diff --git a/config.sub b/config.sub
index 61cb4bc..d6e23cb 100755
--- a/config.sub
+++ b/config.sub
@@ -334,6 +334,9 @@ case $basic_machine in
 	ms1)
 		basic_machine=mt-unknown
 		;;
+	riscv)
+		basic_machine=riscv-ucb
+		;;
 
 	strongarm | thumb | xscale)
 		basic_machine=arm-unknown
diff --git a/gcc/config.gcc b/gcc/config.gcc
index 9d3fa57..b7ebc07 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -447,6 +447,10 @@ powerpc*-*-*)
 	esac
 	extra_options="${extra_options} g.opt fused-madd.opt rs6000/rs6000-tables.opt"
 	;;
+riscv*)
+	cpu_type=riscv
+	need_64bit_hwint=yes
+	;;
 rs6000*-*-*)
 	need_64bit_hwint=yes
 	extra_options="${extra_options} g.opt fused-madd.opt rs6000/rs6000-tables.opt"
@@ -1949,6 +1953,27 @@ microblaze*-*-elf)
 	cxx_target_objs="${cxx_target_objs} microblaze-c.o"
 	tmake_file="${tmake_file} microblaze/t-microblaze"
         ;;
+riscv32*-*-linux*)				# Linux RISC-V
+	tm_file="elfos.h gnu-user.h linux.h glibc-stdint.h riscv/default-32.h ${tm_file} riscv/linux.h riscv/linux64.h"
+	tmake_file="${tmake_file} riscv/t-linux64"
+	gnu_ld=yes
+	gas=yes
+	gcc_cv_initfini_array=yes
+	;;
+riscv*-*-linux*)				# Linux RISC-V
+	tm_file="elfos.h gnu-user.h linux.h glibc-stdint.h ${tm_file} riscv/linux.h riscv/linux64.h"
+	tmake_file="${tmake_file} riscv/t-linux64"
+	gnu_ld=yes
+	gas=yes
+	gcc_cv_initfini_array=yes
+	;;
+riscv*-*-elf*)				# Linux RISC-V
+	tm_file="elfos.h newlib-stdint.h ${tm_file} riscv/elf.h"
+	tmake_file="${tmake_file} riscv/t-elf"
+	gnu_ld=yes
+	gas=yes
+	gcc_cv_initfini_array=yes
+	;;
 mips*-*-netbsd*)			# NetBSD/mips, either endian.
 	target_cpu_default="MASK_ABICALLS"
 	tm_file="elfos.h ${tm_file} mips/elf.h netbsd.h netbsd-elf.h mips/netbsd.h"
@@ -3756,6 +3781,31 @@ case "${target}" in
 		done
 		;;
 
+	riscv*-*-*)
+		supported_defaults="abi arch arch_32 arch_64 float tune tune_32 tune_64"
+
+		case ${with_float} in
+		"" | soft | hard)
+			# OK
+			;;
+		*)
+			echo "Unknown floating point type used in --with-float=$with_float" 1>&2
+			exit 1
+			;;
+		esac
+
+		case ${with_abi} in
+		"" | 32 | 64)
+			# OK
+			;;
+		*)
+			echo "Unknown ABI used in --with-abi=$with_abi" 1>&2
+			exit 1
+			;;
+		esac
+
+    ;;
+
 	mips*-*-*)
 		supported_defaults="abi arch arch_32 arch_64 float fpu nan tune tune_32 tune_64 divide llsc mips-plt synci"
 
