--- a/aclocal.m4
+++ b/aclocal.m4
@@ -14,17 +14,16 @@ builtin(include, build/autoconf/mozprog.
 builtin(include, build/autoconf/mozheader.m4)dnl
 builtin(include, build/autoconf/mozcommonheader.m4)dnl
 builtin(include, build/autoconf/acwinpaths.m4)dnl
 builtin(include, build/autoconf/lto.m4)dnl
 builtin(include, build/autoconf/gcc-pr49911.m4)dnl
 builtin(include, build/autoconf/frameptr.m4)dnl
 builtin(include, build/autoconf/compiler-opts.m4)dnl
 builtin(include, build/autoconf/expandlibs.m4)dnl
-builtin(include, build/autoconf/arch.m4)dnl
 
 MOZ_PROG_CHECKMSYS()
 
 # Read the user's .mozconfig script.  We can't do this in
 # configure.in: autoconf puts the argument parsing code above anything
 # expanded from configure.in, and we need to get the configure options
 # from .mozconfig in place before that argument parsing code.
 MOZ_READ_MOZCONFIG(.)

deleted file mode 100644
--- a/build/autoconf/arch.m4
+++ /dev/null
@@ -1,220 +0,0 @@
-AC_DEFUN([MOZ_ARCH_OPTS],
-[
-
-dnl ========================================================
-dnl = ARM toolchain tweaks
-dnl ========================================================
-
-MOZ_THUMB=toolchain-default
-MOZ_THUMB_INTERWORK=toolchain-default
-MOZ_FPU=toolchain-default
-MOZ_FLOAT_ABI=toolchain-default
-MOZ_SOFT_FLOAT=toolchain-default
-
-MOZ_ARG_WITH_STRING(arch,
-[  --with-arch=[[type|toolchain-default]]
-                           Use specific CPU features (-march=type). Resets
-                           thumb, fpu, float-abi, etc. defaults when set],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-arch is not supported on non-GNU toolchains])
-    fi
-    MOZ_ARCH=$withval)
-
-if test -z "$MOZ_ARCH"; then
-    dnl Defaults
-    case "${CPU_ARCH}-${OS_TARGET}" in
-    arm-Android)
-        MOZ_THUMB=yes
-        MOZ_ARCH=armv7-a
-        MOZ_FPU=vfp
-        MOZ_FLOAT_ABI=softfp
-        ;;
-    arm-Darwin)
-        MOZ_THUMB=yes
-        ;;
-    arm-*)
-        if test -n "$MOZ_PLATFORM_MAEMO"; then
-            MOZ_THUMB=no
-            MOZ_ARCH=armv7-a
-            MOZ_FLOAT_ABI=softfp
-        fi
-        if test "$MOZ_PLATFORM_MAEMO" = 6; then
-            MOZ_THUMB=yes
-        fi
-        ;;
-    esac
-fi
-
-MOZ_ARG_WITH_STRING(thumb,
-[  --with-thumb[[=yes|no|toolchain-default]]]
-[                          Use Thumb instruction set (-mthumb)],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-thumb is not supported on non-GNU toolchains])
-    fi
-    MOZ_THUMB=$withval)
-
-MOZ_ARG_WITH_STRING(thumb-interwork,
-[  --with-thumb-interwork[[=yes|no|toolchain-default]]
-                           Use Thumb/ARM instuctions interwork (-mthumb-interwork)],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-thumb-interwork is not supported on non-GNU toolchains])
-    fi
-    MOZ_THUMB_INTERWORK=$withval)
-
-MOZ_ARG_WITH_STRING(fpu,
-[  --with-fpu=[[type|toolchain-default]]
-                           Use specific FPU type (-mfpu=type)],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-fpu is not supported on non-GNU toolchains])
-    fi
-    MOZ_FPU=$withval)
-
-MOZ_ARG_WITH_STRING(float-abi,
-[  --with-float-abi=[[type|toolchain-default]]
-                           Use specific arm float ABI (-mfloat-abi=type)],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-float-abi is not supported on non-GNU toolchains])
-    fi
-    MOZ_FLOAT_ABI=$withval)
-
-MOZ_ARG_WITH_STRING(soft-float,
-[  --with-soft-float[[=yes|no|toolchain-default]]
