linaro-toolchain

linaro-toolchain@lists.linaro.org

6 participants
5605 discussions

by Michael Hope

Hi Ramana. You were right about being able to do operations on intrinsic types. Instead of doing the admittedly made up: int16x4_t foo2(int16x4_t a, int16x4_t b) { int16x4_t ca = vdup_n_s16(0.2126*256); int16x4_t cb = vdup_n_s16(0.7152*256); return vadd_s16(vmul_s16(ca, a), vmul_s16(cb, b)); } you can do: int16x4_t foo3(int16x4_t a, int16x4_t b) { int16x4_t ca = vdup_n_s16(0.2126*256); int16x4_t cb = vdup_n_s16(0.7152*256); return ca*a + cb*b; } which is more readable and, as an added bonus, generates the multiply-and-accumulate that I missed when using intrinsics. Nice. -- Michael

13 years, 6 months

[ACTIVITY] Jan 02 - Jan 05

by Ulrich Weigand

== GDB == * Ongoing discussion on remote support for "info proc" and core file generation. * Fixed various GDB 7.4 regressions on multiple platforms. == GCC == * Patch review week. * Started looking into current status of performance patches. Mit freundlichen Gruessen / Best Regards Ulrich Weigand -- Dr. Ulrich Weigand | Phone: +49-7031/16-3727 STSM, GNU compiler and toolchain for Linux on System z and Cell/B.E. IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Martin Jetter | Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht Stuttgart, HRB 243294

13 years, 6 months

Release notes for 2012.01

by Michael Hope

I liked Andrew's idea of sharing the release notes so I stole it for this month: https://wiki.linaro.org/MichaelHope/Sandbox/GCC2012.01ReleaseNotes Please add anything new and noteworthy that you've done to this draft. -- Michael

13 years, 6 months

[ACTIVITY] weekly status

by Ken Werner

Hi, * Android * migrated my linaro android build environment * did a small change to the debuggerd patch (thanks Sylvain) * OpenEmbedded * the linaro binary toolchain uses multiarch paths while OE doesn't -> setup a workaround to make it look like a classic one * however, I think what I really want is to build the libc instead of using the one provided by the binary external toolchain * The core-image-minimal still doesn't boot properly because 'init' doesn't come properly Regards Ken

13 years, 6 months

Patch drop: fwprop.c patch for neon-strided-load-extract

by Richard Sandiford

The remaining change for neon-strided-load-extract is to allow fwprop.c to propagate: (set (reg X) (subreg (reg Y) N)) even if no further simplifications are possible. I posted the original patch for comments here: http://article.gmane.org/gmane.comp.gcc.patches/246180/ and fixed the problem that H.J. spotted. I wasn't entirely happy with the benchmark results though, so it never became an RFA. Richard gcc/ * fwprop.c (propagate_rtx): Also set PR_CAN_APPEAR for subregs. Index: gcc/fwprop.c =================================================================== --- gcc/fwprop.c 2011-09-15 14:36:23.206143787 +0100 +++ gcc/fwprop.c 2011-09-15 14:36:40.995131564 +0100 @@ -664,7 +664,12 @@ propagate_rtx (rtx x, enum machine_mode return NULL_RTX; flags = 0; - if (REG_P (new_rtx) || CONSTANT_P (new_rtx)) + if (REG_P (new_rtx) + || CONSTANT_P (new_rtx) + || (GET_CODE (new_rtx) == SUBREG + && REG_P (SUBREG_REG (new_rtx)) + && (GET_MODE_SIZE (mode) + <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (new_rtx)))))) flags |= PR_CAN_APPEAR; if (!for_each_rtx (&new_rtx, varying_mem_p, NULL)) flags |= PR_HANDLE_MEM;

13 years, 6 months

[ACTIVITY] 2011-12-23 - and goodbye

by David Gilbert

== QEMU == * Wrote the context routines for Eglibc, including those that QEMU uses These pass all the context tests I could find, including QEMUs coroutine tests, and with them QEMU seems to boot OK. I've got a full eglibc test run going at the moment, but I don't think anything else uses them. I posted them with comments and a question to libc-ports; I'll try and chase follow ups. == String routines == * I posted the strchr and strlen routines to eglibc (libc-ports) * On strchr the question of whether it was worth using the longer version that's faster for longer strings (but slower for shorter strings) came up. I posted some stats, observations etc - and there is still a discussion on going about it. * For strlen, rth noted the same trick that I'd originally seen in newlib (and for which RichardS and Ramana had suggested) of a quicker end-of-string sequence using clz. I'd avoided this because I'd originally seen it in newlib and didn't want to copy it; but since 3 people have individually suggested it it would seem using. == Goodbye! == Thank you all for a fun & interesting year! I'm sure many of us will meet online again in the future. I'll try and follow my linaro.org address while it's still live to check for any replies to any patches/comments etc. Feel free to mail me at davidgil(a)uk.ibm.com (work) or dave(a)treblig.org (home); for Linaro people I've also added some more contact methods at: https://wiki.linaro.org/Internal/People/DaveGilbert/Contact Thanks again! Dave

