lib1funcs.asm (ctzsi2): New function.

* arm/lib1funcs.asm (ctzsi2): New function.
* arm/t-elf (LIB1ASMFUNCS): Add _ctzsi2.
* arm/t-linux (LIB1ASMFUNCS): Likewise.
* arm/t-strongarm-elf (LIB1ASMFUNCS): Likewise.
* arm/t-symbian (LIB1ASMFUNCS): Likewise.
* arm/t-vxworks (LIB1ASMFUNCS): Likewise.
* arm/t-wince-pe (LIB1ASMFUNCS): Likewise.

From-SVN: r185698

libgcc/ChangeLog

+2012-03-22  Richard Earnshaw  <rearnsha@arm.com>
+
+	* arm/lib1funcs.asm (ctzsi2): New function.
+	* arm/t-elf (LIB1ASMFUNCS): Add _ctzsi2.
+	* arm/t-linux (LIB1ASMFUNCS): Likewise.
+	* arm/t-strongarm-elf (LIB1ASMFUNCS): Likewise.
+	* arm/t-symbian (LIB1ASMFUNCS): Likewise.
+	* arm/t-vxworks (LIB1ASMFUNCS): Likewise.
+	* arm/t-wince-pe (LIB1ASMFUNCS): Likewise.
+
 2012-03-21  Andreas Tobler  <andreast@fgznet.ch>
 
 	* config.host: Add bits to support powerpc64-*-freebsd*.

libgcc/config/arm/lib1funcs.S

@@ -1594,6 +1594,70 @@ ARM_FUNC_START clzdi2
 #endif
 #endif /* L_clzdi2 */
 
+#ifdef L_ctzsi2
+#if defined(__ARM_ARCH_6M__)
+FUNC_START ctzsi2
+	neg	r1, r0
+	and	r0, r0, r1
+	mov	r1, #28
+	mov	r3, #1
+	lsl	r3, r3, #16
+	cmp	r0, r3 /* 0x10000 */
+	bcc	2f
+	lsr	r0, r0, #16
+	sub	r1, r1, #16
+2:	lsr	r3, r3, #8
+	cmp	r0, r3 /* #0x100 */
+	bcc	2f
+	lsr	r0, r0, #8
+	sub	r1, r1, #8
+2:	lsr	r3, r3, #4
+	cmp	r0, r3 /* #0x10 */
+	bcc	2f
+	lsr	r0, r0, #4
+	sub	r1, r1, #4
+2:	adr	r2, 1f
+	ldrb	r0, [r2, r0]
+	sub	r0, r0, r1
+	bx lr
+.align 2
+1:
+.byte	27, 28, 29, 29, 30, 30, 30, 30, 31, 31, 31, 31, 31, 31, 31, 31
+	FUNC_END ctzsi2
+#else
+ARM_FUNC_START ctzsi2
+	rsb	r1, r0, #0
+	and	r0, r0, r1
+# if defined(HAVE_ARM_CLZ)
+	clz	r0, r0
+	rsb	r0, r0, #31
+	RET
+# else
+	mov	r1, #28
+	cmp	r0, #0x10000
+	do_it	cs, t
+	movcs	r0, r0, lsr #16
+	subcs	r1, r1, #16
+	cmp	r0, #0x100
+	do_it	cs, t
+	movcs	r0, r0, lsr #8
+	subcs	r1, r1, #8
+	cmp	r0, #0x10
+	do_it	cs, t
+	movcs	r0, r0, lsr #4
+	subcs	r1, r1, #4
+	adr	r2, 1f
+	ldrb	r0, [r2, r0]
+	sub	r0, r0, r1
+	RET
+.align 2
+1:
+.byte	27, 28, 29, 29, 30, 30, 30, 30, 31, 31, 31, 31, 31, 31, 31, 31
+# endif /* !HAVE_ARM_CLZ */
+	FUNC_END ctzsi2
+#endif
+#endif /* L_clzsi2 */
+
 /* ------------------------------------------------------------------------ */
 /* These next two sections are here despite the fact that they contain Thumb 
    assembler because their presence allows interworked code to be linked even

libgcc/config/arm/t-elf

@@ -10,7 +10,7 @@ LIB1ASMFUNCS += _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_tls _bb_init_func \
 	_arm_truncdfsf2 _arm_negsf2 _arm_addsubsf3 _arm_muldivsf3 \
 	_arm_cmpsf2 _arm_unordsf2 _arm_fixsfsi _arm_fixunssfsi \
 	_arm_floatdidf _arm_floatdisf _arm_floatundidf _arm_floatundisf \
-	_clzsi2 _clzdi2 
+	_clzsi2 _clzdi2 _ctzsi2
 
 # Currently there is a bug somewhere in GCC's alias analysis
 # or scheduling code that is breaking _fpmul_parts in fp-bit.c.

libgcc/config/arm/t-linux

 LIB1ASMSRC = arm/lib1funcs.S
 LIB1ASMFUNCS = _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_lnx _clzsi2 _clzdi2 \
-	_arm_addsubdf3 _arm_addsubsf3
+	_ctzsi2 _arm_addsubdf3 _arm_addsubsf3
 
 # Just for these, we omit the frame pointer since it makes such a big
 # difference.

libgcc/config/arm/t-strongarm-elf

-LIB1ASMFUNCS += _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_tls _bb_init_func _clzsi2 _clzdi2
+LIB1ASMFUNCS += _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_tls _bb_init_func _clzsi2 _clzdi2 _ctzsi2
 
 # Currently there is a bug somewhere in GCC's alias analysis
 # or scheduling code that is breaking _fpmul_parts in fp-bit.c.

libgcc/config/arm/t-symbian

-LIB1ASMFUNCS += _bb_init_func _call_via_rX _interwork_call_via_rX _clzsi2 _clzdi2
+LIB1ASMFUNCS += _bb_init_func _call_via_rX _interwork_call_via_rX _clzsi2 _clzdi2 _ctzsi2
 
 # These functions have __aeabi equivalents and will never be called by GCC.  
 # By putting them in LIB1ASMFUNCS, we avoid the standard libgcc2.c code being

libgcc/config/arm/t-vxworks

-LIB1ASMFUNCS += _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_tls _bb_init_func _call_via_rX _interwork_call_via_rX _clzsi2 _clzdi2
+LIB1ASMFUNCS += _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_tls _bb_init_func _call_via_rX _interwork_call_via_rX _clzsi2 _clzdi2 _ctzsi2

libgcc/config/arm/t-wince-pe

-LIB1ASMFUNCS += _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_tls _call_via_rX _interwork_call_via_rX _clzsi2 _clzdi2
+LIB1ASMFUNCS += _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_tls _call_via_rX _interwork_call_via_rX _clzsi2 _clzdi2 _ctzsi2