diff --git a/cop.h b/cop.h
index 33463a0ab27a..fd0e12a84a15 100644
--- a/cop.h
+++ b/cop.h
@@ -885,7 +885,7 @@ struct block_loop {
  *  Note the contrast with CvLVALUE(), which is a property of the sub
  *  rather than the call site.
  */
-#define CxLVAL(c)	(0 + ((c)->blk_u16 & 0xff))
+#define CxLVAL(c)	(0 + ((U8)((c)->blk_u16)))
 
 
 
diff --git a/dist/Storable/Storable.pm b/dist/Storable/Storable.pm
index 27c9cf54c345..c1c94f04c197 100644
--- a/dist/Storable/Storable.pm
+++ b/dist/Storable/Storable.pm
@@ -28,7 +28,7 @@ our @EXPORT_OK = qw(
 our ($canonical, $forgive_me);
 
 BEGIN {
-  our $VERSION = '3.23';
+  our $VERSION = '3.24';
 }
 
 our $recursion_limit;
diff --git a/dist/Storable/Storable.xs b/dist/Storable/Storable.xs
index 70dddf3f100c..30fd69fbece0 100644
--- a/dist/Storable/Storable.xs
+++ b/dist/Storable/Storable.xs
@@ -1247,7 +1247,7 @@ static const char byteorderstr_56[] = {BYTEORDER_BYTES_56, 0};
 #    define Sntohl(x) (x)
 #  else
 static U32 Sntohl(U32 x) {
-    return ((x & 0xFF) << 24) + ((x * 0xFF00) << 8)
+    return (((U8) x) << 24) + ((x * 0xFF00) << 8)
 	+ ((x & 0xFF0000) >> 8) + ((x & 0xFF000000) >> 24);
 }
 #  endif
diff --git a/dist/Unicode-Normalize/Normalize.pm b/dist/Unicode-Normalize/Normalize.pm
index fd6f1cb700fb..918c4d832e35 100644
--- a/dist/Unicode-Normalize/Normalize.pm
+++ b/dist/Unicode-Normalize/Normalize.pm
@@ -16,7 +16,7 @@ use Carp;
 
 no warnings 'utf8';
 
-our $VERSION = '1.28';
+our $VERSION = '1.29';
 our $PACKAGE = __PACKAGE__;
 
 our @EXPORT = qw( NFC NFD NFKC NFKD );
diff --git a/dist/Unicode-Normalize/Normalize.xs b/dist/Unicode-Normalize/Normalize.xs
index 0c151b71b0cb..2695f8394124 100644
--- a/dist/Unicode-Normalize/Normalize.xs
+++ b/dist/Unicode-Normalize/Normalize.xs
@@ -139,8 +139,8 @@ static U8* dec_canonical(UV uv)
     plane = (U8***)UNF_canon[uv >> 16];
     if (! plane)
 	return NULL;
-    row = plane[(uv >> 8) & 0xff];
-    return row ? row[uv & 0xff] : NULL;
+    row = plane[(U8) (uv >> 8)];
+    return row ? row[(U8) uv] : NULL;
 }
 
 static U8* dec_compat(UV uv)
@@ -151,8 +151,8 @@ static U8* dec_compat(UV uv)
     plane = (U8***)UNF_compat[uv >> 16];
     if (! plane)
 	return NULL;
-    row = plane[(uv >> 8) & 0xff];
-    return row ? row[uv & 0xff] : NULL;
+    row = plane[(U8) (uv >> 8)];
+    return row ? row[(U8) uv] : NULL;
 }
 
 static UV composite_uv(UV uv, UV uv2)
@@ -175,10 +175,10 @@ static UV composite_uv(UV uv, UV uv2)
     plane = UNF_compos[uv >> 16];
     if (! plane)
 	return 0;
-    row = plane[(uv >> 8) & 0xff];
+    row = plane[(U8) (uv >> 8)];
     if (! row)
 	return 0;
-    cell = row[uv & 0xff];
+    cell = row[(U8) uv];
     if (! cell)
 	return 0;
     for (i = cell; i->nextchar; i++) {
@@ -196,8 +196,8 @@ static U8 getCombinClass(UV uv)
     plane = (U8**)UNF_combin[uv >> 16];
     if (! plane)
 	return 0;
-    row = plane[(uv >> 8) & 0xff];
-    return row ? row[uv & 0xff] : 0;
+    row = plane[(U8) (uv >> 8)];
+    return row ? row[(U8) uv] : NULL;
 }
 