13 years, 6 months

Fwd: New question: problem in installing Linaro tools on Ask Linaro

by Andy Doan

anyone have a suggestion for this person? -------- Original Message -------- Subject: New question: problem in installing Linaro tools on Ask Linaro Date: Mon, 26 Dec 2011 21:31:57 -0800 (PST) From: Ask Linaro <dnsadmin(a)linaro.org> To: doanac <andy.doan(a)linaro.org> Ask Linaro - Q & A forum for Linaro developers <http://ask.linaro.org/> ------------------------------------------------------------------------ Hello doanac, chandrakala <http://ask.linaro.org/users/172/chandrakala> has just posted a new question on Ask Linaro, entitled problem in installing Linaro tools <http://ask.linaro.org/questions/456/problem-in-installing-linaro-tools> and tagged "/linaro <http://ask.linaro.org/tags/linaro/> installation <http://ask.linaro.org/tags/installation/>/". Here's what it says: Hi all, Iam new to linux and gnu tools. i have downloaded linaro gnu tools to install cortex-a8 on my ubuntu machine. iam able to successfully install gcc tools. But when i try to install arm tools it is throwing error. following are the commands used to install gnu tools and the error it is generated mckala@mckala:~/Desktop/gstreamer/gcc_objdir$ ../gcc-linaro-4.6-2011.12/gcc-linaro-4.6-2011.12/configure --target=arm-*-elf --disable-bootstrap --enable-languages=c,c++ --with-mode=thumb --with-arch=armv7-a --with-tune=cortex-a8 --with-fpu=neon --with-float=softfp --prefix=/home/mckala/Desktop/gstreamer/gcc_objdir --disable-werror --with-newlib mckala@mckala:~/Desktop/gstreamer/gcc_objdir$ make all-host mckala@mckala:~/Desktop/gstreamer/gcc_objdir$ make install-host with this gnu tools installation is completed and i did not get any error. when i used the following command to install cross compiler, it is giving error mckala@mckala:~/Desktop/gstreamer/gcc_objdir$ make The error is checking for suffix of object files... configure: error: in |/home/mckala/Desktop/gstreamer/gcc_objdir/arm-*-elf/libgcc': configure: error: cannot compute suffix of object files: cannot compile See|config.log' for more details. make[1]: *** [configure-target-libgcc] Error 1 config.log file is showing the following error. gcc_objdir/arm-/-elf/bin/ -B/home/mckala/Desktop/gstreamer/gcc_objdir/arm-/-elf/lib/ -isystem /home/mckala/Desktop/gstreamer/gcc_objdir/arm-/-elf/include -isystem /home/mckala/Desktop/gstreamer/gcc_objdir/arm-/-elf/sys-include -V >&5 xgcc: fatal error: no input files compilation terminated. Can any one please help on this. Thanks in advance. Don't forget to come over and cast your vote. Thanks, Ask Linaro P.S. You can always fine-tune which notifications you receive here <http://ask.linaro.org//users/16/doanac/subscriptions/>. ------------------------------------------------------------------------

13 years, 6 months

Round-up and goodbye

by Richard Sandiford

I've posted all my WIP patches to this list over the last few days. Please treat them kindly. :-) I've also tried to update the relevant blueprints. I pinged the 4.5 and 4.6 backports for lp736661 on gcc-patches last week, then again this week, but there's obviously not likely to be much response at this time of year. I therefore went ahead with the Linaro merges of the branches rather than relying on them being committed to FSF branches in time for next month's Linaro release. I'll continue to ping though. If I've forgotten anything, or if you need more info, please don't hesitate to ask. I'll continue to monitor my Linaro email address as long as it remains active, although rdsandiford(a)googlemail.com is likely to be a better bet. With all that out of the way, I just wanted to say thank you to everyone for making this a really enjoyable project to work on. It feels like we managed to get through a fair number of new features, performance improvements and bug fixes this year. I hope Linaro will be around for a good few years yet and that it continues to go from strength to strength. Happy New Year, and all the best, Richard