-                           Use soft float library (-msoft-float)],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-soft-float is not supported on non-GNU toolchains])
-    fi
-    MOZ_SOFT_FLOAT=$withval)
-
-case "$MOZ_ARCH" in
-toolchain-default|"")
-    arch_flag=""
-    MOZ_ARCH=toolchain-default
-    ;;
-*)
-    arch_flag="-march=$MOZ_ARCH"
-    ;;
-esac
-
-case "$MOZ_THUMB" in
-yes)
-    MOZ_THUMB2=1
-    thumb_flag="-mthumb"
-    ;;
-no)
-    MOZ_THUMB2=
-    thumb_flag="-marm"
-    ;;
-*)
-    _SAVE_CFLAGS="$CFLAGS"
-    CFLAGS="$arch_flag"
-    AC_TRY_COMPILE([],[return sizeof(__thumb2__);],
-        MOZ_THUMB2=1,
-        MOZ_THUMB2=)
-    CFLAGS="$_SAVE_CFLAGS"
-    thumb_flag=""
-    ;;
-esac
-
-if test "$MOZ_THUMB2" = 1; then
-    AC_DEFINE(MOZ_THUMB2)
-fi
-
-case "$MOZ_THUMB_INTERWORK" in
-yes)
-    thumb_interwork_flag="-mthumb-interwork"
-    ;;
-no)
-    thumb_interwork_flag="-mno-thumb-interwork"
-    ;;
-*) # toolchain-default
-    thumb_interwork_flag=""
-    ;;
-esac
-
-case "$MOZ_FPU" in
-toolchain-default|"")
-    fpu_flag=""
-    ;;
-*)
-    fpu_flag="-mfpu=$MOZ_FPU"
-    ;;
-esac
-
-case "$MOZ_FLOAT_ABI" in
-toolchain-default|"")
-    float_abi_flag=""
-    ;;
-*)
-    float_abi_flag="-mfloat-abi=$MOZ_FLOAT_ABI"
-    ;;
-esac
-
-case "$MOZ_SOFT_FLOAT" in
-yes)
-    soft_float_flag="-msoft-float"
-    ;;
-no)
-    soft_float_flag="-mno-soft-float"
-    ;;
-*) # toolchain-default
-    soft_float_flag=""
-    ;;
-esac
-
-dnl Use echo to avoid accumulating space characters
-all_flags=`echo $arch_flag $thumb_flag $thumb_interwork_flag $fpu_flag $float_abi_flag $soft_float_flag`
-if test -n "$all_flags"; then
-    _SAVE_CFLAGS="$CFLAGS"
-    CFLAGS="$all_flags"
-    AC_MSG_CHECKING(whether the chosen combination of compiler flags ($all_flags) works)
-    AC_TRY_COMPILE([],[return 0;],
-        AC_MSG_RESULT([yes]),
-        AC_MSG_ERROR([no]))
-
-    CFLAGS="$_SAVE_CFLAGS $all_flags"
-    CXXFLAGS="$CXXFLAGS $all_flags"
-    ASFLAGS="$ASFLAGS $all_flags"
-    if test -n "$thumb_flag"; then
-        LDFLAGS="$LDFLAGS $thumb_flag"
-    fi
-fi
-
-AC_SUBST(MOZ_THUMB2)
-
-if test "$CPU_ARCH" = "arm"; then
-  AC_MSG_CHECKING(for ARM SIMD support in compiler)
-  # We try to link so that this also fails when
-  # building with LTO.
-  AC_TRY_LINK([],
-                 [asm("uqadd8 r1, r1, r2");],
-                 result="yes", result="no")
-  AC_MSG_RESULT("$result")
-  if test "$result" = "yes"; then
-      AC_DEFINE(HAVE_ARM_SIMD)
-      HAVE_ARM_SIMD=1
-  fi
-
-  AC_MSG_CHECKING(for ARM NEON support in compiler)
-  # We try to link so that this also fails when
-  # building with LTO.
-  AC_TRY_LINK([],
-                 [asm(".fpu neon\n vadd.i8 d0, d0, d0");],
-                 result="yes", result="no")
-  AC_MSG_RESULT("$result")
-  if test "$result" = "yes"; then
-      AC_DEFINE(HAVE_ARM_NEON)
-      HAVE_ARM_NEON=1
-  fi
-fi # CPU_ARCH = arm
-
-AC_SUBST(HAVE_ARM_SIMD)
-AC_SUBST(HAVE_ARM_NEON)
-
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-arch=$MOZ_ARCH"
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-thumb=$MOZ_THUMB"
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-thumb-interwork=$MOZ_THUMB_INTERWORK"
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-fpu=$MOZ_FPU"
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-float-abi=$MOZ_FLOAT_ABI"
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-soft-float=$MOZ_SOFT_FLOAT"
-
-])

--- a/configure.in
+++ b/configure.in
@@ -1538,19 +1538,214 @@ OS_CONFIG="${OS_TARGET}${OS_RELEASE}"
 dnl Set INTEL_ARCHITECTURE if we're compiling for x86-32 or x86-64.
