[PATCH v2 6/6] math: Disable exception check for soft-fp routine with compiler-rt

[Adhemerval Zanella]

The compiler-rt does not support throwing floating-point exceptions
for math builtin (__addtf3, __multf3, __divtf3, etc.) [1][2][3].
So disable the check when compiler-rt is used instead of libgcc.

Checked on x86_64-linux-gnu and aarch64-linux-gnu with clang.

[1] https://github.com/llvm/llvm-project/issues/59924
[2] https://github.com/llvm/llvm-project/issues/60141
[3] https://github.com/llvm/llvm-project/issues/172499
---
 config.h.in                             |  3 +++
 configure                               |  4 +++
 configure.ac                            |  3 +++
 sysdeps/aarch64/math-tests-exceptions.h | 34 +++++++++++++++++++++++++
 sysdeps/x86_64/math-tests-exceptions.h  | 33 ++++++++++++++++++++++++
 5 files changed, 77 insertions(+)
 create mode 100644 sysdeps/aarch64/math-tests-exceptions.h
 create mode 100644 sysdeps/x86_64/math-tests-exceptions.h

diff --git a/config.h.in b/config.h.in
index 125532ec6b..215b223e12 100644
--- a/config.h.in
+++ b/config.h.in
@@ -231,6 +231,9 @@
 /* Define to 1 if compiler runtime provides __sfp_handle_exceptions */
 #undef HAVE_SFP_HANDLE_EXCEPTIONS
 
+/* Define to 1 if compiler uses compiler-rt instead of libgcc.  */
+#undef HAVE_COMPILER_RT_RUNTIME
+
 /*
  */
 
diff --git a/configure b/configure
index d156912063..4ccf5600d7 100755
--- a/configure
+++ b/configure
@@ -9398,6 +9398,10 @@ esac
 fi
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_runtime_library" >&5
 printf "%s\n" "$libc_cv_runtime_library" >&6; }
+if test $libc_cv_runtime_library = compiler-rt; then
+  printf "%s\n" "#define HAVE_COMPILER_RT_RUNTIME 1" >>confdefs.h
+
+fi
 config_vars="$config_vars
 libgcc-name = $libc_cv_libgcc"
 config_vars="$config_vars
diff --git a/configure.ac b/configure.ac
index 776695486a..9ced9ec0f5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2152,6 +2152,9 @@ AC_CACHE_CHECK([for the usable compiler runtime library], [libc_cv_runtime_libra
       ;;
     *) AC_MSG_FAILURE([non supported compiler runtime library]) ;;
   esac])
+if test $libc_cv_runtime_library = compiler-rt; then
+  AC_DEFINE([HAVE_COMPILER_RT_RUNTIME])
+fi
 LIBC_CONFIG_VAR([libgcc-name], [$libc_cv_libgcc])
 LIBC_CONFIG_VAR([libgcc_eh-name], [$libc_cv_libgcc_eh])
 
diff --git a/sysdeps/aarch64/math-tests-exceptions.h b/sysdeps/aarch64/math-tests-exceptions.h
new file mode 100644
index 0000000000..dc824c25a5
--- /dev/null
+++ b/sysdeps/aarch64/math-tests-exceptions.h
@@ -0,0 +1,34 @@
+/* Configuration for math tests: support for exceptions.  AArch64 version.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _MATH_TESTS_EXCEPTIONS_H
+#define _MATH_TESTS_EXCEPTIONS_H 1
+
+#define EXCEPTION_TESTS_float	1
+#define EXCEPTION_TESTS_double	1
+/* compiler-rt does not support floating-point exceptions for the
+   long double / __float128 math builtins.  */
+#ifdef HAVE_COMPILER_RT_RUNTIME
+# define EXCEPTION_TESTS_long_double	0
+# define EXCEPTION_TESTS_float128	0
+#else
+# define EXCEPTION_TESTS_long_double	1
+# define EXCEPTION_TESTS_float128	1
+#endif
+
+#endif /* math-tests-exceptions.h.  */
diff --git a/sysdeps/x86_64/math-tests-exceptions.h b/sysdeps/x86_64/math-tests-exceptions.h
new file mode 100644
index 0000000000..fa60397b79
--- /dev/null
+++ b/sysdeps/x86_64/math-tests-exceptions.h
@@ -0,0 +1,33 @@
+/* Configuration for math tests: support for exceptions.  x86_64 version.
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _MATH_TESTS_EXCEPTIONS_H
+#define _MATH_TESTS_EXCEPTIONS_H 1
+
+#define EXCEPTION_TESTS_float	1
+#define EXCEPTION_TESTS_double	1
+#define EXCEPTION_TESTS_long_double	1
+/* compiler-rt does not support floating-point exceptions for the
+   _float128 math builtins.  */
+#ifdef HAVE_COMPILER_RT_RUNTIME
+# define EXCEPTION_TESTS_float128	0
+#else
+# define EXCEPTION_TESTS_float128	1
+#endif
+
+#endif /* math-tests-exceptions.h.  */
-- 
2.43.0