13 years, 6 months

Patch drop: sms-and-memory-dependencies

by Richard Sandiford

Here's the patch for sms-and-memory-dependencies. The idea is to bypass the sched-deps.c {output,read,anti,true}_dependence tests altogether -- which is easy to do thanks to the note_mem_dep hook -- and instead handle them in ddg.c. The ddg.c tests then use RTL loop iv analysis to try to get longer distances on the memory dependencies. (Note that other memory-related dependencies, such as those between volatile MEMs and other volatile instructions, are still handled by sched-deps.c.) Dependencies are now always created in pairs, so there's no need for get_sched_window to set an upper bound when processing incoming MEM_DEPs, or a lower bound when processing outgoing MEM_DEPs; we can rely on the partnering edge to do that instead. Richard gcc/ * Makefile.in (ddg.o): Depend on $(TREE_PASS_H). * ddg.h (REG_OR_MEM_DEP, REG_AND_MEM_DEP): Delete. (ddg_mem_ref): New structure. (ddg): Add loads and stores array. (create_ddg): Add a loop argument. (add_edges_to_ddg): Declare. (MAX_DDG_DISTANCE): New macro. * ddg.c: Include tree-pass.h. (mem_ref_p, mark_mem_use, mark_mem_use_1, mem_read_insn_p) (mark_mem_store, mem_write_insn_p, rtx_mem_access_p) (mem_access_insn_p): Delete. (create_mem_ref): New function. (graph_and_node): New structure. (record_loads, record_stores): New functions. (create_ddg_dep_from_intra_loop_link): Treat all dependencies as register dependencies. (walk_mems_2, walk_mems_1, insns_may_alias_p, add_intra_loop_mem_dep) (add_inter_loop_mem_dep): Delete. (build_intra_loop_deps): Ignore memory dependencies created by sched-deps.c. Don't handle memory dependencies here. (measure_mem_distance, add_memory_dep): New functions. (FOR_EACH_LATER_MEM_REF): New macro. (build_memory_deps): New function. (create_ddg): Take the loop as argument. Don't count loads and stores here. Call iv_analysis_loop_init. Pass all loads to record_loads and all stores to record_stores. Move edge creation to... (add_edges_to_ddg): ...this new function. Also call build_memory_deps. * modulo-sched.c (sat_mulpp, sat_addsp, sat_subsp): New functions. (schedule_reg_moves): Only handle register dependencies. (sms_schedule): Update call to create_ddg. Call iv_analysis_done after creating all ddgs. Only set issue_rate if there are ddgs. Only call setup_sched_infos and haifa_sched_init if there are ddgs. Call add_edges_to_ddg before processing each ddg. (get_sched_window): Use saturating arithmetic. Do not add an implicit upper bound for incoming MEM_DEPs, or an implicit lower bound for outgoing MEM_DEPs. Rework calculation of final window. (calculate_must_precede_follow, compute_split_row): Use saturating arithmetic. Index: gcc/Makefile.in =================================================================== --- gcc/Makefile.in 2011-12-30 13:13:45.077544981 +0000 +++ gcc/Makefile.in 2011-12-30 13:24:57.330195801 +0000 @@ -3316,7 +3316,7 @@ ddg.o : ddg.c $(DDG_H) $(CONFIG_H) $(SYS $(DIAGNOSTIC_CORE_H) $(RTL_H) $(TM_P_H) $(REGS_H) $(FUNCTION_H) \ $(FLAGS_H) insn-config.h $(INSN_ATTR_H) $(EXCEPT_H) $(RECOG_H) \ $(SCHED_INT_H) $(CFGLAYOUT_H) $(CFGLOOP_H) $(EXPR_H) $(BITMAP_H) \ - hard-reg-set.h sbitmap.h $(TM_H) + hard-reg-set.h sbitmap.h $(TM_H) $(TREE_PASS_H) modulo-sched.o : modulo-sched.c $(DDG_H) $(CONFIG_H) $(CONFIG_H) $(SYSTEM_H) \ coretypes.h $(TARGET_H) $(DIAGNOSTIC_CORE_H) $(RTL_H) $(TM_P_H) $(REGS_H) $(FUNCTION_H) \ $(FLAGS_H) insn-config.h $(INSN_ATTR_H) $(EXCEPT_H) $(RECOG_H) \ Index: gcc/ddg.h =================================================================== --- gcc/ddg.h 2011-12-30 13:13:45.077544981 +0000 +++ gcc/ddg.h 2011-12-30 13:24:57.324195831 +0000 @@ -35,8 +35,7 @@ typedef struct ddg_scc *ddg_scc_ptr; typedef struct ddg_all_sccs *ddg_all_sccs_ptr; typedef enum {TRUE_DEP, OUTPUT_DEP, ANTI_DEP} dep_type; -typedef enum {REG_OR_MEM_DEP, REG_DEP, MEM_DEP, REG_AND_MEM_DEP} - dep_data_type; +typedef enum {REG_DEP, MEM_DEP} dep_data_type; /* The following two macros enables direct access to the successors and predecessors bitmaps held in each ddg_node. Do not make changes to @@ -44,6 +43,28 @@ typedef enum {REG_OR_MEM_DEP, REG_DEP, M #define NODE_SUCCESSORS(x) ((x)->successors) #define NODE_PREDECESSORS(x) ((x)->predecessors) +/* A structure that represents a memory read or write in the DDG; + context decides which. */ +struct ddg_mem_ref { + /* The previous reference of the same type (read or write) in the DDG. */ + struct ddg_mem_ref *prev; + + /* The DDG node that contains the memory reference. */ + ddg_node_ptr node; + + /* The memory reference itself. */ + rtx mem; + + /* If the address is a known induction variable, its value in iteration + I is given by: + + BASE + OFFSET + I * STEP + + In other cases BASE is null. */ + rtx base; + HOST_WIDE_INT offset, step; +}; + /* A structure that represents a node in the DDG. */ struct ddg_node { @@ -117,6 +138,11 @@ struct ddg /* Number of instructions in the basic block. */ int num_nodes; + /* The loads and stores in the BB, from the end of the block to + the beginning. */ + struct ddg_mem_ref *loads; + struct ddg_mem_ref *stores; + /* Number of load/store instructions in the BB - statistics. */ int num_loads; int num_stores; @@ -167,7 +193,9 @@ struct ddg_all_sccs }; -ddg_ptr create_ddg (basic_block, int closing_branch_deps); +struct loop; +ddg_ptr create_ddg (struct loop *, basic_block, int closing_branch_deps); +void add_edges_to_ddg (ddg_ptr); void free_ddg (ddg_ptr); void print_ddg (FILE *, ddg_ptr); @@ -188,4 +216,7 @@ int longest_simple_path (ddg_ptr, int fr bool autoinc_var_is_used_p (rtx, rtx); +/* The maximum allowable distance on a DDG edge. */ +#define MAX_DDG_DISTANCE INT_MAX + #endif /* GCC_DDG_H */ Index: gcc/ddg.c =================================================================== --- gcc/ddg.c 2011-12-30 13:13:45.077544981 +0000 +++ gcc/ddg.c 2011-12-30 13:36:35.005498271 +0000 @@ -43,6 +43,7 @@ Software Foundation; either version 3, o #include "expr.h" #include "bitmap.h" #include "ddg.h" +#include "tree-pass.h" #ifdef INSN_SCHEDULING @@ -61,88 +62,102 @@ static ddg_edge_ptr create_ddg_edge (ddg dep_data_type, int, int); static void add_edge_to_ddg (ddg_ptr g, ddg_edge_ptr); -/* Auxiliary variable for mem_read_insn_p/mem_write_insn_p. */ -static bool mem_ref_p; +/* Create a memory reference record for MEM, which occurs in NODE. + PREV is the previous reference of the same type. */ +static struct ddg_mem_ref * +create_mem_ref (struct ddg_mem_ref *prev, ddg_node_ptr node, rtx mem) +{ + struct ddg_mem_ref *entry; + enum machine_mode pmode; + struct rtx_iv iv; + rtx x; + + entry = XCNEW (struct ddg_mem_ref); + entry->prev = prev; + entry->node = node; + entry->mem = mem; + + pmode = targetm.addr_space.address_mode (MEM_ADDR_SPACE (mem)); + if (iv_analyze_expr (node->insn, XEXP (mem, 0), pmode, &iv) + && iv.extend == UNKNOWN + && CONST_INT_P (iv.step)) + { + x = iv.base; + if (GET_CODE (x) == PLUS && CONST_INT_P (XEXP (x, 1))) + { + entry->base = XEXP (x, 0); + entry->offset = INTVAL (XEXP (x, 1)); + } + else + { + entry->base = x; + entry->offset = 0; + } + entry->step = INTVAL (iv.step); + } -/* Auxiliary function for mem_read_insn_p. */ -static int -mark_mem_use (rtx *x, void *data ATTRIBUTE_UNUSED) -{ - if (MEM_P (*x)) - mem_ref_p = true; - return 0; + if (dump_file) + { + fprintf (dump_file, "Found memory reference in insn %d:\n", + INSN_UID (node->insn)); + print_rtl (dump_file, mem); + if (entry->base) + { + fprintf (dump_file, "\nwith base:"); + print_rtl (dump_file, entry->base); + fprintf (dump_file, "\noffset " HOST_WIDE_INT_PRINT_DEC + " and