Annotation of gforth/arch/alpha/machine.h, revision 1.11
1.5 anton 1: /* DEC Alpha
1.1 anton 2:
1.8 anton 3: Copyright (C) 1995,1996,1997,1998,2000 Free Software Foundation, Inc.
1.1 anton 4:
5: This file is part of Gforth.
6:
7: Gforth is free software; you can redistribute it and/or
8: modify it under the terms of the GNU General Public License
9: as published by the Free Software Foundation; either version 2
10: of the License, or (at your option) any later version.
11:
12: This program is distributed in the hope that it will be useful,
13: but WITHOUT ANY WARRANTY; without even the implied warranty of
14: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15: GNU General Public License for more details.
16:
17: You should have received a copy of the GNU General Public License
18: along with this program; if not, write to the Free Software
1.9 anton 19: Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
1.1 anton 20: */
21:
22: /* Be careful: long long on Alpha are 64 bit :-(( */
1.5 anton 23:
24: #ifndef THREADING_SCHEME
25: #define THREADING_SCHEME 5
26: #endif
1.1 anton 27:
28: #if !defined(USE_TOS) && !defined(USE_NO_TOS)
29: #define USE_TOS
30: #endif
31:
32: #define FLUSH_ICACHE(addr,size) asm("call_pal 0x86") /* imb (instruction-memory barrier) */
33:
1.2 jwilke 34: #include "../generic/machine.h"
1.1 anton 35:
36: #ifdef DIRECT_THREADED
37: #ifdef WORDS_BIGENDIAN
38: #error Direct threading only supported for little-endian Alphas.
39: /* big-endian Alphas still store instructions in little-endian format,
40: so you would have to reverse the instruction accesses in the following
41: */
42: #endif
43: #if SIZEOF_CHAR_P != 8
44: #error Direct threading only supported for Alphas with 64-bit Cells.
45: /* some of the stuff below assumes that the first cell in a code field
46: can contain 2 instructions
47:
48: A simple way around this problem would be to have _alpha_docol
49: contain &&dodoes. This would slow down colon defs, however.
50:
51: Another way is to use a special DOES_HANDLER, like most other CPUs */
52: #endif
53:
54: #warning Direct threading for Alpha may not work with all gcc versions
55: #warning ;CODE does not work on the Alpha with direct threading
56: /* ;CODE puts a jump to the code after ;CODE into the defined
57: word. The code generated for the jump can only jump to targets near
58: docol (near means: within 32KB). Because the code is far from
59: docol, this does not work.
60:
61: Solution: let the code be: x=cfa[1]; goto *x;
62: */
63:
64: typedef int Int32;
65: typedef short Int16;
66:
67: /* PFA gives the parameter field address corresponding to a cfa */
68: #define PFA(cfa) (((Cell *)cfa)+2)
69: /* PFA1 is a special version for use just after a NEXT1 */
70: /* the improvement here is that we may destroy cfa before using PFA1 */
71: #define PFA1(cfa) PFA(cfa)
72:
73: /*
74: On the Alpha, code (in the text segment) typically cannot be
75: reached from the dictionary (in the data segment) with a normal
76: branch. It also usually takes too long (and too much space on
77: 32-bit systems) to load the address as literal and jump indirectly.
78:
79: So, what we do is this: a pointer into our code (at docol, to be
80: exact) is kept in a register: _alpha_docol. When the inner
81: interpreter jumps to the word address of a variable etc., the
82: destination address is computed from that with a lda instruction
83: and stored in another register: _alpha_ca. Then an indirect jump
84: through _alpha_ca is performed. For docol, we need not compute
85: _alpha_ca first.
86:
87: How do we tell gcc all this? We declare the registers as variables:
88: _alpha_docol as explicit variable, to avoid spilling; _alpha_ca is
89: so short-lived, so it hopefully won't be spilled. A
90: pseudo-primitive cpu_dep is created with code that lets gcc's data
91: flow analysis know that _alpha_docol is used and that _alpha_ca may
92: be defined and used after any NEXT and before any primitive. We
93: let gcc choose the register for _alpha_ca and simply change the
94: code gcc produces for the cpu_dep routine.
