llvm/test/Transforms/LoopInterchange/function-attr.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
; RUN: opt < %s -passes=loop-interchange -loop-interchange-profitabilities=ignore -S | FileCheck %s

; for (i = 0; i < 100; i++)
;   for (j = 0; j < 100; j++)
;     writeonly(A);
;
; The writeonly call may write to `%A` at some unknown index, so we cannot
; interchange the loops.
;
define void @call_writeonly(ptr %A) {
; CHECK-LABEL: define void @call_writeonly(
; CHECK-SAME: ptr [[A:%.*]]) {
; CHECK-NEXT:  [[INNER:.*]]:
; CHECK-NEXT:    br label %[[INNER1:.*]]
; CHECK:       [[INNER1]]:
; CHECK-NEXT:    [[I:%.*]] = phi i64 [ 0, %[[INNER]] ], [ [[I_NEXT:%.*]], %[[OUTER_LATCH:.*]] ]
; CHECK-NEXT:    br label %[[OUTER_HEADER_PREHEADER1:.*]]
; CHECK:       [[OUTER_HEADER_PREHEADER1]]:
; CHECK-NEXT:    [[J:%.*]] = phi i64 [ 0, %[[INNER1]] ], [ [[TMP2:%.*]], %[[OUTER_HEADER_PREHEADER1]] ]
; CHECK-NEXT:    call void @writeonly(ptr [[A]])
; CHECK-NEXT:    [[TMP2]] = add i64 [[J]], 1
; CHECK-NEXT:    [[TMP3:%.*]] = icmp eq i64 [[TMP2]], 100
; CHECK-NEXT:    br i1 [[TMP3]], label %[[OUTER_LATCH]], label %[[OUTER_HEADER_PREHEADER1]]
; CHECK:       [[OUTER_LATCH]]:
; CHECK-NEXT:    [[I_NEXT]] = add i64 [[I]], 1
; CHECK-NEXT:    [[EC_OUTER:%.*]] = icmp eq i64 [[I_NEXT]], 100
; CHECK-NEXT:    br i1 [[EC_OUTER]], label %[[EXIT:.*]], label %[[INNER1]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    ret void
;
entry:
  br label %outer.header

outer.header:
  %i = phi i64 [ 0, %entry ], [ %i.next, %outer.latch ]
  br label %inner

inner:
  %j = phi i64 [ 0, %outer.header ], [ %j.next, %inner ]
  call void @writeonly(ptr %A)
  %j.next = add i64 %j, 1
  %ec.inner = icmp eq i64 %j.next, 100
  br i1 %ec.inner, label %outer.latch, label %inner

outer.latch:
  %i.next = add i64 %i, 1
  %ec.outer = icmp eq i64 %i.next, 100
  br i1 %ec.outer, label %exit, label %outer.header

exit:
  ret void
}

; for (i = 0; i < 100; i++)
;   for (j = 0; j < 100; j++) {
;     A[j][i] = 0;
;     val = mem_none(A);
;     B[j][i] = val;
;   }
;
; The mem_none call doesn't read or write the memory, so we can interchange the
; loops.
;
define void @call_mem_none(ptr noalias %A, ptr noalias %B) {
; CHECK-LABEL: define void @call_mem_none(
; CHECK-SAME: ptr noalias [[A:%.*]], ptr noalias [[B:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    br label %[[INNER_PREHEADER:.*]]
; CHECK:       [[OUTER_HEADER_PREHEADER:.*]]:
; CHECK-NEXT:    br label %[[OUTER_HEADER:.*]]
; CHECK:       [[OUTER_HEADER]]:
; CHECK-NEXT:    [[I:%.*]] = phi i64 [ [[I_NEXT:%.*]], %[[OUTER_LATCH:.*]] ], [ 0, %[[OUTER_HEADER_PREHEADER]] ]
; CHECK-NEXT:    br label %[[INNER_SPLIT1:.*]]
; CHECK:       [[INNER_PREHEADER]]:
; CHECK-NEXT:    br label %[[INNER:.*]]
; CHECK:       [[INNER]]:
; CHECK-NEXT:    [[J:%.*]] = phi i64 [ [[TMP0:%.*]], %[[INNER_SPLIT:.*]] ], [ 0, %[[INNER_PREHEADER]] ]
; CHECK-NEXT:    br label %[[OUTER_HEADER_PREHEADER]]
; CHECK:       [[INNER_SPLIT1]]:
; CHECK-NEXT:    [[GEP_A:%.*]] = getelementptr [100 x i32], ptr [[A]], i64 [[J]], i64 [[I]]
; CHECK-NEXT:    store i32 0, ptr [[GEP_A]], align 4
; CHECK-NEXT:    [[VAL:%.*]] = call i32 @mem_none(ptr [[A]])
; CHECK-NEXT:    [[GEP_B:%.*]] = getelementptr [100 x i32], ptr [[B]], i64 [[J]], i64 [[I]]
; CHECK-NEXT:    store i32 [[VAL]], ptr [[GEP_B]], align 4
; CHECK-NEXT:    [[J_NEXT:%.*]] = add i64 [[J]], 1
; CHECK-NEXT:    [[EC_INNER:%.*]] = icmp eq i64 [[J_NEXT]], 100
; CHECK-NEXT:    br label %[[OUTER_LATCH]]
; CHECK:       [[INNER_SPLIT]]:
; CHECK-NEXT:    [[TMP0]] = add i64 [[J]], 1
; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i64 [[TMP0]], 100
; CHECK-NEXT:    br i1 [[TMP1]], label %[[EXIT:.*]], label %[[INNER]]
; CHECK:       [[OUTER_LATCH]]:
; CHECK-NEXT:    [[I_NEXT]] = add i64 [[I]], 1
; CHECK-NEXT:    [[EC_OUTER:%.*]] = icmp eq i64 [[I_NEXT]], 100
; CHECK-NEXT:    br i1 [[EC_OUTER]], label %[[INNER_SPLIT]], label %[[OUTER_HEADER]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    ret void
;
entry:
  br label %outer.header

