1: /*-
2: * Copyright (c) 1993 The Regents of the University of California.
3: * All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: * 3. All advertising materials mentioning features or use of this software
14: * must display the following acknowledgement:
15: * This product includes software developed by the University of
16: * California, Berkeley and its contributors.
17: * 4. Neither the name of the University nor the names of its contributors
18: * may be used to endorse or promote products derived from this software
19: * without specific prior written permission.
20: *
21: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31: * SUCH DAMAGE.
32: *
33: * $FreeBSD: src/sys/i386/include/asmacros.h,v 1.18 1999/08/28 00:44:06 peter Exp $
34: * $DragonFly: src/sys/i386/include/asmacros.h,v 1.5 2003/07/20 04:20:32 dillon Exp $
35: */
36:
37: #ifndef _MACHINE_ASMACROS_H_
38: #define _MACHINE_ASMACROS_H_
39:
40: #include <sys/cdefs.h>
41:
42: /*
43: * Access to a per-cpu data element
44: */
45: #define PCPU(x) %fs:gd_ ## x
46:
47: /*
48: * CNAME and HIDENAME manage the relationship between symbol names in C
49: * and the equivalent assembly language names. CNAME is given a name as
50: * it would be used in a C program. It expands to the equivalent assembly
51: * language name. HIDENAME is given an assembly-language name, and expands
52: * to a possibly-modified form that will be invisible to C programs.
53: */
54: #define CNAME(csym) csym
55: #define HIDENAME(asmsym) __CONCAT(.,asmsym)
56:
57: #define ALIGN_PAGE .p2align PAGE_SHIFT /* page alignment */
58: #define ALIGN_DATA .p2align 2 /* 4 byte alignment, zero filled */
59: #ifdef GPROF
60: #define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
61: #else
62: #define ALIGN_TEXT .p2align 2,0x90 /* 4-byte alignment, nop filled */
63: #endif
64: #define SUPERALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
65:
66: #define GEN_ENTRY(name) ALIGN_TEXT; .globl CNAME(name); \
67: .type CNAME(name),@function; CNAME(name):
68: #define NON_GPROF_ENTRY(name) GEN_ENTRY(name)
69: #define NON_GPROF_RET .byte 0xc3 /* opcode for `ret' */
70:
71: #ifdef GPROF
72: /*
73: * __mcount is like [.]mcount except that doesn't require its caller to set
74: * up a frame pointer. It must be called before pushing anything onto the
75: * stack. gcc should eventually generate code to call __mcount in most
76: * cases. This would make -pg in combination with -fomit-frame-pointer
77: * useful. gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to
78: * allow profiling before setting up the frame pointer, but this is
79: * inadequate for good handling of special cases, e.g., -fpic works best
80: * with profiling after the prologue.
81: *
82: * [.]mexitcount is a new function to support non-statistical profiling if an
83: * accurate clock is available. For C sources, calls to it are generated
84: * by the FreeBSD extension `-mprofiler-epilogue' to gcc. It is best to
85: * call [.]mexitcount at the end of a function like the MEXITCOUNT macro does,
86: * but gcc currently generates calls to it at the start of the epilogue to
87: * avoid problems with -fpic.
88: *
89: * [.]mcount and __mcount will not clobber the call-used registers or %ef.
90: * [.]mexitcount will not clobber the call-used registers or %ef.
91: *
92: * Cross-jumping makes non-statistical profiling timing more complicated.
93: * It is handled in many cases by calling [.]mexitcount before jumping. It
94: * is handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL().
95: * It is handled for some fault-handling jumps by not sharing the exit
96: * routine.
97: *
98: * ALTENTRY() must be before a corresponding ENTRY() so that it can jump to
99: * the main entry point. Note that alt entries are counted twice. They
100: * have to be counted as ordinary entries for gprof to get the call times
101: * right for the ordinary entries.
102: *
103: * High local labels are used in macros to avoid clashes with local labels
104: * in functions.
105: *
106: * Ordinary `ret' is used instead of a macro `RET' because there are a lot
107: * of `ret's. 0xc3 is the opcode for `ret' (`#define ret ... ret' can't
108: * be used because this file is sometimes preprocessed in traditional mode).
109: * `ret' clobbers eflags but this doesn't matter.
110: */
111: #define ALTENTRY(name) GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f
112: #define CROSSJUMP(jtrue, label, jfalse) \
113: jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8:
114: #define CROSSJUMPTARGET(label) \
115: ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label
116: #define ENTRY(name) GEN_ENTRY(name) ; 9: ; MCOUNT
117: #define FAKE_MCOUNT(caller) pushl caller ; call __mcount ; addl $4,%esp
118: #define MCOUNT call __mcount
119: #define MCOUNT_LABEL(name) GEN_ENTRY(name) ; nop ; ALIGN_TEXT
120: #define MEXITCOUNT call HIDENAME(mexitcount)
121: #define ret MEXITCOUNT ; NON_GPROF_RET
122:
123: #else /* !GPROF */
124: /*
125: * ALTENTRY() has to align because it is before a corresponding ENTRY().
126: * ENTRY() has to align to because there may be no ALTENTRY() before it.
127: * If there is a previous ALTENTRY() then the alignment code for ENTRY()
128: * is empty.
129: */
130: #define ALTENTRY(name) GEN_ENTRY(name)
131: #define CROSSJUMP(jtrue, label, jfalse) jtrue label
132: #define CROSSJUMPTARGET(label)
133: #define ENTRY(name) GEN_ENTRY(name)
134: #define FAKE_MCOUNT(caller)
135: #define MCOUNT
136: #define MCOUNT_LABEL(name)
137: #define MEXITCOUNT
138: #endif /* GPROF */
139:
140: #endif /* !_MACHINE_ASMACROS_H_ */
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