xref: /aosp_15_r20/external/pytorch/c10/core/SymIntArrayRef.h (revision da0073e96a02ea20f0ac840b70461e3646d07c45)
1 #pragma once
2 
3 #include <c10/core/SymInt.h>
4 #include <c10/util/ArrayRef.h>
5 #include <c10/util/DimVector.h>
6 #include <c10/util/Exception.h>
7 #include <c10/util/irange.h>
8 #include <cstdint>
9 #include <optional>
10 
11 namespace c10 {
12 using SymIntArrayRef = ArrayRef<SymInt>;
13 
asIntArrayRefUnchecked(c10::SymIntArrayRef ar)14 inline at::IntArrayRef asIntArrayRefUnchecked(c10::SymIntArrayRef ar) {
15   return IntArrayRef(reinterpret_cast<const int64_t*>(ar.data()), ar.size());
16 }
17 
18 // TODO: a SymIntArrayRef containing a heap allocated large negative integer
19 // can actually technically be converted to an IntArrayRef... but not with
20 // the non-owning API we have here.  We can't reinterpet cast; we have to
21 // allocate another buffer and write the integers into it.  If you need it,
22 // we can do it.  But I don't think you need it.
23 
asIntArrayRefSlowOpt(c10::SymIntArrayRef ar)24 inline std::optional<at::IntArrayRef> asIntArrayRefSlowOpt(
25     c10::SymIntArrayRef ar) {
26   for (const c10::SymInt& sci : ar) {
27     if (sci.is_heap_allocated()) {
28       return std::nullopt;
29     }
30   }
31 
32   return {asIntArrayRefUnchecked(ar)};
33 }
34 
asIntArrayRefSlow(c10::SymIntArrayRef ar,const char * file,int64_t line)35 inline at::IntArrayRef asIntArrayRefSlow(
36     c10::SymIntArrayRef ar,
37     const char* file,
38     int64_t line) {
39   for (const c10::SymInt& sci : ar) {
40     TORCH_CHECK(
41         !sci.is_heap_allocated(),
42         file,
43         ":",
44         line,
45         ": SymIntArrayRef expected to contain only concrete integers");
46   }
47   return asIntArrayRefUnchecked(ar);
48 }
49 
50 // Even slower than asIntArrayRefSlow, as it forces an allocation for a
51 // destination int, BUT it is able to force specialization (it never errors)
asIntArrayRefSlowAlloc(c10::SymIntArrayRef ar,const char * file,int64_t line)52 inline c10::DimVector asIntArrayRefSlowAlloc(
53     c10::SymIntArrayRef ar,
54     const char* file,
55     int64_t line) {
56   c10::DimVector res(ar.size(), 0);
57   for (const auto i : c10::irange(ar.size())) {
58     res[i] = ar[i].guard_int(file, line);
59   }
60   return res;
61 }
62 
63 #define C10_AS_INTARRAYREF_SLOW(a) c10::asIntArrayRefSlow(a, __FILE__, __LINE__)
64 #define C10_AS_INTARRAYREF_SLOW_ALLOC(a) \
65   c10::asIntArrayRefSlowAlloc(a, __FILE__, __LINE__)
66 
67 // Prefer using a more semantic constructor, like
68 // fromIntArrayRefKnownNonNegative
fromIntArrayRefUnchecked(IntArrayRef array_ref)69 inline SymIntArrayRef fromIntArrayRefUnchecked(IntArrayRef array_ref) {
70   return SymIntArrayRef(
71       reinterpret_cast<const SymInt*>(array_ref.data()), array_ref.size());
72 }
73 
fromIntArrayRefKnownNonNegative(IntArrayRef array_ref)74 inline SymIntArrayRef fromIntArrayRefKnownNonNegative(IntArrayRef array_ref) {
75   return fromIntArrayRefUnchecked(array_ref);
76 }
77 
fromIntArrayRefSlow(IntArrayRef array_ref)78 inline SymIntArrayRef fromIntArrayRefSlow(IntArrayRef array_ref) {
79   for (long i : array_ref) {
80     TORCH_CHECK(
81         SymInt::check_range(i),
82         "IntArrayRef contains an int that cannot be represented as a SymInt: ",
83         i);
84   }
85   return SymIntArrayRef(
86       reinterpret_cast<const SymInt*>(array_ref.data()), array_ref.size());
87 }
88 
89 } // namespace c10
90