llvm/test/Transforms/LoopVectorize/select-index-interleaving.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals none --version 5
; RUN: opt -passes=loop-vectorize -force-vector-width=4 -force-vector-interleave=2 -S %s | FileCheck %s

define i64 @test_vectorize_select_umin_first_idx(ptr %src, i64 %n) {
; CHECK-LABEL: define i64 @test_vectorize_select_umin_first_idx(
; CHECK-SAME: ptr [[SRC:%.*]], i64 [[N:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_IDX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_IDX_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_VAL:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_VAL_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i64, ptr [[SRC]], i64 [[IV]]
; CHECK-NEXT:    [[L:%.*]] = load i64, ptr [[GEP]], align 4
; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[MIN_VAL]], [[L]]
; CHECK-NEXT:    [[MIN_VAL_NEXT]] = tail call i64 @llvm.umin.i64(i64 [[MIN_VAL]], i64 [[L]])
; CHECK-NEXT:    [[MIN_IDX_NEXT]] = select i1 [[CMP]], i64 [[IV]], i64 [[MIN_IDX]]
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV_NEXT]], [[N]]
; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    [[RES:%.*]] = phi i64 [ [[MIN_IDX_NEXT]], %[[LOOP]] ]
; CHECK-NEXT:    ret i64 [[RES]]
;
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  %min.idx = phi i64 [ 0, %entry ], [ %min.idx.next, %loop ]
  %min.val = phi i64 [ 0, %entry ], [ %min.val.next, %loop ]
  %gep = getelementptr i64, ptr %src, i64 %iv
  %l = load i64, ptr %gep
  %cmp = icmp ugt i64 %min.val, %l
  %min.val.next = tail call i64 @llvm.umin.i64(i64 %min.val, i64 %l)
  %min.idx.next = select i1 %cmp, i64 %iv, i64 %min.idx
  %iv.next = add nuw nsw i64 %iv, 1
  %exitcond.not = icmp eq i64 %iv.next, %n
  br i1 %exitcond.not, label %exit, label %loop

exit:
  %res = phi i64 [ %min.idx.next, %loop ]
  ret i64 %res
}

define i64 @test_vectorize_select_umin_last_idx(ptr %src, i64 %n) {
; CHECK-LABEL: define i64 @test_vectorize_select_umin_last_idx(
; CHECK-SAME: ptr [[SRC:%.*]], i64 [[N:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_IDX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_IDX_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_VAL:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_VAL_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i64, ptr [[SRC]], i64 [[IV]]
; CHECK-NEXT:    [[L:%.*]] = load i64, ptr [[GEP]], align 4
; CHECK-NEXT:    [[CMP:%.*]] = icmp uge i64 [[MIN_VAL]], [[L]]
; CHECK-NEXT:    [[MIN_VAL_NEXT]] = tail call i64 @llvm.umin.i64(i64 [[MIN_VAL]], i64 [[L]])
; CHECK-NEXT:    [[MIN_IDX_NEXT]] = select i1 [[CMP]], i64 [[IV]], i64 [[MIN_IDX]]
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV_NEXT]], [[N]]
; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    [[RES:%.*]] = phi i64 [ [[MIN_IDX_NEXT]], %[[LOOP]] ]
; CHECK-NEXT:    ret i64 [[RES]]
;
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  %min.idx = phi i64 [ 0, %entry ], [ %min.idx.next, %loop ]
  %min.val = phi i64 [ 0, %entry ], [ %min.val.next, %loop ]
  %gep = getelementptr i64, ptr %src, i64 %iv
  %l = load i64, ptr %gep
  %cmp = icmp uge i64 %min.val, %l
  %min.val.next = tail call i64 @llvm.umin.i64(i64 %min.val, i64 %l)
  %min.idx.next = select i1 %cmp, i64 %iv, i64 %min.idx
  %iv.next = add nuw nsw i64 %iv, 1
  %exitcond.not = icmp eq i64 %iv.next, %n
  br i1 %exitcond.not, label %exit, label %loop

