[reactos] 04/08: [CRT] math.h: fix definition of NAN

[Timo Kreuzer]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=736fea6c44cad243fcb8f…

commit 736fea6c44cad243fcb8f19b70acc803b5e20b30
Author:     Timo Kreuzer <timo.kreuzer(a)reactos.org>
AuthorDate: Thu Jan 30 19:27:53 2025 +0200
Commit:     Timo Kreuzer <timo.kreuzer(a)reactos.org>
CommitDate: Wed Feb 12 16:54:45 2025 +0200

    [CRT] math.h: fix definition of NAN
    
    - Use positive NAN by default
    - add support for _UCRT_NEGATIVE_NAN to legacy CRT headers
    - Use __builtin_nanf() on GCC/Clang
---
 sdk/include/crt/math.h          | 16 +++++++++++++++-
 sdk/include/ucrt/corecrt_math.h |  8 ++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/sdk/include/crt/math.h b/sdk/include/crt/math.h
index 33f460db5f6..09113acef86 100644
--- a/sdk/include/crt/math.h
+++ b/sdk/include/crt/math.h
@@ -57,7 +57,21 @@ typedef double double_t;
 #define HUGE_VALD ((double)INFINITY)
 #define HUGE_VALF ((float)INFINITY)
 #define HUGE_VALL ((long double)INFINITY)
-#define NAN       ((float)(INFINITY * 0.0F))
+#ifndef _UCRT_NEGATIVE_NAN
+// This operation creates a negative NAN adding a - to make it positive
+#ifdef _MSC_VER
+#define NAN        (-(float)(INFINITY * 0.0F))
+#else
+#define NAN        (__builtin_nanf(""))
+#endif
+#else
+// Keep this for backwards compatibility
+#ifdef _MSC_VER
+#define NAN        ((float)(INFINITY * 0.0F))
+#else
+#define NAN        (-__builtin_nanf(""))
+#endif
+#endif
 
 #define _DENORM  (-2)
 #define _FINITE  (-1)
diff --git a/sdk/include/ucrt/corecrt_math.h b/sdk/include/ucrt/corecrt_math.h
index fdfe1f02e66..215a0b96422 100644
--- a/sdk/include/ucrt/corecrt_math.h
+++ b/sdk/include/ucrt/corecrt_math.h
@@ -91,10 +91,18 @@ _CRT_BEGIN_C_HEADER
 #define HUGE_VALL  ((long double)INFINITY)
 #ifndef _UCRT_NEGATIVE_NAN
 // This operation creates a negative NAN adding a - to make it positive
+#ifdef _MSC_VER
 #define NAN        (-(float)(INFINITY * 0.0F))
 #else
+#define NAN        (__builtin_nanf(""))
+#endif
+#else
 // Keep this for backwards compatibility
+#ifdef _MSC_VER
 #define NAN        ((float)(INFINITY * 0.0F))
+#else
+#define NAN        (-__builtin_nanf(""))
+#endif
 #endif
 
 #define _DENORM    (-2)