Resolve "comparison of signed and unsigned values" compiler warnings.

* allchblk.c (GC_allochblk_nth): Cast MAX_BLACK_LIST_ALLOC and
HBLKSIZE to signed_word.
* mallocx.c (GC_generic_malloc_many): Cast my_bytes_allocd to word.
* mark.c (GC_do_local_mark): Cast the result of local_top minus
local_mark_stack to word (since is non-negative).
* misc.c (GC_base): Declare sz as unsigned word.
* misc.c (GC_enable_incremental): Cast bytes_written to size_t in
comparison to len.
* obj_map.c (GC_initialize_offsets): Declare 'i' as unsigned.
* os_dep.c (GC_or_pages): Ditto.
* typd_mlc.c (GC_init_explicit_typing): Ditto.
* ptr_chck.c (GC_is_visible): Cast the result of p minus base to word.
* typd_mlc.c (GC_make_descriptor): Cast last_set_bit to word (since
non-negative) when compared to BITMAP_BITS.

1 files changed, 4 insertions, 3 deletions

diff --git a/typd_mlc.c b/typd_mlc.c
index b031f61e..32a9b0f3 100644
--- a/typd_mlc.c
+++ b/typd_mlc.c
@@ -346,7 +346,7 @@ STATIC mse * GC_array_mark_proc(word * addr, mse * mark_stack_ptr,
 /* Caller does not hold allocation lock. */
 STATIC void GC_init_explicit_typing(void)
 {
-    register int i;
+    register unsigned i;
     DCL_LOCK_STATE;
 
     GC_STATIC_ASSERT(sizeof(struct LeafDescriptor) % sizeof(word) == 0);
@@ -540,7 +540,8 @@ GC_API GC_descr GC_CALL GC_make_descriptor(GC_bitmap bm, size_t len)
 #   define HIGH_BIT (((word)1) << (WORDSZ - 1))
 
     if (!GC_explicit_typing_initialized) GC_init_explicit_typing();
-    while (last_set_bit >= 0 && !GC_get_bit(bm, last_set_bit)) last_set_bit --;
+    while (last_set_bit >= 0 && !GC_get_bit(bm, last_set_bit))
+      last_set_bit--;
     if (last_set_bit < 0) return(0 /* no pointers */);
 #   if ALIGNMENT == CPP_WORDSZ/8
     {
@@ -557,7 +558,7 @@ GC_API GC_descr GC_CALL GC_make_descriptor(GC_bitmap bm, size_t len)
       }
     }
 #   endif
-    if (last_set_bit < BITMAP_BITS) {
+    if ((word)last_set_bit < BITMAP_BITS) {
         /* Hopefully the common case.                   */
         /* Build bitmap descriptor (with bits reversed) */
         result = HIGH_BIT;