LoongArch: Add soft float support.

scripts/build-many-glibcs.py

@@ -222,6 +222,10 @@ class Context(object):
                         os_name='linux-gnu',
                         variant='lp64d',
                         gcc_cfg=['--with-abi=lp64d','--disable-multilib'])
+        self.add_config(arch='loongarch64',
+                        os_name='linux-gnu',
+                        variant='lp64s',
+                        gcc_cfg=['--with-abi=lp64s','--disable-multilib'])
         self.add_config(arch='m68k',
                         os_name='linux-gnu',
                         gcc_cfg=['--disable-multilib'])

sysdeps/loongarch/Makefile

@@ -5,11 +5,3 @@ endif
 # LoongArch's assembler also needs to know about PIC as it changes the
 # definition of some assembler macros.
 ASFLAGS-.os += $(pic-ccflag)
-
-abi-variants := lp64
-
-ifeq (,$(filter $(default-abi),$(abi-variants)))
-$(error Unknown ABI $(default-abi), must be one of $(abi-variants))
-endif
-
-abi-lp64-condition    := defined __loongarch_lp64

sysdeps/loongarch/__longjmp.S

@@ -41,6 +41,7 @@ ENTRY (__longjmp)
 	REG_L s7, a0, 11*SZREG
 	REG_L s8, a0, 12*SZREG
 
+#ifndef __loongarch_soft_float
 	FREG_L $f24, a0, 13*SZREG + 0*SZFREG
 	FREG_L $f25, a0, 13*SZREG + 1*SZFREG
 	FREG_L $f26, a0, 13*SZREG + 2*SZFREG
@@ -49,6 +50,7 @@ ENTRY (__longjmp)
 	FREG_L $f29, a0, 13*SZREG + 5*SZFREG
 	FREG_L $f30, a0, 13*SZREG + 6*SZFREG
 	FREG_L $f31, a0, 13*SZREG + 7*SZFREG
+#endif
 
 	sltui	a0,a1,1
 	ADD	a0, a0, a1	 # a0 = (a1 == 0) ? 1 : a1

sysdeps/loongarch/bits/setjmp.h

@@ -31,8 +31,11 @@ typedef struct __jmp_buf_internal_tag
   long int __fp;
   /* Callee-saved registers.  */
   long int __regs[9];
+
+#ifndef __loongarch_soft_float
   /* Callee-saved floating point registers.  */
   double __fpregs[8];
+#endif
 
 } __jmp_buf[1];
 

sysdeps/loongarch/dl-trampoline.S

@@ -21,8 +21,11 @@
 
 /* Assembler veneer called from the PLT header code for lazy loading.
    The PLT header passes its own args in t0-t2.  */
-
+#ifdef __loongarch_soft_float
-# define FRAME_SIZE (-((-10 * SZREG - 8 * SZFREG) & ALMASK))
+#define FRAME_SIZE (-((-10 * SZREG) & ALMASK))
+#else
+#define FRAME_SIZE (-((-10 * SZREG - 8 * SZFREG) & ALMASK))
+#endif
 
 ENTRY (_dl_runtime_resolve)
 
@@ -39,6 +42,7 @@ ENTRY (_dl_runtime_resolve)
 	REG_S	a6, sp, 7*SZREG
 	REG_S	a7, sp, 8*SZREG
 
+#ifndef __loongarch_soft_float
 	FREG_S	fa0, sp, 10*SZREG + 0*SZFREG
 	FREG_S	fa1, sp, 10*SZREG + 1*SZFREG
 	FREG_S	fa2, sp, 10*SZREG + 2*SZFREG
@@ -47,6 +51,7 @@ ENTRY (_dl_runtime_resolve)
 	FREG_S	fa5, sp, 10*SZREG + 5*SZFREG
 	FREG_S	fa6, sp, 10*SZREG + 6*SZFREG
 	FREG_S	fa7, sp, 10*SZREG + 7*SZFREG
+#endif
 
 	/* Update .got.plt and obtain runtime address of callee */
 	SLLI	a1, t1, 1
@@ -67,6 +72,7 @@ ENTRY (_dl_runtime_resolve)
 	REG_L	a6, sp, 7*SZREG
 	REG_L	a7, sp, 8*SZREG
 
+#ifndef __loongarch_soft_float
 	FREG_L	fa0, sp, 10*SZREG + 0*SZFREG
 	FREG_L	fa1, sp, 10*SZREG + 1*SZFREG
 	FREG_L	fa2, sp, 10*SZREG + 2*SZFREG
@@ -75,6 +81,7 @@ ENTRY (_dl_runtime_resolve)
 	FREG_L	fa5, sp, 10*SZREG + 5*SZFREG
 	FREG_L	fa6, sp, 10*SZREG + 6*SZFREG
 	FREG_L	fa7, sp, 10*SZREG + 7*SZFREG
+#endif
 