diff --git a/gcc/configure b/gcc/configure
index 291e463..dae2d8f 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -23515,6 +23515,25 @@ x3:	.space 4
 	tls_first_minor=14
 	tls_as_opt="-a32 --fatal-warnings"
 	;;
+  riscv*-*-*)
+    conftest_s='
+	.section .tdata,"awT",@progbits
+x:
+	.word 2
+	.text
+	la.tls.gd a0,x
+	la.tls.ie a1,x
+	lui a0,%tls_ie_pcrel_hi(x)
+	lw a0,%pcrel_lo(x)(a0)
+	add a0,a0,tp
+	lw a0,0(a0)
+	lui a0,%tprel_hi(x)
+	add a0,a0,tp,%tprel_add(x)
+	lw a0,%tprel_lo(x)(a0)'
+	tls_first_major=2
+	tls_first_minor=21
+	tls_as_opt='-m32 --fatal-warnings'
+	;;
   s390-*-*)
     conftest_s='
 	.section ".tdata","awT",@progbits
diff --git a/gcc/configure.ac b/gcc/configure.ac
index b9a3799..c39db9a 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -3178,6 +3178,25 @@ x3:	.space 4
 	tls_first_minor=14
 	tls_as_opt="-a32 --fatal-warnings"
 	;;
+  riscv*-*-*)
+    conftest_s='
+	.section .tdata,"awT",@progbits
+x:
+	.word 2
+	.text
+	la.tls.gd a0,x
+	la.tls.ie a1,x
+	lui a0,%tls_ie_pcrel_hi(x)
+	lw a0,%pcrel_lo(x)(a0)
+	add a0,a0,tp
+	lw a0,0(a0)
+	lui a0,%tprel_hi(x)
+	add a0,a0,tp,%tprel_add(x)
+	lw a0,%tprel_lo(x)(a0)'
+	tls_first_major=2
+	tls_first_minor=21
+	tls_as_opt='-m32 --fatal-warnings'
+	;;
   s390-*-*)
     conftest_s='
 	.section ".tdata","awT",@progbits
diff --git a/gcc/testsuite/gcc.c-torture/execute/20101011-1.c b/gcc/testsuite/gcc.c-torture/execute/20101011-1.c
index 1952dbd..7015082 100644
--- a/gcc/testsuite/gcc.c-torture/execute/20101011-1.c
+++ b/gcc/testsuite/gcc.c-torture/execute/20101011-1.c
@@ -6,6 +6,9 @@
 #elif defined (__powerpc__) || defined (__PPC__) || defined (__ppc__) || defined (__POWERPC__) || defined (__ppc)
   /* On PPC division by zero does not trap.  */
 # define DO_TEST 0
+#elif defined (__riscv__)
+  /* On RISC-V division by zero does not trap.  */
+# define DO_TEST 0
 #elif defined (__SPU__)
   /* On SPU division by zero does not trap.  */
 # define DO_TEST 0
diff --git a/gcc/testsuite/gcc.dg/20020312-2.c b/gcc/testsuite/gcc.dg/20020312-2.c
index 63fbfcc..b346eba 100644
--- a/gcc/testsuite/gcc.dg/20020312-2.c
+++ b/gcc/testsuite/gcc.dg/20020312-2.c
@@ -66,6 +66,8 @@ extern void abort (void);
 # else
 #  define PIC_REG  "30"
 # endif
+#elif defined(__riscv__)
+/* No pic register.  */
 #elif defined(__RX__)
 /* No pic register.  */
 #elif defined(__s390__)
diff --git a/gcc/testsuite/gcc.dg/20040813-1.c b/gcc/testsuite/gcc.dg/20040813-1.c
index 8be831d..bc74ec8 100644
--- a/gcc/testsuite/gcc.dg/20040813-1.c
+++ b/gcc/testsuite/gcc.dg/20040813-1.c
@@ -2,7 +2,7 @@
 /* Contributed by Devang Patel  <dpatel@apple.com>  */
 
 /* { dg-do compile } */
-/* { dg-skip-if "No stabs" { aarch64*-*-* mmix-*-* *-*-aix* alpha*-*-* hppa*64*-*-* ia64-*-* tile*-*-* nios2-*-* *-*-vxworks* } { "*" } { "" } } */
+/* { dg-skip-if "No stabs" { aarch64*-*-* mmix-*-* *-*-aix* alpha*-*-* hppa*64*-*-* ia64-*-* riscv*-*-* tile*-*-* nios2-*-* *-*-vxworks* } { "*" } { "" } } */
 /* { dg-options "-gstabs" } */
 
 int
diff --git a/gcc/testsuite/gcc.dg/stack-usage-1.c b/gcc/testsuite/gcc.dg/stack-usage-1.c
index 05e3df7..4afc483 100644
--- a/gcc/testsuite/gcc.dg/stack-usage-1.c
+++ b/gcc/testsuite/gcc.dg/stack-usage-1.c
@@ -61,6 +61,8 @@
 #  else
 #    define SIZE 240
 #  endif
+#elif defined (__riscv__)
+#  define SIZE 240
 #elif defined (__AVR__)
 #  define SIZE 254
 #elif defined (__s390x__)
diff --git a/libatomic/cas_n.c b/libatomic/cas_n.c
index 801262d..a885afa 100644
--- a/libatomic/cas_n.c
+++ b/libatomic/cas_n.c
@@ -70,7 +70,7 @@ SIZE(libat_compare_exchange) (UTYPE *mptr, UTYPE *eptr, UTYPE newval,
       mask = -1;
     }
 
