From 84eb13b9d6a9979825f5deaa1c17762bf8c8ef9f Mon Sep 17 00:00:00 2001
From: Matthias Kretz <m.kretz@gsi.de>
Date: Mon, 17 Jan 2022 10:38:29 +0100
Subject: [PATCH] libstdc++: Don't fail if math_errhandling is not defined
Older glibc does not define math_errhandling with -ffast-math, in which
case floating-point exceptions are not used.
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd.h (__floating_point_flags): Do
not rely on the presence of the math_errhandling macro.
---
libstdc++-v3/include/experimental/bits/simd.h | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/libstdc++-v3/include/experimental/bits/simd.h b/libstdc++-v3/include/experimental/bits/simd.h
index d837d0efb21e..c991e3f223e9 100644
--- a/libstdc++-v3/include/experimental/bits/simd.h
+++ b/libstdc++-v3/include/experimental/bits/simd.h
@@ -283,11 +283,20 @@ constexpr inline bool __have_power_vmx = __have_power_vsx;
namespace __detail
{
+ constexpr bool __handle_fpexcept =
+#ifdef math_errhandling
+ math_errhandling & MATH_ERREXCEPT;
+#elif defined __FAST_MATH__
+ false;
+#else
+ true;
+#endif
+
constexpr std::uint_least64_t
__floating_point_flags()
{
std::uint_least64_t __flags = 0;
- if constexpr (math_errhandling & MATH_ERREXCEPT)
+ if constexpr (__handle_fpexcept)
__flags |= 1;
#ifdef __FAST_MATH__
__flags |= 1 << 1;
--
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