root/src/cmd/cc/bv.c

DEFINITIONS

1. bvsize
2. bvalloc
3. bvset

// 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 "cc.h"

enum {
        WORDSIZE = sizeof(uint32),
        WORDBITS = 32,
};

uintptr
bvsize(uintptr n)
{
        return ((n + WORDBITS - 1) / WORDBITS) * WORDSIZE;
}

Bvec*
bvalloc(int32 n)
{
        Bvec *bv;
        uintptr nbytes;

        if(n < 0)
                fatal(Z, "bvalloc: initial size is negative\n");
        nbytes = sizeof(Bvec) + bvsize(n);
        bv = malloc(nbytes);
        if(bv == nil)
                fatal(Z, "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(Z, "bvset: index %d is out of bounds with length %d\n", i, bv->n);
        mask = 1 << (i % WORDBITS);
        bv->b[i / WORDBITS] |= mask;
}