From 75acd14e43f2ffb698fc7032498f31095b56adb5 Mon Sep 17 00:00:00 2001 From: Richard Leach Date: Sun, 6 Feb 2022 22:52:54 +0000 Subject: Make newSV_type an inline function When a new SV is created and upgraded to a type known at compile time, uprooting a SV head and then using the general-purpose upgrade function (sv_upgrade) is clunky. Specifically, while uprooting a SV head is lightweight (assuming there are unused SVs), sv_upgrade is too big to be inlined, contains many branches that can logically be resolved at compile time for known start & end types, and the lookup of the correct body_details struct may add CPU cycles. This commit tries to address that by making newSV_type an inline function and including only the parts of sv_upgrade needed to upgrade a SVt_NULL. When the destination type is known at compile time, a decent compiler will inline a call to newSV_type and use the type information to throw away all the irrelevant parts of the sv_upgrade logic. Because of the spread of type definitions across header files, it did not seem possible to make the necessary changed inside sv.h, and so a new header file (sv_inline.h) was created. For the inlined function to work outside of sv.c, many definitions from that file were moved to sv_inline.h. Finally, in order to also benefit from this change, existing code in sv.c that does things like this: SV* sv; new_SV(sv); sv_upgrade(sv, SVt_PV) has been modified to read something like: SV* sv = newSV_type(SVt_PV); --- sv_inline.h | 495 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 495 insertions(+) create mode 100644 sv_inline.h (limited to 'sv_inline.h') diff --git a/sv_inline.h b/sv_inline.h new file mode 100644 index 0000000000..70ebb4ae3b --- /dev/null +++ b/sv_inline.h @@ -0,0 +1,495 @@ +/* sv.h + * + * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, + * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by Larry Wall and others + * + * You may distribute under the terms of either the GNU General Public + * License or the Artistic License, as specified in the README file. + * + */ + + +/* 2022 */ +/* BLAH BLAH BLAH */ + +/* This came from perl.h*/ + +/* The old value was hard coded at 1008. (4096-16) seems to be a bit faster, + at least on FreeBSD. YMMV, so experiment. */ +#ifndef PERL_ARENA_SIZE +#define PERL_ARENA_SIZE 4080 +#endif + +/* All other pre-existing definitions and functions that were moved into this + * file originally came from sv.c. */ + +#ifdef PERL_POISON +# define SvARENA_CHAIN(sv) ((sv)->sv_u.svu_rv) +# define SvARENA_CHAIN_SET(sv,val) (sv)->sv_u.svu_rv = MUTABLE_SV((val)) +/* Whilst I'd love to do this, it seems that things like to check on + unreferenced scalars +# define POISON_SV_HEAD(sv) PoisonNew(sv, 1, struct STRUCT_SV) +*/ +# define POISON_SV_HEAD(sv) PoisonNew(&SvANY(sv), 1, void *), \ + PoisonNew(&SvREFCNT(sv), 1, U32) +#else +# define SvARENA_CHAIN(sv) SvANY(sv) +# define SvARENA_CHAIN_SET(sv,val) SvANY(sv) = (void *)(val) +# define POISON_SV_HEAD(sv) +#endif + +#ifdef PERL_MEM_LOG +# define MEM_LOG_NEW_SV(sv, file, line, func) \ + Perl_mem_log_new_sv(sv, file, line, func) +# define MEM_LOG_DEL_SV(sv, file, line, func) \ + Perl_mem_log_del_sv(sv, file, line, func) +#else +# define MEM_LOG_NEW_SV(sv, file, line, func) NOOP +# define MEM_LOG_DEL_SV(sv, file, line, func) NOOP +#endif + +#define uproot_SV(p) \ + STMT_START { \ + (p) = PL_sv_root; \ + PL_sv_root = MUTABLE_SV(SvARENA_CHAIN(p)); \ + ++PL_sv_count; \ + } STMT_END + +/* Perl_more_sv lives in sv.c, we don't want to inline it. + * but the function declaration seems to be needed? */ +SV* Perl_more_sv(pTHX); + +/* new_SV(): return a new, empty SV head */ + +#ifdef DEBUG_LEAKING_SCALARS +/* provide a real function for a debugger to play with */ +STATIC SV* +S_new_SV(pTHX_ const char *file, int line, const char *func) +{ + SV* sv; + + if (PL_sv_root) + uproot_SV(sv); + else + sv = Perl_more_sv(aTHX); + SvANY(sv) = 0; + SvREFCNT(sv) = 1; + SvFLAGS(sv) = 0; + sv->sv_debug_optype = PL_op ? PL_op->op_type : 0; + sv->sv_debug_line = (U16) (PL_parser && PL_parser->copline != NOLINE + ? PL_parser->copline + : PL_curcop + ? CopLINE(PL_curcop) + : 0 + ); + sv->sv_debug_inpad = 0; + sv->sv_debug_parent = NULL; + sv->sv_debug_file = PL_curcop ? savesharedpv(CopFILE(PL_curcop)): NULL; + + sv->sv_debug_serial = PL_sv_serial++; + + MEM_LOG_NEW_SV(sv, file, line, func); + DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%" UVxf ": (%05ld) new_SV (from %s:%d [%s])\n", + PTR2UV(sv), (long)sv->sv_debug_serial, file, line, func)); + + return sv; +} +# define new_SV(p) (p)=S_new_SV(aTHX_ __FILE__, __LINE__, FUNCTION__) + +#else +# define new_SV(p) \ + STMT_START { \ + if (PL_sv_root) \ + uproot_SV(p); \ + else \ + (p) = Perl_more_sv(aTHX); \ + SvANY(p) = 0; \ + SvREFCNT(p) = 1; \ + SvFLAGS(p) = 0; \ + MEM_LOG_NEW_SV(p, __FILE__, __LINE__, FUNCTION__); \ + } STMT_END +#endif + + +typedef struct xpvhv_with_aux XPVHV_WITH_AUX; + +struct body_details { + U8 body_size; /* Size to allocate */ + U8 copy; /* Size of structure to copy (may be shorter) */ + U8 offset; /* Size of unalloced ghost fields to first alloced field*/ + PERL_BITFIELD8 type : 4; /* We have space for a sanity check. */ + PERL_BITFIELD8 cant_upgrade : 1;/* Cannot upgrade this type */ + PERL_BITFIELD8 zero_nv : 1; /* zero the NV when upgrading from this */ + PERL_BITFIELD8 arena : 1; /* Allocated from an arena */ + U32 arena_size; /* Size of arena to allocate */ +}; + +#define ALIGNED_TYPE_NAME(name) name##_aligned +#define ALIGNED_TYPE(name) \ + typedef union { \ + name align_me; \ + NV nv; \ + IV iv; \ + } ALIGNED_TYPE_NAME(name) + +ALIGNED_TYPE(regexp); +ALIGNED_TYPE(XPVGV); +ALIGNED_TYPE(XPVLV); +ALIGNED_TYPE(XPVAV); +ALIGNED_TYPE(XPVHV); +ALIGNED_TYPE(XPVHV_WITH_AUX); +ALIGNED_TYPE(XPVCV); +ALIGNED_TYPE(XPVFM); +ALIGNED_TYPE(XPVIO); + +#define HADNV FALSE +#define NONV TRUE + + +#ifdef PURIFY +/* With -DPURFIY we allocate everything directly, and don't use arenas. + This seems a rather elegant way to simplify some of the code below. */ +#define HASARENA FALSE +#else +#define HASARENA TRUE +#endif +#define NOARENA FALSE + +/* Size the arenas to exactly fit a given number of bodies. A count + of 0 fits the max number bodies into a PERL_ARENA_SIZE.block, + simplifying the default. If count > 0, the arena is sized to fit + only that many