Import xiph/opus @ 034c1b61a250457649d788bbf983b3f0fb63f02eHEADmaster

Snapshot for re3/reVC vendoring, per @lzcnt.
Source: https://github.com/xiph/opus (034c1b61a250457649d788bbf983b3f0fb63f02e).

3 files changed, 180 insertions, 0 deletions

diff --git a/m4/as-gcc-inline-assembly.m4 b/m4/as-gcc-inline-assembly.m4
new file mode 100644
index 0000000..b0d2da4
--- /dev/null
+++ b/m4/as-gcc-inline-assembly.m4
@@ -0,0 +1,98 @@
+dnl as-gcc-inline-assembly.m4 0.1.0
+
+dnl autostars m4 macro for detection of gcc inline assembly
+
+dnl David Schleef <[email protected]>
+
+dnl AS_COMPILER_FLAG(ACTION-IF-ACCEPTED, [ACTION-IF-NOT-ACCEPTED])
+dnl Tries to compile with the given CFLAGS.
+dnl Runs ACTION-IF-ACCEPTED if the compiler can compile with the flags,
+dnl and ACTION-IF-NOT-ACCEPTED otherwise.
+
+AC_DEFUN([AS_GCC_INLINE_ASSEMBLY],
+[
+  AC_MSG_CHECKING([if compiler supports gcc-style inline assembly])
+
+  AC_TRY_COMPILE([], [
+#ifdef __GNUC_MINOR__
+#if (__GNUC__ * 1000 + __GNUC_MINOR__) < 3004
+#error GCC before 3.4 has critical bugs compiling inline assembly
+#endif
+#endif
+__asm__ (""::) ], [flag_ok=yes], [flag_ok=no])
+
+  if test "X$flag_ok" = Xyes ; then
+    $1
+    true
+  else
+    $2
+    true
+  fi
+  AC_MSG_RESULT([$flag_ok])
+])
+
+AC_DEFUN([AS_ASM_ARM_NEON],
+[
+  AC_MSG_CHECKING([if assembler supports NEON instructions on ARM])
+
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[__asm__("vorr d0,d0,d0")])],
+                    [AC_MSG_RESULT([yes])
+                     $1],
+                    [AC_MSG_RESULT([no])
+                     $2])
+])
+
+AC_DEFUN([AS_ASM_ARM_NEON_FORCE],
+[
+  AC_MSG_CHECKING([if assembler supports NEON instructions on ARM])
+
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[__asm__(".arch armv7-a\n.fpu neon\n.object_arch armv4t\nvorr d0,d0,d0")])],
+                    [AC_MSG_RESULT([yes])
+                     $1],
+                    [AC_MSG_RESULT([no])
+                     $2])
+])
+
+AC_DEFUN([AS_ASM_ARM_MEDIA],
+[
+  AC_MSG_CHECKING([if assembler supports ARMv6 media instructions on ARM])
+
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[__asm__("shadd8 r3,r3,r3")])],
+                    [AC_MSG_RESULT([yes])
+                     $1],
+                    [AC_MSG_RESULT([no])
+                     $2])
+])
+
+AC_DEFUN([AS_ASM_ARM_MEDIA_FORCE],
+[
+  AC_MSG_CHECKING([if assembler supports ARMv6 media instructions on ARM])
+
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[__asm__(".arch armv6\n.object_arch armv4t\nshadd8 r3,r3,r3")])],
+                    [AC_MSG_RESULT([yes])
+                     $1],
+                    [AC_MSG_RESULT([no])
+                     $2])
+])
+
+AC_DEFUN([AS_ASM_ARM_EDSP],
+[
+  AC_MSG_CHECKING([if assembler supports EDSP instructions on ARM])
+
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[__asm__("qadd r3,r3,r3")])],
+                    [AC_MSG_RESULT([yes])
+                     $1],
+                    [AC_MSG_RESULT([no])
+                     $2])
+])
+
+AC_DEFUN([AS_ASM_ARM_EDSP_FORCE],
+[