 static U8* pv_cat_decompHangul(pTHX_ U8* d, UV uv)
diff --git a/doop.c b/doop.c
index e179c0f83557..f359aab1303d 100644
--- a/doop.c
+++ b/doop.c
@@ -363,7 +363,8 @@ S_do_trans_count_invmap(pTHX_ SV * const sv, AV * const invmap)
         SSize_t i;
         STRLEN s_len;
 
-        /* Get the code point of the next character in the string */
+        /* remove from loop; look for all INVARIANT calls in the code; should be replaceable
+         * Get the code point of the next character in the string */
         if (! SvUTF8(sv) || UTF8_IS_INVARIANT(*s)) {
             from = *s;
             s_len = 1;
diff --git a/dump.c b/dump.c
index a72accddb3bf..a939c3ff5649 100644
--- a/dump.c
+++ b/dump.c
@@ -181,7 +181,7 @@ Perl_pv_escape( pTHX_ SV *dsv, char const * const str,
     
     for ( ; (pv < end && (!max || (wrote < max))) ; pv += readsize ) {
         const UV u= (isuni) ? utf8_to_uvchr_buf((U8*)pv, (U8*) end, &readsize) : (U8)*pv;
-        const U8 c = (U8)u & 0xFF;
+        const U8 c = (U8)u;
         
         if ( ( u > 255 )
           || (flags & PERL_PV_ESCAPE_ALL)
diff --git a/ext/Opcode/Opcode.xs b/ext/Opcode/Opcode.xs
index f574ca2cd7a2..3923386a117a 100644
--- a/ext/Opcode/Opcode.xs
+++ b/ext/Opcode/Opcode.xs
@@ -68,7 +68,7 @@ op_names_init(pTHX)
     bitmap = (U8*)SvPV(opset_all, len);
     memset(bitmap, 0xFF, len-1); /* deal with last byte specially, see below */
     /* Take care to set the right number of bits in the last byte */
-    bitmap[len-1] = (PL_maxo & 0x07) ? ((~(0xFF << (PL_maxo & 0x07))) & 0xFF)
+    bitmap[len-1] = (PL_maxo & 0x07) ? ((U8) (~(0xFF << (PL_maxo & 0x07))))
                                      : 0xFF;
     put_op_bitspec(aTHX_ STR_WITH_LEN(":all"), opset_all); /* don't mortalise */
 }
diff --git a/ext/POSIX/POSIX.xs b/ext/POSIX/POSIX.xs
index 27ba2dc45919..c26651016994 100644
--- a/ext/POSIX/POSIX.xs
+++ b/ext/POSIX/POSIX.xs
@@ -1678,7 +1678,7 @@ static const struct lconv_offset lconv_integers[] = {
  * in the first place, though. -- Ingo Weinhold
  */
 #if defined(__HAIKU__)
-#    define WMUNGE(x) (((x) & 0xFF00) >> 8 | ((x) & 0x00FF) << 8)
+#    define WMUNGE(x) (((x) & 0xFF00) >> 8 | (((U8) (x)) << 8))
 #else
 #    define WMUNGE(x) (x)
 #endif
diff --git a/ext/POSIX/lib/POSIX.pm b/ext/POSIX/lib/POSIX.pm
index 8305c3014a60..918dd9a73efb 100644
--- a/ext/POSIX/lib/POSIX.pm
+++ b/ext/POSIX/lib/POSIX.pm
@@ -4,7 +4,7 @@ use warnings;
 
 our ($AUTOLOAD, %SIGRT);
 
