llvm/test/Analysis/ScalarEvolution/backedge-taken-count-guard-info.ll

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

define void @loop_guard_improves_exact_backedge_taken_count_1(i32 %conv) {
; CHECK-LABEL: 'loop_guard_improves_exact_backedge_taken_count_1'
; CHECK-NEXT:  Classifying expressions for: @loop_guard_improves_exact_backedge_taken_count_1
; CHECK-NEXT:    %and = and i32 %conv, 1
; CHECK-NEXT:    --> (zext i1 (trunc i32 %conv to i1) to i32) U: [0,2) S: [0,2)
; CHECK-NEXT:    %conv8 = zext i32 %and to i64
; CHECK-NEXT:    --> (zext i1 (trunc i32 %conv to i1) to i64) U: [0,2) S: [0,2)
; CHECK-NEXT:    %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%loop> U: [0,1) S: [0,1) Exits: 0 LoopDispositions: { %loop: Computable }
; CHECK-NEXT:    %iv.next = add i64 %iv, 1
; CHECK-NEXT:    --> {1,+,1}<nuw><nsw><%loop> U: [1,2) S: [1,2) Exits: 1 LoopDispositions: { %loop: Computable }
; CHECK-NEXT:  Determining loop execution counts for: @loop_guard_improves_exact_backedge_taken_count_1
; CHECK-NEXT:  Loop %loop: backedge-taken count is i64 0
; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i64 0
; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is i64 0
; CHECK-NEXT:  Loop %loop: Trip multiple is 1
;
entry:
  %and = and i32 %conv, 1
  %conv8 = zext i32 %and to i64
  %c = icmp ugt i32 %and, 0
  br i1 %c, label %exit, label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  call void @clobber()
  %iv.next = add i64 %iv, 1
  %exitcond = icmp eq i64 %iv, %conv8
  br i1 %exitcond, label %exit, label %loop

exit:
  ret void
}

define void @loop_guard_improves_exact_backedge_taken_count_2(i32 %conv) {
; CHECK-LABEL: 'loop_guard_improves_exact_backedge_taken_count_2'
; CHECK-NEXT:  Classifying expressions for: @loop_guard_improves_exact_backedge_taken_count_2
; CHECK-NEXT:    %and = and i32 %conv, 1
; CHECK-NEXT:    --> (zext i1 (trunc i32 %conv to i1) to i32) U: [0,2) S: [0,2)
; CHECK-NEXT:    %conv8 = zext i32 %and to i64
; CHECK-NEXT:    --> (zext i1 (trunc i32 %conv to i1) to i64) U: [0,2) S: [0,2)
; CHECK-NEXT:    %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%loop> U: [0,2) S: [0,2) Exits: (zext i1 (trunc i32 %conv to i1) to i64) LoopDispositions: { %loop: Computable }
; CHECK-NEXT:    %iv.next = add i64 %iv, 1
; CHECK-NEXT:    --> {1,+,1}<nuw><nsw><%loop> U: [1,3) S: [1,3) Exits: (1 + (zext i1 (trunc i32 %conv to i1) to i64))<nuw><nsw> LoopDispositions: { %loop: Computable }
; CHECK-NEXT:  Determining loop execution counts for: @loop_guard_improves_exact_backedge_taken_count_2
; CHECK-NEXT:  Loop %loop: backedge-taken count is (zext i1 (trunc i32 %conv to i1) to i64)
; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i64 1
; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is (zext i1 (trunc i32 %conv to i1) to i64)
; CHECK-NEXT:  Loop %loop: Trip multiple is 2
;
entry:
  %and = and i32 %conv, 1
  %conv8 = zext i32 %and to i64
  %c = icmp eq i32 %and, 1
  br i1 %c, label %loop, label %exit

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  call void @clobber()
  %iv.next = add i64 %iv, 1
  %exitcond = icmp eq i64 %iv, %conv8
  br i1 %exitcond, label %exit, label %loop

exit:
  ret void
}

declare void @use(i32)

