From: "Junxian Zhu" <zhujunxian@oss.cipunited.com>
To: <libc-alpha@sourceware.org>
Cc: "Junxian Zhu" <zhujunxian@oss.cipunited.com>
Subject: [PATCH] mips: Use builtins for ffs and ffsll
Date: Sun, 4 Feb 2024 18:11:33 +0800 [thread overview]
Message-ID: <20240204101132.653-2-zhujunxian@oss.cipunited.com> (raw)
From: Junxian Zhu <zhujunxian@oss.cipunited.com>
__builtin_ffs{,ll} basically on __builtin_ctz{,ll} in MIPS GCC compiler.
The hardware ctz instructions were available after MIPS{32,64} Release1. By using builtin ctz. It can also reduce code size of ffs/ffsll.
Checked on mips o32. mips64.
Signed-off-by: Junxian Zhu <zhujunxian@oss.cipunited.com>
---
sysdeps/mips/math-use-builtins-ffs.h | 2 ++
1 file changed, 2 insertions(+)
create mode 100644 sysdeps/mips/math-use-builtins-ffs.h
diff --git a/sysdeps/mips/math-use-builtins-ffs.h b/sysdeps/mips/math-use-builtins-ffs.h
new file mode 100644
index 0000000000..78b3f14fae
--- /dev/null
+++ b/sysdeps/mips/math-use-builtins-ffs.h
@@ -0,0 +1,2 @@
+#define USE_FFS_BUILTIN (__mips_isa_rev >= 1)
+#define USE_FFSLL_BUILTIN (__mips_isa_rev >= 1)
--
2.43.0.windows.1
next reply other threads:[~2024-02-04 10:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-04 10:11 Junxian Zhu [this message]
2024-02-05 14:19 ` Adhemerval Zanella Netto
2024-02-05 18:28 ` Adhemerval Zanella Netto
2024-05-12 17:06 ` Maciej W. Rozycki
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