RISC-V: Support the 32-bit ABI implementation

This patch adds the ABI implementation for 32-bit RISC-V.  It contains
the Linux-specific and RISC-V architecture code.

Reviewed-by: Maciej W. Rozycki <macro@wdc.com>

7 files changed, 146 insertions, 22 deletions

diff --git a/sysdeps/riscv/bits/wordsize.h b/sysdeps/riscv/bits/wordsize.h
index faccc71828..4929dcf873 100644
--- a/sysdeps/riscv/bits/wordsize.h
+++ b/sysdeps/riscv/bits/wordsize.h
@@ -22,8 +22,9 @@
 # error unsupported ABI
 #endif
 
-#if __riscv_xlen == 64
-# define __WORDSIZE_TIME64_COMPAT32 1
-#else
-# error "rv32i-based targets are not supported"
+#define __WORDSIZE_TIME64_COMPAT32  1
+
+#if __WORDSIZE == 32
+# define __WORDSIZE32_SIZE_ULONG    0
+# define __WORDSIZE32_PTRDIFF_LONG  0
 #endif
diff --git a/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h b/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
index c3c72d6c10..8a602e864a 100644
--- a/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
@@ -21,18 +21,22 @@
 
 #include <bits/endian.h>
 
-#if __riscv_xlen == 64
-# define __SIZEOF_PTHREAD_ATTR_T 		56
-# define __SIZEOF_PTHREAD_MUTEX_T 		40
-# define __SIZEOF_PTHREAD_MUTEXATTR_T 		 4
-# define __SIZEOF_PTHREAD_COND_T 		48
-# define __SIZEOF_PTHREAD_CONDATTR_T 		 4
-# define __SIZEOF_PTHREAD_RWLOCK_T 		56
-# define __SIZEOF_PTHREAD_RWLOCKATTR_T 		 8
-# define __SIZEOF_PTHREAD_BARRIER_T 		32
-# define __SIZEOF_PTHREAD_BARRIERATTR_T 	 4
+#define __SIZEOF_PTHREAD_MUTEXATTR_T		4
+#define __SIZEOF_PTHREAD_COND_T			48
+#define __SIZEOF_PTHREAD_CONDATTR_T		4
+#define __SIZEOF_PTHREAD_RWLOCKATTR_T		8
+#define __SIZEOF_PTHREAD_BARRIERATTR_T		4
+
+#if __WORDSIZE == 64
+# define __SIZEOF_PTHREAD_ATTR_T		56
+# define __SIZEOF_PTHREAD_MUTEX_T		40
+# define __SIZEOF_PTHREAD_RWLOCK_T		56
+# define __SIZEOF_PTHREAD_BARRIER_T		32
 #else
-# error "rv32i-based systems are not supported"
+# define __SIZEOF_PTHREAD_ATTR_T		32
+# define __SIZEOF_PTHREAD_MUTEX_T		32
+# define __SIZEOF_PTHREAD_RWLOCK_T		48
+# define __SIZEOF_PTHREAD_BARRIER_T		20
 #endif
 
 #define __LOCK_ALIGNMENT
diff --git a/sysdeps/riscv/nptl/bits/struct_rwlock.h b/sysdeps/riscv/nptl/bits/struct_rwlock.h
index acfaa75e1b..dc467d42c7 100644
--- a/sysdeps/riscv/nptl/bits/struct_rwlock.h
+++ b/sysdeps/riscv/nptl/bits/struct_rwlock.h
@@ -15,7 +15,7 @@
 
    You should have received a copy of the GNU Lesser General Public
    License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
+   <https://www.gnu.org/licenses/>.  */
 