 dnl ===============================================================
 INTEL_ARCHITECTURE=
 case "$OS_TEST" in
     x86_64|i?86)
       INTEL_ARCHITECTURE=1
 esac
 
-dnl Configure platform-specific CPU architecture compiler options.
-dnl ==============================================================
-MOZ_ARCH_OPTS
+dnl ========================================================
+dnl = ARM toolchain tweaks
+dnl ========================================================
+
+dnl Defaults
+case "${CPU_ARCH}-${OS_TARGET}" in
+arm-Android)
+    MOZ_THUMB=yes
+    MOZ_ARCH=armv7-a
+    MOZ_FPU=vfp
+    MOZ_FLOAT_ABI=softfp
+    ;;
+arm-*)
+    if test -n "$MOZ_PLATFORM_MAEMO"; then
+        MOZ_THUMB=no
+        MOZ_ARCH=armv7-a
+        MOZ_FLOAT_ABI=softfp
+    fi
+    if test "$MOZ_PLATFORM_MAEMO" = 6; then
+        MOZ_THUMB=yes
+    fi
+    ;;
+esac
+
+dnl Kept for compatibility with some buildbot mozconfig
+MOZ_ARG_DISABLE_BOOL(thumb2, [], MOZ_THUMB=no, MOZ_THUMB=yes)
+
+MOZ_ARG_WITH_STRING(thumb,
+[  --with-thumb[[=yes|no|toolchain-default]]]
+[                          Use Thumb instruction set (-mthumb)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-thumb is not supported on non-GNU toolchains])
+    fi
+    MOZ_THUMB=$withval)
+
+MOZ_ARG_WITH_STRING(thumb-interwork,
+[  --with-thumb-interwork[[=yes|no|toolchain-default]]
+                           Use Thumb/ARM instuctions interwork (-mthumb-interwork)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-thumb-interwork is not supported on non-GNU toolchains])
+    fi
+    MOZ_THUMB_INTERWORK=$withval)
+
+MOZ_ARG_WITH_STRING(arch,
+[  --with-arch=[[type|toolchain-default]]
+                           Use specific CPU features (-march=type)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-arch is not supported on non-GNU toolchains])
+    fi
+    MOZ_ARCH=$withval)
+
+MOZ_ARG_WITH_STRING(fpu,
+[  --with-fpu=[[type|toolchain-default]]
+                           Use specific FPU type (-mfpu=type)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-fpu is not supported on non-GNU toolchains])
+    fi
+    MOZ_FPU=$withval)
+
+MOZ_ARG_WITH_STRING(float-abi,
+[  --with-float-abi=[[type|toolchain-default]]
+                           Use specific arm float ABI (-mfloat-abi=type)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-float-abi is not supported on non-GNU toolchains])
+    fi
+    MOZ_FLOAT_ABI=$withval)
+
+MOZ_ARG_WITH_STRING(soft-float,
+[  --with-soft-float[[=yes|no|toolchain-default]]
+                           Use soft float library (-msoft-float)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-soft-float is not supported on non-GNU toolchains])
+    fi
+    MOZ_SOFT_FLOAT=$withval)
+
+case "$MOZ_ARCH" in
+toolchain-default|"")
+    arch_flag=""
+    ;;
+*)
+    arch_flag="-march=$MOZ_ARCH"
+    ;;
+esac
+
+case "$MOZ_THUMB" in
+yes)
+    MOZ_THUMB2=1
+    thumb_flag="-mthumb"
+    ;;
+no)
+    MOZ_THUMB2=
+    thumb_flag="-marm"
+    ;;
+*)
+    _SAVE_CFLAGS="$CFLAGS"
+    CFLAGS="$arch_flag"
+    AC_TRY_COMPILE([],[return sizeof(__thumb2__);],
+        MOZ_THUMB2=1,
+        MOZ_THUMB2=)
+    CFLAGS="$_SAVE_CFLAGS"
+    thumb_flag=""
+    ;;
+esac
+
