From dcae2e32f7d8a1ca5fb8c1e4aa81313be854dd73 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
Date: Wed, 18 Feb 2015 00:40:06 +0200
Subject: [PATCH] arm: Suppress tags about used cpu arch and extensions
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
When all the codepaths using manually set .arch/.fpu code is
behind runtime detection, the elf attributes should be suppressed.
This allows tools to know that the final built binary doesn't
strictly require these extensions.
Signed-off-by: Martin Storsjö <martin@martin.st>
---
configure | 6 ++++++
libavutil/arm/asm.S | 6 ++++++
2 files changed, 12 insertions(+)
diff --git a/configure b/configure
index 0e182b484f2..59438b833e8 100755
--- a/configure
+++ b/configure
@@ -1494,6 +1494,7 @@ SYSTEM_FUNCS="
TOOLCHAIN_FEATURES="
as_dn_directive
as_func
+ as_object_arch
asm_mod_q
attribute_may_alias
attribute_packed
@@ -3868,6 +3869,11 @@ if enabled_any arm aarch64 || enabled_all ppc altivec && enabled asm; then
check_as <<EOF && enable as_func
.func test
.endfunc
+EOF
+
+ # llvm's integrated assembler supports .object_arch from llvm 3.5
+ enabled arm && test "$objformat" = elf && check_as <<EOF && enable as_object_arch
+.object_arch armv4
EOF
fi
diff --git a/libavutil/arm/asm.S b/libavutil/arm/asm.S
index 8479304f5fd..943c1cea3fc 100644
--- a/libavutil/arm/asm.S
+++ b/libavutil/arm/asm.S
@@ -49,11 +49,17 @@
#elif HAVE_ARMV5TE
.arch armv5te
#endif
+#if HAVE_AS_OBJECT_ARCH
+ELF .object_arch armv4
+#endif
#if HAVE_NEON
.fpu neon
+ELF .eabi_attribute 10, 0 @ suppress Tag_FP_arch
+ELF .eabi_attribute 12, 0 @ suppress Tag_Advanced_SIMD_arch
#elif HAVE_VFP
.fpu vfp
+ELF .eabi_attribute 10, 0 @ suppress Tag_FP_arch
#endif
.syntax unified
--
GitLab