 #ifndef _RWLOCK_INTERNAL_H
 #define _RWLOCK_INTERNAL_H
@@ -32,14 +32,37 @@ struct __pthread_rwlock_arch_t
   unsigned int __writers_futex;
   unsigned int __pad3;
   unsigned int __pad4;
+#if __WORDSIZE == 64
   int __cur_writer;
   int __shared;
   unsigned long int __pad1;
   unsigned long int __pad2;
   unsigned int __flags;
+#else
+# if __BYTE_ORDER == __BIG_ENDIAN
+  unsigned char __pad1;
+  unsigned char __pad2;
+  unsigned char __shared;
+  unsigned char __flags;
+# else
+  unsigned char __flags;
+  unsigned char __shared;
+  unsigned char __pad1;
+  unsigned char __pad2;
+# endif
+  int __cur_writer;
+#endif
 };
 
-#define __PTHREAD_RWLOCK_INITIALIZER(__flags) \
+#if __WORDSIZE == 64
+# define __PTHREAD_RWLOCK_INITIALIZER(__flags) \
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, __flags
+#elif __BYTE_ORDER == __BIG_ENDIAN
+# define __PTHREAD_RWLOCK_INITIALIZER(__flags) \
+  0, 0, 0, 0, 0, 0, 0, 0, 0, __flags, 0
+#else
+# define __PTHREAD_RWLOCK_INITIALIZER(__flags) \
+  0, 0, 0, 0, 0, 0, __flags, 0, 0, 0, 0
+#endif
 
 #endif
diff --git a/sysdeps/riscv/nptl/pthread-offsets.h b/sysdeps/riscv/nptl/pthread-offsets.h
index 31f0587bec..d76c6cfb95 100644
--- a/sysdeps/riscv/nptl/pthread-offsets.h
+++ b/sysdeps/riscv/nptl/pthread-offsets.h
@@ -1,3 +1,16 @@
-#define __PTHREAD_MUTEX_KIND_OFFSET		16
+#if __WORDSIZE == 64
+# define __PTHREAD_MUTEX_KIND_OFFSET		16
+#else
+# define __PTHREAD_MUTEX_KIND_OFFSET		12
+#endif
 
-#define __PTHREAD_RWLOCK_FLAGS_OFFSET		48
+
+#if __WORDSIZE == 64
+# define __PTHREAD_RWLOCK_FLAGS_OFFSET		48
+#else
+# if __BYTE_ORDER == __BIG_ENDIAN
+#  define __PTHREAD_RWLOCK_FLAGS_OFFSET		27
+# else
+#  define __PTHREAD_RWLOCK_FLAGS_OFFSET		24
+# endif
+#endif
diff --git a/sysdeps/riscv/sfp-machine.h b/sysdeps/riscv/sfp-machine.h
index 08a84fd701..bbeb9b37cf 100644
--- a/sysdeps/riscv/sfp-machine.h
+++ b/sysdeps/riscv/sfp-machine.h
@@ -22,7 +22,32 @@
 
 #if __riscv_xlen == 32
 
-# error "rv32i-based targets are not supported"
+# define _FP_W_TYPE_SIZE	32
+# define _FP_W_TYPE		unsigned long
+# define _FP_WS_TYPE		signed long
+# define _FP_I_TYPE		long
+
+# define _FP_MUL_MEAT_S(R, X, Y)				\
+  _FP_MUL_MEAT_1_wide (_FP_WFRACBITS_S, R, X, Y, umul_ppmm)
+# define _FP_MUL_MEAT_D(R, X, Y)				\
+  _FP_MUL_MEAT_2_wide (_FP_WFRACBITS_D, R, X, Y, umul_ppmm)
+# define _FP_MUL_MEAT_Q(R, X, Y)				\
+  _FP_MUL_MEAT_4_wide (_FP_WFRACBITS_Q, R, X, Y, umul_ppmm)
+
+# define _FP_MUL_MEAT_DW_S(R, X, Y)					\
+  _FP_MUL_MEAT_DW_1_wide (_FP_WFRACBITS_S, R, X, Y, umul_ppmm)
+# define _FP_MUL_MEAT_DW_D(R, X, Y)					\
+  _FP_MUL_MEAT_DW_2_wide (_FP_WFRACBITS_D, R, X, Y, umul_ppmm)
+# define _FP_MUL_MEAT_DW_Q(R, X, Y)					\
+  _FP_MUL_MEAT_DW_4_wide (_FP_WFRACBITS_Q, R, X, Y, umul_ppmm)
+
+# define _FP_DIV_MEAT_S(R, X, Y)	_FP_DIV_MEAT_1_udiv_norm (S, R, X, Y)
+# define _FP_DIV_MEAT_D(R, X, Y)	_FP_DIV_MEAT_2_udiv (D, R, X, Y)
+# define _FP_DIV_MEAT_Q(R, X, Y)	_FP_DIV_MEAT_4_udiv (Q, R, X, Y)
+
+# define _FP_NANFRAC_S		_FP_QNANBIT_S
+# define _FP_NANFRAC_D		_FP_QNANBIT_D, 0
+# define _FP_NANFRAC_Q		_FP_QNANBIT_Q, 0, 0, 0
 