+if test "$MOZ_THUMB2" = 1; then
+    AC_DEFINE(MOZ_THUMB2)
+fi
+
+case "$MOZ_THUMB_INTERWORK" in
+yes)
+    thumb_interwork_flag="-mthumb-interwork"
+    ;;
+no)
+    thumb_interwork_flag="-mno-thumb-interwork"
+    ;;
+*) # toolchain-default
+    thumb_interwork_flag=""
+    ;;
+esac
+
+case "$MOZ_FPU" in
+toolchain-default|"")
+    fpu_flag=""
+    ;;
+*)
+    fpu_flag="-mfpu=$MOZ_FPU"
+    ;;
+esac
+
+case "$MOZ_FLOAT_ABI" in
+toolchain-default|"")
+    float_abi_flag=""
+    ;;
+*)
+    float_abi_flag="-mfloat-abi=$MOZ_FLOAT_ABI"
+    ;;
+esac
+
+case "$MOZ_SOFT_FLOAT" in
+yes)
+    soft_float_flag="-msoft-float"
+    ;;
+no)
+    soft_float_flag="-mno-soft-float"
+    ;;
+*) # toolchain-default
+    soft_float_flag=""
+    ;;
+esac
+
+dnl Use echo to avoid accumulating space characters
+all_flags=`echo $arch_flag $thumb_flag $thumb_interwork_flag $fpu_flag $float_abi_flag $soft_float_flag`
+if test -n "$all_flags"; then
+    _SAVE_CFLAGS="$CFLAGS"
+    CFLAGS="$all_flags"
+    AC_MSG_CHECKING(whether the chosen combination of compiler flags ($all_flags) works)
+    AC_TRY_COMPILE([],[return 0;],
+        AC_MSG_RESULT([yes]),
+        AC_MSG_ERROR([no]))
+
+    CFLAGS="$_SAVE_CFLAGS $all_flags"
+    CXXFLAGS="$CXXFLAGS $all_flags"
+    ASFLAGS="$ASFLAGS $all_flags"
+    if test -n "$thumb_flag"; then
+        LDFLAGS="$LDFLAGS $thumb_flag"
+    fi
+fi
+
+AC_SUBST(MOZ_THUMB2)
+
+if test "$CPU_ARCH" = "arm"; then
+  AC_MSG_CHECKING(for ARM SIMD support in compiler)
+  # We try to link so that this also fails when
+  # building with LTO.
+  AC_TRY_LINK([],
+                 [asm("uqadd8 r1, r1, r2");],
+                 result="yes", result="no")
+  AC_MSG_RESULT("$result")
+  if test "$result" = "yes"; then
+      AC_DEFINE(HAVE_ARM_SIMD)
+      HAVE_ARM_SIMD=1
+  fi
+
+  AC_MSG_CHECKING(for ARM NEON support in compiler)
+  # We try to link so that this also fails when
+  # building with LTO.
+  AC_TRY_LINK([],
+                 [asm(".fpu neon\n vadd.i8 d0, d0, d0");],
+                 result="yes", result="no")
+  AC_MSG_RESULT("$result")
+  if test "$result" = "yes"; then
+      AC_DEFINE(HAVE_ARM_NEON)
+      HAVE_ARM_NEON=1
+  fi
+fi # CPU_ARCH = arm
+
+AC_SUBST(HAVE_ARM_SIMD)
+AC_SUBST(HAVE_ARM_NEON)
 
 dnl =================================================================
 dnl Set up and test static assertion macros used to avoid AC_TRY_RUN,
 dnl which is bad when cross compiling.
 dnl =================================================================
 if test "$COMPILE_ENVIRONMENT"; then
 configure_static_assert_macros='
 #define CONFIGURE_STATIC_ASSERT(condition) CONFIGURE_STATIC_ASSERT_IMPL(condition, __LINE__)
@@ -8988,17 +9183,16 @@ if test -z "$MOZ_NATIVE_NSPR"; then
         ac_configure_args="$ac_configure_args --disable-optimize"
     fi
     if test -n "$HAVE_64BIT_OS"; then
         ac_configure_args="$ac_configure_args --enable-64bit"
     fi
     if test -n "$USE_ARM_KUSER"; then
         ac_configure_args="$ac_configure_args --with-arm-kuser"
     fi
-    ac_configure_args="$ac_configure_args $NSPR_CONFIGURE_ARGS"
     if test -n "$MOZ_LINKER" -a -z "$MOZ_OLD_LINKER" -a "$ac_cv_func_dladdr" = no ; then