-  weval = *eptr << shift;
+  weval = (UWORD)*eptr << shift;
   wnewval = (UWORD)newval << shift;
   woldval = __atomic_load_n (wptr, __ATOMIC_RELAXED);
   do
diff --git a/libatomic/configure.tgt b/libatomic/configure.tgt
index a3757ef..516348d 100644
--- a/libatomic/configure.tgt
+++ b/libatomic/configure.tgt
@@ -29,6 +29,7 @@
 case "${target_cpu}" in
   alpha*)		ARCH=alpha ;;
   rs6000 | powerpc*)	ARCH=powerpc ;;
+  riscv*)		ARCH=riscv ;;
   sh*)			ARCH=sh ;;
 
   arm*)
diff --git a/libatomic/fop_n.c b/libatomic/fop_n.c
index 4a18da9..854d648 100644
--- a/libatomic/fop_n.c
+++ b/libatomic/fop_n.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2012-2014 Free Software Foundation, Inc.
+/* Copyright (C) 2012-2015 Free Software Foundation, Inc.
    Contributed by Richard Henderson <rth@redhat.com>.
 
    This file is part of the GNU Atomic Library (libatomic).
@@ -112,9 +112,9 @@ SIZE(C2(libat_fetch_,NAME)) (UTYPE *mptr, UTYPE opval, int smodel)
 
   pre_barrier (smodel);
 
-  wptr = (UWORD *)mptr;
-  shift = 0;
-  mask = -1;
+  wptr = (UWORD *)((uintptr_t)mptr & -WORDSIZE);
+  shift = (((uintptr_t)mptr % WORDSIZE) * CHAR_BIT) ^ SIZE(INVERT_MASK);
+  mask = SIZE(MASK) << shift;
 
   wopval = (UWORD)opval << shift;
   woldval = __atomic_load_n (wptr, __ATOMIC_RELAXED);
@@ -136,9 +136,9 @@ SIZE(C3(libat_,NAME,_fetch)) (UTYPE *mptr, UTYPE opval, int smodel)
 
   pre_barrier (smodel);
 
-  wptr = (UWORD *)mptr;
-  shift = 0;
-  mask = -1;
+  wptr = (UWORD *)((uintptr_t)mptr & -WORDSIZE);
+  shift = (((uintptr_t)mptr % WORDSIZE) * CHAR_BIT) ^ SIZE(INVERT_MASK);
+  mask = SIZE(MASK) << shift;
 