bodies, allowing arenas to be used for large, rare + bodies (XPVFM, XPVIO) without undue waste. The arena size is + limited by PERL_ARENA_SIZE, so we can safely oversize the + declarations. + */ +#define FIT_ARENA0(body_size) \ + ((size_t)(PERL_ARENA_SIZE / body_size) * body_size) +#define FIT_ARENAn(count,body_size) \ + ( count * body_size <= PERL_ARENA_SIZE) \ + ? count * body_size \ + : FIT_ARENA0 (body_size) +#define FIT_ARENA(count,body_size) \ + (U32)(count \ + ? FIT_ARENAn (count, body_size) \ + : FIT_ARENA0 (body_size)) + +/* Calculate the length to copy. Specifically work out the length less any + final padding the compiler needed to add. See the comment in sv_upgrade + for why copying the padding proved to be a bug. */ + +#define copy_length(type, last_member) \ + STRUCT_OFFSET(type, last_member) \ + + sizeof (((type*)SvANY((const SV *)0))->last_member) + +static const struct body_details bodies_by_type[] = { + /* HEs use this offset for their arena. */ + { 0, 0, 0, SVt_NULL, FALSE, NONV, NOARENA, 0 }, + + /* IVs are in the head, so the allocation size is 0. */ + { 0, + sizeof(IV), /* This is used to copy out the IV body. */ + STRUCT_OFFSET(XPVIV, xiv_iv), SVt_IV, FALSE, NONV, + NOARENA /* IVS don't need an arena */, 0 + }, + +#if NVSIZE <= IVSIZE + { 0, sizeof(NV), + STRUCT_OFFSET(XPVNV, xnv_u), + SVt_NV, FALSE, HADNV, NOARENA, 0 }, +#else + { sizeof(NV), sizeof(NV), + STRUCT_OFFSET(XPVNV, xnv_u), + SVt_NV, FALSE, HADNV, HASARENA, FIT_ARENA(0, sizeof(NV)) }, +#endif + + { sizeof(XPV) - STRUCT_OFFSET(XPV, xpv_cur), + copy_length(XPV, xpv_len) - STRUCT_OFFSET(XPV, xpv_cur), + + STRUCT_OFFSET(XPV, xpv_cur), + SVt_PV, FALSE, NONV, HASARENA, + FIT_ARENA(0, sizeof(XPV) - STRUCT_OFFSET(XPV, xpv_cur)) }, + + { sizeof(XINVLIST) - STRUCT_OFFSET(XPV, xpv_cur), + copy_length(XINVLIST, is_offset) - STRUCT_OFFSET(XPV, xpv_cur), + + STRUCT_OFFSET(XPV, xpv_cur), + SVt_INVLIST, TRUE, NONV, HASARENA, + FIT_ARENA(0, sizeof(XINVLIST) - STRUCT_OFFSET(XPV, xpv_cur)) }, + + { sizeof(XPVIV) - STRUCT_OFFSET(XPV, xpv_cur), + copy_length(XPVIV, xiv_u) - STRUCT_OFFSET(XPV, xpv_cur), + + STRUCT_OFFSET(XPV, xpv_cur), + SVt_PVIV, FALSE, NONV, HASARENA, + FIT_ARENA(0, sizeof(XPVIV) - STRUCT_OFFSET(XPV, xpv_cur)) }, + + { sizeof(XPVNV) - STRUCT_OFFSET(XPV, xpv_cur), + copy_length(XPVNV, xnv_u) - STRUCT_OFFSET(XPV, xpv_cur), + + STRUCT_OFFSET(XPV, xpv_cur), + SVt_PVNV, FALSE, HADNV, HASARENA, + FIT_ARENA(0, sizeof(XPVNV) - STRUCT_OFFSET(XPV, xpv_cur)) }, + + { sizeof(XPVMG), copy_length(XPVMG, xnv_u), 0, SVt_PVMG, FALSE, HADNV, + HASARENA, FIT_ARENA(0, sizeof(XPVMG)) }, + + { sizeof(ALIGNED_TYPE_NAME(regexp)), + sizeof(regexp), + 0, + SVt_REGEXP, TRUE, NONV, HASARENA, + FIT_ARENA(0, sizeof(ALIGNED_TYPE_NAME(regexp))) + }, + + { sizeof(ALIGNED_TYPE_NAME(XPVGV)), sizeof(XPVGV), 0, SVt_PVGV, TRUE, HADNV, + HASARENA, FIT_ARENA(0, sizeof(ALIGNED_TYPE_NAME(XPVGV))) }, + + { sizeof(ALIGNED_TYPE_NAME(XPVLV)), sizeof(XPVLV), 0, SVt_PVLV, TRUE, HADNV, + HASARENA, FIT_ARENA(0, sizeof(ALIGNED_TYPE_NAME(XPVLV))) }, + + { sizeof(ALIGNED_TYPE_NAME(XPVAV)), + copy_length(XPVAV, xav_alloc), + 