Reorganisation of the source tree
[ghc.git] / includes / Stg.h
1 /* -----------------------------------------------------------------------------
2 *
3 * (c) The GHC Team, 1998-2004
4 *
5 * Top-level include file for everything STG-ish.
6 *
7 * This file is included *automatically* by all .hc files.
8 *
9 * NOTE: always include Stg.h *before* any other headers, because we
10 * define some register variables which must be done before any inline
11 * functions are defined (some system headers have been known to
12 * define the odd inline function).
13 *
14 * We generally try to keep as little visible as possible when
15 * compiling .hc files. So for example the definitions of the
16 * InfoTable structs, closure structs and other RTS types are not
17 * visible here. The compiler knows enough about the representations
18 * of these types to generate code which manipulates them directly
19 * with pointer arithmetic.
20 *
21 * ---------------------------------------------------------------------------*/
22
23 #ifndef STG_H
24 #define STG_H
25
26
27 /* If we include "Stg.h" directly, we're in STG code, and we therefore
28 * get all the global register variables, macros etc. that go along
29 * with that. If "Stg.h" is included via "Rts.h", we're assumed to
30 * be in vanilla C.
31 */
32 #ifndef IN_STG_CODE
33 # define IN_STG_CODE 1
34 #endif
35
36 #if IN_STG_CODE == 0
37 # define NO_GLOBAL_REG_DECLS /* don't define fixed registers */
38 #endif
39
40 /* Configuration */
41 #include "ghcconfig.h"
42 #include "RtsConfig.h"
43
44 /* -----------------------------------------------------------------------------
45 Useful definitions
46 -------------------------------------------------------------------------- */
47
48 /*
49 * The C backend like to refer to labels by just mentioning their
50 * names. Howevver, when a symbol is declared as a variable in C, the
51 * C compiler will implicitly dereference it when it occurs in source.
52 * So we must subvert this behaviour for .hc files by declaring
53 * variables as arrays, which eliminates the implicit dereference.
54 */
55 #if IN_STG_CODE
56 #define RTS_VAR(x) (x)[]
57 #define RTS_DEREF(x) (*(x))
58 #else
59 #define RTS_VAR(x) x
60 #define RTS_DEREF(x) x
61 #endif
62
63 /* bit macros
64 */
65 #define BITS_PER_BYTE 8
66 #define BITS_IN(x) (BITS_PER_BYTE * sizeof(x))
67
68 /*
69 * 'Portable' inlining
70 */
71 #if defined(__GNUC__) || defined( __INTEL_COMPILER)
72 # define INLINE_HEADER static inline
73 # define INLINE_ME inline
74 # define STATIC_INLINE INLINE_HEADER
75 #elif defined(_MSC_VER)
76 # define INLINE_HEADER __inline static
77 # define INLINE_ME __inline
78 # define STATIC_INLINE INLINE_HEADER
79 #else
80 # error "Don't know how to inline functions with your C compiler."
81 #endif
82
83 /*
84 * GCC attributes
85 */
86 #if defined(__GNUC__)
87 #define GNU_ATTRIBUTE(at) __attribute__((at))
88 #else
89 #define GNU_ATTRIBUTE(at)
90 #endif
91
92 #if __GNUC__ >= 3
93 #define GNUC3_ATTRIBUTE(at) __attribute__((at))
94 #else
95 #define GNUC3_ATTRIBUTE(at)
96 #endif
97
98 #define STG_UNUSED GNUC3_ATTRIBUTE(__unused__)
99
100 /* -----------------------------------------------------------------------------
101 Global type definitions
102 -------------------------------------------------------------------------- */
103
104 #include "MachDeps.h"
105 #include "StgTypes.h"
106
107 /* -----------------------------------------------------------------------------
108 Shorthand forms
109 -------------------------------------------------------------------------- */
110
111 typedef StgChar C_;
112 typedef StgWord W_;
113 typedef StgWord* P_;
114 typedef P_* PP_;
115 typedef StgInt I_;
116 typedef StgAddr A_;
117 typedef const StgWord* D_;
118 typedef StgFunPtr F_;
119 typedef StgByteArray B_;
120 typedef StgClosurePtr L_;
121
122 typedef StgInt64 LI_;
123 typedef StgWord64 LW_;
124
125 #define IF_(f) static F_ GNUC3_ATTRIBUTE(used) f(void)
126 #define FN_(f) F_ f(void)
127 #define EF_(f) extern F_ f(void)
128
129 typedef StgWord StgWordArray[];
130 #define EI_ extern StgWordArray
131 #define II_ static StgWordArray
132
133 /* -----------------------------------------------------------------------------
134 Tail calls
135
136 This needs to be up near the top as the register line on alpha needs
137 to be before all procedures (inline & out-of-line).
