[PATCH] Fix ARM NEON support detection on ARMv6 target

Jussi Kivilinna jussi.kivilinna at iki.fi
Wed Mar 16 20:24:54 CET 2016

* configure.ac (gcry_cv_gcc_inline_asm_neon): Use '.arm' directive
instead of '.thumb'.

Fix allows building ARM NEON assembly implementations when compiler
target is ARMv6. This enables NEON implementations on ARMv7+NEON CPUs
running on ARMv6 OS (for example, Raspbian on Raspberry Pi 2/3).

Signed-off-by: Jussi Kivilinna <jussi.kivilinna at iki.fi>
 configure.ac |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index ff72e3f..f76e875 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1487,7 +1487,7 @@ AC_CACHE_CHECK([whether GCC inline assembler supports NEON instructions],
                 ".syntax unified\n\t"
-                ".thumb\n\t"
+                ".arm\n\t"
                 ".fpu neon\n\t"
                 "vld1.64 {%q0-%q1}, [%r0]!;\n\t"
                 "vrev64.8 %q0, %q3;\n\t"

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