0, + SVt_PVAV, TRUE, NONV, HASARENA, + FIT_ARENA(0, sizeof(ALIGNED_TYPE_NAME(XPVAV))) }, + + { sizeof(ALIGNED_TYPE_NAME(XPVHV)), + copy_length(XPVHV, xhv_max), + 0, + SVt_PVHV, TRUE, NONV, HASARENA, + FIT_ARENA(0, sizeof(ALIGNED_TYPE_NAME(XPVHV))) }, + + { sizeof(ALIGNED_TYPE_NAME(XPVCV)), + sizeof(XPVCV), + 0, + SVt_PVCV, TRUE, NONV, HASARENA, + FIT_ARENA(0, sizeof(ALIGNED_TYPE_NAME(XPVCV))) }, + + { sizeof(ALIGNED_TYPE_NAME(XPVFM)), + sizeof(XPVFM), + 0, + SVt_PVFM, TRUE, NONV, NOARENA, + FIT_ARENA(20, sizeof(ALIGNED_TYPE_NAME(XPVFM))) }, + + { sizeof(ALIGNED_TYPE_NAME(XPVIO)), + sizeof(XPVIO), + 0, + SVt_PVIO, TRUE, NONV, HASARENA, + FIT_ARENA(24, sizeof(ALIGNED_TYPE_NAME(XPVIO))) }, +}; + +#define new_body_allocated(sv_type) \ + (void *)((char *)S_new_body(aTHX_ sv_type) \ + - bodies_by_type[sv_type].offset) + +#ifdef PURIFY +#if !(NVSIZE <= IVSIZE) +# define new_XNV() safemalloc(sizeof(XPVNV)) +#endif +#define new_XPVNV() safemalloc(sizeof(XPVNV)) +#define new_XPVMG() safemalloc(sizeof(XPVMG)) + +#define del_body_by_type(p, type) safefree(p) + +#else /* !PURIFY */ + +#if !(NVSIZE <= IVSIZE) +# define new_XNV() new_body_allocated(SVt_NV) +#endif +#define new_XPVNV() new_body_allocated(SVt_PVNV) +#define new_XPVMG() new_body_allocated(SVt_PVMG) + +#define del_body_by_type(p, type) \ + del_body(p + bodies_by_type[(type)].offset, \ + &PL_body_roots[(type)]) + +#endif /* PURIFY */ + +/* no arena for you! */ + +#define new_NOARENA(details) \ + safemalloc((details)->body_size + (details)->offset) +#define new_NOARENAZ(details) \ + safecalloc((details)->body_size + (details)->offset, 1) + +#ifndef PURIFY + +/* grab a new thing from the arena's free list, allocating more if necessary. */ +#define new_body_from_arena(xpv, root_index, type_meta) \ + STMT_START { \ + void ** const r3wt = &PL_body_roots[root_index]; \ + xpv = (PTR_TBL_ENT_t*) (*((void **)(r3wt)) \ + ? *((void **)(r3wt)) : Perl_more_bodies(aTHX_ root_index, \ + type_meta.body_size,\ + type_meta.arena_size)); \ + *(r3wt) = *(void**)(xpv); \ + } STMT_END + +PERL_STATIC_INLINE void * +S_new_body(pTHX_ const svtype sv_type) +{ + void *xpv; + new_body_from_arena(xpv, sv_type, bodies_by_type[sv_type]); + return xpv; +} + +#endif + +static const struct body_details fake_rv = + { 0, 0, 0, SVt_IV, FALSE, NONV, NOARENA, 0 }; + +static const struct body_details fake_hv_with_aux = + /* The SVt_IV arena is used for (larger) PVHV bodies. */ + { sizeof(ALIGNED_TYPE_NAME(XPVHV_WITH_AUX)), + copy_length(XPVHV, xhv_max), + 0, + SVt_PVHV, TRUE, NONV, HASARENA, + FIT_ARENA(0, sizeof(ALIGNED_TYPE_NAME(XPVHV_WITH_AUX))) }; + +/* +=for apidoc newSV_type + +Creates a new SV, of the type specified. The reference count for the new SV +is set to 1. + +=cut +*/ + +PERL_STATIC_INLINE SV * +Perl_newSV_type(pTHX_ const svtype type) +{ + SV *sv; + void* new_body; + const struct body_details *type_details; + + new_SV(sv); + + type_details = bodies_by_type + type; + + SvFLAGS(sv) &= ~SVTYPEMASK; + SvFLAGS(sv) |= type; + + switch (type) { + case SVt_NULL: + break; + case SVt_IV: + SET_SVANY_FOR_BODYLESS_IV(sv); + SvIV_set(sv, 0); + break; + case SVt_NV: +#if NVSIZE <= IVSIZE + SET_SVANY_FOR_BODYLESS_NV(sv); +#else + SvANY(sv) = new_XNV(); +#endif + SvNV_set(sv, 0); + break; + case SVt_PVHV: + case SVt_PVAV: + assert(type_details->body_size); + +#ifndef PURIFY + assert(type_details->arena); + assert(type_details->arena_size); + /* This points to the start of the allocated area. */ + new_body = S_new_body(aTHX_ type); + /* xpvav and xpvhv have no offset, so no need to adjust new_body */ + assert(!