95: */
96:
1.7 anton 97: /* if you change this, also change _DOCOL_LABEL below */
98: #define DO_BASE (&&docol)
99:
100: #define CPU_DEP2 register Label _alpha_docol asm("$9")=DO_BASE; \
1.1 anton 101: register Label _alpha_ca;
102:
103: #define CPU_DEP3 cpu_dep: asm("lda %0, 500(%1)":"=r"(_alpha_ca):"r"(_alpha_docol)); goto *_alpha_ca;
104:
105: #define CPU_DEP1 (&&cpu_dep)
106:
107:
108: /* CODE_ADDRESS is the address of the code jumped to through the code field */
1.7 anton 109: #define CODE_ADDRESS(wa) ({ \
110: Int32 *_wa=(Int32 *)(wa); \
111: (_wa[0]&0xfc000000)==0x68000000 ? /*JMP?*/\
112: DO_BASE : \
113: ((((_wa[0]^((Int32 *)_CPU_DEP_LABEL)[0]) & 0xffff0000)==0 && \
114: ((_wa[1]^((Int32 *)_CPU_DEP_LABEL)[1]) & 0xffffc000)==0 ) ? \
115: (DO_BASE+((Int16 *)_wa)[0]) : \
116: (Label)_wa); })
1.1 anton 117:
118: #define _CPU_DEP_LABEL (symbols[DOESJUMP])
119: #define _DOCOL_LABEL (symbols[DOCOL])
120:
121: /* MAKE_CF creates an appropriate code field at the wa; ca is the code
122: address. For the Alpha, this is a lda followed by a jmp (or just a
1.7 anton 123: jmp, if ca==DO_BASE). We patch the jmp with a good hint (on the
1.1 anton 124: 21064A this saves 5 cycles!) */
125: #define MAKE_CF(wa,ca) ({ \
1.7 anton 126: Int32 *_wa=(Int32 *)(wa); \
127: Label _ca=(Label)(ca); \
128: if (_ca==_DOCOL_LABEL) \
129: _wa[0]=(((0x1a<<26)|(31<<21)|(9<<16))| \
130: (((((Cell)_ca)-((Cell)_wa)-4) & 0xffff)>>2)); \
131: else { \
132: _wa[0]=((((Int32 *)_CPU_DEP_LABEL)[0] & 0xffff0000)| \
133: ((((Cell)_ca)-((Cell)_DOCOL_LABEL)) & 0xffff)); \
134: _wa[1]=((((Int32 *)_CPU_DEP_LABEL)[1] & 0xffffc000)| \
135: (((((Cell)_ca)-((Cell)_wa)-8) & 0xffff)>>2)); \
136: } \
137: })
1.1 anton 138:
139: /* this is the point where the does code for the word with the xt cfa
140: starts. Because the jump to the code field takes only one cell on
141: 64-bit systems we can use the second cell of the cfa for storing
142: the does address */
143: #define DOES_CODE(cfa) \
144: ({ Int32 *_wa=(cfa); \
145: (_wa[0] == ((((Int32 *)_CPU_DEP_LABEL)[0] & 0xffff0000)| \
1.7 anton 146: ((((Cell)&&dodoes)-((Cell)DO_BASE)) & 0xffff)) && \
1.1 anton 147: (_wa[1]&0xffffc000) == (((Int32 *)_CPU_DEP_LABEL)[1] & 0xffffc000)) \
148: ? DOES_CODE1(_wa) : 0; })
149:
150: /* this is a special version of DOES_CODE for use in dodoes */
151: #define DOES_CODE1(cfa) ((Xt *)(((Cell *)(cfa))[1]))
152:
153: /* the does handler resides between DOES> and the following Forth
154: code. Since the code-field jumps directly to dodoes, the
155: does-handler is not needed for the Alpha architecture */
1.6 anton 156: #define MAKE_DOES_HANDLER(addr) ((void)0)
1.1 anton 157:
158: /* This makes a code field for a does-defined word. doesp is the
159: address of the does-code. On the Alpha, the code field consists of
160: a jump to dodoes and the address of the does code */
161: #define MAKE_DOES_CF(cfa,doesp) ({Xt *_cfa = (Xt *)(cfa); \
162: MAKE_CF(_cfa, symbols[DODOES]); \
163: _cfa[1] = (doesp); })
164: #endif
165:
1.10 anton 166: /* dynamic superinstruction stuff */
167:
168: #define INST_GRANULARITY 4
169: #define IND_JUMP_LENGTH 4
170: #define IS_NEXT_JUMP(_addr) (((*(unsigned *)(_addr))&0xffe00000) == 0x6be00000)
171: #define ALIGN_CODE { \
172: int align_diff; \
173: old_code_here = (Address)(((((Cell)old_code_here)-1)|0xf)+1); \
174: align_diff = old_code_here - code_here; \
175: memcpy(code_here, ((char *)(int []){0x47ff041f,0x2fe00000,0x47ff041f,0x2fe00000})+16-align_diff,align_diff); \
176: code_here = old_code_here; \
177: }
178:
1.4 anton 179: #ifdef FORCE_REG
180: /* $9-$14 are callee-saved, $1-$8 and $22-$25 are caller-saved */
181: #define IPREG asm("$10")
182: #define SPREG asm("$11")
183: #define RPREG asm("$12")
184: #define LPREG asm("$13")
185: #define TOSREG asm("$14")
1.5 anton 186: /* #define CFAREG asm("$22") egcs-1.0.3 crashes with any caller-saved
187: register decl */
1.4 anton 188: #endif /* FORCE_REG */
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to machine.h CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [gforth] / gforth / arch / alpha