2 * Copyright (c) 1993 The Regents of the University of California.
3 * All rights reserved.
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.
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.
33 * $FreeBSD: stable/3/sys/i386/include/asmacros.h 56947 2000-02-02 03:50:27Z bde $
36 #ifndef _MACHINE_ASMACROS_H_
37 #define _MACHINE_ASMACROS_H_
39 #include <sys/cdefs.h>
40 #include <machine/asnames.h>
42 /* XXX too much duplication in various asm*.h's. */
45 * CNAME and HIDENAME manage the relationship between symbol names in C
46 * and the equivalent assembly language names. CNAME is given a name as
47 * it would be used in a C program. It expands to the equivalent assembly
48 * language name. HIDENAME is given an assembly-language name, and expands
49 * to a possibly-modified form that will be invisible to C programs.
51 #if defined(__ELF__)
52 #define CNAME(csym) csym
53 #define HIDENAME(asmsym) __CONCAT(.,asmsym)
55 #define CNAME(csym) __CONCAT(_,csym)
56 #define HIDENAME(asmsym) asmsym
59 #define ALIGN_DATA .p2align 2 /* 4 byte alignment, zero filled */
60 #ifdef GPROF
61 #define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
63 #define ALIGN_TEXT .p2align 2,0x90 /* 4-byte alignment, nop filled */
65 #define SUPERALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
67 #define GEN_ENTRY(name) ALIGN_TEXT; .globl CNAME(name); \
68 .type CNAME(name),@function; CNAME(name):
69 #define NON_GPROF_ENTRY(name) GEN_ENTRY(name)
70 #define NON_GPROF_RET .byte 0xc3 /* opcode for `ret' */
72 #ifdef GPROF
74 * __mcount is like [.]mcount except that doesn't require its caller to set
75 * up a frame pointer. It must be called before pushing anything onto the
76 * stack. gcc should eventually generate code to call __mcount in most
77 * cases. This would make -pg in combination with -fomit-frame-pointer
78 * useful. gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to
79 * allow profiling before setting up the frame pointer, but this is
80 * inadequate for good handling of special cases, e.g., -fpic works best
81 * with profiling after the prologue.
83 * [.]mexitcount is a new function to support non-statistical profiling if an
84 * accurate clock is available. For C sources, calls to it are generated
85 * by the FreeBSD extension `-mprofiler-epilogue' to gcc. It is best to
86 * call [.]mexitcount at the end of a function like the MEXITCOUNT macro does,
87 * but gcc currently generates calls to it at the start of the epilogue to
88 * avoid problems with -fpic.
90 * [.]mcount and __mcount may clobber the call-used registers and %ef.
91 * [.]mexitcount may clobber %ecx and %ef.
93 * Cross-jumping makes non-statistical profiling timing more complicated.
94 * It is handled in many cases by calling [.]mexitcount before jumping. It
95 * is handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL().
96 * It is handled for some fault-handling jumps by not sharing the exit
97 * routine.
99 * ALTENTRY() must be before a corresponding ENTRY() so that it can jump to
100 * the main entry point. Note that alt entries are counted twice. They
101 * have to be counted as ordinary entries for gprof to get the call times
102 * right for the ordinary entries.
104 * High local labels are used in macros to avoid clashes with local labels
105 * in functions.
107 * Ordinary `ret' is used instead of a macro `RET' because there are a lot
108 * of `ret's. 0xc3 is the opcode for `ret' (`#define ret ... ret' can't
109 * be used because this file is sometimes preprocessed in traditional mode).
110 * `ret' clobbers eflags but this doesn't matter.
112 #define ALTENTRY(name) GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f
113 #define CROSSJUMP(jtrue, label, jfalse) \
114 jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8:
115 #define CROSSJUMPTARGET(label) \
116 ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label
117 #define ENTRY(name) GEN_ENTRY(name) ; 9: ; MCOUNT
118 #define FAKE_MCOUNT(caller) pushl caller ; call __mcount ; popl %ecx
119 #define MCOUNT call __mcount
120 #define MCOUNT_LABEL(name) GEN_ENTRY(name) ; nop ; ALIGN_TEXT
121 #define MEXITCOUNT call HIDENAME(mexitcount)
122 #define ret MEXITCOUNT ; NON_GPROF_RET
124 #else /* !GPROF */
126 * ALTENTRY() has to align because it is before a corresponding ENTRY().
127 * ENTRY() has to align to because there may be no ALTENTRY() before it.
128 * If there is a previous ALTENTRY() then the alignment code for ENTRY()
129 * is empty.
131 #define ALTENTRY(name) GEN_ENTRY(name)
132 #define CROSSJUMP(jtrue, label, jfalse) jtrue label
133 #define CROSSJUMPTARGET(label)
134 #define ENTRY(name) GEN_ENTRY(name)
135 #define FAKE_MCOUNT(caller)
136 #define MCOUNT
137 #define MCOUNT_LABEL(name)
138 #define MEXITCOUNT
139 #endif /* GPROF */
141 #endif /* !_MACHINE_ASMACROS_H_ */
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