https://gcc.gnu.org/g:73a62377ae638ce85c0a40327e67b41c861fb156
commit r14-11538-g73a62377ae638ce85c0a40327e67b41c861fb156
Author: Lulu Cheng <chengl...@loongson.cn>
Date: Mon Apr 7 10:00:27 2025 +0800
LoongArch: Add LoongArch architecture detection to __float128 support in
libgfortran and libquadmath [PR119408].
In GCC14, LoongArch added __float128 as an alias for _Float128.
In commit r15-8962, support for q/Q suffixes for 128-bit floating point
numbers. This will cause the compiler to automatically link libquadmath
when compiling Fortran programs. But on LoongArch `long double` is
IEEE quad, so there is no need to implement libquadmath.
This causes link failure.
PR target/119408
libgfortran/ChangeLog:
* acinclude.m4: When checking for __float128 support, determine
whether the current architecture is LoongArch. If so, return false.
* configure: Regenerate.
libquadmath/ChangeLog:
* configure.ac: When checking for __float128 support, determine
whether the current architecture is LoongArch. If so, return false.
* configure: Regenerate.
Sigend-off-by: Xi Ruoyao <xry...@xry111.site>
Sigend-off-by: Jakub Jelinek <ja...@redhat.com>
(cherry picked from commit 1534f0099c98ea14c08a401302b05edf2231f411)
Diff:
---
libgfortran/acinclude.m4 | 4 ++++
libgfortran/configure | 8 ++++++++
libquadmath/configure | 8 ++++++++
libquadmath/configure.ac | 4 ++++
4 files changed, 24 insertions(+)
diff --git a/libgfortran/acinclude.m4 b/libgfortran/acinclude.m4
index a73207e54656..23fd621e5188 100644
--- a/libgfortran/acinclude.m4
+++ b/libgfortran/acinclude.m4
@@ -274,6 +274,10 @@ AC_DEFUN([LIBGFOR_CHECK_FLOAT128], [
AC_CACHE_CHECK([whether we have a usable _Float128 type],
libgfor_cv_have_float128, [
GCC_TRY_COMPILE_OR_LINK([
+ #ifdef __loongarch__
+ #error On LoongArch we should use long double instead; __float128 is only
for porting existing code easier.
+ #endif
+
_Float128 foo (_Float128 x)
{
_Complex _Float128 z1, z2;
diff --git a/libgfortran/configure b/libgfortran/configure
index 774dd52fc95d..16bad2924749 100755
--- a/libgfortran/configure
+++ b/libgfortran/configure
@@ -30288,6 +30288,10 @@ else
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
+ #ifdef __loongarch__
+ #error On LoongArch we should use long double instead; __float128 is only
for porting existing code easier.
+ #endif
+
_Float128 foo (_Float128 x)
{
_Complex _Float128 z1, z2;
@@ -30341,6 +30345,10 @@ fi
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
+ #ifdef __loongarch__
+ #error On LoongArch we should use long double instead; __float128 is only
for porting existing code easier.
+ #endif
+
_Float128 foo (_Float128 x)
{
_Complex _Float128 z1, z2;
diff --git a/libquadmath/configure b/libquadmath/configure
index 49d70809218c..f82dd3d0d6d4 100755
--- a/libquadmath/configure
+++ b/libquadmath/configure
@@ -12843,6 +12843,10 @@ else
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
+ #ifdef __loongarch__
+ #error On LoongArch we should use long double instead; __float128 is only
for porting existing code easier.
+ #endif
+
#if (!defined(_ARCH_PPC)) || defined(__LONG_DOUBLE_IEEE128__)
typedef _Complex float __attribute__((mode(TC))) __complex128;
#else
@@ -12894,6 +12898,10 @@ fi
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
+ #ifdef __loongarch__
+ #error On LoongArch we should use long double instead; __float128 is only
for porting existing code easier.
+ #endif
+
#if (!defined(_ARCH_PPC)) || defined(__LONG_DOUBLE_IEEE128__)
typedef _Complex float __attribute__((mode(TC))) __complex128;
#else
diff --git a/libquadmath/configure.ac b/libquadmath/configure.ac
index 349be2607c64..c64a84892191 100644
--- a/libquadmath/configure.ac
+++ b/libquadmath/configure.ac
@@ -233,6 +233,10 @@ AM_CONDITIONAL(LIBQUAD_USE_SYMVER_SUN, [test
"x$quadmath_use_symver" = xsun])
AC_CACHE_CHECK([whether __float128 is supported], [libquad_cv_have_float128],
[GCC_TRY_COMPILE_OR_LINK([
+ #ifdef __loongarch__
+ #error On LoongArch we should use long double instead; __float128 is only
for porting existing code easier.
+ #endif
+
#if (!defined(_ARCH_PPC)) || defined(__LONG_DOUBLE_IEEE128__)
typedef _Complex float __attribute__((mode(TC))) __complex128;
#else