exit:
  %res = phi i64 [ %min.idx.next, %loop ]
  ret i64 %res
}

define i64 @test_vectorize_select_smin_first_idx(ptr %src, i64 %n) {
; CHECK-LABEL: define i64 @test_vectorize_select_smin_first_idx(
; CHECK-SAME: ptr [[SRC:%.*]], i64 [[N:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_IDX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_IDX_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_VAL:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_VAL_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i64, ptr [[SRC]], i64 [[IV]]
; CHECK-NEXT:    [[L:%.*]] = load i64, ptr [[GEP]], align 4
; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i64 [[MIN_VAL]], [[L]]
; CHECK-NEXT:    [[MIN_VAL_NEXT]] = tail call i64 @llvm.smin.i64(i64 [[MIN_VAL]], i64 [[L]])
; CHECK-NEXT:    [[MIN_IDX_NEXT]] = select i1 [[CMP]], i64 [[IV]], i64 [[MIN_IDX]]
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV_NEXT]], [[N]]
; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    [[RES:%.*]] = phi i64 [ [[MIN_IDX_NEXT]], %[[LOOP]] ]
; CHECK-NEXT:    ret i64 [[RES]]
;
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  %min.idx = phi i64 [ 0, %entry ], [ %min.idx.next, %loop ]
  %min.val = phi i64 [ 0, %entry ], [ %min.val.next, %loop ]
  %gep = getelementptr i64, ptr %src, i64 %iv
  %l = load i64, ptr %gep
  %cmp = icmp sgt i64 %min.val, %l
  %min.val.next = tail call i64 @llvm.smin.i64(i64 %min.val, i64 %l)
  %min.idx.next = select i1 %cmp, i64 %iv, i64 %min.idx
  %iv.next = add nuw nsw i64 %iv, 1
  %exitcond.not = icmp eq i64 %iv.next, %n
  br i1 %exitcond.not, label %exit, label %loop

exit:
  %res = phi i64 [ %min.idx.next, %loop ]
  ret i64 %res
}

define i64 @test_vectorize_select_smin_last_idx(ptr %src, i64 %n) {
; CHECK-LABEL: define i64 @test_vectorize_select_smin_last_idx(
; CHECK-SAME: ptr [[SRC:%.*]], i64 [[N:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_IDX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_IDX_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_VAL:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_VAL_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i64, ptr [[SRC]], i64 [[IV]]
; CHECK-NEXT:    [[L:%.*]] = load i64, ptr [[GEP]], align 4
; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i64 [[MIN_VAL]], [[L]]
; CHECK-NEXT:    [[MIN_VAL_NEXT]] = tail call i64 @llvm.smin.i64(i64 [[MIN_VAL]], i64 [[L]])
; CHECK-NEXT:    [[MIN_IDX_NEXT]] = select i1 [[CMP]], i64 [[IV]], i64 [[MIN_IDX]]
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV_NEXT]], [[N]]
; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    [[RES:%.*]] = phi i64 [ [[MIN_IDX_NEXT]], %[[LOOP]] ]
; CHECK-NEXT:    ret i64 [[RES]]
;
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  %min.idx = phi i64 [ 0, %entry ], [ %min.idx.next, %loop ]
  %min.val = phi i64 [ 0, %entry ], [ %min.val.next, %loop ]
  %gep = getelementptr i64, ptr %src, i64 %iv
  %l = load i64, ptr %gep
  %cmp = icmp sge i64 %min.val, %l
  %min.val.next = tail call i64 @llvm.smin.i64(i64 %min.val, i64 %l)
  %min.idx.next = select i1 %cmp, i64 %iv, i64 %min.idx
  %iv.next = add nuw nsw i64 %iv, 1
  %exitcond.not = icmp eq i64 %iv.next, %n
  br i1 %exitcond.not, label %exit, label %loop