   wopval = (UWORD)opval << shift;
   woldval = __atomic_load_n (wptr, __ATOMIC_RELAXED);
diff --git a/libcpp/configure b/libcpp/configure
index b421e48..1270509 100755
--- a/libcpp/configure
+++ b/libcpp/configure
@@ -7163,6 +7163,7 @@ case $target in
 	mips*-*-* | \
 	mmix-*-* | \
 	powerpc*-*-* | \
+	riscv*-*-* | \
 	rs6000*-*-* | \
 	s390*-*-* | \
 	sparc*-*-* | \
diff --git a/libcpp/configure.ac b/libcpp/configure.ac
index 8515abf..89df04d 100644
--- a/libcpp/configure.ac
+++ b/libcpp/configure.ac
@@ -192,6 +192,7 @@ case $target in
 	mips*-*-* | \
 	mmix-*-* | \
 	powerpc*-*-* | \
+	riscv*-*-* | \
 	rs6000*-*-* | \
 	s390*-*-* | \
 	sparc*-*-* | \
diff --git a/libgcc/config.host b/libgcc/config.host
index f4a7428..e1f49c8 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -167,6 +167,9 @@ powerpc*-*-*)
 	;;
 rs6000*-*-*)
 	;;
+riscv*)
+	cpu_type=riscv
+	;;
 score*-*-*)
 	cpu_type=score
 	;;
@@ -1002,6 +1005,18 @@ powerpcle-*-eabi*)
 	tmake_file="${tmake_file} rs6000/t-ppccomm rs6000/t-crtstuff t-crtstuff-pic t-fdpbit"
 	extra_parts="$extra_parts crtbegin.o crtend.o crtbeginS.o crtendS.o crtbeginT.o ecrti.o ecrtn.o ncrti.o ncrtn.o"
 	;;
+riscv32*-*-linux*)
+	tmake_file="${tmake_file} riscv/t-fpbit riscv/t-dpbit riscv/t-tpbit riscv/t-elf riscv/t-elf32"
+	extra_parts="$extra_parts crtbegin.o crtend.o crti.o crtn.o crtendS.o crtbeginT.o"
+	;;
+riscv*-*-linux*)
+	tmake_file="${tmake_file} riscv/t-fpbit riscv/t-dpbit riscv/t-tpbit riscv/t-elf"
+	extra_parts="$extra_parts crtbegin.o crtend.o crti.o crtn.o crtendS.o crtbeginT.o"
+	;;
+riscv*-*-*)
+	tmake_file="${tmake_file} riscv/t-fpbit riscv/t-dpbit riscv/t-elf"
+	extra_parts="$extra_parts crtbegin.o crtend.o crti.o crtn.o"
+	;;
 rs6000-ibm-aix4.[3456789]* | powerpc-ibm-aix4.[3456789]*)
 	md_unwind_header=rs6000/aix-unwind.h
 	tmake_file="t-fdpbit rs6000/t-ppc64-fp rs6000/t-slibgcc-aix rs6000/t-ibm-ldouble"
diff --git a/libsanitizer/asan/asan_linux.cc b/libsanitizer/asan/asan_linux.cc
index 0692eb1..2a7b656 100644
--- a/libsanitizer/asan/asan_linux.cc
+++ b/libsanitizer/asan/asan_linux.cc
@@ -98,6 +98,11 @@ void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
   *pc = ucontext->uc_mcontext.gregs[31];
   *bp = ucontext->uc_mcontext.gregs[30];
   *sp = ucontext->uc_mcontext.gregs[29];
+# elif defined(__riscv__)
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.gregs[REG_PC];
+  *bp = ucontext->uc_mcontext.gregs[REG_S0];
+  *sp = ucontext->uc_mcontext.gregs[REG_SP];
 #else
 # error "Unsupported arch"
 #endif
diff --git a/libsanitizer/sanitizer_common/sanitizer_linux.cc b/libsanitizer/sanitizer_common/sanitizer_linux.cc
index 69c9c10..2419ae6 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_linux.cc
@@ -93,11 +93,11 @@ uptr internal_close(fd_t fd) {
 }
 
 uptr internal_open(const char *filename, int flags) {
-  return internal_syscall(__NR_open, (uptr)filename, flags);
+  return internal_syscall(__NR_openat, AT_FDCWD, (uptr)filename, flags);
 }
 
 uptr internal_open(const char *filename, int flags, u32 mode) {
-  return internal_syscall(__NR_open, (uptr)filename, flags, mode);
+  return internal_syscall(__NR_openat, AT_FDCWD, (uptr)filename, flags, mode);
 }
 
 uptr OpenFile(const char *filename, bool write) {
@@ -139,7 +139,7 @@ static void stat64_to_stat(struct stat64 *in, struct stat *out) {
 
 uptr internal_stat(const char *path, void *buf) {
 #if SANITIZER_LINUX_USES_64BIT_SYSCALLS
-  return internal_syscall(__NR_stat, (uptr)path, (uptr)buf);
+  return internal_syscall(__NR_newfstatat, AT_FDCWD, (uptr)path, (uptr)buf, 0);
 #else
   struct stat64 buf64;
   int res = internal_syscall(__NR_stat64, path, &buf64);
@@ -150,7 +150,7 @@ uptr internal_stat(const char *path, void *buf) {
 