outer.header:
  %i = phi i64 [ 0, %entry ], [ %i.next, %outer.latch ]
  br label %inner

inner:
  %j = phi i64 [ 0, %outer.header ], [ %j.next, %inner ]
  %gep.A = getelementptr [100 x i32], ptr %A, i64 %j, i64 %i
  store i32 0, ptr %gep.A
  %val = call i32 @mem_none(ptr %A)
  %gep.B = getelementptr [100 x i32], ptr %B, i64 %j, i64 %i
  store i32 %val, ptr %gep.B
  %j.next = add i64 %j, 1
  %ec.inner = icmp eq i64 %j.next, 100
  br i1 %ec.inner, label %outer.latch, label %inner

outer.latch:
  %i.next = add i64 %i, 1
  %ec.outer = icmp eq i64 %i.next, 100
  br i1 %ec.outer, label %exit, label %outer.header

exit:
  ret void
}

; for (i = 0; i < 10; i++)
;   for (j = 0; j < 10; j++) {
;     A[j][i] = 0;
;     if (j == 1)
;       throw_exception();
;   }
;
; Interchanging the loops changes the semantics of the program, e.g., `A[0][9]`
; will be overwritten in the original code, but not in the interchanged one.
;
define void @call_throw_exception(ptr %A) {
; CHECK-LABEL: define void @call_throw_exception(
; CHECK-SAME: ptr [[A:%.*]]) {
; CHECK-NEXT:  [[INNER_HEADER_PREHEADER:.*]]:
; CHECK-NEXT:    br label %[[INNER_HEADER:.*]]
; CHECK:       [[INNER_HEADER]]:
; CHECK-NEXT:    [[I:%.*]] = phi i64 [ 0, %[[INNER_HEADER_PREHEADER]] ], [ [[I_NEXT:%.*]], %[[OUTER_LATCH:.*]] ]
; CHECK-NEXT:    br label %[[OUTER_HEADER_PREHEADER:.*]]
; CHECK:       [[OUTER_HEADER_PREHEADER]]:
; CHECK-NEXT:    [[J:%.*]] = phi i64 [ 0, %[[INNER_HEADER]] ], [ [[TMP0:%.*]], %[[INNER_LATCH:.*]] ]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr [10 x i8], ptr [[A]], i64 [[J]], i64 [[I]]
; CHECK-NEXT:    store i8 0, ptr [[GEP]], align 1
; CHECK-NEXT:    [[COND:%.*]] = icmp eq i64 [[J]], 1
; CHECK-NEXT:    br i1 [[COND]], label %[[UNWIND:.*]], label %[[INNER_LATCH]]
; CHECK:       [[UNWIND]]:
; CHECK-NEXT:    call void @throw_exception()
; CHECK-NEXT:    br label %[[INNER_LATCH]]
; CHECK:       [[INNER_LATCH]]:
; CHECK-NEXT:    [[TMP0]] = add i64 [[J]], 1
; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i64 [[TMP0]], 10
; CHECK-NEXT:    br i1 [[TMP1]], label %[[OUTER_LATCH]], label %[[OUTER_HEADER_PREHEADER]]
; CHECK:       [[OUTER_LATCH]]:
; CHECK-NEXT:    [[I_NEXT]] = add i64 [[I]], 1
; CHECK-NEXT:    [[EC_OUTER:%.*]] = icmp eq i64 [[I_NEXT]], 10
; CHECK-NEXT:    br i1 [[EC_OUTER]], label %[[EXIT:.*]], label %[[INNER_HEADER]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    ret void
;
entry:
  br label %outer.header

