From 3d558f4ec7fecbac0dddb4d321a1ec10f14e8e03 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Sat, 31 Jul 1999 05:15:48 +0000 Subject: Update. * configure.in: Add test for local label subtraction. * config.h.in: Ad HAVE_SUBTRACT_LOCAL_LABELS. * stdio-common/vfprintf.c (vfprintf): Use subtraction of local labels to reduce number of runtime relocations and move jump tables in read-only seciton. --- stdio-common/vfprintf.c | 44 +++++++++++++++++++++++++++++++++++--------- 1 file changed, 35 insertions(+), 9 deletions(-) (limited to 'stdio-common') diff --git a/stdio-common/vfprintf.c b/stdio-common/vfprintf.c index 902a70df40..742213282f 100644 --- a/stdio-common/vfprintf.c +++ b/stdio-common/vfprintf.c @@ -271,7 +271,24 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) #define NOT_IN_JUMP_RANGE(Ch) ((Ch) < L_(' ') || (Ch) > L_('z')) #define CHAR_CLASS(Ch) (jump_table[(INT_T) (Ch) - L_(' ')]) -#define JUMP(ChExpr, table) \ +#if defined HAVE_SUBTRACT_LOCAL_LABELS && defined PIC + /* 'int' is enough and it saves some space on 64 bit systems. */ +# define JUMP_TABLE_TYPE const int +# define JUMP(ChExpr, table) \ + do \ + { \ + int offset; \ + void *ptr; \ + spec = (ChExpr); \ + offset = NOT_IN_JUMP_RANGE (spec) ? REF (form_unknown) \ + : table[CHAR_CLASS (spec)]; \ + ptr = &&do_form_unknown + offset; \ + goto *ptr; \ + } \ + while (0) +#else +# define JUMP_TABLE_TYPE const void *const +# define JUMP(ChExpr, table) \ do \ { \ const void *ptr; \ @@ -281,10 +298,11 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) goto *ptr; \ } \ while (0) +#endif #define STEP0_3_TABLE \ /* Step 0: at the beginning. */ \ - static const void *step0_jumps[29] = \ + static JUMP_TABLE_TYPE step0_jumps[29] = \ { \ REF (form_unknown), \ REF (flag_space), /* for ' ' */ \ @@ -317,7 +335,7 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) REF (mod_intmax_t), /* for 'j' */ \ }; \ /* Step 1: after processing width. */ \ - static const void *step1_jumps[29] = \ + static JUMP_TABLE_TYPE step1_jumps[29] = \ { \ REF (form_unknown), \ REF (form_unknown), /* for ' ' */ \ @@ -350,7 +368,7 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) REF (mod_intmax_t) /* for 'j' */ \ }; \ /* Step 2: after processing precision. */ \ - static const void *step2_jumps[29] = \ + static JUMP_TABLE_TYPE step2_jumps[29] = \ { \ REF (form_unknown), \ REF (form_unknown), /* for ' ' */ \ @@ -383,7 +401,7 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) REF (mod_intmax_t) /* for 'j' */ \ }; \ /* Step 3a: after processing first 'h' modifier. */ \ - static const void *step3a_jumps[29] = \ + static JUMP_TABLE_TYPE step3a_jumps[29] = \ { \ REF (form_unknown), \ REF (form_unknown), /* for ' ' */ \ @@ -416,7 +434,7 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) REF (form_unknown) /* for 'j' */ \ }; \ /* Step 3b: after processing first 'l' modifier. */ \ - static const void *step3b_jumps[29] = \ + static JUMP_TABLE_TYPE step3b_jumps[29] = \ { \ REF (form_unknown), \ REF (form_unknown), /* for ' ' */ \ @@ -451,7 +469,7 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) #define STEP4_TABLE \ /* Step 4: processing format specifier. */ \ - static const void *step4_jumps[29] = \ + static JUMP_TABLE_TYPE step4_jumps[29] = \ { \ REF (form_unknown), \ REF (form_unknown), /* for ' ' */ \ @@ -1179,7 +1197,11 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) /* Process whole format string. */ do { -#define REF(Name) &&do_##Name +#if defined HAVE_SUBTRACT_LOCAL_LABELS && defined PIC +# define REF(Name) &&do_##Name - &&do_form_unknown +#else +# define REF(Name) &&do_##Name +#endif #define LABEL(Name) do_##Name STEP0_3_TABLE; STEP4_TABLE; @@ -1560,7 +1582,11 @@ do_positional: for (; (size_t) nspecs_done < nspecs; ++nspecs_done) { #undef REF -#define REF(Name) &&do2_##Name +#if defined HAVE_SUBTRACT_LOCAL_LABELS && defined PIC +# define REF(Name) &&do2_##Name - &&do_form_unknown +#else +# define REF(Name) &&do2_##Name +#endif #undef LABEL #define LABEL(Name) do2_##Name STEP4_TABLE; -- cgit v1.2.3