138 -------------------------------------------------------------------------- */
139
140 #include "TailCalls.h"
141
142 /* -----------------------------------------------------------------------------
143 Other Stg stuff...
144 -------------------------------------------------------------------------- */
145
146 #include "StgDLL.h"
147 #include "MachRegs.h"
148 #include "Regs.h"
149 #include "StgProf.h" /* ToDo: separate out RTS-only stuff from here */
150
151 #if IN_STG_CODE
152 /*
153 * This is included later for RTS sources, after definitions of
154 * StgInfoTable, StgClosure and so on.
155 */
156 #include "StgMiscClosures.h"
157 #endif
158
159 /* RTS external interface */
160 #include "RtsExternal.h"
161
162 /* -----------------------------------------------------------------------------
163 Moving Floats and Doubles
164
165 ASSIGN_FLT is for assigning a float to memory (usually the
166 stack/heap). The memory address is guaranteed to be
167 StgWord aligned (currently == sizeof(void *)).
168
169 PK_FLT is for pulling a float out of memory. The memory is
170 guaranteed to be StgWord aligned.
171 -------------------------------------------------------------------------- */
172
173 INLINE_HEADER void ASSIGN_FLT (W_ [], StgFloat);
174 INLINE_HEADER StgFloat PK_FLT (W_ []);
175
176 #if ALIGNMENT_FLOAT <= ALIGNMENT_LONG
177
178 INLINE_HEADER void ASSIGN_FLT(W_ p_dest[], StgFloat src) { *(StgFloat *)p_dest = src; }
179 INLINE_HEADER StgFloat PK_FLT (W_ p_src[]) { return *(StgFloat *)p_src; }
180
181 #else /* ALIGNMENT_FLOAT > ALIGNMENT_UNSIGNED_INT */
182
183 INLINE_HEADER void ASSIGN_FLT(W_ p_dest[], StgFloat src)
184 {
185 float_thing y;
186 y.f = src;
187 *p_dest = y.fu;
188 }
189
190 INLINE_HEADER StgFloat PK_FLT(W_ p_src[])
191 {
192 float_thing y;
193 y.fu = *p_src;
194 return(y.f);
195 }
196
197 #endif /* ALIGNMENT_FLOAT > ALIGNMENT_LONG */
198
199 #if ALIGNMENT_DOUBLE <= ALIGNMENT_LONG
200
201 INLINE_HEADER void ASSIGN_DBL (W_ [], StgDouble);
202 INLINE_HEADER StgDouble PK_DBL (W_ []);
203
204 INLINE_HEADER void ASSIGN_DBL(W_ p_dest[], StgDouble src) { *(StgDouble *)p_dest = src; }
205 INLINE_HEADER StgDouble PK_DBL (W_ p_src[]) { return *(StgDouble *)p_src; }
206
207 #else /* ALIGNMENT_DOUBLE > ALIGNMENT_LONG */
208
209 /* Sparc uses two floating point registers to hold a double. We can
210 * write ASSIGN_DBL and PK_DBL by directly accessing the registers
211 * independently - unfortunately this code isn't writable in C, we
212 * have to use inline assembler.