exit:
  %res = phi i64 [ %min.idx.next, %loop ]
  ret i64 %res
}

define i64 @test_vectorize_select_umax_first_idx(ptr %src, i64 %n) {
; CHECK-LABEL: define i64 @test_vectorize_select_umax_first_idx(
; CHECK-SAME: ptr [[SRC:%.*]], i64 [[N:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_IDX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_IDX_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_VAL:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_VAL_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i64, ptr [[SRC]], i64 [[IV]]
; CHECK-NEXT:    [[L:%.*]] = load i64, ptr [[GEP]], align 4
; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i64 [[MIN_VAL]], [[L]]
; CHECK-NEXT:    [[MIN_VAL_NEXT]] = tail call i64 @llvm.umax.i64(i64 [[MIN_VAL]], i64 [[L]])
; CHECK-NEXT:    [[MIN_IDX_NEXT]] = select i1 [[CMP]], i64 [[IV]], i64 [[MIN_IDX]]
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV_NEXT]], [[N]]
; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    [[RES:%.*]] = phi i64 [ [[MIN_IDX_NEXT]], %[[LOOP]] ]
; CHECK-NEXT:    ret i64 [[RES]]
;
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  %min.idx = phi i64 [ 0, %entry ], [ %min.idx.next, %loop ]
  %min.val = phi i64 [ 0, %entry ], [ %min.val.next, %loop ]
  %gep = getelementptr i64, ptr %src, i64 %iv
  %l = load i64, ptr %gep
  %cmp = icmp ult i64 %min.val, %l
  %min.val.next = tail call i64 @llvm.umax.i64(i64 %min.val, i64 %l)
  %min.idx.next = select i1 %cmp, i64 %iv, i64 %min.idx
  %iv.next = add nuw nsw i64 %iv, 1
  %exitcond.not = icmp eq i64 %iv.next, %n
  br i1 %exitcond.not, label %exit, label %loop

exit:
  %res = phi i64 [ %min.idx.next, %loop ]
  ret i64 %res
}

define i64 @test_vectorize_select_umax_last_idx(ptr %src, i64 %n) {
; CHECK-LABEL: define i64 @test_vectorize_select_umax_last_idx(
; CHECK-SAME: ptr [[SRC:%.*]], i64 [[N:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_IDX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_IDX_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_VAL:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_VAL_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i64, ptr [[SRC]], i64 [[IV]]
; CHECK-NEXT:    [[L:%.*]] = load i64, ptr [[GEP]], align 4
; CHECK-NEXT:    [[CMP:%.*]] = icmp ule i64 [[MIN_VAL]], [[L]]
; CHECK-NEXT:    [[MIN_VAL_NEXT]] = tail call i64 @llvm.umax.i64(i64 [[MIN_VAL]], i64 [[L]])
; CHECK-NEXT:    [[MIN_IDX_NEXT]] = select i1 [[CMP]], i64 [[IV]], i64 [[MIN_IDX]]
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV_NEXT]], [[N]]
; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    [[RES:%.*]] = phi i64 [ [[MIN_IDX_NEXT]], %[[LOOP]] ]
; CHECK-NEXT:    ret i64 [[RES]]
;
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  %min.idx = phi i64 [ 0, %entry ], [ %min.idx.next, %loop ]
  %min.val = phi i64 [ 0, %entry ], [ %min.val.next, %loop ]
  %gep = getelementptr i64, ptr %src, i64 %iv
  %l = load i64, ptr %gep
  %cmp = icmp ule i64 %min.val, %l
  %min.val.next = tail call i64 @llvm.umax.i64(i64 %min.val, i64 %l)
  %min.idx.next = select i1 %cmp, i64 %iv, i64 %min.idx
  %iv.next = add nuw nsw i64 %iv, 1
  %exitcond.not = icmp eq i64 %iv.next, %n
  br i1 %exitcond.not, label %exit, label %loop