       # dladdr is supported by the new linker, even when the system linker doesn't
       # support it. Trick nspr into using dladdr when it's not supported.
       _SAVE_CPPFLAGS="$CPPFLAGS"
       export CPPFLAGS="-include $_topsrcdir/mozglue/linker/dladdr.h $CPPFLAGS"
     fi
     _SAVE_LDFLAGS="$LDFLAGS"
     export LDFLAGS="$LDFLAGS $NSPR_LDFLAGS"

--- a/js/src/aclocal.m4
+++ b/js/src/aclocal.m4
@@ -11,11 +11,10 @@ builtin(include, build/autoconf/mozprog.
 builtin(include, build/autoconf/mozheader.m4)dnl
 builtin(include, build/autoconf/mozcommonheader.m4)dnl
 builtin(include, build/autoconf/acwinpaths.m4)dnl
 builtin(include, build/autoconf/lto.m4)dnl
 builtin(include, build/autoconf/gcc-pr49911.m4)dnl
 builtin(include, build/autoconf/frameptr.m4)dnl
 builtin(include, build/autoconf/compiler-opts.m4)dnl
 builtin(include, build/autoconf/expandlibs.m4)dnl
-builtin(include, build/autoconf/arch.m4)dnl
 
 MOZ_PROG_CHECKMSYS()

deleted file mode 100644
--- a/js/src/build/autoconf/arch.m4
+++ /dev/null
@@ -1,220 +0,0 @@
-AC_DEFUN([MOZ_ARCH_OPTS],
-[
-
-dnl ========================================================
-dnl = ARM toolchain tweaks
-dnl ========================================================
-
-MOZ_THUMB=toolchain-default
-MOZ_THUMB_INTERWORK=toolchain-default
-MOZ_FPU=toolchain-default
-MOZ_FLOAT_ABI=toolchain-default
-MOZ_SOFT_FLOAT=toolchain-default
-
-MOZ_ARG_WITH_STRING(arch,
-[  --with-arch=[[type|toolchain-default]]
-                           Use specific CPU features (-march=type). Resets
-                           thumb, fpu, float-abi, etc. defaults when set],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-arch is not supported on non-GNU toolchains])
-    fi
-    MOZ_ARCH=$withval)
-
-if test -z "$MOZ_ARCH"; then
-    dnl Defaults
-    case "${CPU_ARCH}-${OS_TARGET}" in
-    arm-Android)
-        MOZ_THUMB=yes
-        MOZ_ARCH=armv7-a
-        MOZ_FPU=vfp
-        MOZ_FLOAT_ABI=softfp
-        ;;
-    arm-Darwin)
-        MOZ_THUMB=yes
-        ;;
-    arm-*)
-        if test -n "$MOZ_PLATFORM_MAEMO"; then
-            MOZ_THUMB=no
-            MOZ_ARCH=armv7-a
-            MOZ_FLOAT_ABI=softfp
-        fi
-        if test "$MOZ_PLATFORM_MAEMO" = 6; then
-            MOZ_THUMB=yes
-        fi
-        ;;
-    esac
-fi
-
-MOZ_ARG_WITH_STRING(thumb,
-[  --with-thumb[[=yes|no|toolchain-default]]]
-[                          Use Thumb instruction set (-mthumb)],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-thumb is not supported on non-GNU toolchains])
-    fi
-    MOZ_THUMB=$withval)
-
-MOZ_ARG_WITH_STRING(thumb-interwork,
-[  --with-thumb-interwork[[=yes|no|toolchain-default]]
-                           Use Thumb/ARM instuctions interwork (-mthumb-interwork)],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-thumb-interwork is not supported on non-GNU toolchains])
-    fi
-    MOZ_THUMB_INTERWORK=$withval)
-
-MOZ_ARG_WITH_STRING(fpu,
-[  --with-fpu=[[type|toolchain-default]]
-                           Use specific FPU type (-mfpu=type)],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-fpu is not supported on non-GNU toolchains])