 	ADDI	sp, sp, FRAME_SIZE
 

sysdeps/loongarch/fpu_control.h

@@ -51,6 +51,17 @@
 
 #include <features.h>
 
+#ifdef __loongarch_soft_float
+
+#define _FPU_RESERVED 0xffffffff
+#define _FPU_DEFAULT 0x00000000
+typedef unsigned int fpu_control_t;
+#define _FPU_GETCW(cw) (cw) = 0
+#define _FPU_SETCW(cw) (void) (cw)
+extern fpu_control_t __fpu_control;
+
+#else /* __loongarch_soft_float */
+
 /* Masks for interrupts.  */
 #define _FPU_MASK_V 0x10 /* Invalid operation */
 #define _FPU_MASK_Z 0x08 /* Division by zero  */
@@ -86,4 +97,6 @@ extern void __loongarch_fpu_setcw (fpu_control_t) __THROW;
 /* Default control word set at startup.  */
 extern fpu_control_t __fpu_control;
 
+#endif /* __loongarch_soft_float */
+
 #endif /* fpu_control.h */

sysdeps/loongarch/nofpu/Implies

@@ -0,0 +1 @@
+ieee754/soft-fp

sysdeps/loongarch/nofpu/math-tests-exceptions.h

@@ -0,0 +1,28 @@
+/* Configuration for math tests: support for exceptions.
+   Copyright (C) 2022 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 LOONGARCH_NOFPU_MATH_TESTS_EXCEPTIONS_H
+#define LOONGARCH_NOFPU_MATH_TESTS_EXCEPTIONS_H 1
+
+/* We support setting floating-point exception flags on hard-float
+   targets.  These are not supported on soft-float targets.  */
+#define EXCEPTION_TESTS_float 0
+#define EXCEPTION_TESTS_double        0
+#define EXCEPTION_TESTS_long_double   0
+
+#endif /* math-tests-exceptions.h.  */

sysdeps/loongarch/nofpu/math-tests-rounding.h

@@ -0,0 +1,27 @@
+/* Configuration for math tests: rounding mode support.
+   Copyright (C) 2022 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 LOONGARCH_NOFPU_MATH_TESTS_ROUNDING_H
+#define LOONGARCH_NOFPU_MATH_TESTS_ROUNDING_H 1
+
+/* On soft-float targets we only support the "to nearest" rounding mode.  */
+#define ROUNDING_TESTS_float(MODE)		((MODE) == FE_TONEAREST)
+#define ROUNDING_TESTS_double(MODE)		((MODE) == FE_TONEAREST)
+#define ROUNDING_TESTS_long_double(MODE)	((MODE) == FE_TONEAREST)
+
+#endif /* math-tests-rounding.h.  */

sysdeps/loongarch/preconfigure

@@ -12,7 +12,6 @@ loongarch*)
     case "$float_abi" in
     soft)
 	abi_flen=0
-	as_fn_error 1 "loongarch does not yet support soft floating-point  ABI!!" "$LINENO" 5
 	;;
     single)
 	as_fn_error 1 "glibc does not yet support the single floating-point ABI!!" "$LINENO" 5

sysdeps/loongarch/preconfigure.ac

@@ -12,7 +12,6 @@ loongarch*)
     case "$float_abi" in
     soft)
 	abi_flen=0
-	AC_MSG_ERROR([loongarch does not yet support soft floating-point  ABI!!], 1)
 	;;
     single)
 	AC_MSG_ERROR([glibc does not yet support the single floating-point ABI!!], 1)

sysdeps/loongarch/setjmp.S

@@ -50,6 +50,7 @@ ENTRY (__sigsetjmp)
 	REG_S s7, a0, 11*SZREG
 	REG_S s8, a0, 12*SZREG
 
+#ifndef __loongarch_soft_float
 	FREG_S $f24, a0, 13*SZREG + 0*SZFREG
 	FREG_S $f25, a0, 13*SZREG + 1*SZFREG
 	FREG_S $f26, a0, 13*SZREG + 2*SZFREG
@@ -58,6 +59,7 @@ ENTRY (__sigsetjmp)
 	FREG_S $f29, a0, 13*SZREG + 5*SZFREG
 	FREG_S $f30, a0, 13*SZREG + 6*SZFREG
 	FREG_S $f31, a0, 13*SZREG + 7*SZFREG
+#endif
 
 #if !IS_IN (libc) && IS_IN(rtld)
 	li.w		v0, 0

sysdeps/unix/sysv/linux/loongarch/Makefile

@@ -1,3 +1,12 @@
 ifeq ($(subdir),stdlib)
 gen-as-const-headers += ucontext_i.sym
 endif
+
+abi-variants := lp64s lp64d
+
+ifeq (,$(filter $(default-abi),$(abi-variants)))
+$(error Unknown ABI $(default-abi), must be one of $(abi-variants))
+endif
+
+abi-lp64s-condition	:= __WORDSIZE == 64 && defined __loongarch_soft_float
+abi-lp64d-condition	:= __WORDSIZE == 64 && defined __loongarch_double_float

sysdeps/unix/sysv/linux/loongarch/configure

@@ -151,11 +151,56 @@ if test $libc_cv_loongarch_int_abi = no; then
   as_fn_error $? "Unable to determine integer ABI" "$LINENO" 5
 fi
 
