From f1e004b954c2a6a0dc8d2ac03042bcf75eae49d0 Mon Sep 17 00:00:00 2001
From: Richard Barnes <rbarnes@fb.com>
Date: Wed, 17 Feb 2021 22:05:31 -0800
Subject: [PATCH] Fix compiler warning for MathConstants.h (#52123)

Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52123

Compiler currently complains:
```
caffe2/c10/util/MatchConstants.h(18): warning: calling a constexpr __host__ function("from_bits") from a __host__ __device__ function("pi") is not allowed.
```
This diff extirpates the warning

Test Plan: Sandcastle tests

Reviewed By: xush6528

Differential Revision: D26379485

fbshipit-source-id: ab4821119cba8c43fd1d5788c4632d0613529ec8
---
 c10/util/BFloat16.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/c10/util/BFloat16.h b/c10/util/BFloat16.h
index 0bd115d568f..ce0d229b72c 100644
--- a/c10/util/BFloat16.h
+++ b/c10/util/BFloat16.h
@@ -81,7 +81,7 @@ struct alignas(2) BFloat16 {
 #endif
 
   struct from_bits_t {};
-  static constexpr from_bits_t from_bits() {
+  static constexpr C10_HOST_DEVICE from_bits_t from_bits() {
     return from_bits_t();
   }