(type_details->offset)); +#else + /* We always allocated the full length item with PURIFY. To do this + we fake things so that arena is false for all 16 types.. */ + new_body = new_NOARENAZ(type_details); +#endif + SvANY(sv) = new_body; + + SvSTASH_set(sv, NULL); + SvMAGIC_set(sv, NULL); + + if (type == SVt_PVAV) { + AvFILLp(sv) = -1; + AvMAX(sv) = -1; + AvALLOC(sv) = NULL; + + AvREAL_only(sv); + } else { + HvTOTALKEYS(sv) = 0; + /* start with PERL_HASH_DEFAULT_HvMAX+1 buckets: */ + HvMAX(sv) = PERL_HASH_DEFAULT_HvMAX; + + assert(!SvOK(sv)); + SvOK_off(sv); +#ifndef NODEFAULT_SHAREKEYS + HvSHAREKEYS_on(sv); /* key-sharing on by default */ +#endif + /* start with PERL_HASH_DEFAULT_HvMAX+1 buckets: */ + HvMAX(sv) = PERL_HASH_DEFAULT_HvMAX; + } + + sv->sv_u.svu_array = NULL; /* or svu_hash */ + break; + + case SVt_PVIV: + case SVt_PVIO: + case SVt_PVGV: + case SVt_PVCV: + case SVt_PVLV: + case SVt_INVLIST: + case SVt_REGEXP: + case SVt_PVMG: + case SVt_PVNV: + case SVt_PV: + /* For a type known at compile time, it should be possible for the + * compiler to deduce the value of (type_details->arena), resolve + * that branch below, and inline the relevant values from + * bodies_by_type. Except, at least for gcc, it seems not to do that. + * We help it out here with two deviations from sv_upgrade: + * (1) Minor rearrangement here, so that PVFM - the only type at this + * point not to be allocated from an array appears last, not PV. + * (2) The ASSUME() statement here for everything that isn't PVFM. + * Obviously this all only holds as long as it's a true reflection of + * the bodies_by_type lookup table. */ +#ifndef PURIFY + ASSUME(type_details->arena); +#endif + /* FALLTHROUGH */ + case SVt_PVFM: + + assert(type_details->body_size); + /* We always allocated the full length item with PURIFY. To do this + we fake things so that arena is false for all 16 types.. */ +#ifndef PURIFY + if(type_details->arena) { + /* This points to the start of the allocated area. */ + new_body = S_new_body(aTHX_ type); + Zero(new_body, type_details->body_size, char); + new_body = ((char *)new_body) - type_details->offset; + } else +#endif + { + new_body = new_NOARENAZ(type_details); + } + SvANY(sv) = new_body; + + if (UNLIKELY(type == SVt_PVIO)) { + IO * const io = MUTABLE_IO(sv); + GV *iogv = gv_fetchpvs("IO::File::", GV_ADD, SVt_PVHV); + + SvOBJECT_on(io); + /* Clear the stashcache because a new IO could overrule a package + name */ + DEBUG_o(Perl_deb(aTHX_ "sv_upgrade clearing PL_stashcache\n")); + hv_clear(PL_stashcache); + + SvSTASH_set(io, MUTABLE_HV(SvREFCNT_inc(GvHV(iogv)))); + IoPAGE_LEN(sv) = 60; + } + + sv->sv_u.svu_rv = NULL; + break; + default: + Perl_croak(aTHX_ "panic: sv_upgrade to unknown type %lu", + (unsigned long)type); + } + + return sv; +} + +/* + * ex: set ts=8 sts=4 sw=4 et: + */ -- cgit v1.2.1