| From 7722fb8a3189fea0f6381f02a0e4f63c847f0393 Mon Sep 17 00:00:00 2001 |
| From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> |
| 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 <thomas.petazzoni@free-electrons.com> |
| Signed-off-by: Tanu Kaskinen <tanuk@iki.fi> |
| 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 |
| |