-our $VERSION = '1.98';
+our $VERSION = '1.99';
 
 require XSLoader;
 
diff --git a/inline.h b/inline.h
index 55b26e0d7810..e540e832cf9d 100644
--- a/inline.h
+++ b/inline.h
@@ -667,6 +667,7 @@ Perl_is_utf8_invariant_string_loc(const U8* const s, STRLEN len, const U8 ** ep)
 #ifndef EBCDIC
 
 PERL_STATIC_INLINE unsigned int
+/* rename to pos */
 Perl_variant_byte_number(PERL_UINTMAX_T word)
 {
 
diff --git a/perl.h b/perl.h
index 4acb23aefc15..2e72ce9f0910 100644
--- a/perl.h
+++ b/perl.h
@@ -1224,18 +1224,18 @@ Use L</UV> to declare variables of the maximum usable size on this platform.
 
 /* byte-swapping functions for big-/little-endian conversion */
 # define _swab_16_(x) ((U16)( \
-         (((U16)(x) & UINT16_C(0x00ff)) << 8) | \
-         (((U16)(x) & UINT16_C(0xff00)) >> 8) ))
+         (((U16)(U8) (x)                   ) << 8) |  \
+         (((U16)     (x) & UINT16_C(0xff00)) >> 8) ))
 
 # define _swab_32_(x) ((U32)( \
-         (((U32)(x) & UINT32_C(0x000000ff)) << 24) | \
+         (((U32)(U8)(x)                   ) << 24) | \
          (((U32)(x) & UINT32_C(0x0000ff00)) <<  8) | \
          (((U32)(x) & UINT32_C(0x00ff0000)) >>  8) | \
          (((U32)(x) & UINT32_C(0xff000000)) >> 24) ))
 
 # ifdef HAS_QUAD
 #  define _swab_64_(x) ((U64)( \
-          (((U64)(x) & UINT64_C(0x00000000000000ff)) << 56) | \
+          (((U64)(U8)(x)                           ) << 56) | \
           (((U64)(x) & UINT64_C(0x000000000000ff00)) << 40) | \
           (((U64)(x) & UINT64_C(0x0000000000ff0000)) << 24) | \
           (((U64)(x) & UINT64_C(0x00000000ff000000)) <<  8) | \
@@ -3512,7 +3512,7 @@ EXTERN_C int perl_tsa_mutex_unlock(perl_mutex* mutex)
             if (MY_POSIX_EXIT) { \
               if (evalue <= 0xFF00) {		\
                   if (evalue > 0xFF)			\
-                    evalue = (evalue >> child_offset_bits) & 0xFF; \
+                    evalue = ((U8) (evalue >> child_offset_bits)); \
                   PL_statusvalue_vms =		\
                     (C_FAC_POSIX | (evalue << 3 ) |	\
                     ((evalue == 1) ? (STS$K_ERROR | STS$M_INHIB_MSG) : 1)); \
@@ -4220,11 +4220,11 @@ my_swap16(const U16 x) {
 #  define htovl(x)      vtohl(x)
 #  define htovs(x)      vtohs(x)
 #elif BYTEORDER == 0x4321 || BYTEORDER == 0x87654321
-#  define vtohl(x)	((((x)&0xFF)<<24)	\
-                        +(((x)>>24)&0xFF)	\
+#  define vtohl(x)	((((U8) (x)) << 24)     \
+                        +((U8) ((x) >> 24))     \
                         +(((x)&0x0000FF00)<<8)	\
                         +(((x)&0x00FF0000)>>8)	)
-#  define vtohs(x)	((((x)&0xFF)<<8) + (((x)>>8)&0xFF))
+#  define vtohs(x)	((((U8) (x)) << 8) + ((U8) ((x) >> 8)))
 #  define htovl(x)	vtohl(x)
 #  define htovs(x)	vtohs(x)
 #else
diff --git a/pp_pack.c b/pp_pack.c
index 27b0a7116243..60cbfa529b2f 100644
--- a/pp_pack.c
+++ b/pp_pack.c
@@ -223,7 +223,7 @@ S_mul128(pTHX_ SV *sv, U8 m)
 #define TYPE_IS_PACK		0x800
 #define TYPE_ENDIANNESS_MASK	(TYPE_IS_BIG_ENDIAN|TYPE_IS_LITTLE_ENDIAN)
 #define TYPE_MODIFIERS(t)	((t) & ~0xFF)
-#define TYPE_NO_MODIFIERS(t)	((t) & 0xFF)
+#define TYPE_NO_MODIFIERS(t)	((U8) (t))
 