define void @rewrite_preserve_add_nsw(i32 %a) {
; CHECK-LABEL: 'rewrite_preserve_add_nsw'
; CHECK-NEXT:  Classifying expressions for: @rewrite_preserve_add_nsw
; CHECK-NEXT:    %add = add nsw i32 %a, 4
; CHECK-NEXT:    --> (4 + %a)<nsw> U: [-2147483644,-2147483648) S: [-2147483644,-2147483648)
; CHECK-NEXT:    %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
; CHECK-NEXT:    --> {0,+,1}<nuw><%loop> U: [0,-2147483648) S: [0,-2147483648) Exits: (4 + %a)<nsw> LoopDispositions: { %loop: Computable }
; CHECK-NEXT:    %iv.next = add i32 %iv, 1
; CHECK-NEXT:    --> {1,+,1}<nuw><%loop> U: [1,-2147483647) S: [1,-2147483647) Exits: (5 + %a) LoopDispositions: { %loop: Computable }
; CHECK-NEXT:  Determining loop execution counts for: @rewrite_preserve_add_nsw
; CHECK-NEXT:  Loop %loop: backedge-taken count is (4 + %a)<nsw>
; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i32 2147483647
; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is (4 + %a)<nsw>
; CHECK-NEXT:  Loop %loop: Trip multiple is 1
;
entry:
  %add = add nsw i32 %a, 4
  call void @use(i32 noundef %add)
  %pre = icmp sgt i32 %a, -4
  br i1 %pre, label %loop, label %exit

loop:
  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
  call void @clobber()
  %iv.next = add i32 %iv, 1
  %ec = icmp slt i32 %iv, %add
  br i1 %ec, label %loop, label %exit

exit:
  ret void
}

declare void @clobber()


declare void @clobber.i32(i32)

define void @test_guards_across_loops(i32 %N) {
; CHECK-LABEL: 'test_guards_across_loops'
; CHECK-NEXT:  Classifying expressions for: @test_guards_across_loops
; CHECK-NEXT:    %iv.1 = phi i32 [ 0, %entry ], [ %iv.1.next, %loop.1 ]
; CHECK-NEXT:    --> {0,+,1}<%loop.1> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %loop.1: Computable }
; CHECK-NEXT:    %iv.1.next = add i32 %iv.1, 1
; CHECK-NEXT:    --> {1,+,1}<%loop.1> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %loop.1: Computable }
; CHECK-NEXT:    %iv.2 = phi i32 [ 0, %loop.1 ], [ %iv.2.next, %loop.2 ]
; CHECK-NEXT:    --> {0,+,1}<nuw><%loop.2> U: full-set S: full-set Exits: (1 + %N) LoopDispositions: { %loop.2: Computable }
; CHECK-NEXT:    %iv.2.next = add i32 %iv.2, 1
; CHECK-NEXT:    --> {1,+,1}<nw><%loop.2> U: full-set S: full-set Exits: (2 + %N) LoopDispositions: { %loop.2: Computable }
; CHECK-NEXT:  Determining loop execution counts for: @test_guards_across_loops
; CHECK-NEXT:  Loop %loop.2: backedge-taken count is (1 + (zext i32 %N to i64))<nuw><nsw>
; CHECK-NEXT:  Loop %loop.2: constant max backedge-taken count is i64 4294967296
; CHECK-NEXT:  Loop %loop.2: symbolic max backedge-taken count is (1 + (zext i32 %N to i64))<nuw><nsw>
; CHECK-NEXT:  Loop %loop.2: Trip multiple is 1
; CHECK-NEXT:  Loop %loop.1: Unpredictable backedge-taken count.
; CHECK-NEXT:  Loop %loop.1: Unpredictable constant max backedge-taken count.
; CHECK-NEXT:  Loop %loop.1: Unpredictable symbolic max backedge-taken count.
; CHECK-NEXT:  Loop %loop.1: Predicated backedge-taken count is (1 + (zext i32 %N to i64))<nuw><nsw>
; CHECK-NEXT:   Predicates:
; CHECK-NEXT:      {0,+,1}<%loop.1> Added Flags: <nusw>
; CHECK-NEXT:  Loop %loop.1: Predicated constant max backedge-taken count is i64 4294967296
; CHECK-NEXT:   Predicates:
; CHECK-NEXT:      {0,+,1}<%loop.1> Added Flags: <nusw>
; CHECK-NEXT:  Loop %loop.1: Predicated symbolic max backedge-taken count is (1 + (zext i32 %N to i64))<nuw><nsw>
; CHECK-NEXT:   Predicates:
; CHECK-NEXT:      {0,+,1}<%loop.1> Added Flags: <nusw>
;
entry:
  br label %loop.1

loop.1:
  %iv.1 = phi i32 [ 0, %entry ], [ %iv.1.next, %loop.1 ]
  call void @clobber.i32(i32 %iv.1)
  %ec.1 = icmp ugt i32 %iv.1, %N
  %iv.1.next = add i32 %iv.1, 1
  br i1 %ec.1, label %loop.2, label %loop.1

loop.2:
  %iv.2 = phi i32  [ 0, %loop.1 ], [ %iv.2.next, %loop.2 ]
  call void @clobber.i32(i32 %iv.2)
  %ec.2 = icmp ugt i32 %iv.2, %N
  %iv.2.next = add i32 %iv.2, 1
  br i1 %ec.2, label %exit, label %loop.2

exit:
  ret void
}