[Openmp-commits] [openmp] fix endianness dependent definitions in kmp.h for MSVC (PR #84530)

[Vadim Paretsky via Openmp-commits]

https://github.com/vadikp-intel created https://github.com/llvm/llvm-project/pull/84530

MSVC does not define __BYTE_ORDER__ making the check for BigEndian erroneously evaluate to true and breaking the struct definitions in MSVC compiled builds correspondingly. The fix adds an additional check for whether __BYTE_ORDER__ is defined by the compiler to fix these.

>From 75d7c576bf4e5a0f13a4fdb0fda036e3955bed89 Mon Sep 17 00:00:00 2001
From: Vadim Paretsky <b-vadipa at microsoft.com>
Date: Fri, 8 Mar 2024 10:17:46 -0800
Subject: [PATCH] fix endianess dependent definitions for MSVC in kmp.h

---
 openmp/runtime/src/kmp.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/openmp/runtime/src/kmp.h b/openmp/runtime/src/kmp.h
index 121e7e959129ea..59a90ea702f688 100644
--- a/openmp/runtime/src/kmp.h
+++ b/openmp/runtime/src/kmp.h
@@ -2507,7 +2507,7 @@ typedef struct kmp_depend_info {
   union {
     kmp_uint8 flag; // flag as an unsigned char
     struct { // flag as a set of 8 bits
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
       /* Same fields as in the #else branch, but in reverse order */
       unsigned all : 1;
       unsigned unused : 3;
@@ -2672,7 +2672,7 @@ typedef struct kmp_task_stack {
 #endif // BUILD_TIED_TASK_STACK
 
 typedef struct kmp_tasking_flags { /* Total struct must be exactly 32 bits */
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
   /* Same fields as in the #else branch, but in reverse order */
 #if OMPX_TASKGRAPH
   unsigned reserved31 : 6;