llvm/test/Analysis/ScalarEvolution/outer_phi.ll

; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
; RUN: opt < %s -S -disable-output "-passes=print<scalar-evolution>" 2>&1 | FileCheck %s

declare i1 @cond()

define i32 @test_01(i32 %a, i32 %b) {
; CHECK-LABEL: 'test_01'
; CHECK-NEXT:  Classifying expressions for: @test_01
; CHECK-NEXT:    %outer.iv = phi i32 [ 0, %entry ], [ %iv.next, %outer.backedge ]
; CHECK-NEXT:    --> %outer.iv U: [0,-2147483647) S: [0,-2147483647) Exits: <<Unknown>> LoopDispositions: { %outer: Variant, %inner: Invariant }
; CHECK-NEXT:    %iv = phi i32 [ 0, %outer ], [ %iv.next, %inner.backedge ]
; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%inner> U: [0,-2147483648) S: [0,-2147483648) Exits: <<Unknown>> LoopDispositions: { %inner: Computable, %outer: Variant }
; CHECK-NEXT:    %iv.next = add nuw nsw i32 %iv, 1
; CHECK-NEXT:    --> {1,+,1}<nuw><%inner> U: [1,-2147483647) S: [1,-2147483647) Exits: <<Unknown>> LoopDispositions: { %inner: Computable, %outer: Variant }
; CHECK-NEXT:    %inner.loop.cond = call i1 @cond()
; CHECK-NEXT:    --> %inner.loop.cond U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %inner: Variant, %outer: Variant }
; CHECK-NEXT:    %outer.loop.cond = call i1 @cond()
; CHECK-NEXT:    --> %outer.loop.cond U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %outer: Variant, %inner: Invariant }
; CHECK-NEXT:  Determining loop execution counts for: @test_01
; CHECK-NEXT:  Loop %inner: <multiple exits> Unpredictable backedge-taken count.
; CHECK-NEXT:    exit count for inner: %b
; CHECK-NEXT:    exit count for inner.backedge: ***COULDNOTCOMPUTE***
; CHECK-NEXT:  Loop %inner: max backedge-taken count is 2147483647
; CHECK-NEXT:  Loop %inner: Unpredictable predicated backedge-taken count.
; CHECK-NEXT:  Loop %outer: <multiple exits> Unpredictable backedge-taken count.
; CHECK-NEXT:    exit count for inner: ***COULDNOTCOMPUTE***
; CHECK-NEXT:    exit count for outer.backedge: ***COULDNOTCOMPUTE***
; CHECK-NEXT:  Loop %outer: Unpredictable max backedge-taken count.
; CHECK-NEXT:  Loop %outer: Unpredictable predicated backedge-taken count.
;
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 [0, %outer], [%iv.next, %inner.backedge]
  %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

failure:
  unreachable

side.exit:
  ret i32 0

exit:
  ret i32 1
}

; FIXME: both outer.iv and iv here can be proved non-negative.
define i32 @test_02(i32 %a, i32 %b) {
; CHECK-LABEL: 'test_02'
; CHECK-NEXT:  Classifying expressions for: @test_02
; CHECK-NEXT:    %outer.iv = phi i32 [ 0, %entry ], [ %iv.next, %outer.backedge ]
; CHECK-NEXT:    --> %outer.iv U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %outer: Variant, %inner: Invariant }
; CHECK-NEXT:    %iv = phi i32 [ %outer.iv, %outer ], [ %iv.next, %inner.backedge ]
; CHECK-NEXT:    --> {%outer.iv,+,1}<nuw><nsw><%inner> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %inner: Computable, %outer: Variant }
; CHECK-NEXT:    %iv.next = add nuw nsw i32 %iv, 1
; CHECK-NEXT:    --> {(1 + %outer.iv),+,1}<nw><%inner> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %inner: Computable, %outer: Variant }
; CHECK-NEXT:    %inner.loop.cond = call i1 @cond()
; CHECK-NEXT:    --> %inner.loop.cond U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %inner: Variant, %outer: Variant }
; CHECK-NEXT:    %outer.loop.cond = call i1 @cond()
; CHECK-NEXT:    --> %outer.loop.cond U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %outer: Variant, %inner: Invariant }
; CHECK-NEXT:  Determining loop execution counts for: @test_02
; CHECK-NEXT:  Loop %inner: <multiple exits> Unpredictable backedge-taken count.
; CHECK-NEXT:    exit count for inner: ((-1 * %outer.iv) + (%b smax %outer.iv))
; CHECK-NEXT:    exit count for inner.backedge: ***COULDNOTCOMPUTE***
; CHECK-NEXT:  Loop %inner: max backedge-taken count is -1
; CHECK-NEXT:  Loop %inner: Unpredictable predicated backedge-taken count.
; CHECK-NEXT:  Loop %outer: <multiple exits> Unpredictable backedge-taken count.
; CHECK-NEXT:    exit count for inner: ***COULDNOTCOMPUTE***
; CHECK-NEXT:    exit count for outer.backedge: ***COULDNOTCOMPUTE***
; CHECK-NEXT:  Loop %outer: Unpredictable max backedge-taken count.
; CHECK-NEXT:  Loop %outer: Unpredictable predicated backedge-taken count.
;
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.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
}