step " HOST_WIDE_INT_PRINT_DEC "\n\n", + entry->offset, entry->step); + } + else + fprintf (dump_file, "\nwhich isn't a recognized iv\n\n"); + } + return entry; } -/* Auxiliary function for mem_read_insn_p. */ -static void -mark_mem_use_1 (rtx *x, void *data) -{ - for_each_rtx (x, mark_mem_use, data); -} +/* A structure for pairing a node and the graph to which it belongs. */ +struct graph_and_node { + ddg_ptr g; + ddg_node_ptr node; +}; -/* Returns nonzero if INSN reads from memory. */ -static bool -mem_read_insn_p (rtx insn) +/* A for_each_rtx callback. Record all loads in an instruction. + DATA points to a graph_and_node. */ +static int +record_loads_1 (rtx *loc, void *data) { - mem_ref_p = false; - note_uses (&PATTERN (insn), mark_mem_use_1, NULL); - return mem_ref_p; -} + struct graph_and_node *gn; -static void -mark_mem_store (rtx loc, const_rtx setter ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED) -{ - if (MEM_P (loc)) - mem_ref_p = true; + if (MEM_P (*loc)) + { + gn = (struct graph_and_node *) data; + gn->g->loads = create_mem_ref (gn->g->loads, gn->node, *loc); + gn->g->num_loads++; + } + return 0; } -/* Returns nonzero if INSN writes to memory. */ -static bool -mem_write_insn_p (rtx insn) +/* A note_uses callback. Record all loads in an instruction. + DATA points to a graph_and_node. */ +static void +record_loads (rtx *loc, void *data) { - mem_ref_p = false; - note_stores (PATTERN (insn), mark_mem_store, NULL); - return mem_ref_p; + for_each_rtx (loc, record_loads_1, data); } -/* Returns nonzero if X has access to memory. */ -static bool -rtx_mem_access_p (rtx x) +/* A note_stores callback. Record all stores in an instruction. + DATA points to a graph_and_node. */ +static void +record_stores (rtx x, const_rtx setter ATTRIBUTE_UNUSED, void *data) { - int i, j; - const char *fmt; - enum rtx_code code; - - if (x == 0) - return false; + struct graph_and_node *gn; if (MEM_P (x)) - return true; - - code = GET_CODE (x); - fmt = GET_RTX_FORMAT (code); - for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { - if (fmt[i] == 'e') - { - if (rtx_mem_access_p (XEXP (x, i))) - return true; - } - else if (fmt[i] == 'E') - for (j = 0; j < XVECLEN (x, i); j++) - { - if (rtx_mem_access_p (XVECEXP (x, i, j))) - return true; - } + gn = (struct graph_and_node *) data; + gn->g->stores = create_mem_ref (gn->g->stores, gn->node, x); + gn->g->num_stores++; } - return false; -} - -/* Returns nonzero if INSN reads to or writes from memory. */ -static bool -mem_access_insn_p (rtx insn) -{ - return rtx_mem_access_p (PATTERN (insn)); } /* Return true if DEF_INSN contains address being auto-inc or auto-dec @@ -175,9 +190,6 @@ create_ddg_dep_from_intra_loop_link (ddg ddg_edge_ptr e; int latency, distance = 0; dep_type t = TRUE_DEP; - dep_data_type dt = (mem_access_insn_p (src_node->insn) - && mem_access_insn_p (dest_node->insn) ? MEM_DEP - : REG_DEP); gcc_assert (src_node->cuid < dest_node->cuid); gcc_assert (link); @@ -201,7 +213,7 @@ create_ddg_dep_from_intra_loop_link (ddg TODO: support the removal of all anti-deps edges, i.e. including those whose register has multiple defs in the loop. */ if (flag_modulo_sched_allow_regmoves - && (t == ANTI_DEP && dt == REG_DEP) + && t == ANTI_DEP && !autoinc_var_is_used_p (dest_node->insn, src_node->insn)) { rtx set; @@ -224,7 +236,7 @@ create_ddg_dep_from_intra_loop_link (ddg } latency = dep_cost (link); - e = create_ddg_edge (src_node, dest_node, t, dt, latency, distance); + e = create_ddg_edge (src_node, dest_node, t, REG_DEP, latency, distance); add_edge_to_ddg (g, e); } @@ -380,107 +392,6 @@ build_inter_loop_deps (ddg_ptr g) } } - -static int -walk_mems_2 (rtx *x, rtx mem) -{ - if (MEM_P (*x)) - { - if (may_alias_p (*x, mem)) - return 1; - - return -1; - } - return 0; -} - -static int -walk_mems_1 (rtx *x, rtx *pat) -{ - if (MEM_P (*x)) - { - /* Visit all MEMs in *PAT and check indepedence. */ - if (for_each_rtx (pat, (rtx_function) walk_mems_2, *x)) - /* Indicate that dependence was determined and stop traversal. */ - return 1; - - return -1; - } - return 0; -} - -/* Return 1 if two specified instructions have mem expr with conflict alias sets*/ -static int -insns_may_alias_p (rtx insn1, rtx insn2) -{ - /* For each pair of MEMs in INSN1 and INSN2 check their independence. */ - return for_each_rtx (&PATTERN (insn1), (rtx_function) walk_mems_1, - &PATTERN (insn2)); -} - -/* Given two nodes, analyze their RTL insns and add intra-loop mem deps - to ddg G. */ -static void -add_intra_loop_mem_dep (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to) -{ - - if ((from->cuid == to->cuid) - || !insns_may_alias_p (from->insn, to->insn)) - /* Do not create edge if memory references have disjoint alias sets - or 'to' and 'from' are the same instruction. */ - return; - - if (mem_write_insn_p (from->insn)) - { - if (mem_read_insn_p (to->insn)) - create_ddg_dep_no_link (g, from, to, - DEBUG_INSN_P (to->insn) - ? ANTI_DEP : TRUE_DEP, MEM_DEP, 0); - else - create_ddg_dep_no_link (g, from, to, - DEBUG_INSN_P (to->insn) - ? ANTI_DEP : OUTPUT_DEP, MEM_DEP, 0); - } - else if (!mem_read_insn_p (to->insn)) - create_ddg_dep_no_link (g, from, to, ANTI_DEP, MEM_DEP, 0); -} - -/* Given two nodes, analyze their RTL insns and add inter-loop mem deps - to ddg G. */ -static void -add_inter_loop_mem_dep (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to) -{ - if (!insns_may_alias_p (from->insn, to->insn)) - /* Do not create edge if memory references have disjoint alias sets. */ - return; - - if (mem_write_insn_p (from->insn)) - { - if (mem_read_insn_p (to->insn)) - create_ddg_dep_no_link (g, from, to, - DEBUG_INSN_P (to->insn) - ? ANTI_DEP : TRUE_DEP, MEM_DEP, 1); - else if (from->cuid != to->cuid) - create_ddg_dep_no_link (g, from, to, - DEBUG_INSN_P (to->insn) - ? ANTI_DEP : OUTPUT_DEP, MEM_DEP, 1); - } - else - { - if (mem_read_insn_p (to->insn)) - return; - else if (from->cuid != to->cuid) - { - create_ddg_dep_no_link (g, from, to, ANTI_DEP, MEM_DEP, 1); - if (DEBUG_INSN_P (from->insn) || DEBUG_INSN_P (to->insn)) - create_ddg_dep_no_link (g, to, from, ANTI_DEP, MEM_DEP, 1); - else - create_ddg_dep_no_link (g, to, from, TRUE_DEP, MEM_DEP, 1); - } - } - -} - /* Perform intra-block Data Dependency analysis and connect the nodes in the DDG. We assume the loop has a single basic block. */ static void @@ -493,6 +404,9 @@ build_intra_loop_deps (ddg_ptr g) /* Build the dependence information, using the sched_analyze function. */ init_deps_global (); + /* Ignore the usual dependencies between two MEM rtxes. We still rely + on sched_analyze to handle memory barriers and the like. */ + sched_deps_info->note_mem_dep = 0; init_deps (&tmp_deps, false); /* Do the intra-block data dependence analysis for the given block. */ @@ -519,37 +433,6 @@ build_intra_loop_deps (ddg_ptr g) create_ddg_dep_from_intra_loop_link (g, src_node, dest_node, dep); } - - /* If this insn modifies memory, add an edge to all insns that access - memory. */ - if (mem_access_insn_p (dest_node->insn)) - { - int j; - - for (j = 0; j <= i; j++) - { - ddg_node_ptr j_node = &g->nodes[j]; - if (DEBUG_INSN_P (j_node->insn)) - continue; - if (mem_access_insn_p (j_node->insn)) - { - /* Don't bother calculating inter-loop dep if an intra-loop dep - already exists. */ - if (! TEST_BIT (dest_node->successors, j)) - add_inter_loop_mem_dep (g, dest_node, j_node); - /* If -fmodulo-sched-allow-regmoves - is set certain anti-dep edges are not created. - It might be that these anti-dep edges are on the - path from one memory instruction to another such that - removing these edges could cause a violation of the - memory