diff options
Diffstat (limited to 'sys/amd64/include/asmacros.h')
| -rw-r--r-- | sys/amd64/include/asmacros.h | 56 |
1 files changed, 30 insertions, 26 deletions
diff --git a/sys/amd64/include/asmacros.h b/sys/amd64/include/asmacros.h index 4ecabdf..6471865 100644 --- a/sys/amd64/include/asmacros.h +++ b/sys/amd64/include/asmacros.h @@ -30,7 +30,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: asmacros.h,v 1.7 1996/03/31 04:17:25 bde Exp $ + * $Id: asmacros.h,v 1.8 1996/05/31 01:08:05 peter Exp $ */ #ifndef _MACHINE_ASMACROS_H_ @@ -39,14 +39,16 @@ #ifdef KERNEL #include <sys/cdefs.h> -/* XXX too much duplication in various asm*.h's and gprof.h's */ +/* XXX too much duplication in various asm*.h's. */ #define ALIGN_DATA .align 2 /* 4 byte alignment, zero filled */ #define ALIGN_TEXT .align 2,0x90 /* 4-byte alignment, nop filled */ -#define SUPERALIGN_TEXT .align 4,0x90 /* 16-byte alignment (better for 486), nop filled */ +#define SUPERALIGN_TEXT .align 4,0x90 /* 16-byte alignment, nop filled */ -#define GEN_ENTRY(name) ALIGN_TEXT; .globl __CONCAT(_,name); __CONCAT(_,name): +#define GEN_ENTRY(name) ALIGN_TEXT; .globl __CONCAT(_,name); \ + __CONCAT(_,name): #define NON_GPROF_ENTRY(name) GEN_ENTRY(name) +#define NON_GPROF_RET .byte 0xc3 /* opcode for `ret' */ #ifdef GPROF /* @@ -59,26 +61,21 @@ * inadequate for good handling of special cases, e.g., -fpic works best * with profiling after the prologue. * - * Neither __mcount nor mcount requires %eax to point to 4 bytes of data, - * so don't waste space allocating the data or time setting it up. Changes - * to avoid the wastage in gcc-2.4.5-compiled code are available. - * - * mexitcount is a new profiling feature to allow accurate timing of all - * functions if an accurate clock is available. Changes to gcc-2.4.5 to - * support it are are available. The changes currently don't allow not - * generating mexitcounts for non-kernel code. It is best to call - * mexitcount right at the end of a function like the MEXITCOUNT macro - * does, but the changes to gcc only implement calling it as the first - * thing in the epilogue to avoid problems with -fpic. + * mexitcount is a new function to support non-statistical profiling if an + * accurate clock is available. For C sources, calls to it are generated + * by the FreeBSD extension `-mprofiler-epilogue' to gcc. It is best to + * call mexitcount at the end of a function like the MEXITCOUNT macro does, + * but gcc currently generates calls to it at the start of the epilogue to + * avoid problems with -fpic. * * mcount and __mexitcount may clobber the call-used registers and %ef. * mexitcount may clobber %ecx and %ef. * - * Cross-jumping makes accurate timing more difficult. It is handled in - * many cases by calling mexitcount before jumping. It is not handled - * for some conditional jumps (e.g., in bcopyx) or for some fault-handling - * jumps. It is handled for some fault-handling jumps by not sharing the - * exit routine. + * Cross-jumping makes non-statistical profiling timing more complicated. + * It is handled in many cases by calling mexitcount before jumping. It is + * handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL(). + * It is handled for some fault-handling jumps by not sharing the exit + * routine. * * ALTENTRY() must be before a corresponding ENTRY() so that it can jump to * the main entry point. Note that alt entries are counted twice. They @@ -88,19 +85,24 @@ * High local labels are used in macros to avoid clashes with local labels * in functions. * - * "ret" is used instead of "RET" because there are a lot of "ret"s. - * 0xc3 is the opcode for "ret" (#define ret ... ret fails because this - * file is preprocessed in traditional mode). "ret" clobbers eflags - * but this doesn't matter. + * Ordinary `ret' is used instead of a macro `RET' because there are a lot + * of `ret's. 0xc3 is the opcode for `ret' (`#define ret ... ret' can't + * be used because this file is sometimes preprocessed in traditional mode). + * `ret' clobbers eflags but this doesn't matter. */ #define ALTENTRY(name) GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f +#define CROSSJUMP(jtrue, label, jfalse) \ + jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8: +#define CROSSJUMPTARGET(label) \ + ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label #define ENTRY(name) GEN_ENTRY(name) ; 9: ; MCOUNT #define FAKE_MCOUNT(caller) pushl caller ; call __mcount ; popl %ecx #define MCOUNT call __mcount #define MCOUNT_LABEL(name) GEN_ENTRY(name) ; nop ; ALIGN_TEXT #define MEXITCOUNT call mexitcount -#define ret MEXITCOUNT ; .byte 0xc3 -#else /* not GPROF */ +#define ret MEXITCOUNT ; NON_GPROF_RET + +#else /* !GPROF */ /* * ALTENTRY() has to align because it is before a corresponding ENTRY(). * ENTRY() has to align to because there may be no ALTENTRY() before it. @@ -108,6 +110,8 @@ * is empty. */ #define ALTENTRY(name) GEN_ENTRY(name) +#define CROSSJUMP(jtrue, label, jfalse) jtrue label +#define CROSSJUMPTARGET(label) #define ENTRY(name) GEN_ENTRY(name) #define FAKE_MCOUNT(caller) #define MCOUNT |
