You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
Original commit message:
[msvc] fix build with neon intrinsics
This compilation error was found by NodeJS when updating V8:
nodejs/node-v8#240
MSVC reports an error with "too many initializer" for type uint32x4_t.
---
Under gcc/clang, this is a typedef to a builtin type.
For MSVC, it is a typedef to this union:
typedef union __n128
{
unsigned __int64 n128_u64[2];
unsigned __int32 n128_u32[4];
...
} __n128;
C++ mandates that only first member of union can be initialized at
declaration. Thus, it can only be initialized with {uint64_t, uint64_t}.
VS people proposed to use designated initializer instead:
var = {.n128_u32={1, 2, 3, 8}}
https://developercommunity.visualstudio.com/t/error-c2078-too-many-initializers-when-using-arm-n/402911
But, you need to use /std:c++20 for this, which is not the case in v8.
---
Thus, the only solution is to implement a hack specifically for MSVC,
where you build two uint64, from four uint32.
---------------------------------------
Once solved, another error is reported:
templated function extract_first_nonzero_index is specialized twice.
This is because, with MSVC, uint32x4_t and uint64x2_t are typedef to the
same __n128 union. The fix is to drop templates, and use explicit
function names instead.
Bug: v8:13312
Change-Id: I231d8cf01c05af01af319d56d5666c415f8b989b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3913035
Reviewed-by: Igor Sheludko <[email protected]>
Reviewed-by: Jakob Kummerow <[email protected]>
Commit-Queue: Jakob Kummerow <[email protected]>
Cr-Commit-Position: refs/heads/main@{#83404}
Refs: v8/v8@1b3a4f0
PR-URL: #44741
Reviewed-By: Ben Noordhuis <[email protected]>
Reviewed-By: Jiawen Geng <[email protected]>
Reviewed-By: James M Snell <[email protected]>
0 commit comments