-config_vars="$config_vars
+libc_cv_loongarch_float_abi=no
-default-abi = $libc_cv_loongarch_int_abi"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#ifdef __loongarch_double_float
+		   yes
+		   #endif
 
-case $libc_cv_loongarch_int_abi in
+_ACEOF
-lp64)
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  $EGREP "yes" >/dev/null 2>&1; then :
+  libc_cv_loongarch_float_abi=d
+fi
+rm -f conftest*
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#ifdef __loongarch_soft_float
+		   yes
+		   #endif
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  $EGREP "yes" >/dev/null 2>&1; then :
+  libc_cv_loongarch_float_abi=s
+fi
+rm -f conftest*
+
+if test "$libc_cv_loongarch_float_abi" = no; then
+  as_fn_error $? "Unable to determine floating-point ABI" "$LINENO" 5
+fi
+
+config_vars="$config_vars
+default-abi = $libc_cv_loongarch_int_abi$libc_cv_loongarch_float_abi"
+
+case $libc_cv_loongarch_int_abi$libc_cv_loongarch_float_abi in
+lp64s)
+  test -n "$libc_cv_slibdir" ||
+case "$prefix" in
+/usr | /usr/)
+  libc_cv_slibdir='/lib64/sf'
+  libc_cv_rtlddir='/lib64'
+  if test "$libdir" = '${exec_prefix}/lib'; then
+    libdir='${exec_prefix}/lib64/sf';
+    # Locale data can be shared between 32-bit and 64-bit libraries.
+    libc_cv_complocaledir='${exec_prefix}/lib/locale'
+  fi
+  ;;
+esac
+  ;;
+lp64d)
   test -n "$libc_cv_slibdir" ||
 case "$prefix" in
 /usr | /usr/)

sysdeps/unix/sysv/linux/loongarch/configure.ac

@@ -11,10 +11,26 @@ if test $libc_cv_loongarch_int_abi = no; then
   AC_MSG_ERROR([Unable to determine integer ABI])
 fi
 
-LIBC_CONFIG_VAR([default-abi], [$libc_cv_loongarch_int_abi])
+libc_cv_loongarch_float_abi=no
+AC_EGREP_CPP(yes, [#ifdef __loongarch_double_float
+		   yes
+		   #endif
+  ],libc_cv_loongarch_float_abi=d)
+AC_EGREP_CPP(yes, [#ifdef __loongarch_soft_float
+		   yes
+		   #endif
+  ],libc_cv_loongarch_float_abi=s)
+if test "$libc_cv_loongarch_float_abi" = no; then
+  AC_MSG_ERROR([Unable to determine floating-point ABI])
+fi
 
-case $libc_cv_loongarch_int_abi in
+LIBC_CONFIG_VAR([default-abi], [$libc_cv_loongarch_int_abi$libc_cv_loongarch_float_abi])
-lp64)
+
+case $libc_cv_loongarch_int_abi$libc_cv_loongarch_float_abi in
+lp64s)
+  LIBC_SLIBDIR_RTLDDIR([lib64/sf], [lib64])
+  ;;
+lp64d)
   LIBC_SLIBDIR_RTLDDIR([lib64], [lib64])
   ;;
 esac

sysdeps/unix/sysv/linux/loongarch/ldd-rewrite.sed

@@ -1 +1 @@
-s_^\(RTLDLIST=\)\(.*lib\)\(\|64\|32\)\(/[^/]*\)\(-loongarch\)\(64\|32\)\(\.so\.[0-9.]*\)[[:blank:]]*$_\1"\2\4\7 \264\4-loongarch64\7 \232\4-loongarch32\7"_
+s_^\(RTLDLIST=\)\(.*lib\)\(\|64\|32\)\(/ld-linux-loongarch-\)\(lp\|ilp\)\(64\|32\)\(d\|s\)\(\.so\.[0-9.]*\)[[:blank:]]*$_\1"\264\4lp64d\8 \264\4lp64s\8"_

sysdeps/unix/sysv/linux/loongarch/shlib-versions

@@ -2,6 +2,8 @@ DEFAULT		GLIBC_2.36
 
 %if LOONGARCH_ABI_GRLEN == 64 && LOONGARCH_ABI_FRLEN == 64
 ld=ld-linux-loongarch-lp64d.so.1
+%elif LOONGARCH_ABI_GRLEN == 64 && LOONGARCH_ABI_FRLEN == 0
+ld=ld-linux-loongarch-lp64s.so.1
 %else
 %error cannot determine ABI
 %endif