 # define TYPE_ENDIANNESS(t)	((t) & TYPE_ENDIANNESS_MASK)
 # define TYPE_NO_ENDIANNESS(t)	((t) & ~TYPE_ENDIANNESS_MASK)
@@ -263,7 +263,7 @@ utf8_to_byte(pTHX_ const char **s, const char *end, I32 datumtype)
         Perl_ck_warner(aTHX_ packWARN(WARN_UNPACK),
                        "Character in '%c' format wrapped in unpack",
                        (int) TYPE_NO_MODIFIERS(datumtype));
-        val &= 0xff;
+        val = (U8) val;
     }
     *s += retlen;
     return (U8)val;
@@ -296,7 +296,7 @@ S_utf8_to_bytes(pTHX_ const char **s, const char *end, const char *buf, SSize_t
         } else from += retlen;
         if (val >= 0x100) {
             bad |= 2;
-            val &= 0xff;
+            val = (U8) val;
         }
         if (UNLIKELY(needs_swap))
             *(U8 *)--buf = (U8)val;
@@ -2573,7 +2573,7 @@ S_pack_rec(pTHX_ SV *cat, tempsym_t* symptr, SV **beglist, SV **endlist )
                 if ((-128 > aiv || aiv > 127))
                     Perl_ck_warner(aTHX_ packWARN(WARN_PACK),
                                    "Character in 'c' format wrapped in pack");
-                PUSH_BYTE(utf8, cur, (U8)(aiv & 0xff));
+                PUSH_BYTE(utf8, cur, (U8)aiv);
             }
             break;
         case 'C':
@@ -2588,7 +2588,7 @@ S_pack_rec(pTHX_ SV *cat, tempsym_t* symptr, SV **beglist, SV **endlist )
                 if ((0 > aiv || aiv > 0xff))
                     Perl_ck_warner(aTHX_ packWARN(WARN_PACK),
                                    "Character in 'C' format wrapped in pack");
-                PUSH_BYTE(utf8, cur, (U8)(aiv & 0xff));
+                PUSH_BYTE(utf8, cur, (U8)aiv);
             }
             break;
         case 'W': {
@@ -2628,7 +2628,7 @@ S_pack_rec(pTHX_ SV *cat, tempsym_t* symptr, SV **beglist, SV **endlist )
                         }
                         Perl_ck_warner(aTHX_ packWARN(WARN_PACK),
                                        "Character in 'W' format wrapped in pack");
-                        auv &= 0xff;
+                        auv = (U8) auv;
                     }
                     if (cur >= end) {
                         *cur = '\0';
diff --git a/regcomp.h b/regcomp.h
index b92a08820f97..22847ca6b292 100644
--- a/regcomp.h
+++ b/regcomp.h
@@ -592,7 +592,7 @@ struct regnode_ssc {
  * are cautioned about its shared nature */
 #define ANYOF_SHARED_d_MATCHES_ALL_NON_UTF8_NON_ASCII_non_d_WARN_SUPER 0x80
 
-#define ANYOF_FLAGS_ALL		(0xff & ~0x10)
+#define ANYOF_FLAGS_ALL		((U8) ~0x10)
 
 #define ANYOF_LOCALE_FLAGS (ANYOFL_FOLD | ANYOF_MATCHES_POSIXL)
 
diff --git a/t/op/vec.t b/t/op/vec.t
index 0e8b5cee954a..c875bd92a2f9 100644
--- a/t/op/vec.t
+++ b/t/op/vec.t
@@ -6,12 +6,15 @@ BEGIN {
     set_up_inc('../lib');
 }
 