 uptr internal_lstat(const char *path, void *buf) {
 #if SANITIZER_LINUX_USES_64BIT_SYSCALLS
-  return internal_syscall(__NR_lstat, (uptr)path, (uptr)buf);
+  return internal_syscall(__NR_newfstatat, AT_FDCWD, (uptr)path, (uptr)buf, AT_SYMLINK_NOFOLLOW);
 #else
   struct stat64 buf64;
   int res = internal_syscall(__NR_lstat64, path, &buf64);
@@ -178,15 +178,15 @@ uptr internal_filesize(fd_t fd) {
 }
 
 uptr internal_dup2(int oldfd, int newfd) {
-  return internal_syscall(__NR_dup2, oldfd, newfd);
+  return internal_syscall(__NR_dup3, oldfd, newfd, 0);
 }
 
 uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
-  return internal_syscall(__NR_readlink, (uptr)path, (uptr)buf, bufsize);
+  return internal_syscall(__NR_readlinkat, AT_FDCWD, (uptr)path, (uptr)buf, bufsize);
 }
 
 uptr internal_unlink(const char *path) {
-  return internal_syscall(__NR_unlink, (uptr)path);
+  return internal_syscall(__NR_unlinkat, AT_FDCWD, (uptr)path);
 }
 
 uptr internal_sched_yield() {
@@ -588,7 +588,7 @@ uptr internal_getppid() {
 }
 
 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
-  return internal_syscall(__NR_getdents, fd, (uptr)dirp, count);
+  return internal_syscall(__NR_getdents64, fd, (uptr)dirp, count);
 }
 
 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_linux.cc b/libsanitizer/sanitizer_common/sanitizer_platform_limits_linux.cc
index ac56f33..8e1ec46 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_linux.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_linux.cc
@@ -63,7 +63,7 @@ namespace __sanitizer {
   unsigned struct_statfs64_sz = sizeof(struct statfs64);
 }  // namespace __sanitizer
 
-#if !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__sparc__)
+#if !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__sparc__) && !defined(__riscv__)
 COMPILER_CHECK(struct___old_kernel_stat_sz == sizeof(struct __old_kernel_stat));
 #endif
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
index aec9504..c063107 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
@@ -67,6 +67,10 @@ namespace __sanitizer {
   const unsigned struct___old_kernel_stat_sz = 0;
   const unsigned struct_kernel_stat_sz = 144;
   const unsigned struct_kernel_stat64_sz = 104;
+#elif defined(__riscv__)
+  const unsigned struct___old_kernel_stat_sz = 0;
+  const unsigned struct_kernel_stat_sz = 128;
+  const unsigned struct_kernel_stat64_sz = 128;
 #elif defined(__sparc__) && defined(__arch64__)
   const unsigned struct___old_kernel_stat_sz = 0;
   const unsigned struct_kernel_stat_sz = 104;
@@ -367,7 +371,7 @@ namespace __sanitizer {
   typedef long __sanitizer___kernel_off_t;
 #endif
 
-#if defined(__powerpc__)
+#if defined(__powerpc__) || defined(__riscv__)
   typedef unsigned int __sanitizer___kernel_old_uid_t;
   typedef unsigned int __sanitizer___kernel_old_gid_t;
 #else
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 16e09f0..acd62fc 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -16550,7 +16550,7 @@ ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
   # Long term, -std=c++0x could be even better, could manage to explicitly
   # request C99 facilities to the underlying C headers.
   ac_save_CXXFLAGS="$CXXFLAGS"
-  CXXFLAGS="$CXXFLAGS -std=c++98"
+  CXXFLAGS="$CXXFLAGS -std=gnu++98"
   ac_save_LIBS="$LIBS"
   ac_save_gcc_no_link="$gcc_no_link"
 
@@ -17170,9 +17170,11 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 $as_echo "$glibcxx_cv_c99_wchar" >&6; }
   fi
 
+  # For newlib, don't check complex since missing c99 functions, but
+  #   rest of c99 stuff is there so don't loose it
   # Option parsed, now set things appropriately.
   if test x"$glibcxx_cv_c99_math" = x"no" ||
-     test x"$glibcxx_cv_c99_complex" = x"no" ||
+     # test x"$glibcxx_cv_c99_complex" = x"no" ||
      test x"$glibcxx_cv_c99_stdio" = x"no" ||
      test x"$glibcxx_cv_c99_stdlib" = x"no" ||
      test x"$glibcxx_cv_c99_wchar" = x"no"; then