2 * Copyright (c) 1993 The Regents of the University of California.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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
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/Attic/asmacros.h,v 1.3 2003/06/20 02:09:54 dillon Exp $
37 #ifndef _MACHINE_ASMACROS_H_
38 #define _MACHINE_ASMACROS_H_
40 #include <sys/cdefs.h>
41 #include <machine/asnames.h>
43 /* XXX too much duplication in various asm*.h's. */
46 * CNAME and HIDENAME manage the relationship between symbol names in C
47 * and the equivalent assembly language names. CNAME is given a name as
48 * it would be used in a C program. It expands to the equivalent assembly
49 * language name. HIDENAME is given an assembly-language name, and expands
50 * to a possibly-modified form that will be invisible to C programs.
53 #define CNAME(csym) csym
54 #define HIDENAME(asmsym) __CONCAT(.,asmsym)
56 #define CNAME(csym) __CONCAT(_,csym)
57 #define HIDENAME(asmsym) asmsym
60 #define ALIGN_PAGE .p2align PAGE_SHIFT /* page alignment */
61 #define ALIGN_DATA .p2align 2 /* 4 byte alignment, zero filled */
63 #define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
65 #define ALIGN_TEXT .p2align 2,0x90 /* 4-byte alignment, nop filled */
67 #define SUPERALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
69 #define GEN_ENTRY(name) ALIGN_TEXT; .globl CNAME(name); \
70 .type CNAME(name),@function; CNAME(name):
71 #define NON_GPROF_ENTRY(name) GEN_ENTRY(name)
72 #define NON_GPROF_RET .byte 0xc3 /* opcode for `ret' */
76 * __mcount is like [.]mcount except that doesn't require its caller to set
77 * up a frame pointer. It must be called before pushing anything onto the
78 * stack. gcc should eventually generate code to call __mcount in most
79 * cases. This would make -pg in combination with -fomit-frame-pointer
80 * useful. gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to
81 * allow profiling before setting up the frame pointer, but this is
82 * inadequate for good handling of special cases, e.g., -fpic works best
83 * with profiling after the prologue.
85 * [.]mexitcount is a new function to support non-statistical profiling if an
86 * accurate clock is available. For C sources, calls to it are generated
87 * by the FreeBSD extension `-mprofiler-epilogue' to gcc. It is best to
88 * call [.]mexitcount at the end of a function like the MEXITCOUNT macro does,
89 * but gcc currently generates calls to it at the start of the epilogue to
90 * avoid problems with -fpic.
92 * [.]mcount and __mcount may clobber the call-used registers and %ef.
93 * [.]mexitcount may clobber %ecx and %ef.
95 * Cross-jumping makes non-statistical profiling timing more complicated.
96 * It is handled in many cases by calling [.]mexitcount before jumping. It
97 * is handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL().
98 * It is handled for some fault-handling jumps by not sharing the exit
101 * ALTENTRY() must be before a corresponding ENTRY() so that it can jump to
102 * the main entry point. Note that alt entries are counted twice. They
103 * have to be counted as ordinary entries for gprof to get the call times
104 * right for the ordinary entries.
106 * High local labels are used in macros to avoid clashes with local labels
109 * Ordinary `ret' is used instead of a macro `RET' because there are a lot
110 * of `ret's. 0xc3 is the opcode for `ret' (`#define ret ... ret' can't
111 * be used because this file is sometimes preprocessed in traditional mode).
112 * `ret' clobbers eflags but this doesn't matter.
114 #define ALTENTRY(name) GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f
115 #define CROSSJUMP(jtrue, label, jfalse) \
116 jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8:
117 #define CROSSJUMPTARGET(label) \
118 ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label
119 #define ENTRY(name) GEN_ENTRY(name) ; 9: ; MCOUNT
120 #define FAKE_MCOUNT(caller) pushl caller ; call __mcount ; popl %ecx
121 #define MCOUNT call __mcount
122 #define MCOUNT_LABEL(name) GEN_ENTRY(name) ; nop ; ALIGN_TEXT
123 #define MEXITCOUNT call HIDENAME(mexitcount)
124 #define ret MEXITCOUNT ; NON_GPROF_RET
128 * ALTENTRY() has to align because it is before a corresponding ENTRY().
129 * ENTRY() has to align to because there may be no ALTENTRY() before it.
130 * If there is a previous ALTENTRY() then the alignment code for ENTRY()
133 #define ALTENTRY(name) GEN_ENTRY(name)
134 #define CROSSJUMP(jtrue, label, jfalse) jtrue label
135 #define CROSSJUMPTARGET(label)
136 #define ENTRY(name) GEN_ENTRY(name)
137 #define FAKE_MCOUNT(caller)
139 #define MCOUNT_LABEL(name)
143 #endif /* !_MACHINE_ASMACROS_H_ */