+use warnings;
+use strict;
 use Config;
 
 plan(tests => 78);
 
 my $exception_134139 = "Use of strings with code points over 0xFF as arguments to vec is forbidden";
 
+my $foo;
 is(vec($foo,0,1), 0);
 is(length($foo), undef);
 vec($foo,0,1) = 1;
@@ -29,11 +32,14 @@ is(vec($foo,1,8), 0xf1);
 is((unpack('C',substr($foo,1,1)) & 255), 0xf1);
 is(vec($foo,2,4), 1);;
 is(vec($foo,3,4), 15);
+
+my $Vec;
 vec($Vec, 0, 32) = 0xbaddacab;
 is($Vec, "\xba\xdd\xac\xab");
 is(vec($Vec, 0, 32), 3135089835);
 
 # ensure vec() handles numericalness correctly
+my ($bar, $baz);
 $foo = $bar = $baz = 0;
 vec($foo = 0,0,1) = 1;
 vec($bar = 0,1,1) = 1;
@@ -44,7 +50,7 @@ ok("$foo $bar $baz" eq "1 2 3");
 
 # error cases
 
-$x = eval { vec $foo, 0, 3 };
+my $x = eval { vec $foo, 0, 3 };
 like($@, qr/^Illegal number of bits in vec/);
 $@ = undef;
 $x = eval { vec $foo, 0, 0 };
@@ -67,7 +73,7 @@ is(vec($x, 0, 8), 255);
 $@ = undef;
 {
     local $@;
-    eval { vec($foo, 1, 8) };
+    eval { my $foo = vec($foo, 1, 8) };
     like($@, qr/$exception_134139/,
         "Caught exception: code point over 0xFF used as argument to vec");
     $@ = undef;
@@ -236,7 +242,7 @@ like($@, qr/^Modification of a read-only value attempted at /,
     like($@, qr/Negative offset to vec in lvalue context/, "RT131083 lval -1");
 
     $off = ~0;
-    my $v = RT131083(0, vec($s, $off, 8));
+    $v = RT131083(0, vec($s, $off, 8));
     is($v, 0, "RT131083 rval ~0");
     $v = eval { RT131083(1, vec($s, $off, 8)); };
     like($@, qr/Out of memory!/, "RT131083 lval ~0");
@@ -247,7 +253,7 @@ like($@, qr/^Modification of a read-only value attempted at /,
 
     local $@;
     my $foo = "\x{100}" . "\xff\xfe";
-    eval { vec($foo, 1, 8) };
+    eval { my $bar = vec($foo, 1, 8) };
     like($@, qr/$exception_134139/,
         "RT 134139: Use of strings with code points over 0xFF as arguments to 'vec' is now forbidden");
 }
diff --git a/toke.c b/toke.c
index 18e342efd52b..e6f7a3a42fd7 100644
--- a/toke.c
+++ b/toke.c
@@ -9283,7 +9283,7 @@ Perl_yylex(pTHX)
                     if (PL_lex_brackets > 100)
                         Renew(PL_lex_brackstack, PL_lex_brackets + 10, char);
                     PL_lex_brackstack[PL_lex_brackets++] =
-                        (char) ((next_type >> 16) & 0xff);
+                        (char) ((U8) (next_type >> 16));
                 }
                 if (next_type & (2<<24))
                     PL_lex_allbrackets++;
diff --git a/vms/vms.c b/vms/vms.c
index abdbe11bfec4..6c9fbc8ac0d1 100644
--- a/vms/vms.c
+++ b/vms/vms.c
@@ -601,8 +601,8 @@ copy_expand_vms_filename_escape(char *outspec, const char *inspec, int *output_c
             if (scnt == 4) {
                 unsigned int c1, c2;
                 scnt = sscanf(inspec, "%2x%2x", &c1, &c2);
-                outspec[0] = c1 & 0xff;
-                outspec[1] = c2 & 0xff;
+                outspec[0] = (U8) c1;
+                outspec[1] = (U8) c2;
                 if (scnt > 1) {
                     (*output_cnt) += 2;
                     count += 4;
diff --git a/win32/fcrypt.c b/win32/fcrypt.c
index 219f4f0b866d..35e0dbe19548 100644
--- a/win32/fcrypt.c
+++ b/win32/fcrypt.c
@@ -35,10 +35,10 @@ typedef struct des_ks_struct
                          l|=((unsigned long)(*((c)++)))<<16, \
                          l|=((unsigned long)(*((c)++)))<<24)
 
