llvm.smax.i32(i32 %a, i32 %outer.iv)
  br label %outer.backedge

if.false:
  br label %outer.backedge

inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.merge = phi i32 [%smax, %if.true], [%outer.iv, %if.false], [%iv.next, %inner.backedge]
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

failure:
  unreachable

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; Same as test_01, but non-negativity of %b is known without context.
; FIXME: We can remove 2nd check in loop.
define i32 @test_05(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_05(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG0:![0-9]+]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !0
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}


; Same as test_01a, but non-negativity of %b is known without context.
define i32 @test_05a(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_05a(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG0]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    br i1 true, label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !0
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.1, label %side.exit

inner.1:
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; Similar to test_05a, but inverted 2nd condition.
define i32 @test_05b(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_05b(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG0]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    br i1 true, label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !0
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.1, label %side.exit

inner.1:
  %signed_cond = icmp sgt i32 %b, %iv
  br i1 %signed_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; We should prove implication: iv <s b, b <s 0 => iv <u b.
define i32 @test_05c(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_05c(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG1:![0-9]+]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    br i1 true, label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !1
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; Same as test_05c, but 2nd condition reversed.
define i32 @test_05d(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_05d(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG1]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    br i1 true, label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !1
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ugt i32 %b, %iv
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}


; Same as test_05a, but 1st condition inverted.
define i32 @test_05e(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_05e(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG0]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ugt i32 [[B]], [[IV]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    br i1 true, label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !0
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %unsigned_cond = icmp ugt i32 %b, %iv
  br i1 %unsigned_cond, label %inner.1, label %side.exit

inner.1:
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; Same as test_05b, but 1st condition inverted.
define i32 @test_05f(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_05f(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG0]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ugt i32 [[B]], [[IV]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    br i1 true, label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !0
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %unsigned_cond = icmp ugt i32 %b, %iv
  br i1 %unsigned_cond, label %inner.1, label %side.exit

inner.1:
  %signed_cond = icmp sgt i32 %b, %iv
  br i1 %signed_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; Same as test_05c, but 1st condition inverted.
define i32 @test_05g(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_05g(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG1]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp sgt i32 [[B]], [[IV]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    br i1 true, label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !1
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp sgt i32 %b, %iv
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; Same as test_05d, but 1st condition inverted.
define i32 @test_05h(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_05h(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG1]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp sgt i32 [[B]], [[IV]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    br i1 true, label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !1
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp sgt i32 %b, %iv
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ugt i32 %b, %iv
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; Same as test_02, but non-negativity of %b is known without context.
; FIXME: We can remove 2nd check in loop.
define i32 @test_06(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_06(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG0]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[OUTER_MERGE:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[OUTER_MERGE]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !0
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%outer.merge, %outer.backedge]
  br label %inner


inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.merge = phi i32 [%iv.next, %inner.backedge]
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; Same as test_03, but non-negativity of %b is known without context.
; FIXME: We can remove 2nd check in loop.
define i32 @test_07(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_07(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG0]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[OUTER_MERGE:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[OUTER_COND_1:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_COND_1]], label [[INNER_PREHEADER:%.*]], label [[NO_INNER:%.*]]
; CHECK:       inner.preheader:
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       no_inner:
; CHECK-NEXT:    [[OUTER_COND_2:%.*]] = call i1 @cond()
; CHECK-NEXT:    br label [[OUTER_BACKEDGE]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ], [ [[OUTER_IV]], [[INNER_PREHEADER]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE_LOOPEXIT:%.*]]
; CHECK:       outer.backedge.loopexit:
; CHECK-NEXT:    [[IV_NEXT_LCSSA:%.*]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    br label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[OUTER_MERGE]] = phi i32 [ [[OUTER_IV]], [[NO_INNER]] ], [ [[IV_NEXT_LCSSA]], [[OUTER_BACKEDGE_LOOPEXIT]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !0
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%outer.merge, %outer.backedge]
  %outer_cond_1 = call i1 @cond()
  br i1 %outer_cond_1, label %inner, label %no_inner

