[libspirv][generic] re-use __clc_ctz implementation for __spirv_ocl_ctz (#18478)

Add schar variant of __clc_ctz since libspirv requires schar variant.

Author: wenju-he

libclc/clc/lib/generic/integer/clc_ctz.cl

@@ -14,6 +14,10 @@ _CLC_OVERLOAD _CLC_DEF char __clc_ctz(char x) {
   return __clc_ctz(__clc_as_uchar(x));
 }
 
+_CLC_OVERLOAD _CLC_DEF schar __clc_ctz(schar x) {
+  return __clc_ctz(__clc_as_uchar(x));
+}
+
 _CLC_OVERLOAD _CLC_DEF uchar __clc_ctz(uchar x) { return __builtin_ctzg(x, 8); }
 
 _CLC_OVERLOAD _CLC_DEF short __clc_ctz(short x) {
@@ -39,6 +43,7 @@ _CLC_OVERLOAD _CLC_DEF ulong __clc_ctz(ulong x) {
 }
 
 _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, char, __clc_ctz, char)
+_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, schar, __clc_ctz, schar)
 _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, uchar, __clc_ctz, uchar)
 _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, short, __clc_ctz, short)
 _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, ushort, __clc_ctz, ushort)

libclc/libspirv/lib/generic/integer/ctz.cl

@@ -6,51 +6,11 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include <clc/clcmacro.h>
+#include <clc/integer/clc_ctz.h>
 #include <libspirv/spirv.h>
 
-_CLC_OVERLOAD _CLC_DEF short __spirv_ocl_ctz(short x) {
-  return x ? __builtin_ctzs(x) : 16;
-}
+#define FUNCTION __spirv_ocl_ctz
+#define __CLC_FUNCTION(x) __clc_ctz
+#define __CLC_BODY <clc/shared/unary_def.inc>
 
-_CLC_OVERLOAD _CLC_DEF ushort __spirv_ocl_ctz(ushort x) {
-  return x ? __builtin_ctzs(x) : 16;
-}
-
-_CLC_OVERLOAD _CLC_DEF int __spirv_ocl_ctz(int x) {
-  return x ? __builtin_ctz(x) : 32;
-}
-
-_CLC_OVERLOAD _CLC_DEF uint __spirv_ocl_ctz(uint x) {
-  return x ? __builtin_ctz(x) : 32;
-}
-
-_CLC_OVERLOAD _CLC_DEF long __spirv_ocl_ctz(long x) {
-  return x ? __builtin_ctzl(x) : 64;
-}
-
-_CLC_OVERLOAD _CLC_DEF ulong __spirv_ocl_ctz(ulong x) {
-  return x ? __builtin_ctzl(x) : 64;
-}
-
-_CLC_OVERLOAD _CLC_DEF char __spirv_ocl_ctz(char x) {
-  return x ? __spirv_ocl_ctz((ushort)(uchar)x) : 8;
-}
-
-_CLC_OVERLOAD _CLC_DEF schar __spirv_ocl_ctz(schar x) {
-  return x ? __spirv_ocl_ctz((ushort)(uchar)x) : 8;
-}
-
-_CLC_OVERLOAD _CLC_DEF uchar __spirv_ocl_ctz(uchar x) {
-  return x ? __spirv_ocl_ctz((ushort)x) : 8;
-}
-
-_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, char, __spirv_ocl_ctz, char)
-_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, schar, __spirv_ocl_ctz, schar)
-_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, uchar, __spirv_ocl_ctz, uchar)
-_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, short, __spirv_ocl_ctz, short)
-_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, ushort, __spirv_ocl_ctz, ushort)
-_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, int, __spirv_ocl_ctz, int)
-_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, uint, __spirv_ocl_ctz, uint)
-_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, long, __spirv_ocl_ctz, long)
-_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, ulong, __spirv_ocl_ctz, ulong)
+#include <clc/integer/gentype.inc>