add __clzsi2()

arch/sparc/kernel/ttable.S

@@ -149,10 +149,9 @@ fpe_trap_handler:
 hw_div0_trap_handler:
 	.global __interrupt_entry
 __interrupt_entry:
-	.global __clzsi2
-__clzsi2:
 	.global memset
 memset:
+	ta 1
 	.global nmi_entry
 nmi_entry:
 	.global reg_access_trap_handler
@@ -165,8 +164,6 @@ strtol:
 syscall_tbl:
 	.global syscall_trap
 syscall_trap:
-	.global tag_overflow_trap_handler
-tag_overflow_trap_handler:
 	.global .udiv
 .udiv:
 	.global .umul

lib/Makefile

@@ -9,3 +9,4 @@ lib-y			+= elf.o
 lib-y			+= data_proc_tracker.o
 lib-y			+= data_proc_task.o
 lib-y			+= data_proc_net.o
+lib-y			+= libc_bitops.o

lib/libc_bitops.c

+// SPDX-License-Identifier: GPL-2.0
+/**
+ * @file lib/libc_bitops.c
+ *
+ * @ingroup libc
+ * @defgroup functions expected by the compiler
+ *
+ * @note these can be overridden by linking architecture-specific implementation
+ *
+ * @note add as needed
+ *
+ * @see https://gcc.gnu.org/onlinedocs/gccint/Integer-library-routines.html
+ *
+ */
+
+
+#include <kernel/export.h>
+
+
+/**
+ * @brief locates the most significant bit set in a word
+ * @note taken from linux: include/asm-generic/bitops/fls.h
+ */
+
+static int fls(int x)
+{
+	int r = 32;
+
+	if (!x)
+		return 0;
+	if (!(x & 0xffff0000u)) {
+		x <<= 16;
+		r -= 16;
+	}
+	if (!(x & 0xff000000u)) {
+		x <<= 8;
+		r -= 8;
+	}
+	if (!(x & 0xf0000000u)) {
+		x <<= 4;
+		r -= 4;
+	}
+	if (!(x & 0xc0000000u)) {
+		x <<= 2;
+		r -= 2;
+	}
+	if (!(x & 0x80000000u)) {
+		x <<= 1;
+		r -= 1;
+	}
+	return r;
+}
+
+
+/**
+ * @brief returns the number of leading 0-bits in a,
+ *	  starting at the most significant bit position.
+ *	  If a is zero, the result is undefined.
+ */
+
+int __attribute__((weak)) __clzsi2(unsigned int a);
+int __attribute__((weak)) __clzsi2(unsigned int a)
+{
+	return 32 - fls(a);
+}
+EXPORT_SYMBOL(__clzsi2);