213 */
214 #if sparc_HOST_ARCH
215
216 #define ASSIGN_DBL(dst0,src) \
217 { StgPtr dst = (StgPtr)(dst0); \
218 __asm__("st %2,%0\n\tst %R2,%1" : "=m" (((P_)(dst))[0]), \
219 "=m" (((P_)(dst))[1]) : "f" (src)); \
220 }
221
222 #define PK_DBL(src0) \
223 ( { StgPtr src = (StgPtr)(src0); \
224 register double d; \
225 __asm__("ld %1,%0\n\tld %2,%R0" : "=f" (d) : \
226 "m" (((P_)(src))[0]), "m" (((P_)(src))[1])); d; \
227 } )
228
229 #else /* ! sparc_HOST_ARCH */
230
231 INLINE_HEADER void ASSIGN_DBL (W_ [], StgDouble);
232 INLINE_HEADER StgDouble PK_DBL (W_ []);
233
234 typedef struct
235 { StgWord dhi;
236 StgWord dlo;
237 } unpacked_double;
238
239 typedef union
240 { StgDouble d;
241 unpacked_double du;
242 } double_thing;
243
244 INLINE_HEADER void ASSIGN_DBL(W_ p_dest[], StgDouble src)
245 {
246 double_thing y;
247 y.d = src;
248 p_dest[0] = y.du.dhi;
249 p_dest[1] = y.du.dlo;
250 }
251
252 /* GCC also works with this version, but it generates
253 the same code as the previous one, and is not ANSI
254
255 #define ASSIGN_DBL( p_dest, src ) \
256 *p_dest = ((double_thing) src).du.dhi; \
257 *(p_dest+1) = ((double_thing) src).du.dlo \
258 */
259
260 INLINE_HEADER StgDouble PK_DBL(W_ p_src[])
261 {
262 double_thing y;
263 y.du.dhi = p_src[0];
264 y.du.dlo = p_src[1];
265 return(y.d);
266 }
267
268 #endif /* ! sparc_HOST_ARCH */
269
270 #endif /* ALIGNMENT_DOUBLE > ALIGNMENT_UNSIGNED_INT */
271
272
273 /* -----------------------------------------------------------------------------
274 Moving 64-bit quantities around
275
276 ASSIGN_Word64 assign an StgWord64/StgInt64 to a memory location
277 PK_Word64 load an StgWord64/StgInt64 from a amemory location
278
279 In both cases the memory location might not be 64-bit aligned.
280 -------------------------------------------------------------------------- */
281
282 #ifdef SUPPORT_LONG_LONGS
283
284 typedef struct
285 { StgWord dhi;
286 StgWord dlo;
287 } unpacked_double_word;
288
289 typedef union
290 { StgInt64 i;
291 unpacked_double_word iu;
292 } int64_thing;
293
294 typedef union
295 { StgWord64 w;
296 unpacked_double_word wu;
297 } word64_thing;
298
299 INLINE_HEADER void ASSIGN_Word64(W_ p_dest[], StgWord64 src)
300 {
301 word64_thing y;
302 y.w = src;
303 p_dest[0] = y.wu.dhi;
304 p_dest[1] = y.wu.dlo;
305 }
306
307 INLINE_HEADER StgWord64 PK_Word64(W_ p_src[])
308 {
309 word64_thing y;
310 y.wu.dhi = p_src[0];
311 y.wu.dlo = p_src[1];
312 return(y.w);
313 }
314
315 INLINE_HEADER void ASSIGN_Int64(W_ p_dest[], StgInt64 src)
316 {
317 int64_thing y;
318 y.i = src;
319 p_dest[0] = y.iu.dhi;
320 p_dest[1] = y.iu.dlo;
321 }
322
323 INLINE_HEADER StgInt64 PK_Int64(W_ p_src[])
324 {
325 int64_thing y;
326 y.iu.dhi = p_src[0];
327 y.iu.dlo = p_src[1];
328 return(y.i);
329 }
330
331 #elif SIZEOF_VOID_P == 8
332
333 INLINE_HEADER void ASSIGN_Word64(W_ p_dest[], StgWord64 src)
334 {
335 p_dest[0] = src;
336 }
337
338 INLINE_HEADER StgWord64 PK_Word64(W_ p_src[])
339 {
340 return p_src[0];
341 }
342
343 INLINE_HEADER void ASSIGN_Int64(W_ p_dest[], StgInt64 src)
344 {
345 p_dest[0] = src;
346 }
