From 7722fb8a3189fea0f6381f02a0e4f63c847f0393 Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Sat, 6 Aug 2016 11:02:43 +0200 Subject: [PATCH 3/6] build: fix architecture detection The current architecture detection, based on the "host_cpu" part of the tuple does not work properly for a number of reason: - The code assumes that if host_cpu starts with "arm" then ARM instructions are available, which is incorrect. Indeed, Cortex-M platforms can run Linux, they are ARM platforms (so host_cpu = arm), but they don't support ARM instructions: they support only the Thumb-2 instruction set. - The armv7 case is also not very useful, as it is not standard at all to pass armv7 as host_cpu even if the host system is actually ARMv7 based. - For the same reason, the armv8 case is not very useful: ARMv8 is AArch64, and there is already a separate case to handle this architecture. So, this commit moves away from a host_cpu based logic, and instead tests using AC_CHECK_DECLS() the built-in definitions of the compiler: - If we have __ARM_ARCH_ISA_ARM defined, then it's an ARM processor that supports the ARM instruction set (this allows to exclude Thumb-2 only processors). - If we have __ARM_ARCH_7A__, then we have an ARMv7-A processor, and we can enable the corresponding optimizations - Same for __aarch64__, __i386__ and __x86_64__. In addition, we remove the AC_MSG_ERROR() that makes the build fail for all architectures but the ones that are explicitly supported. Indeed, webrtc-audio-processing builds just fine for other architectures (tested on MIPS), it's just that none of the architecture-specific optimizations will be used. Signed-off-by: Thomas Petazzoni Signed-off-by: Tanu Kaskinen Upstream-Status: Accepted [expected in 0.4] --- configure.ac | 35 +++++++++++------------------------ 1 file changed, 11 insertions(+), 24 deletions(-) diff --git a/configure.ac b/configure.ac index be20514..e898014 100644 --- a/configure.ac +++ b/configure.ac @@ -55,30 +55,17 @@ AS_CASE(["${host}"], ) AC_SUBST(PLATFORM_CFLAGS) -AS_CASE(["${host_cpu}"], - [i?86|x86_64], - [ - HAVE_X86=1 - ], - [armv7*|armv8*], - [ - HAVE_ARM=1 - HAVE_ARMV7=1 - ARCH_CFLAGS="-DWEBRTC_ARCH_ARM -DWEBRTC_ARCH_ARM_V7" - ], - [arm*], - [ - HAVE_ARM=1 - ARCH_CFLAGS="-DWEBRTC_ARCH_ARM" - ], - [aarch64*], - [ - HAVE_NEON=1 - ARCH_CFLAGS="-DWEBRTC_HAS_NEON -DWEBRTC_ARCH_ARM64" - ], - # FIXME: Add MIPS support, see webrtc/BUILD.gn for defines - [AC_MSG_ERROR([Unsupported CPU type $host_cpu])] -) +# Testing __ARM_ARCH_ISA_ARM since the code contains ARM instructions, +# which don't work on Thumb-2 only platforms (ARMv7-M). +AC_CHECK_DECLS([__ARM_ARCH_ISA_ARM], + [HAVE_ARM=1; ARCH_CFLAGS="${ARCH_CFLAGS} -DWEBRTC_ARCH_ARM"]) +AC_CHECK_DECLS([__ARM_ARCH_7A__], + [HAVE_ARMV7=1; ARCH_CFLAGS="${ARCH_CFLAGS} -DWEBRTC_ARCH_ARM_V7"]) +AC_CHECK_DECLS([__aarch64__], + [HAVE_NEON=1; ARCH_CFLAGS="${ARCH_CFLAGS} -DWEBRTC_HAS_NEON -DWEBRTC_ARCH_ARM64"]) +AC_CHECK_DECLS([__i386__], [HAVE_X86=1]) +AC_CHECK_DECLS([__x86_64__], [HAVE_X86=1]) + AM_CONDITIONAL(HAVE_X86, [test "x${HAVE_X86}" = "x1"]) AM_CONDITIONAL(HAVE_ARM, [test "x${HAVE_ARM}" = "x1"]) AM_CONDITIONAL(HAVE_ARMV7, [test "x${HAVE_ARMV7}" = "x1"]) -- 2.11.0