; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
; RUN: llc -mattr=+sve2 -verify-machineinstrs < %s -o - | FileCheck %s

target triple = "aarch64-unknown-linux-gnu"

; This test is reduced from a real world example that would cause the DAGCombiner to hang.

define void @histcnt_loop(ptr %0, i64 %1, ptr %2, i64 %3, i64 %4) {
; CHECK-LABEL: histcnt_loop:
; CHECK:       // %bb.0: // %entry
; CHECK-NEXT:    mov z0.d, #1 // =0x1
; CHECK-NEXT:    ptrue p0.d
; CHECK-NEXT:    mov x8, xzr
; CHECK-NEXT:    add x9, x0, x1
; CHECK-NEXT:  .LBB0_1: // %loop
; CHECK-NEXT:    // =>This Inner Loop Header: Depth=1
; CHECK-NEXT:    ld1h { z1.d }, p0/z, [x0, x8, lsl #1]
; CHECK-NEXT:    lsl x10, x8, #1
; CHECK-NEXT:    add x11, x0, x10
; CHECK-NEXT:    add x10, x9, x10
; CHECK-NEXT:    lsl z1.d, z1.d, #1
; CHECK-NEXT:    ld1h { z4.d }, p0/z, [x11, #1, mul vl]
; CHECK-NEXT:    ld1h { z5.d }, p0/z, [x10, #1, mul vl]
; CHECK-NEXT:    histcnt z2.d, p0/z, z1.d, z1.d
; CHECK-NEXT:    ld1h { z3.d }, p0/z, [x2, z1.d]
; CHECK-NEXT:    mad z2.d, p0/m, z0.d, z3.d
; CHECK-NEXT:    ld1h { z3.d }, p0/z, [x9, x8, lsl #1]
; CHECK-NEXT:    add x8, x8, x3
; CHECK-NEXT:    cmp x4, x8
; CHECK-NEXT:    st1h { z2.d }, p0, [x2, z1.d]
; CHECK-NEXT:    lsl z1.d, z4.d, #1
; CHECK-NEXT:    histcnt z2.d, p0/z, z1.d, z1.d
; CHECK-NEXT:    ld1h { z4.d }, p0/z, [x2, z1.d]
; CHECK-NEXT:    mad z2.d, p0/m, z0.d, z4.d
; CHECK-NEXT:    st1h { z2.d }, p0, [x2, z1.d]
; CHECK-NEXT:    lsl z1.d, z3.d, #1
; CHECK-NEXT:    histcnt z2.d, p0/z, z1.d, z1.d
; CHECK-NEXT:    ld1h { z3.d }, p0/z, [x2, z1.d]
; CHECK-NEXT:    mad z2.d, p0/m, z0.d, z3.d
; CHECK-NEXT:    st1h { z2.d }, p0, [x2, z1.d]
; CHECK-NEXT:    lsl z1.d, z5.d, #1
; CHECK-NEXT:    histcnt z2.d, p0/z, z1.d, z1.d
; CHECK-NEXT:    ld1h { z3.d }, p0/z, [x2, z1.d]
; CHECK-NEXT:    mad z2.d, p0/m, z0.d, z3.d
; CHECK-NEXT:    st1h { z2.d }, p0, [x2, z1.d]
; CHECK-NEXT:    b.ne .LBB0_1
; CHECK-NEXT:  // %bb.2: // %exit
; CHECK-NEXT:    ret
entry:
  br label %loop

loop:
  %6 = phi i64 [ 0, %entry ], [ %15, %loop ]
  %7 = getelementptr inbounds nuw i16, ptr %0, i64 %6
  %8 = getelementptr inbounds nuw i8, ptr %7, i64 %1
  %9 = load <vscale x 4 x i16>, ptr %7, align 2
  %10 = load <vscale x 4 x i16>, ptr %8, align 2
  %11 = zext <vscale x 4 x i16> %9 to <vscale x 4 x i64>
  %12 = zext <vscale x 4 x i16> %10 to <vscale x 4 x i64>
  %13 = getelementptr inbounds nuw [16 x i16], ptr %2, i64 0, <vscale x 4 x i64> %11
  %14 = getelementptr inbounds nuw [16 x i16], ptr %2, i64 0, <vscale x 4 x i64> %12
  call void @llvm.experimental.vector.histogram.add.nxv4p0.i16(<vscale x 4 x ptr> %13, i16 1, <vscale x 4 x i1> splat (i1 true))
  call void @llvm.experimental.vector.histogram.add.nxv4p0.i16(<vscale x 4 x ptr> %14, i16 1, <vscale x 4 x i1> splat (i1 true))
  %15 = add nuw i64 %6, %3
  %16 = icmp eq i64 %15, %4
  br i1 %16, label %exit, label %loop

exit:
  ret void
}