Mercurial > projects > ldc
view lphobos/gc/gcbits.d @ 1168:ab186e535e72
A different fix to #218 and DMD2682 that does not lead to constant folding regressions.
Fixes run/const_15, run/c/const_16_B.
The price is removing the lvalueness of struct literals. If it turns out too
much code depends on this behavior or we don't want to break with DMD, we
could keep struct literals as lvalues and instead convert struct literals used
as expression initializers into struct initializers.
author | Christian Kamm <kamm incasoftware de> |
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date | Sun, 29 Mar 2009 11:43:45 +0200 |
parents | 373489eeaf90 |
children |
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// Copyright (C) 2001-2002 by Digital Mars // All Rights Reserved // www.digitalmars.com // Written by Walter Bright /* NOTE: This file has been patched from the original DMD distribution to work with the GDC compiler. Modified by David Friedman, September 2004 */ import std.c.string; import std.c.stdlib; import std.outofmemory; import std.intrinsic; //version = Asm86; version (GNU) { // bitop intrinsics not implemented yet } else { version = bitops; } struct GCBits { const int BITS_PER_WORD = 32; const int BITS_SHIFT = 5; const int BITS_MASK = 31; uint *data = null; uint nwords = 0; // allocated words in data[] excluding sentinals uint nbits = 0; // number of bits in data[] excluding sentinals void Dtor() { if (data) { free(data); data = null; } } invariant { if (data) { assert(nwords * data[0].sizeof * 8 >= nbits); } } void alloc(uint nbits) { this.nbits = nbits; nwords = (nbits + (BITS_PER_WORD - 1)) >> BITS_SHIFT; data = cast(uint *)calloc(nwords + 2, uint.sizeof); if (!data) _d_OutOfMemory(); } uint test(uint i) in { assert(i < nbits); } body { //return (cast(bit *)(data + 1))[i]; return data[1 + (i >> BITS_SHIFT)] & (1 << (i & BITS_MASK)); } void set(uint i) in { assert(i < nbits); } body { //(cast(bit *)(data + 1))[i] = 1; data[1 + (i >> BITS_SHIFT)] |= (1 << (i & BITS_MASK)); } void clear(uint i) in { assert(i < nbits); } body { //(cast(bit *)(data + 1))[i] = 0; data[1 + (i >> BITS_SHIFT)] &= ~(1 << (i & BITS_MASK)); } uint testClear(uint i) { version (bitops) { return std.intrinsic.btr(data + 1, i); } else version (Asm86) { asm { naked ; mov EAX,data[EAX] ; mov ECX,i-4[ESP] ; btr 4[EAX],ECX ; sbb EAX,EAX ; ret 4 ; } } else { uint result; //result = (cast(bit *)(data + 1))[i]; //(cast(bit *)(data + 1))[i] = 0; uint *p = &data[1 + (i >> BITS_SHIFT)]; uint mask = (1 << (i & BITS_MASK)); result = *p & mask; *p &= ~mask; return result; } } void zero() { memset(data + 1, 0, nwords * uint.sizeof); } void copy(GCBits *f) in { assert(nwords == f.nwords); } body { memcpy(data + 1, f.data + 1, nwords * uint.sizeof); } uint *base() in { assert(data); } body { return data + 1; } } unittest { GCBits b; b.alloc(786); assert(b.test(123) == 0); assert(b.testClear(123) == 0); b.set(123); assert(b.test(123) != 0); assert(b.testClear(123) != 0); assert(b.test(123) == 0); b.set(785); b.set(0); assert(b.test(785) != 0); assert(b.test(0) != 0); b.zero(); assert(b.test(785) == 0); assert(b.test(0) == 0); GCBits b2; b2.alloc(786); b2.set(38); b.copy(&b2); assert(b.test(38) != 0); b2.Dtor(); b.Dtor(); } /+ void main() { } +/