+  AC_MSG_CHECKING([if assembler supports EDSP instructions on ARM])
+
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[__asm__(".arch armv5te\n.object_arch armv4t\nqadd r3,r3,r3")])],
+                    [AC_MSG_RESULT([yes])
+                     $1],
+                    [AC_MSG_RESULT([no])
+                     $2])
+])
diff --git a/m4/ax_add_fortify_source.m4 b/m4/ax_add_fortify_source.m4
new file mode 100644
index 0000000..1c89e41
--- /dev/null
+++ b/m4/ax_add_fortify_source.m4
@@ -0,0 +1,53 @@
+# ===========================================================================
+#   Modified from https://www.gnu.org/software/autoconf-archive/ax_add_fortify_source.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_ADD_FORTIFY_SOURCE
+#
+# DESCRIPTION
+#
+#   Check whether -D_FORTIFY_SOURCE=2 can be added to CFLAGS without macro
+#   redefinition warnings. Some distributions (such as Gentoo Linux) enable
+#   _FORTIFY_SOURCE globally in their compilers, leading to unnecessary
+#   warnings in the form of
+#
+#     <command-line>:0:0: error: "_FORTIFY_SOURCE" redefined [-Werror]
+#     <built-in>: note: this is the location of the previous definition
+#
+#   which is a problem if -Werror is enabled. This macro checks whether
+#   _FORTIFY_SOURCE is already defined, and if not, adds -D_FORTIFY_SOURCE=2
+#   to CFLAGS.
+#
+# LICENSE
+#
+#   Copyright (c) 2017 David Seifert <[email protected]>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
+
+#serial 1
+
+AC_DEFUN([AX_ADD_FORTIFY_SOURCE],[
+    AC_MSG_CHECKING([whether to add -D_FORTIFY_SOURCE=2 to CFLAGS])
+    AC_LINK_IFELSE([
+        AC_LANG_SOURCE(
+            [[
+                int main() {
+                #ifndef _FORTIFY_SOURCE
+                    return 0;
+                #else
+                    this_is_an_error;
+                #endif
+                }
+            ]]
+        )], [
+            AC_MSG_RESULT([yes])
+            CFLAGS="$CFLAGS -D_FORTIFY_SOURCE=2"
+        ], [
+            AC_MSG_RESULT([no])
+    ])
+])
diff --git a/m4/opus-intrinsics.m4 b/m4/opus-intrinsics.m4
new file mode 100644
index 0000000..a262ca1
--- /dev/null
+++ b/m4/opus-intrinsics.m4
@@ -0,0 +1,29 @@
+dnl opus-intrinsics.m4
+dnl macro for testing for support for compiler intrinsics, either by default or with a compiler flag
+
+dnl OPUS_CHECK_INTRINSICS(NAME-OF-INTRINSICS, COMPILER-FLAG-FOR-INTRINSICS, VAR-IF-PRESENT, VAR-IF-DEFAULT, TEST-PROGRAM-HEADER, TEST-PROGRAM-BODY)
+AC_DEFUN([OPUS_CHECK_INTRINSICS],
+[
+   AC_MSG_CHECKING([if compiler supports $1 intrinsics])
+   AC_LINK_IFELSE(
+     [AC_LANG_PROGRAM($5, $6)],
+     [
+        $3=1
+        $4=1
+        AC_MSG_RESULT([yes])
+      ],[
+        $4=0
+        AC_MSG_RESULT([no])
+        AC_MSG_CHECKING([if compiler supports $1 intrinsics with $2])
+        save_CFLAGS="$CFLAGS"; CFLAGS="$CFLAGS $2"
+        AC_LINK_IFELSE([AC_LANG_PROGRAM($5, $6)],
+        [
+           AC_MSG_RESULT([yes])
+           $3=1
+        ],[
+           AC_MSG_RESULT([no])
+           $3=0
+        ])
+        CFLAGS="$save_CFLAGS"
+     ])
+])