asmacros.h revision 16029
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 * $Id: asmacros.h,v 1.7 1996/03/31 04:17:25 bde Exp $ 34 */ 35 36#ifndef _MACHINE_ASMACROS_H_ 37#define _MACHINE_ASMACROS_H_ 38 39#ifdef KERNEL 40#include <sys/cdefs.h> 41 42/* XXX too much duplication in various asm*.h's and gprof.h's */ 43 44#define ALIGN_DATA .align 2 /* 4 byte alignment, zero filled */ 45#define ALIGN_TEXT .align 2,0x90 /* 4-byte alignment, nop filled */ 46#define SUPERALIGN_TEXT .align 4,0x90 /* 16-byte alignment (better for 486), nop filled */ 47 48#define GEN_ENTRY(name) ALIGN_TEXT; .globl __CONCAT(_,name); __CONCAT(_,name): 49#define NON_GPROF_ENTRY(name) GEN_ENTRY(name) 50 51#ifdef GPROF 52/* 53 * __mcount is like mcount except that doesn't require its caller to set 54 * up a frame pointer. It must be called before pushing anything onto the 55 * stack. gcc should eventually generate code to call __mcount in most 56 * cases. This would make -pg in combination with -fomit-frame-pointer 57 * useful. gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to 58 * allow profiling before setting up the frame pointer, but this is 59 * inadequate for good handling of special cases, e.g., -fpic works best 60 * with profiling after the prologue. 61 * 62 * Neither __mcount nor mcount requires %eax to point to 4 bytes of data, 63 * so don't waste space allocating the data or time setting it up. Changes 64 * to avoid the wastage in gcc-2.4.5-compiled code are available. 65 * 66 * mexitcount is a new profiling feature to allow accurate timing of all 67 * functions if an accurate clock is available. Changes to gcc-2.4.5 to 68 * support it are are available. The changes currently don't allow not 69 * generating mexitcounts for non-kernel code. It is best to call 70 * mexitcount right at the end of a function like the MEXITCOUNT macro 71 * does, but the changes to gcc only implement calling it as the first 72 * thing in the epilogue to avoid problems with -fpic. 73 * 74 * mcount and __mexitcount may clobber the call-used registers and %ef. 75 * mexitcount may clobber %ecx and %ef. 76 * 77 * Cross-jumping makes accurate timing more difficult. It is handled in 78 * many cases by calling mexitcount before jumping. It is not handled 79 * for some conditional jumps (e.g., in bcopyx) or for some fault-handling 80 * jumps. It is handled for some fault-handling jumps by not sharing the 81 * exit routine. 82 * 83 * ALTENTRY() must be before a corresponding ENTRY() so that it can jump to 84 * the main entry point. Note that alt entries are counted twice. They 85 * have to be counted as ordinary entries for gprof to get the call times 86 * right for the ordinary entries. 87 * 88 * High local labels are used in macros to avoid clashes with local labels 89 * in functions. 90 * 91 * "ret" is used instead of "RET" because there are a lot of "ret"s. 92 * 0xc3 is the opcode for "ret" (#define ret ... ret fails because this 93 * file is preprocessed in traditional mode). "ret" clobbers eflags 94 * but this doesn't matter. 95 */ 96#define ALTENTRY(name) GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f 97#define ENTRY(name) GEN_ENTRY(name) ; 9: ; MCOUNT 98#define FAKE_MCOUNT(caller) pushl caller ; call __mcount ; popl %ecx 99#define MCOUNT call __mcount 100#define MCOUNT_LABEL(name) GEN_ENTRY(name) ; nop ; ALIGN_TEXT 101#define MEXITCOUNT call mexitcount 102#define ret MEXITCOUNT ; .byte 0xc3 103#else /* not GPROF */ 104/* 105 * ALTENTRY() has to align because it is before a corresponding ENTRY(). 106 * ENTRY() has to align to because there may be no ALTENTRY() before it. 107 * If there is a previous ALTENTRY() then the alignment code for ENTRY() 108 * is empty. 109 */ 110#define ALTENTRY(name) GEN_ENTRY(name) 111#define ENTRY(name) GEN_ENTRY(name) 112#define FAKE_MCOUNT(caller) 113#define MCOUNT 114#define MCOUNT_LABEL(name) 115#define MEXITCOUNT 116#endif /* GPROF */ 117 118#else /* !KERNEL */ 119 120#include "/usr/src/lib/libc/i386/DEFS.h" /* XXX blech */ 121 122#ifndef RCSID 123#define RCSID(a) 124#endif 125 126#endif /* KERNEL */ 127 128#endif /* !_MACHINE_ASMACROS_H_ */ 129