7 files changed, 15 insertions, 12 deletions

diff --git a/array.c b/array.c
index 73e8a3c9ce..a33c43bdbf 100644
--- a/array.c
+++ b/array.c
@@ -1389,7 +1389,7 @@ ary_make_partial_step(VALUE ary, VALUE klass, long offset, long len, long step)
     }
 
     long ustep = (step < 0) ? -step : step;
-    len = (len + ustep - 1) / ustep;
+    len = roomof(len, ustep);
 
     long i;
     long j = offset + ((step > 0) ? 0 : (orig_len - 1));
diff --git a/bignum.c b/bignum.c
index 9901a807b1..4f8349dd17 100644
--- a/bignum.c
+++ b/bignum.c
@@ -977,7 +977,7 @@ integer_unpack_num_bdigits_small(size_t numwords, size_t wordsize, size_t nails,
 {
     /* nlp_bits stands for number of leading padding bits */
     size_t num_bits = (wordsize * CHAR_BIT - nails) * numwords;
-    size_t num_bdigits = (num_bits + BITSPERDIG - 1) / BITSPERDIG;
+    size_t num_bdigits = roomof(num_bits, BITSPERDIG);
     *nlp_bits_ret = (int)(num_bdigits * BITSPERDIG - num_bits);
     return num_bdigits;
 }
@@ -987,7 +987,7 @@ integer_unpack_num_bdigits_generic(size_t numwords, size_t wordsize, size_t nail
 {
     /* BITSPERDIG = SIZEOF_BDIGIT * CHAR_BIT */
     /* num_bits = (wordsize * CHAR_BIT - nails) * numwords */
-    /* num_bdigits = (num_bits + BITSPERDIG - 1) / BITSPERDIG */
+    /* num_bdigits = roomof(num_bits, BITSPERDIG) */
 
     /* num_bits = CHAR_BIT * (wordsize * numwords) - nails * numwords = CHAR_BIT * num_bytes1 - nails * numwords */
     size_t num_bytes1 = wordsize * numwords;
diff --git a/gc.c b/gc.c
index a5e37b72e2..52d5609c3e 100644
--- a/gc.c
+++ b/gc.c
@@ -870,7 +870,7 @@ typedef struct rb_objspace {
 
 #define BASE_SLOT_SIZE sizeof(RVALUE)
 
-#define CEILDIV(i, mod) (((i) + (mod) - 1)/(mod))
+#define CEILDIV(i, mod) roomof(i, mod)
 enum {
     HEAP_PAGE_ALIGN = (1UL << HEAP_PAGE_ALIGN_LOG),
     HEAP_PAGE_ALIGN_MASK = (~(~0UL << HEAP_PAGE_ALIGN_LOG)),
diff --git a/internal/numeric.h b/internal/numeric.h
index 19069cb3bc..89bc54b307 100644
--- a/internal/numeric.h
+++ b/internal/numeric.h
@@ -35,12 +35,16 @@ enum ruby_num_rounding_mode {
     RUBY_NUM_ROUND_DEFAULT = ROUND_DEFAULT,
 };
 
+/* same as internal.h */
+#define numberof(array) ((int)(sizeof(array) / sizeof((array)[0])))
+#define roomof(x, y) (((x) + (y) - 1) / (y))
+#define type_roomof(x, y) roomof(sizeof(x), sizeof(y))
+
 #if SIZEOF_DOUBLE <= SIZEOF_VALUE
 typedef double rb_float_value_type;
 #else
 typedef struct {
-    VALUE values[(SIZEOF_DOUBLE + SIZEOF_VALUE - 1) / SIZEOF_VALUE];
-    /* roomof() needs internal.h, and the order of some macros may matter */
+    VALUE values[roomof(SIZEOF_DOUBLE, SIZEOF_VALUE)];
 } rb_float_value_type;
 #endif
 
diff --git a/numeric.c b/numeric.c
index 4f927f00fb..8607d69794 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1055,7 +1055,7 @@ flo_to_s(VALUE flt)
 {
     enum {decimal_mant = DBL_MANT_DIG-DBL_DIG};
     enum {float_dig = DBL_DIG+1};
-    char buf[float_dig + (decimal_mant + CHAR_BIT - 1) / CHAR_BIT + 10];
+    char buf[float_dig + roomof(decimal_mant, CHAR_BIT) + 10];
     double value = RFLOAT_VALUE(flt);
     VALUE s;
     char *p, *e;
diff --git a/regcomp.c b/regcomp.c
index 94640639d8..be85d85f93 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -341,7 +341,7 @@ static int
 select_str_opcode(int mb_len, OnigDistance byte_len, int ignore_case)
 {
   int op;
-  OnigDistance str_len = (byte_len + mb_len - 1) / mb_len;
+  OnigDistance str_len = roomof(byte_len, mb_len);
 
   if (ignore_case) {
     switch (str_len) {
diff --git a/regenc.h b/regenc.h
index 8c4ff0483b..1c40901054 100644
--- a/regenc.h
+++ b/regenc.h
@@ -125,10 +125,9 @@ typedef struct {
 #define POSIX_BRACKET_ENTRY_INIT(name, ctype) \
   {(short int )(sizeof(name) - 1), name, (ctype)}
 
-#ifndef numberof
-# define numberof(array) (int )(sizeof(array) / sizeof((array)[0]))
-#endif
-
+#define numberof(array) ((int)(sizeof(array) / sizeof((array)[0])))
+#define roomof(x, y) (((x) + (y) - 1) / (y))
+#define type_roomof(x, y) roomof(sizeof(x), sizeof(y))
 
 #define USE_CRNL_AS_LINE_TERMINATOR
 #define USE_UNICODE_PROPERTIES