[glibc] arm: Support gcc older than 10 for find_zero_all

[glibc] arm: Support gcc older than 10 for find_zero_all

[Adhemerval Zanella]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=97830304bb477f18b67b7bc11989fb3357da443e

commit 97830304bb477f18b67b7bc11989fb3357da443e
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Mon Feb 20 13:46:36 2023 -0300

    arm: Support gcc older than 10 for find_zero_all
    
    __builtin_arm_uqsub8 is only available on gcc newer or equal than 10.
    
    Checked on arm-linux-gnueabihf built with gcc 9.
    
    Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Diff:
---
 sysdeps/arm/armv6t2/string-fza.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sysdeps/arm/armv6t2/string-fza.h b/sysdeps/arm/armv6t2/string-fza.h
index 76274ccca7..d85ce86434 100644
--- a/sysdeps/arm/armv6t2/string-fza.h
+++ b/sysdeps/arm/armv6t2/string-fza.h
@@ -33,7 +33,13 @@ find_zero_all (op_t x)
   /* Use unsigned saturated subtraction from 1 in each byte.
      That leaves 1 for every byte that was zero.  */
   op_t ones = repeat_bytes (0x01);
+#if __GNUC_PREREQ (10, 0)
   return __builtin_arm_uqsub8 (ones, x);
+#else
+  op_t ret;
+  asm ("uqsub8 %0,%1,%2" : "=r"(ret) : "r"(ones), "r"(x));
+  return ret;
+#endif
 }
 
 /* Identify bytes that are equal between X1 and X2.  */