-    fi
-    MOZ_FPU=$withval)
-
-MOZ_ARG_WITH_STRING(float-abi,
-[  --with-float-abi=[[type|toolchain-default]]
-                           Use specific arm float ABI (-mfloat-abi=type)],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-float-abi is not supported on non-GNU toolchains])
-    fi
-    MOZ_FLOAT_ABI=$withval)
-
-MOZ_ARG_WITH_STRING(soft-float,
-[  --with-soft-float[[=yes|no|toolchain-default]]
-                           Use soft float library (-msoft-float)],
-    if test -z "$GNU_CC"; then
-        AC_MSG_ERROR([--with-soft-float is not supported on non-GNU toolchains])
-    fi
-    MOZ_SOFT_FLOAT=$withval)
-
-case "$MOZ_ARCH" in
-toolchain-default|"")
-    arch_flag=""
-    MOZ_ARCH=toolchain-default
-    ;;
-*)
-    arch_flag="-march=$MOZ_ARCH"
-    ;;
-esac
-
-case "$MOZ_THUMB" in
-yes)
-    MOZ_THUMB2=1
-    thumb_flag="-mthumb"
-    ;;
-no)
-    MOZ_THUMB2=
-    thumb_flag="-marm"
-    ;;
-*)
-    _SAVE_CFLAGS="$CFLAGS"
-    CFLAGS="$arch_flag"
-    AC_TRY_COMPILE([],[return sizeof(__thumb2__);],
-        MOZ_THUMB2=1,
-        MOZ_THUMB2=)
-    CFLAGS="$_SAVE_CFLAGS"
-    thumb_flag=""
-    ;;
-esac
-
-if test "$MOZ_THUMB2" = 1; then
-    AC_DEFINE(MOZ_THUMB2)
-fi
-
-case "$MOZ_THUMB_INTERWORK" in
-yes)
-    thumb_interwork_flag="-mthumb-interwork"
-    ;;
-no)
-    thumb_interwork_flag="-mno-thumb-interwork"
-    ;;
-*) # toolchain-default
-    thumb_interwork_flag=""
-    ;;
-esac
-
-case "$MOZ_FPU" in
-toolchain-default|"")
-    fpu_flag=""
-    ;;
-*)
-    fpu_flag="-mfpu=$MOZ_FPU"
-    ;;
-esac
-
-case "$MOZ_FLOAT_ABI" in
-toolchain-default|"")
-    float_abi_flag=""
-    ;;
-*)
-    float_abi_flag="-mfloat-abi=$MOZ_FLOAT_ABI"
-    ;;
-esac
-
-case "$MOZ_SOFT_FLOAT" in
-yes)
-    soft_float_flag="-msoft-float"
-    ;;
-no)
-    soft_float_flag="-mno-soft-float"
-    ;;
-*) # toolchain-default
-    soft_float_flag=""
-    ;;
-esac
-
-dnl Use echo to avoid accumulating space characters
-all_flags=`echo $arch_flag $thumb_flag $thumb_interwork_flag $fpu_flag $float_abi_flag $soft_float_flag`
-if test -n "$all_flags"; then
-    _SAVE_CFLAGS="$CFLAGS"
-    CFLAGS="$all_flags"
-    AC_MSG_CHECKING(whether the chosen combination of compiler flags ($all_flags) works)
-    AC_TRY_COMPILE([],[return 0;],
-        AC_MSG_RESULT([yes]),
-        AC_MSG_ERROR([no]))
-
-    CFLAGS="$_SAVE_CFLAGS $all_flags"
-    CXXFLAGS="$CXXFLAGS $all_flags"
-    ASFLAGS="$ASFLAGS $all_flags"
-    if test -n "$thumb_flag"; then
-        LDFLAGS="$LDFLAGS $thumb_flag"
-    fi
-fi
-
-AC_SUBST(MOZ_THUMB2)
-
-if test "$CPU_ARCH" = "arm"; then
-  AC_MSG_CHECKING(for ARM SIMD support in compiler)
-  # We try to link so that this also fails when
-  # building with LTO.
-  AC_TRY_LINK([],
-                 [asm("uqadd8 r1, r1, r2");],
-                 result="yes", result="no")
-  AC_MSG_RESULT("$result")
-  if test "$result" = "yes"; then
-      AC_DEFINE(HAVE_ARM_SIMD)
-      HAVE_ARM_SIMD=1
-  fi
-
-  AC_MSG_CHECKING(for ARM NEON support in compiler)
-  # We try to link so that this also fails when
-  # building with LTO.
