From 614862c8bb76e418c62102ea04c9b99d3f680d40 Mon Sep 17 00:00:00 2001
From: jsg <jsg@openbsd.org>
Date: Wed, 14 Dec 2022 23:50:31 +0000
Subject: [PATCH] add __ctzdi2 to sparc64 kernel

If __builtin_ctzl() is used on sparc64, gcc 4.2 will emit a call to
__ctzdi2.  For userland this is in libgcc or compiler-rt.  In the kernel
we put these functions in libkern.

'looks good' deraadt@ miod@
---
 sys/arch/sparc64/conf/files.sparc64 |  4 +-
 sys/lib/libkern/ctzdi2.c            | 61 +++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 1 deletion(-)
 create mode 100644 sys/lib/libkern/ctzdi2.c

diff --git a/sys/arch/sparc64/conf/files.sparc64 b/sys/arch/sparc64/conf/files.sparc64
index cfc824e214f..f49cf0cad93 100644
--- a/sys/arch/sparc64/conf/files.sparc64
+++ b/sys/arch/sparc64/conf/files.sparc64
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.sparc64,v 1.154 2020/08/13 10:04:37 jca Exp $
+#	$OpenBSD: files.sparc64,v 1.155 2022/12/14 23:50:31 jsg Exp $
 #	$NetBSD: files.sparc64,v 1.50 2001/08/10 20:53:50 eeh Exp $
 
 # maxpartitions must be first item in files.${ARCH}
@@ -341,6 +341,8 @@ file	arch/sparc64/sparc64/db_interface.c	ddb
 file	arch/sparc64/sparc64/db_trace.c		ddb
 file	arch/sparc64/sparc64/db_disasm.c	ddb
 
+file	lib/libkern/ctzdi2.c
+
 #
 # Machine-independent SCSI drivers
 #
diff --git a/sys/lib/libkern/ctzdi2.c b/sys/lib/libkern/ctzdi2.c
new file mode 100644
index 00000000000..495657b6011
--- /dev/null
+++ b/sys/lib/libkern/ctzdi2.c
@@ -0,0 +1,61 @@
+/*	$OpenBSD: ctzdi2.c,v 1.1 2022/12/14 23:50:31 jsg Exp $	*/
+
+/*
+ * Public domain.
+ * Written by Dale Rahn.
+ */
+
+#include <lib/libkern/libkern.h>
+
+/*
+ * ffsl -- vax ffs instruction with long arg
+ */
+
+#ifdef __LP64__
+static int
+ffsl(long mask)
+{
+	int bit;
+	unsigned long r = mask;
+	static const signed char t[16] = {
+		-60, 1, 2, 1,
+		  3, 1, 2, 1,
+		  4, 1, 2, 1,
+		  3, 1, 2, 1
+	};
+
+	bit = 0;
+	if (!(r & 0xffffffff)) {
+		bit += 32;
+		r >>= 32;
+	}
+	if (!(r & 0xffff)) {
+		bit += 16;
+		r >>= 16;
+	}
+	if (!(r & 0xff)) {
+		bit += 8;
+		r >>= 8;
+	}
+	if (!(r & 0xf)) {
+		bit += 4;
+		r >>= 4;
+	}
+
+	return (bit + t[ r & 0xf ]);
+}
+#else
+static int
+ffsl(long mask)
+{
+	return ffs(mask);
+}
+#endif
+
+int
+__ctzdi2(long mask)
+{
+	if (mask == 0)
+		return 0;
+	return ffsl(mask) - 1;
+}
-- 
2.20.1