code review 9223046: cmd/5l, cmd/6l, cmd/8l, cmd/gc, runtime: generate and u...

src/cmd/gc/bv.c

 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include <u.h>
 #include <libc.h>
 #include "go.h"
 
 enum {
         WORDSIZE = sizeof(uint32),
-        WORDSIZELOG2 = 2,
-        WORDBITS = WORDSIZE << WORDSIZELOG2,
+        WORDBITS = 32,
 };
 
-static uintptr
-size(uintptr n)
+uintptr
+bvsize(uintptr n)
 {
         return ((n + WORDBITS - 1) / WORDBITS) * WORDSIZE;
 }
 
 Bvec*
 bvalloc(int32 n)
 {
         Bvec *bv;
         uintptr nbytes;
 
         if(n < 0)
-                fatal("initial size is negative\n");
-        nbytes = sizeof(Bvec) + size(n);
+                fatal("bvalloc: initial size is negative\n");
+        nbytes = sizeof(Bvec) + bvsize(n);
         bv = malloc(nbytes);
         if(bv == nil)
-                fatal("malloc failed\n");
+                fatal("bvalloc: malloc failed\n");
         memset(bv, 0, nbytes);
         bv->n = n;
         return bv;
 }
 
 void
 bvset(Bvec *bv, int32 i)
 {
         uint32 mask;
 
         if(i < 0 || i >= bv->n)
-                fatal("index %d is out of bounds with length %d\n", i, bv->n);
+                fatal("bvset: index %d is out of bounds with length %d\n", i, bv->n);
         mask = 1 << (i % WORDBITS);
         bv->b[i / WORDBITS] |= mask;
 }
 
 void
 bvres(Bvec *bv, int32 i)
 {
         uint32 mask;
 
         if(i < 0 || i >= bv->n)
-                fatal("index %d is out of bounds with length %d\n", i, bv->n);
+                fatal("bvres: index %d is out of bounds with length %d\n", i, bv->n);
         mask = ~(1 << (i % WORDBITS));
         bv->b[i / WORDBITS] &= mask;
 }
 
 int
 bvget(Bvec *bv, int32 i)
 {
         uint32 mask, word;
 
         if(i < 0 || i >= bv->n)
-                fatal("index %d is out of bounds with length %d\n", i, bv->n);
+                fatal("bvget: index %d is out of bounds with length %d\n", i, bv->n);
         mask = 1 << (i % WORDBITS);
         word = bv->b[i / WORDBITS] & mask;
-        return (word ? 1 : 0);
+        return word ? 1 : 0;
 }
 
-static int32
-popcnt(uint32 x)
+int
+bvisempty(Bvec *bv)
 {
-        x = x - ((x >> 1) & 0x55555555);
-        x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
-        x = (x + (x >> 4)) & 0x0f0f0f0f;
-        x = x + (x >> 8);
-        x = x + (x >> 16);
-        return x & 0x0000003f;
+        int32 i;
+
+        for(i = 0; i < bv->n; i += WORDBITS)
+                if(bv->b[i / WORDBITS] != 0)
+                        return 0;
+        return 1;
 }
 
-int32
-bvpopcnt(Bvec *bv)
+int bvcmp(Bvec *bv1, Bvec *bv2)
 {
-        int32 i, sum;
+        int32 i;
 
-        sum = 0;
-        for(i = 0; i < bv->n; i += WORDBITS)
-                sum += popcnt(bv->b[i / WORDBITS]);
-        return sum;
+        if(bv1->n != bv2->n) {
+                fatal("bvcmp: size %d != %d\n", bv1->n, bv2->n);
+        }
+        for(i = 0; i < bv1->n; i += WORDBITS) {
+                if(bv1->b[i / WORDBITS] != bv2->b[i / WORDBITS]) {
+                        fatal("bvcmp: element %x != %x @ %d\n", bv1->b[i/WORDBITS], bv2->b[i/WORDBITS], i/WORDBITS);
+                }
+        }
+        return 0;
 }