llvm/test/Transforms/InstCombine/pr100298.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt -S -passes=instcombine < %s | FileCheck %s

; Make sure that the result of computeKnownBits for %indvar is correct.

define i16 @pr100298() {
; CHECK-LABEL: define i16 @pr100298() {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[FOR_INC:.*]]
; CHECK:       [[FOR_INC]]:
; CHECK-NEXT:    [[INDVAR:%.*]] = phi i32 [ -15, %[[ENTRY]] ], [ [[MASK:%.*]], %[[FOR_INC]] ]
; CHECK-NEXT:    [[ADD:%.*]] = add nsw i32 [[INDVAR]], 9
; CHECK-NEXT:    [[MASK]] = and i32 [[ADD]], 65535
; CHECK-NEXT:    [[CMP1:%.*]] = icmp samesign ugt i32 [[MASK]], 5
; CHECK-NEXT:    br i1 [[CMP1]], label %[[FOR_INC]], label %[[FOR_END:.*]]
; CHECK:       [[FOR_END]]:
; CHECK-NEXT:    [[CONV:%.*]] = trunc i32 [[ADD]] to i16
; CHECK-NEXT:    [[CMP2:%.*]] = icmp samesign ugt i32 [[MASK]], 3
; CHECK-NEXT:    [[SHL:%.*]] = shl nuw i16 [[CONV]], 14
; CHECK-NEXT:    [[RES:%.*]] = select i1 [[CMP2]], i16 [[CONV]], i16 [[SHL]]
; CHECK-NEXT:    ret i16 [[RES]]
;
entry:
  br label %for.inc

for.inc:
  %indvar = phi i32 [ -15, %entry ], [ %mask, %for.inc ]
  %add = add nsw i32 %indvar, 9
  %mask = and i32 %add, 65535
  %cmp1 = icmp ugt i32 %mask, 5
  br i1 %cmp1, label %for.inc, label %for.end

for.end:
  %conv = trunc i32 %add to i16
  %cmp2 = icmp ugt i32 %mask, 3
  %shl = shl nuw i16 %conv, 14
  %res = select i1 %cmp2, i16 %conv, i16 %shl
  ret i16 %res
}