-  AC_TRY_LINK([],
-                 [asm(".fpu neon\n vadd.i8 d0, d0, d0");],
-                 result="yes", result="no")
-  AC_MSG_RESULT("$result")
-  if test "$result" = "yes"; then
-      AC_DEFINE(HAVE_ARM_NEON)
-      HAVE_ARM_NEON=1
-  fi
-fi # CPU_ARCH = arm
-
-AC_SUBST(HAVE_ARM_SIMD)
-AC_SUBST(HAVE_ARM_NEON)
-
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-arch=$MOZ_ARCH"
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-thumb=$MOZ_THUMB"
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-thumb-interwork=$MOZ_THUMB_INTERWORK"
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-fpu=$MOZ_FPU"
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-float-abi=$MOZ_FLOAT_ABI"
-NSPR_CONFIGURE_ARGS="$NSPR_CONFIGURE_ARGS --with-soft-float=$MOZ_SOFT_FLOAT"
-
-])

--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -1459,19 +1459,217 @@ OS_CONFIG="${OS_TARGET}${OS_RELEASE}"
 dnl Set INTEL_ARCHITECTURE if we're compiling for x86-32 or x86-64.
 dnl ===============================================================
 INTEL_ARCHITECTURE=
 case "$OS_TEST" in
     x86_64|i?86)
       INTEL_ARCHITECTURE=1
 esac
 
-dnl Configure platform-specific CPU architecture compiler options.
-dnl ==============================================================
-MOZ_ARCH_OPTS
+dnl ========================================================
+dnl = ARM toolchain tweaks
+dnl ========================================================
+
+dnl Defaults
+case "${CPU_ARCH}-${OS_TARGET}" in
+arm-Android)
+    MOZ_THUMB=yes
+    MOZ_ARCH=armv7-a
+    MOZ_FPU=vfp
+    MOZ_FLOAT_ABI=softfp
+    ;;
+arm-Darwin)
+    MOZ_THUMB=yes
+    ;;
+arm-*)
+    if test -n "$MOZ_PLATFORM_MAEMO"; then
+        MOZ_THUMB=no
+        MOZ_ARCH=armv7-a
+        MOZ_FLOAT_ABI=softfp
+    fi
+    if test "$MOZ_PLATFORM_MAEMO" = 6; then
+        MOZ_THUMB=yes
+    fi
+    ;;
+esac
+
+dnl Kept for compatibility with some buildbot mozconfig
+MOZ_ARG_DISABLE_BOOL(thumb2, [], MOZ_THUMB=no, MOZ_THUMB=yes)
+
+MOZ_ARG_WITH_STRING(thumb,
+[  --with-thumb[[=yes|no|toolchain-default]]]
+[                          Use Thumb instruction set (-mthumb)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-thumb is not supported on non-GNU toolchain-defaults])
+    fi
+    MOZ_THUMB=$withval)
+
+MOZ_ARG_WITH_STRING(thumb-interwork,
+[  --with-thumb-interwork[[=yes|no|toolchain-default]]
+                           Use Thumb/ARM instuctions interwork (-mthumb-interwork)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-thumb-interwork is not supported on non-GNU toolchain-defaults])
+    fi
+    MOZ_THUMB_INTERWORK=$withval)
+
+MOZ_ARG_WITH_STRING(arch,
+[  --with-arch=[[type|toolchain-default]]
+                           Use specific CPU features (-march=type)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-arch is not supported on non-GNU toolchain-defaults])
+    fi
+    MOZ_ARCH=$withval)
+
+MOZ_ARG_WITH_STRING(fpu,
+[  --with-fpu=[[type|toolchain-default]]
+                           Use specific FPU type (-mfpu=type)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-fpu is not supported on non-GNU toolchain-defaults])
+    fi
+    MOZ_FPU=$withval)
+
+MOZ_ARG_WITH_STRING(float-abi,
+[  --with-float-abi=[[type|toolchain-default]]
+                           Use specific arm float ABI (-mfloat-abi=type)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-float-abi is not supported on non-GNU toolchain-defaults])
+    fi
+    MOZ_FLOAT_ABI=$withval)
