NPAGES           3311 gc/os_dep.c    PCR_VD_DB  GC_grungy_bits[NPAGES];
NPAGES           3324 gc/os_dep.c        if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE)
NPAGES           3344 gc/os_dep.c        if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits)
NPAGES           3353 gc/os_dep.c        if((ptr_t)h < GC_vd_base || (ptr_t)h >= GC_vd_base + NPAGES*HBLKSIZE) {