outer.header:
  %i = phi i64 [ 0, %entry ], [ %i.next, %outer.latch ]
  br label %inner.header

inner.header:
  %j = phi i64 [ 0, %outer.header ], [ %j.next, %inner.latch ]
  %gep = getelementptr [10 x i8], ptr %A, i64 %j, i64 %i
  store i8 0, ptr %gep
  %cond = icmp eq i64 %j, 1
  br i1 %cond, label %unwind, label %inner.latch

unwind:
  call void @throw_exception()
  br label %inner.latch

inner.latch:
  %j.next = add i64 %j, 1
  %ec.inner = icmp eq i64 %j.next, 10
  br i1 %ec.inner, label %outer.latch, label %inner.header

outer.latch:
  %i.next = add i64 %i, 1
  %ec.outer = icmp eq i64 %i.next, 10
  br i1 %ec.outer, label %exit, label %outer.header

exit:
  ret void
}

; A[100];
; for (i = 0; i < 1000; i++)
;   for (j = 0; j < 10; j++) {
;     A[i*10 + j] = 0;
;     if (j == 1)
;       not_return();
;   }
;
; `no_return` may be something like `exit` or `abort`, and in such cases,
; interchanging the loops will introduce additional accesses that are not
; present in the original code (e.g., `A[9999]`) which results in UB. Thus we
; cannot interchange the loops.
;
define void @call_not_return() {
; CHECK-LABEL: define void @call_not_return() {
; CHECK-NEXT:  [[OUTER_HEADER:.*]]:
; CHECK-NEXT:    br label %[[INNER_HEADER1:.*]]
; CHECK:       [[INNER_HEADER1]]:
; CHECK-NEXT:    [[J:%.*]] = phi i64 [ 0, %[[OUTER_HEADER]] ], [ [[I_NEXT:%.*]], %[[OUTER_LATCH:.*]] ]
; CHECK-NEXT:    br label %[[OUTER_HEADER_PREHEADER:.*]]
; CHECK:       [[OUTER_HEADER_PREHEADER]]:
; CHECK-NEXT:    [[I:%.*]] = phi i64 [ 0, %[[INNER_HEADER1]] ], [ [[TMP0:%.*]], %[[INNER_LATCH:.*]] ]
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr [10 x i8], ptr @ARR_100, i64 [[J]], i64 [[I]]
; CHECK-NEXT:    store i8 0, ptr [[GEP]], align 1
; CHECK-NEXT:    [[COND:%.*]] = icmp eq i64 [[I]], 1
; CHECK-NEXT:    br i1 [[COND]], label %[[TRAP:.*]], label %[[INNER_LATCH]]
; CHECK:       [[TRAP]]:
; CHECK-NEXT:    call void @not_return()
; CHECK-NEXT:    br label %[[INNER_LATCH]]
; CHECK:       [[INNER_LATCH]]:
; CHECK-NEXT:    [[TMP0]] = add i64 [[I]], 1
; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i64 [[TMP0]], 10
; CHECK-NEXT:    br i1 [[TMP1]], label %[[OUTER_LATCH]], label %[[OUTER_HEADER_PREHEADER]]
; CHECK:       [[OUTER_LATCH]]:
; CHECK-NEXT:    [[I_NEXT]] = add i64 [[J]], 1
; CHECK-NEXT:    [[EC_OUTER:%.*]] = icmp eq i64 [[I_NEXT]], 1000
; CHECK-NEXT:    br i1 [[EC_OUTER]], label %[[EXIT:.*]], label %[[INNER_HEADER1]]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    ret void
;
entry:
  br label %outer.header

outer.header:
  %i = phi i64 [ 0, %entry ], [ %i.next, %outer.latch ]
  br label %inner.header

inner.header:
  %j = phi i64 [ 0, %outer.header ], [ %j.next, %inner.latch ]
  %gep = getelementptr [10 x i8], ptr @ARR_100, i64 %i, i64 %j
  store i8 0, ptr %gep
  %cond = icmp eq i64 %j, 1
  br i1 %cond, label %trap, label %inner.latch

trap:
  call void @not_return()
  br label %inner.latch

inner.latch:
  %j.next = add i64 %j, 1
  %ec.inner = icmp eq i64 %j.next, 10
  br i1 %ec.inner, label %outer.latch, label %inner.header

outer.latch:
  %i.next = add i64 %i, 1
  %ec.outer = icmp eq i64 %i.next, 1000
  br i1 %ec.outer, label %exit, label %outer.header

exit:
  ret void
}


@ARR_100 = global [100 x i8] zeroinitializer
declare void @writeonly(ptr %p) nounwind willreturn memory(write)
declare void @mem_none(ptr %p) nounwind willreturn memory(none)
declare void @throw_exception() willreturn memory(none)
declare void @not_return() nounwind memory(none)