no_inner:
  %outer_cond_2 = call i1 @cond()
  br label %outer.backedge

inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.merge = phi i32 [%outer.iv, %no_inner], [%iv.next, %inner.backedge]
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; Same as test_04, but non-negativity of %b is known without context.
; FIXME: We can remove 2nd check in loop.
define i32 @test_08(i32 %a, i32* %bp) {
; CHECK-LABEL: @test_08(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[B:%.*]] = load i32, i32* [[BP:%.*]], align 4, !range [[RNG0]]
; CHECK-NEXT:    br label [[OUTER:%.*]]
; CHECK:       outer:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[OUTER_MERGE:%.*]], [[OUTER_BACKEDGE:%.*]] ]
; CHECK-NEXT:    [[OUTER_COND_1:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_COND_1]], label [[INNER_PREHEADER:%.*]], label [[NO_INNER:%.*]]
; CHECK:       inner.preheader:
; CHECK-NEXT:    br label [[INNER:%.*]]
; CHECK:       no_inner:
; CHECK-NEXT:    [[OUTER_COND_2:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_COND_2]], label [[IF_TRUE:%.*]], label [[IF_FALSE:%.*]]
; CHECK:       if.true:
; CHECK-NEXT:    [[SMAX:%.*]] = call i32 @llvm.smax.i32(i32 [[A:%.*]], i32 [[OUTER_IV]])
; CHECK-NEXT:    br label [[OUTER_BACKEDGE]]
; CHECK:       if.false:
; CHECK-NEXT:    br label [[OUTER_BACKEDGE]]
; CHECK:       inner:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ], [ [[OUTER_IV]], [[INNER_PREHEADER]] ]
; CHECK-NEXT:    [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]]
; CHECK:       inner.1:
; CHECK-NEXT:    [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]]
; CHECK-NEXT:    br i1 [[UNSIGNED_COND]], label [[INNER_BACKEDGE]], label [[SIDE_EXIT]]
; CHECK:       inner.backedge:
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT:    [[INNER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE_LOOPEXIT:%.*]]
; CHECK:       outer.backedge.loopexit:
; CHECK-NEXT:    [[IV_NEXT_LCSSA:%.*]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ]
; CHECK-NEXT:    br label [[OUTER_BACKEDGE]]
; CHECK:       outer.backedge:
; CHECK-NEXT:    [[OUTER_MERGE]] = phi i32 [ [[SMAX]], [[IF_TRUE]] ], [ [[OUTER_IV]], [[IF_FALSE]] ], [ [[IV_NEXT_LCSSA]], [[OUTER_BACKEDGE_LOOPEXIT]] ]
; CHECK-NEXT:    [[OUTER_LOOP_COND:%.*]] = call i1 @cond()
; CHECK-NEXT:    br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]]
; CHECK:       side.exit:
; CHECK-NEXT:    ret i32 0
; CHECK:       exit:
; CHECK-NEXT:    ret i32 1
;
entry:
  %b = load i32, i32* %bp, !range !0
  br label %outer

outer:
  %outer.iv = phi i32 [0, %entry], [%outer.merge, %outer.backedge]
  %outer_cond_1 = call i1 @cond()
  br i1 %outer_cond_1, label %inner, label %no_inner

no_inner:
  %outer_cond_2 = call i1 @cond()
  br i1 %outer_cond_2, label %if.true, label %if.false

if.true:
  %smax = call i32 @llvm.smax.i32(i32 %a, i32 %outer.iv)
  br label %outer.backedge

if.false:
  br label %outer.backedge

inner:
  %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
  %signed_cond = icmp slt i32 %iv, %b
  br i1 %signed_cond, label %inner.1, label %side.exit

inner.1:
  %unsigned_cond = icmp ult i32 %iv, %b
  br i1 %unsigned_cond, label %inner.backedge, label %side.exit

inner.backedge:
  %iv.next = add nuw nsw i32 %iv, 1
  %inner.loop.cond = call i1 @cond()
  br i1 %inner.loop.cond, label %inner, label %outer.backedge

outer.backedge:
  %outer.merge = phi i32 [%smax, %if.true], [%outer.iv, %if.false], [%iv.next, %inner.backedge]
  %outer.loop.cond = call i1 @cond()
  br i1 %outer.loop.cond, label %outer, label %exit

side.exit:
  ret i32 0

exit:
  ret i32 1
}

!0 = !{i32 0, i32 2147483647}
!1 = !{i32 -2147483648, i32 0}