exit:
  %res = phi i64 [ %min.idx.next, %loop ]
  ret i64 %res
}

define i64 @test_vectorize_select_smax_first_idx(ptr %src, i64 %n) {
; CHECK-LABEL: define i64 @test_vectorize_select_smax_first_idx(
; CHECK-SAME: ptr [[SRC:%.*]], i64 [[N:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_IDX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_IDX_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_VAL:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_VAL_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i64, ptr [[SRC]], i64 [[IV]]
; CHECK-NEXT:    [[L:%.*]] = load i64, ptr [[GEP]], align 4
; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i64 [[MIN_VAL]], [[L]]
; CHECK-NEXT:    [[MIN_VAL_NEXT]] = tail call i64 @llvm.smax.i64(i64 [[MIN_VAL]], i64 [[L]])
; CHECK-NEXT:    [[MIN_IDX_NEXT]] = select i1 [[CMP]], i64 [[IV]], i64 [[MIN_IDX]]
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV_NEXT]], [[N]]
; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    [[RES:%.*]] = phi i64 [ [[MIN_IDX_NEXT]], %[[LOOP]] ]
; CHECK-NEXT:    ret i64 [[RES]]
;
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  %min.idx = phi i64 [ 0, %entry ], [ %min.idx.next, %loop ]
  %min.val = phi i64 [ 0, %entry ], [ %min.val.next, %loop ]
  %gep = getelementptr i64, ptr %src, i64 %iv
  %l = load i64, ptr %gep
  %cmp = icmp slt i64 %min.val, %l
  %min.val.next = tail call i64 @llvm.smax.i64(i64 %min.val, i64 %l)
  %min.idx.next = select i1 %cmp, i64 %iv, i64 %min.idx
  %iv.next = add nuw nsw i64 %iv, 1
  %exitcond.not = icmp eq i64 %iv.next, %n
  br i1 %exitcond.not, label %exit, label %loop

exit:
  %res = phi i64 [ %min.idx.next, %loop ]
  ret i64 %res
}

define i64 @test_vectorize_select_smax_last_idx(ptr %src, i64 %n) {
; CHECK-LABEL: define i64 @test_vectorize_select_smax_last_idx(
; CHECK-SAME: ptr [[SRC:%.*]], i64 [[N:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_IDX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_IDX_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[MIN_VAL:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[MIN_VAL_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i64, ptr [[SRC]], i64 [[IV]]
; CHECK-NEXT:    [[L:%.*]] = load i64, ptr [[GEP]], align 4
; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i64 [[MIN_VAL]], [[L]]
; CHECK-NEXT:    [[MIN_VAL_NEXT]] = tail call i64 @llvm.smax.i64(i64 [[MIN_VAL]], i64 [[L]])
; CHECK-NEXT:    [[MIN_IDX_NEXT]] = select i1 [[CMP]], i64 [[IV]], i64 [[MIN_IDX]]
; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV_NEXT]], [[N]]
; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    [[RES:%.*]] = phi i64 [ [[MIN_IDX_NEXT]], %[[LOOP]] ]
; CHECK-NEXT:    ret i64 [[RES]]
;
entry:
  br label %loop

loop:
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
  %min.idx = phi i64 [ 0, %entry ], [ %min.idx.next, %loop ]
  %min.val = phi i64 [ 0, %entry ], [ %min.val.next, %loop ]
  %gep = getelementptr i64, ptr %src, i64 %iv
  %l = load i64, ptr %gep
  %cmp = icmp sle i64 %min.val, %l
  %min.val.next = tail call i64 @llvm.smax.i64(i64 %min.val, i64 %l)
  %min.idx.next = select i1 %cmp, i64 %iv, i64 %min.idx
  %iv.next = add nuw nsw i64 %iv, 1
  %exitcond.not = icmp eq i64 %iv.next, %n
  br i1 %exitcond.not, label %exit, label %loop

exit:
  %res = phi i64 [ %min.idx.next, %loop ]
  ret i64 %res
}