347
348 INLINE_HEADER StgInt64 PK_Int64(W_ p_src[])
349 {
350 return p_src[0];
351 }
352
353 #endif
354
355 /* -----------------------------------------------------------------------------
356 Split markers
357 -------------------------------------------------------------------------- */
358
359 #if defined(USE_SPLIT_MARKERS)
360 #if defined(LEADING_UNDERSCORE)
361 #define __STG_SPLIT_MARKER __asm__("\n___stg_split_marker:");
362 #else
363 #define __STG_SPLIT_MARKER __asm__("\n__stg_split_marker:");
364 #endif
365 #else
366 #define __STG_SPLIT_MARKER /* nothing */
367 #endif
368
369 /* -----------------------------------------------------------------------------
370 Write-combining store
371 -------------------------------------------------------------------------- */
372
373 INLINE_HEADER void
374 wcStore (StgPtr p, StgWord w)
375 {
376 #ifdef x86_64_HOST_ARCH
377 __asm__(
378 "movnti\t%1, %0"
379 : "=m" (*p)
380 : "r" (w)
381 );
382 #else
383 *p = w;
384 #endif
385 }
386
387 /* -----------------------------------------------------------------------------
388 Integer multiply with overflow
389 -------------------------------------------------------------------------- */
390
391 /* Multiply with overflow checking.
392 *
393 * This is tricky - the usual sign rules for add/subtract don't apply.
394 *
395 * On 32-bit machines we use gcc's 'long long' types, finding
396 * overflow with some careful bit-twiddling.
397 *
398 * On 64-bit machines where gcc's 'long long' type is also 64-bits,
399 * we use a crude approximation, testing whether either operand is
400 * larger than 32-bits; if neither is, then we go ahead with the
401 * multiplication.
402 *
403 * Return non-zero if there is any possibility that the signed multiply
404 * of a and b might overflow. Return zero only if you are absolutely sure
405 * that it won't overflow. If in doubt, return non-zero.
406 */
407
408 #if SIZEOF_VOID_P == 4
409
410 #ifdef WORDS_BIGENDIAN
411 #define RTS_CARRY_IDX__ 0
412 #define RTS_REM_IDX__ 1
413 #else
414 #define RTS_CARRY_IDX__ 1
415 #define RTS_REM_IDX__ 0
416 #endif
417
418 typedef union {
419 StgInt64 l;
420 StgInt32 i[2];
421 } long_long_u ;
422
423 #define mulIntMayOflo(a,b) \
424 ({ \
425 StgInt32 r, c; \
426 long_long_u z; \
427 z.l = (StgInt64)a * (StgInt64)b; \
428 r = z.i[RTS_REM_IDX__]; \
429 c = z.i[RTS_CARRY_IDX__]; \
430 if (c == 0 || c == -1) { \
431 c = ((StgWord)((a^b) ^ r)) \
432 >> (BITS_IN (I_) - 1); \
433 } \
434 c; \
435 })
436
437 /* Careful: the carry calculation above is extremely delicate. Make sure
438 * you test it thoroughly after changing it.
439 */
440
441 #else
442
443 /* Approximate version when we don't have long arithmetic (on 64-bit archs) */
444
445 #define HALF_POS_INT (((I_)1) << (BITS_IN (I_) / 2))
446 #define HALF_NEG_INT (-HALF_POS_INT)
447
448 #define mulIntMayOflo(a,b) \
449 ({ \
450 I_ c; \
451 if ((I_)a <= HALF_NEG_INT || a >= HALF_POS_INT \
452 || (I_)b <= HALF_NEG_INT || b >= HALF_POS_INT) {\
453 c = 1; \
454 } else { \
455 c = 0; \
456 } \
457 c; \
458 })
459 #endif
460
461 #endif /* STG_H */