llvm/test/Instrumentation/BoundsChecking/negative.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; Check that negative oob gep do not generate invalid check.
; RUN: opt < %s -passes=bounds-checking -S | FileCheck %s
target datalayout = "e-p:64:64:64-p1:16:16:16-p2:64:64:64:48-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"


@str = global [100 x i8] zeroinitializer, align 1

define i16 @main() {
; CHECK-LABEL: @main(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_COND:%.*]]
; CHECK:       for.cond:
; CHECK-NEXT:    [[I_0:%.*]] = phi i8 [ 65, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[TMP4:%.*]] ]
; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i8 [[I_0]], 76
; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label [[FOR_END:%.*]], label [[TMP4]]
; CHECK:       for.inc:
; CHECK-NEXT:    [[I_0_C:%.*]] = sext i8 [[I_0]] to i64
; CHECK-NEXT:    [[TMP0:%.*]] = add i64 -65, [[I_0_C]]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i8, ptr getelementptr (i8, ptr @str, i8 -65), i8 [[I_0]]
; CHECK-NEXT:    [[TMP1:%.*]] = sub i64 100, [[TMP0]]
; CHECK-NEXT:    store i8 [[I_0]], ptr [[GEP]], align 1
; CHECK-NEXT:    [[INC]] = add nuw nsw i8 [[I_0]], 1
; CHECK-NEXT:    br label [[FOR_COND]]
; CHECK:       for.end:
; CHECK-NEXT:    ret i16 0
;
entry:
  br label %for.cond

for.cond:
  %i.0 = phi i8 [ 65, %entry ], [ %inc, %for.inc ]
  %exitcond.not = icmp eq i8 %i.0, 76
  br i1 %exitcond.not, label %for.end, label %for.inc

for.inc:                                          ; preds = %for.cond
  %gep = getelementptr i8, ptr getelementptr (i8, ptr @str, i8 -65), i8 %i.0
  store i8 %i.0, ptr %gep, align 1
  %inc = add nuw nsw i8 %i.0, 1
  br label %for.cond

for.end:
  ret i16 0
}