github.com/ader1990/go@v0.0.0-20140630135419-8c24447fa791/src/cmd/cc/bv.c (about)

     1  // Copyright 2013 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  #include <u.h>
     6  #include "cc.h"
     7  
     8  enum {
     9  	WORDSIZE = sizeof(uint32),
    10  	WORDBITS = 32,
    11  };
    12  
    13  uintptr
    14  bvsize(uintptr n)
    15  {
    16  	return ((n + WORDBITS - 1) / WORDBITS) * WORDSIZE;
    17  }
    18  
    19  Bvec*
    20  bvalloc(int32 n)
    21  {
    22  	Bvec *bv;
    23  	uintptr nbytes;
    24  
    25  	if(n < 0)
    26  		fatal(Z, "bvalloc: initial size is negative\n");
    27  	nbytes = sizeof(Bvec) + bvsize(n);
    28  	bv = malloc(nbytes);
    29  	if(bv == nil)
    30  		fatal(Z, "bvalloc: malloc failed\n");
    31  	memset(bv, 0, nbytes);
    32  	bv->n = n;
    33  	return bv;
    34  }
    35  
    36  void
    37  bvset(Bvec *bv, int32 i)
    38  {
    39  	uint32 mask;
    40  
    41  	if(i < 0 || i >= bv->n)
    42  		fatal(Z, "bvset: index %d is out of bounds with length %d\n", i, bv->n);
    43  	mask = 1 << (i % WORDBITS);
    44  	bv->b[i / WORDBITS] |= mask;
    45  }