-#define l2c(l,c)	(*((c)++)=(unsigned char)(((l)    )&0xff), \
-                         *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
-                         *((c)++)=(unsigned char)(((l)>>16)&0xff), \
-                         *((c)++)=(unsigned char)(((l)>>24)&0xff))
+#define l2c(l,c)	(*((c)++)=(unsigned char)((l)    ), \
+                         *((c)++)=(unsigned char)((l)>> 8), \
+                         *((c)++)=(unsigned char)((l)>>16), \
+                         *((c)++)=(unsigned char)((l)>>24))
 
 static const unsigned long SPtrans[8][64]={
 { /* nibble 0 */
@@ -357,7 +357,7 @@ des_set_key(des_cblock *key, des_key_schedule schedule)
         PERM_OP (d,c,t,1,0x55555555);
         PERM_OP (c,d,t,8,0x00ff00ff);
         PERM_OP (d,c,t,1,0x55555555);
-        d=	(((d&0x000000ff)<<16)| (d&0x0000ff00)     |
+        d=	((((U8) d)      <<16)| (d&0x0000ff00)     |
                  ((d&0x00ff0000)>>16)|((c&0xf0000000)>>4));
         c&=0x0fffffff;
 
diff --git a/win32/win32.c b/win32/win32.c
index 861e707760fa..70ab455275b6 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -2637,7 +2637,7 @@ win32_internal_wait(pTHX_ int *status, DWORD timeout)
             else
                 i = waitcode - WAIT_OBJECT_0;
             if (GetExitCodeThread(w32_pseudo_child_handles[i], &exitcode)) {
-                *status = (int)((exitcode & 0xff) << 8);
+                *status = (int)(((U8) exitcode) << 8);
                 retval = (int)w32_pseudo_child_pids[i];
                 remove_dead_pseudo_process(i);
                 return -retval;
@@ -2663,7 +2663,7 @@ win32_internal_wait(pTHX_ int *status, DWORD timeout)
         else
             i = waitcode - WAIT_OBJECT_0;
         if (GetExitCodeProcess(w32_child_handles[i], &exitcode) ) {
-            *status = (int)((exitcode & 0xff) << 8);
+            *status = (int)(((U8) exitcode) << 8);
             retval = (int)w32_child_pids[i];
             remove_dead_process(i);
             return retval;
@@ -2695,7 +2695,7 @@ win32_waitpid(int pid, int *status, int flags)
             }
             else if (waitcode == WAIT_OBJECT_0) {
                 if (GetExitCodeThread(hThread, &waitcode)) {
-                    *status = (int)((waitcode & 0xff) << 8);
+                    *status = (int)(((U8) waitcode) << 8);
                     retval = (int)w32_pseudo_child_pids[child];
                     remove_dead_pseudo_process(child);
                     return -retval;
@@ -2718,7 +2718,7 @@ win32_waitpid(int pid, int *status, int flags)
             }
             else if (waitcode == WAIT_OBJECT_0) {
                 if (GetExitCodeProcess(hProcess, &waitcode)) {
-                    *status = (int)((waitcode & 0xff) << 8);
+                    *status = (int)(((U8) waitcode) << 8);
                     retval = (int)w32_child_pids[child];
                     remove_dead_process(child);
                     return retval;
@@ -2737,7 +2737,7 @@ win32_waitpid(int pid, int *status, int flags)
                 }
                 else if (waitcode == WAIT_OBJECT_0) {
                     if (GetExitCodeProcess(hProcess, &waitcode)) {
-                        *status = (int)((waitcode & 0xff) << 8);
+                        *status = (int)(((U8) waitcode) << 8);
                         CloseHandle(hProcess);
                         return pid;
                     }