+
+MOZ_ARG_WITH_STRING(soft-float,
+[  --with-soft-float[[=yes|no|toolchain-default]]
+                           Use soft float library (-msoft-float)],
+    if test -z "$GNU_CC"; then
+        AC_MSG_ERROR([--with-soft-float is not supported on non-GNU toolchain-defaults])
+    fi
+    MOZ_SOFT_FLOAT=$withval)
+
+case "$MOZ_ARCH" in
+toolchain-default|"")
+    arch_flag=""
+    ;;
+*)
+    arch_flag="-march=$MOZ_ARCH"
+    ;;
+esac
+
+case "$MOZ_THUMB" in
+yes)
+    MOZ_THUMB2=1
+    thumb_flag="-mthumb"
+    ;;
+no)
+    MOZ_THUMB2=
+    thumb_flag="-marm"
+    ;;
+*)
+    _SAVE_CFLAGS="$CFLAGS"
+    CFLAGS="$arch_flag"
+    AC_TRY_COMPILE([],[return sizeof(__thumb2__);],
+        MOZ_THUMB2=1,
+        MOZ_THUMB2=)
+    CFLAGS="$_SAVE_CFLAGS"
+    thumb_flag=""
+    ;;
+esac
+
+if test "$MOZ_THUMB2" = 1; then
+    AC_DEFINE(MOZ_THUMB2)
+fi
+
+case "$MOZ_THUMB_INTERWORK" in
+yes)
+    thumb_interwork_flag="-mthumb-interwork"
+    ;;
+no)
+    thumb_interwork_flag="-mno-thumb-interwork"
+    ;;
+*) # toolchain-default
+    thumb_interwork_flag=""
+    ;;
+esac
+
+case "$MOZ_FPU" in
+toolchain-default|"")
+    fpu_flag=""
+    ;;
+*)
+    fpu_flag="-mfpu=$MOZ_FPU"
+    ;;
+esac
+
+case "$MOZ_FLOAT_ABI" in
+toolchain-default|"")
+    float_abi_flag=""
+    ;;
+*)
+    float_abi_flag="-mfloat-abi=$MOZ_FLOAT_ABI"
+    ;;
+esac
+
+case "$MOZ_SOFT_FLOAT" in
+yes)
+    soft_float_flag="-msoft-float"
+    ;;
+no)
+    soft_float_flag="-mno-soft-float"
+    ;;
+*) # toolchain-default
+    soft_float_flag=""
+    ;;
+esac
+
+dnl Use echo to avoid accumulating space characters
+all_flags=`echo $arch_flag $thumb_flag $thumb_interwork_flag $fpu_flag $float_abi_flag $soft_float_flag`
+if test -n "$all_flags"; then
+    _SAVE_CFLAGS="$CFLAGS"
+    CFLAGS="$all_flags"
+    AC_MSG_CHECKING(whether the chosen combination of compiler flags ($all_flags) works)
+    AC_TRY_COMPILE([],[return 0;],
+        AC_MSG_RESULT([yes]),
+        AC_MSG_ERROR([no]))
+
+    CFLAGS="$_SAVE_CFLAGS $all_flags"
+    CXXFLAGS="$CXXFLAGS $all_flags"
+    ASFLAGS="$ASFLAGS $all_flags"
+    if test -n "$thumb_flag"; then
+        LDFLAGS="$LDFLAGS $thumb_flag"
+    fi
+fi
+
+AC_SUBST(MOZ_THUMB2)
+
+if test "$CPU_ARCH" = "arm"; then
+  AC_MSG_CHECKING(for ARM SIMD support in compiler)
+  # We try to link so that this also fails when
+  # building with LTO.
+  AC_TRY_LINK([],
+                 [asm("uqadd8 r1, r1, r2");],
+                 result="yes", result="no")
+  AC_MSG_RESULT("$result")
+  if test "$result" = "yes"; then
+      AC_DEFINE(HAVE_ARM_SIMD)
+      HAVE_ARM_SIMD=1
+  fi
+
+  AC_MSG_CHECKING(for ARM NEON support in compiler)
+  # We try to link so that this also fails when
+  # building with LTO.
+  AC_TRY_LINK([],
+                 [asm(".fpu neon\n vadd.i8 d0, d0, d0");],
+                 result="yes", result="no")
+  AC_MSG_RESULT("$result")
+  if test "$result" = "yes"; then
+      AC_DEFINE(HAVE_ARM_NEON)
+      HAVE_ARM_NEON=1
+  fi
+fi # CPU_ARCH = arm
+
+AC_SUBST(HAVE_ARM_SIMD)
+AC_SUBST(HAVE_ARM_NEON)
 
 dnl =================================================================
 dnl Set up and test static assertion macros used to avoid AC_TRY_RUN,
 dnl which is bad when cross compiling.
 dnl =================================================================
 if test "$COMPILE_ENVIRONMENT"; then
 configure_static_assert_macros='
 #define CONFIGURE_STATIC_ASSERT(condition) CONFIGURE_STATIC_ASSERT_IMPL(condition, __LINE__)