[glibc/azanella/clang] x86_64: Provide __sfp_handle_exceptions if compiler does not

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=a8ac0d97708e82dad8af9aed86d4a631487cc37f

commit a8ac0d97708e82dad8af9aed86d4a631487cc37f
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Wed Feb 21 10:44:47 2024 -0300

    x86_64: Provide __sfp_handle_exceptions if compiler does not

Diff:
---
 config.h.in                   |  3 +++
 sysdeps/x86/fpu/sfp-machine.h | 20 +++++++++++++++++++-
 sysdeps/x86_64/configure      | 31 +++++++++++++++++++++++++++++++
 sysdeps/x86_64/configure.ac   | 20 ++++++++++++++++++++
 4 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/config.h.in b/config.h.in
index cf4212f5eb..98236e11ce 100644
--- a/config.h.in
+++ b/config.h.in
@@ -295,4 +295,7 @@
 /* Define if -mmovbe is enabled by default on x86.  */
 #undef HAVE_X86_MOVBE
 
+/* Define whether compiler runtime library provides __sfp_handle_exceptions.  */
+#undef HAVE_X86_64_SFP_HANDLE_EXCEPTIONS
+
 #endif
diff --git a/sysdeps/x86/fpu/sfp-machine.h b/sysdeps/x86/fpu/sfp-machine.h
index dd23c797bd..c2aa2b6901 100644
--- a/sysdeps/x86/fpu/sfp-machine.h
+++ b/sysdeps/x86/fpu/sfp-machine.h
@@ -217,8 +217,26 @@ typedef unsigned int UTItype __attribute__ ((mode (TI)));
 	(FP_EX_INVALID | FP_EX_DENORM | FP_EX_DIVZERO | FP_EX_OVERFLOW \
 	 | FP_EX_UNDERFLOW | FP_EX_INEXACT)
 
+#ifdef HAVE_X86_64_SFP_HANDLE_EXCEPTIONS
 void __sfp_handle_exceptions (int);
-
+#else
+#include <fenv.h>
+static inline void __sfp_handle_exceptions (int _fex)
+{
+  if (_fex & FP_EX_INVALID)
+    feraiseexcept (FE_INVALID);
+  if (_fex & FP_EX_DENORM)
+    feraiseexcept (__FE_DENORM);
+  if (_fex & FP_EX_DIVZERO)
+    feraiseexcept (FE_DIVBYZERO);
+  if (_fex & FP_EX_OVERFLOW)
+    feraiseexcept (FE_OVERFLOW);
+  if (_fex & FP_EX_UNDERFLOW)
+    feraiseexcept (FE_UNDERFLOW);
+  if (_fex & FP_EX_INEXACT)
+    feraiseexcept (FE_INEXACT);
+}
+#endif
 #define FP_HANDLE_EXCEPTIONS			\
   do {						\
     if (__builtin_expect (_fex, 0))		\
diff --git a/sysdeps/x86_64/configure b/sysdeps/x86_64/configure
index 48cc2989a8..5741a172df 100755
--- a/sysdeps/x86_64/configure
+++ b/sysdeps/x86_64/configure
@@ -186,6 +186,37 @@ printf "%s\n" "$libc_cv_x86_have_amx_tile" >&6; }
 config_vars="$config_vars
 have-mamx-tile = $libc_cv_x86_have_amx_tile"
 
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether compiler standard library provides __sfp_handle_exceptions" >&5
+printf %s "checking whether compiler standard library provides __sfp_handle_exceptions... " >&6; }
+if test ${libc_cv_sfp_handle_exceptions+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  cat > conftest.c <<EOF
+int _start (void) { return 0; }
+int __start (void) { return 0; }
+void __sfp_handle_exceptions (int);
+int main (void) { __sfp_handle_exceptions (0); return 0; }
+EOF
+		 if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $no_ssp -o conftest conftest.c -static -nostartfiles 1>&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }; then
+		   libc_cv_sfp_handle_exceptions=yes
+		 else
+		   libc_cv_sfp_handle_exceptions=no
+		 fi
+		 rm -rf conftest*
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_sfp_handle_exceptions" >&5
+printf "%s\n" "$libc_cv_sfp_handle_exceptions" >&6; }
+if test x"$libc_cv_sfp_handle_exceptions" == xyes; then
+  printf "%s\n" "#define HAVE_X86_64_SFP_HANDLE_EXCEPTIONS 1" >>confdefs.h
+
+fi
+
 test -n "$critic_missing" && as_fn_error $? "
 *** $critic_missing" "$LINENO" 5
 
diff --git a/sysdeps/x86_64/configure.ac b/sysdeps/x86_64/configure.ac
index e4770a366e..e7821c3640 100644
--- a/sysdeps/x86_64/configure.ac
+++ b/sysdeps/x86_64/configure.ac
@@ -85,5 +85,25 @@ EOF
 	       rm -rf conftest*])
 LIBC_CONFIG_VAR([have-mamx-tile], [$libc_cv_x86_have_amx_tile])
 
+dnl Check if compiler standard library provides __sfp_handle_exceptions, used on
+dnl float128 implementation.
+AC_CACHE_CHECK(whether compiler standard library provides __sfp_handle_exceptions,
+	       libc_cv_sfp_handle_exceptions, [dnl
+cat > conftest.c <<EOF
+int _start (void) { return 0; }
+int __start (void) { return 0; }
+void __sfp_handle_exceptions (int);
+int main (void) { __sfp_handle_exceptions (0); return 0; }
+EOF
+		 if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS $no_ssp -o conftest conftest.c -static -nostartfiles 1>&AS_MESSAGE_LOG_FD); then
+		   libc_cv_sfp_handle_exceptions=yes
+		 else
+		   libc_cv_sfp_handle_exceptions=no
+		 fi
+		 rm -rf conftest*])
+if test x"$libc_cv_sfp_handle_exceptions" == xyes; then
+  AC_DEFINE(HAVE_X86_64_SFP_HANDLE_EXCEPTIONS)
+fi
+
 test -n "$critic_missing" && AC_MSG_ERROR([
 *** $critic_missing])