From 813415650235b8ca42fe1afb3fcb0430e8628d30 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Thu, 10 Feb 2022 14:06:27 +0000 Subject: [PATCH] libstdc++: Fix std::to_chars for IEEE128 long double The preprocessor check for _GLIBCXX_USE_FLOAT128 is the wrong condition, because when the compiler is built with --with-long-double-format=ieee configure determines that __float128 is the same as long double, and so should not be used. But we do want the std::to_chars overloads for __float128 in that case, because the floating_to_chars.cc file is built with -mabi=ibmlongdouble and so the __float128 overloads are actually the 'long double' ones for -mabi=ieeelongdouble code. This fixes missing definitions of the __float128 overloads of std::to_chars for --with-long-double-format=ieee builds. Without this, there are symbols present in the --with-long-double-abi=ibm build which are missing from the --with-long-double-abi=ieee build. libstdc++-v3/ChangeLog: * src/c++17/floating_to_chars.cc (FLOAT128_TO_CHARS): Depend on LONG_DOUBLE_ALT128_COMPAT instead of USE_FLOAT128. --- libstdc++-v3/src/c++17/floating_to_chars.cc | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/libstdc++-v3/src/c++17/floating_to_chars.cc b/libstdc++-v3/src/c++17/floating_to_chars.cc index 8da2f2385a0..5825e661bf4 100644 --- a/libstdc++-v3/src/c++17/floating_to_chars.cc +++ b/libstdc++-v3/src/c++17/floating_to_chars.cc @@ -76,16 +76,12 @@ extern "C" int __sprintfieee128(char*, const char*, ...); # define LONG_DOUBLE_KIND LDK_UNSUPPORTED #endif -#if defined _GLIBCXX_USE_FLOAT128 && __FLT128_MANT_DIG__ == 113 +// For now we only support __float128 when it's the powerpc64 __ieee128 type. +#if defined _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __FLT128_MANT_DIG__ == 113 // Define overloads of std::to_chars for __float128. # define FLOAT128_TO_CHARS 1 #endif -// For now we only support __float128 when it's the powerpc64 __ieee128 type. -#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT -# undef FLOAT128_TO_CHARS -#endif - #ifdef FLOAT128_TO_CHARS using F128_type = __float128; #else