From: Chris Hanson <org/chris-hanson/cph>
Date: Mon, 12 Nov 2018 06:59:33 +0000 (-0800)
Subject: Fix bug: -Werror means FOO_length_in_bits won't compile on 32-bit gcc.
X-Git-Tag: mit-scheme-pucked-10.1.2~16^2~108
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=5dd0b42b6ea96882ce31a0df9e6420bfc4eea6e9;p=mit-scheme.git

Fix bug: -Werror means FOO_length_in_bits won't compile on 32-bit gcc.

Before it just issued a warning.  I rewrote it so that it works.
---

diff --git a/src/microcode/bits.h b/src/microcode/bits.h
index ccd7d0be3..27d7e6975 100644
--- a/src/microcode/bits.h
+++ b/src/microcode/bits.h
@@ -76,29 +76,44 @@ NAME (TYPE x)								\
 DEFINE_BIT_COUNT (uintmax_bit_count, uintmax_t)
 DEFINE_BIT_COUNT (ulong_bit_count, unsigned long)
 
-#define DEFINE_LENGTH_IN_BITS(NAME, TYPE, BIT_COUNT)			\
-static inline unsigned int						\
-NAME (TYPE x)								\
-{									\
+#define LENGTH_IN_BITS_32(TYPE_SIZE)					\
   /* Round up to a power of two minus one; i.e., set all bits in x	\
      below and including its most significant set bit.  */		\
-  int i, limit = (CHAR_BIT * (sizeof (TYPE)));				\
-  /* Unrolling this loop substantially improves performance.  The `for'	\
-     at the end is for completeness; a good compiler should realize	\
-     that it is dead code on just about any system.  */			\
+  int limit = (CHAR_BIT * (TYPE_SIZE));					\
+  /* Unrolling this loop substantially improves performance.  */	\
   if (1 < limit) x |= (x >> 1);						\
   if (2 < limit) x |= (x >> 2);						\
   if (4 < limit) x |= (x >> 4);						\
   if (8 < limit) x |= (x >> 8);						\
-  if (0x10 < limit) x |= (x >> 0x10);					\
+  if (0x10 < limit) x |= (x >> 0x10);
+
+#define LENGTH_IN_BITS_64						\
   if (0x20 < limit) x |= (x >> 0x20);					\
+  /* This `for' loop is for completeness; a good compiler should	\
+     realize that it is dead code on just about any system.  */		\
+  int i;								\
   for (i = 0x40; i < limit; i <<= 1)					\
-    x |= (x >> i);							\
-  return (BIT_COUNT (x));						\
+    x |= (x >> i);
+
+static inline unsigned int
+ulong_length_in_bits (unsigned long x)
+{
+  LENGTH_IN_BITS_32(SIZEOF_UNSIGNED_LONG)
+#if (SIZEOF_UNSIGNED_LONG >= 8)
+  LENGTH_IN_BITS_64
+#endif
+  return (ulong_bit_count (x));
 }
 
-DEFINE_LENGTH_IN_BITS (uintmax_length_in_bits, uintmax_t, uintmax_bit_count)
-DEFINE_LENGTH_IN_BITS (ulong_length_in_bits, unsigned long, ulong_bit_count)
+static inline unsigned int
+uintmax_length_in_bits (uintmax_t x)
+{
+  LENGTH_IN_BITS_32(SIZEOF_UINTMAX_T)
+#if (SIZEOF_UINTMAX_T >= 8)
+  LENGTH_IN_BITS_64
+#endif
+  return (uintmax_bit_count (x));
+}
 
 #define DEFINE_FIRST_SET_BIT(NAME, TYPE, LENGTH_IN_BITS)	\
 static inline int						\