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path: root/llvm/test/Analysis/DependenceAnalysis/exact-siv-overflow.ll
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; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 6
; RUN: opt < %s -disable-output "-passes=print<da>" 2>&1 | FileCheck %s
; RUN: opt < %s -disable-output "-passes=print<da>" -da-enable-dependence-test=exact-siv 2>&1 \
; RUN:     | FileCheck %s --check-prefix=CHECK-EXACT-SIV

;; max_i = INT64_MAX/6  // 1537228672809129301
;; for (long long i = 0; i <= max_i; i++) {
;;   A[-6*i + INT64_MAX] = 0;
;;   if (i)
;;     A[3*i - 2] = 1;
;; }
;;
;; FIXME: DependencyAnalsysis currently detects no dependency between
;; `A[-6*i + INT64_MAX]` and `A[3*i - 2]`, but it does exist. For example,
;;
;; | memory location        | -6*i + INT64_MAX       | 3*i - 2
;; |------------------------|------------------------|-----------
;; | A[1]                   | i = max_i              | i = 1
;; | A[4611686018427387901] | i = 768614336404564651 | i = max_i
;;
;; Actually,
;;  * 1                   = -6*max_i              + INT64_MAX = 3*1     - 2
;;  * 4611686018427387901 = -6*768614336404564651 + INT64_MAX = 3*max_i - 2
;;

define void @exactsiv_const_ovfl(ptr %A) {
; CHECK-LABEL: 'exactsiv_const_ovfl'
; CHECK-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
; CHECK-NEXT:    da analyze - none!
; CHECK-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-NEXT:    da analyze - none!
; CHECK-NEXT:  Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-NEXT:    da analyze - none!
;
; CHECK-EXACT-SIV-LABEL: 'exactsiv_const_ovfl'
; CHECK-EXACT-SIV-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
; CHECK-EXACT-SIV-NEXT:    da analyze - consistent output [*]!
; CHECK-EXACT-SIV-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-EXACT-SIV-NEXT:    da analyze - output [*|<]!
; CHECK-EXACT-SIV-NEXT:  Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-EXACT-SIV-NEXT:    da analyze - consistent output [*]!
;
entry:
  br label %loop.header

loop.header:
  %i = phi i64 [ 0, %entry ], [ %i.inc, %loop.latch ]
  %subscript.0 = phi i64 [ 9223372036854775807, %entry ], [ %subscript.0.next, %loop.latch ]
  %subscript.1 = phi i64 [ -2, %entry ], [ %subscript.1.next, %loop.latch ]
  %idx.0 = getelementptr inbounds i8, ptr %A, i64 %subscript.0
  store i8 0, ptr %idx.0
  %cond.store = icmp ne i64 %i, 0
  br i1 %cond.store, label %if.store, label %loop.latch

if.store:
  %idx.1 = getelementptr inbounds i8, ptr %A, i64 %subscript.1
  store i8 1, ptr %idx.1
  br label %loop.latch

loop.latch:
  %i.inc = add nuw nsw i64 %i, 1
  %subscript.0.next = add nsw i64 %subscript.0, -6
  %subscript.1.next = add nsw i64 %subscript.1, 3
  %exitcond = icmp sgt i64 %i.inc, 1537228672809129301
  br i1 %exitcond, label %exit, label %loop.header

exit:
  ret void
}

;; A generalized version of the above case.
;;
;; for (long long i = 0; i <= n / 6; i++) {
;;   A[-6*i + n] = 0;
;;   if (i)
;;     A[3*i - 2] = 1;
;; }

define void @exactsiv_param_ovfl(ptr %A, i64 %n) {
; CHECK-LABEL: 'exactsiv_param_ovfl'
; CHECK-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
; CHECK-NEXT:    da analyze - none!
; CHECK-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-NEXT:    da analyze - output [*|<]!
; CHECK-NEXT:  Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-NEXT:    da analyze - none!
;
; CHECK-EXACT-SIV-LABEL: 'exactsiv_param_ovfl'
; CHECK-EXACT-SIV-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
; CHECK-EXACT-SIV-NEXT:    da analyze - consistent output [*]!
; CHECK-EXACT-SIV-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-EXACT-SIV-NEXT:    da analyze - output [*|<]!
; CHECK-EXACT-SIV-NEXT:  Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
; CHECK-EXACT-SIV-NEXT:    da analyze - consistent output [*]!
;
entry:
  %bound = sdiv i64 %n, 6
  %guard = icmp sgt i64 %n, 0
  br i1 %guard, label %loop.header, label %exit

loop.header:
  %i = phi i64 [ 0, %entry ], [ %i.inc, %loop.latch ]
  %subscript.0 = phi i64 [ %n, %entry ], [ %subscript.0.next, %loop.latch ]
  %subscript.1 = phi i64 [ -2, %entry ], [ %subscript.1.next, %loop.latch ]
  %idx.0 = getelementptr inbounds i8, ptr %A, i64 %subscript.0
  store i8 0, ptr %idx.0
  %cond.store = icmp ne i64 %i, 0
  br i1 %cond.store, label %if.store, label %loop.latch

if.store:
  %idx.1 = getelementptr inbounds i8, ptr %A, i64 %subscript.1
  store i8 1, ptr %idx.1
  br label %loop.latch

loop.latch:
  %i.inc = add nuw nsw i64 %i, 1
  %subscript.0.next = add nsw i64 %subscript.0, -6
  %subscript.1.next = add nsw i64 %subscript.1, 3
  %exitcond = icmp sgt i64 %i.inc, %bound
  br i1 %exitcond, label %exit, label %loop.header

exit:
  ret void
}