 #else
 
diff --git a/sysdeps/riscv/sys/asm.h b/sysdeps/riscv/sys/asm.h
index bd2de17e17..8292ec77b0 100644
--- a/sysdeps/riscv/sys/asm.h
+++ b/sysdeps/riscv/sys/asm.h
@@ -22,11 +22,14 @@
 /* Macros to handle different pointer/register sizes for 32/64-bit code.  */
 #if __riscv_xlen == 64
 # define PTRLOG 3
-# define SZREG	8
+# define SZREG  8
 # define REG_S sd
 # define REG_L ld
 #elif __riscv_xlen == 32
-# error "rv32i-based targets are not supported"
+# define PTRLOG 2
+# define SZREG  4
+# define REG_S sw
+# define REG_L lw
 #else
 # error __riscv_xlen must equal 32 or 64
 #endif
diff --git a/sysdeps/unix/sysv/linux/riscv/jmp_buf-macros.h b/sysdeps/unix/sysv/linux/riscv/jmp_buf-macros.h
new file mode 100644
index 0000000000..234b979a8c
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/jmp_buf-macros.h
@@ -0,0 +1,55 @@
+/* The jump buffer constants for RISC-V.
+   Copyright (C) 2020 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/>.  */
+
+/* Produced by this program:
+
+  #include <stdio.h>
+  #include <unistd.h>
+  #include <setjmp.h>
+  #include <stddef.h>
+
+  int main (int argc, char **argv)
+    {
+      printf ("#define JMP_BUF_SIZE %d\n", sizeof (jmp_buf));
+      printf ("#define JMP_BUF_ALIGN %d\n", __alignof__ (jmp_buf));
+      printf ("#define SIGJMP_BUF_SIZE %d\n", sizeof (sigjmp_buf));
+      printf ("#define SIGJMP_BUF_ALIGN %d\n", __alignof__ (sigjmp_buf));
+      printf ("#define MASK_WAS_SAVED_OFFSET %d\n",
+              offsetof (struct __jmp_buf_tag, __mask_was_saved));
+      printf ("#define SAVED_MASK_OFFSET %d\n",
+              offsetof (struct __jmp_buf_tag, __saved_mask));
+    } */
+
+#if defined __riscv_float_abi_soft
+# define JMP_BUF_SIZE 188
+# define JMP_BUF_ALIGN 4
+# define SIGJMP_BUF_SIZE 188
+# define SIGJMP_BUF_ALIGN 4
+# define MASK_WAS_SAVED_OFFSET 56
+# define SAVED_MASK_OFFSET 60
+#elif defined __riscv_float_abi_double
+# define JMP_BUF_SIZE 288
+# define JMP_BUF_ALIGN 8
+# define SIGJMP_BUF_SIZE 288
+# define SIGJMP_BUF_ALIGN 8
+# define MASK_WAS_SAVED_OFFSET 152
+# define SAVED_MASK_OFFSET 156
+#else
+# error "Unknown RISC-V floating-point ABI"
+#endif