bitset: better implementation of bsiter() and stuff

Also changed the type to size_t for portability

3 files changed, 17 insertions, 11 deletions

diff --git a/common.h b/common.h
index 3d2166b..c3ccc63 100644
--- a/common.h
+++ b/common.h
@@ -294,26 +294,26 @@ extern char pmap_tombstone_[];
       if (kx && kx != pmap_tombstone_)
 
 /** bitset **/
-struct bitset { uvlong u; };
-enum { BSNBIT = 8 * sizeof(uvlong) };
-#define BSSIZE(nbit) ((nbit) / BSNBIT + ((nbit) % BSNBIT != 0))
+struct bitset { size_t u; };
+enum { BSNBIT = 8 * sizeof(struct bitset) };
+#define BSSIZE(nbit) ((nbit)/BSNBIT + ((nbit)%BSNBIT != 0))
 
 static inline bool
 bstest(const struct bitset *bs, uint i)
 {
-   return bs[i / BSNBIT].u >> i % BSNBIT & 1;
+   return bs[i/BSNBIT].u >> i%BSNBIT & 1;
 }
 
 static inline void
 bsset(struct bitset *bs, uint i)
 {
-   bs[i / BSNBIT].u |= 1ull << i % BSNBIT;
+   bs[i/BSNBIT].u |= 1ull << i%BSNBIT;
 }
 
 static inline void
 bsclr(struct bitset *bs, uint i)
 {
-   bs[i / BSNBIT].u &= ~(1ull << i % BSNBIT);
+   bs[i/BSNBIT].u &= ~(1ull << i%BSNBIT);
 }
 
 static inline void
@@ -345,9 +345,15 @@ bscount(struct bitset bs[/*siz*/], uint siz)
 static inline bool
 bsiter(uint *i, struct bitset bs[/*siz*/], uint siz)
 {
-   for (; *i < siz*BSNBIT; ++*i)
-      if (bstest(bs, *i)) return 1;
-   return 0;
+   uint k = *i/BSNBIT, j = *i%BSNBIT;
+   if (k >= siz) return 0;
+   size_t t = bs[k].u & ~(((size_t)1 << j) - 1);
+   while (!t) {
+      if (++k >= siz) return 0;
+      t = bs[k].u;
+   }
+   *i = k*BSNBIT + lowestsetbit(t);
+   return 1;
 }
 #define bs_each(T, var, bs, siz) for (T (var) = 0; bsiter(&(var), (bs), (siz)); ++(var))
 
diff --git a/ir/optmem.c b/ir/optmem.c
index 35544b2..f9ad245 100644
--- a/ir/optmem.c
+++ b/ir/optmem.c
@@ -228,7 +228,7 @@ mem2reg(struct function *fn)
 
    FREQUIRE(FNUSE);
 
-   if (fn->nblk <= 64 * countof(bsbuf[0])) {
+   if (fn->nblk <= BSNBIT * countof(bsbuf[0])) {
       sb.sealed = bsbuf[0];
       sb.marked = bsbuf[1];
       memset(bsbuf[0], 0, BSSIZE(fn->nblk) * sizeof *bsbuf[0]);
diff --git a/ir/regalloc.c b/ir/regalloc.c
index 29d9f88..691793e 100644
--- a/ir/regalloc.c
+++ b/ir/regalloc.c
@@ -194,7 +194,7 @@ allocstk(struct rega *ra)
 
    for (int i = 0; i < BSSIZE(MAXSPILL); ++i) {
       if (ra->freestk[i].u != 0) {
-         s = i*64 + lowestsetbit(ra->freestk[i].u);
+         s = i*BSNBIT + lowestsetbit(ra->freestk[i].u);
          break;
       }
    }