dependencies. Thus we add intra edges between - every two memory instructions in this case. */ - if (flag_modulo_sched_allow_regmoves - && !TEST_BIT (dest_node->predecessors, j)) - add_intra_loop_mem_dep (g, j_node, dest_node); - } - } - } } /* Free the INSN_LISTs. */ @@ -560,13 +443,187 @@ build_intra_loop_deps (ddg_ptr g) sched_free_deps (head, tail, false); } +/* Given a "source" memory reference from iteration 0 and a "target" + memory reference from iteration BASE_DISTANCE, return the first + N >= BASE_DISTANCE such that the source reference in iteration 0 + overlaps the target reference in iteration N. + + FROM_OFFSET is the offset of the source reference from an unspecified + base, while TO_OFFSET is the offset of the target reference from that + same base. FROM_SIZE and TO_SIZE are the sizes of the two references + in bytes. + + PMODE is the mode of both addresses, and STEP is the amount that + will be added to each address by one loop iteration. */ +static int +measure_mem_distance (enum machine_mode pmode, + unsigned HOST_WIDE_INT from_offset, + unsigned HOST_WIDE_INT from_size, + unsigned HOST_WIDE_INT to_offset, + unsigned HOST_WIDE_INT to_size, + unsigned HOST_WIDE_INT base_distance, + HOST_WIDE_INT step) +{ + unsigned HOST_WIDE_INT extra, from2to, to2from; + + from2to = (to_offset - from_offset) & GET_MODE_MASK (pmode); + to2from = (from_offset - to_offset) & GET_MODE_MASK (pmode); + if (from2to < from_size || to2from < to_size) + /* The source reference in iteration 0 overlaps the target reference + in iteration BASE_DISTANCE. The check is written this way to cope + with cases where offset + size overflows. */ + return base_distance; + + /* N > BASE_DISTANCE. To cope more easily with cases where the round-up + divisions: + + (to2from - (to_size - 1) + (step - 1)) / step + (from2to - (from_size - 1) + (step - 1)) / step + + would overflow, bump BASE_DISTANCE and subtract STEP from each + dividend to compensate. */ + base_distance++; + if (step > 0) + extra = (to2from - to_size) / (unsigned HOST_WIDE_INT) step; + else + extra = (from2to - from_size) / (unsigned HOST_WIDE_INT) -step; + if (extra > MAX_DDG_DISTANCE || base_distance + extra > MAX_DDG_DISTANCE) + return MAX_DDG_DISTANCE; + return base_distance + extra; +} + +/* If FROM and TO might alias, record memory dependencies: + + FROM--(FORWARD_TYPE)-->TO + and TO--(BACKWARD_TYPE)-->FROM + + FROM comes before TO in the original loop, and both belong to G. + FORWARD_DISTANCE is the minimum distance of the FROM--->TO dependence. */ +static void +add_memory_dep (ddg_ptr g, struct ddg_mem_ref *from, + struct ddg_mem_ref *to, dep_type forward_type, + dep_type backward_type, int forward_distance) +{ + HOST_WIDE_INT step; + unsigned HOST_WIDE_INT from_size, to_size, to_disp, abs_step, future_offset; + enum machine_mode pmode; + int backward_distance; + + gcc_checking_assert (from->node->cuid < to->node->cuid); + + if (!may_alias_p (from->mem, to->mem)) + return; + + /* In the worst case, the TO---->FROM edge has a distance of 1. */ + backward_distance = 1; + + /* See if we can get more accurate distances. Look for cases where + the addresses of FROM and TO are ivs with the same base and step. */ + if (from->base + && to->base + && from->step + && from->step == to->step + && !MEM_VOLATILE_P (from->mem) + && !MEM_VOLATILE_P (to->mem) + && MEM_SIZE_KNOWN_P (from->mem) + && MEM_SIZE_KNOWN_P (to->mem) + && MEM_ADDR_SPACE (from->mem) == MEM_ADDR_SPACE (to->mem) + && rtx_equal_p (from->base, to->base)) + { + step = to->step; + abs_step = (step < 0 ? -step : step); + from_size = MEM_SIZE (from->mem); + to_size = MEM_SIZE (to->mem); + + /* If the step is a power of two, or the negative of a power of two, + see whether we can prove that the references never overlap. */ + if (abs_step == (abs_step & -abs_step)) + { + to_disp = (to->offset - from->offset) % abs_step; + if (from_size <= to_disp && to_disp + to_size <= abs_step) + return; + } + + pmode = targetm.addr_space.address_mode (MEM_ADDR_SPACE (to->mem)); + future_offset = to->offset + forward_distance * step; + forward_distance = measure_mem_distance (pmode, + from->offset, from_size, + future_offset, to_size, + forward_distance, step); + future_offset = from->offset + backward_distance * step; + backward_distance = measure_mem_distance (pmode, + to->offset, to_size, + future_offset, from_size, + backward_distance, step); + } + + if (DEBUG_INSN_P (from->node->insn) || DEBUG_INSN_P (to->node->insn)) + { + forward_type = ANTI_DEP; + backward_type = ANTI_DEP; + } + create_ddg_dep_no_link (g, from->node, to->node, forward_type, MEM_DEP, + forward_distance); + create_ddg_dep_no_link (g, to->node, from->node, backward_type, MEM_DEP, + backward_distance); +} + +/* Make REF2 iterate over all entries in ddg_mem_ref list LIST + that come later than ddg_mem_ref REF1. */ +#define FOR_EACH_LATER_MEM_REF(REF2, REF1, LIST) \ + for (REF2 = (LIST); \ + REF2 && REF2->node->cuid > REF1->node->cuid; \ + REF2 = REF2->prev) + +/* Check for dependencies between pairs of memory rtxes. */ +static void +build_memory_deps (ddg_ptr g) +{ + struct ddg_mem_ref *ref1, *ref2; + int distance; + + for (ref1 = g->loads; ref1; ref1 = ref1->prev) + { + /* LOAD--->LOAD. */ + if (MEM_VOLATILE_P (ref1->mem)) + FOR_EACH_LATER_MEM_REF (ref2, ref1, g->loads) + if (MEM_VOLATILE_P (ref2->mem)) + add_memory_dep (g, ref1, ref2, ANTI_DEP, ANTI_DEP, 0); + + /* LOAD--->STORE. */ + FOR_EACH_LATER_MEM_REF (ref2, ref1, g->stores) + { + distance = anti_dependence (ref1->mem, ref2->mem) ? 0 : 1; + add_memory_dep (g, ref1, ref2, ANTI_DEP, TRUE_DEP, distance); + } + } + + for (ref1 = g->stores; ref1; ref1 = ref1->prev) + { + /* STORE--->LOAD. */ + FOR_EACH_LATER_MEM_REF (ref2, ref1, g->loads) + { + distance = true_dependence (ref1->mem, VOIDmode, + ref2->mem, rtx_varies_p) ? 0 : 1; + add_memory_dep (g, ref1, ref2, TRUE_DEP, ANTI_DEP, distance); + } + + /* STORE--->STORE. */ + FOR_EACH_LATER_MEM_REF (ref2, ref1, g->stores) + { + distance = output_dependence (ref1->mem, ref2->mem) ? 0 : 1; + add_memory_dep (g, ref1, ref2, OUTPUT_DEP, OUTPUT_DEP, distance); + } + } +} -/* Given a basic block, create its DDG and return a pointer to a variable - of ddg type that represents it. +/* Given a basic block, create the nodes of its DDG and return a pointer + to a variable of ddg type that represents it. Initialize the ddg structure fields to the appropriate values. */ ddg_ptr -create_ddg (basic_block bb, int closing_branch_deps) +create_ddg (struct loop *loop, basic_block bb, int closing_branch_deps) { + struct graph_and_node gn; ddg_ptr g; rtx insn, first_note; int i; @@ -586,13 +643,6 @@ create_ddg (basic_block bb, int closing_ if (DEBUG_INSN_P (insn)) g->num_debug++; - else - { - if (mem_read_insn_p (insn)) - g->num_loads++; - if (mem_write_insn_p (insn)) - g->num_stores++; - } num_nodes++; } @@ -603,6 +653,8 @@ create_ddg (basic_block bb, int closing_ return NULL; } + iv_analysis_loop_init (loop); + /* Allocate the nodes array, and initialize the nodes. */ g->num_nodes = num_nodes; g->nodes = (ddg_node_ptr) xcalloc (num_nodes, sizeof (struct ddg_node)); @@ -637,18 +689,31 @@ create_ddg (basic_block bb, int closing_ g->nodes[i].predecessors = sbitmap_alloc (num_nodes); sbitmap_zero (g->nodes[i].predecessors); g->nodes[i].first_note = (first_note ? first_note : insn); - g->nodes[i++].insn = insn; + g->nodes[i].insn = insn; first_note = NULL_RTX; + + gn.g = g; + gn.node = &g->nodes[i]; + note_uses (&PATTERN (insn), record_loads, &gn); + note_stores (PATTERN (insn), record_stores, &gn); + + i++; } /* We must have found a branch in DDG. */ gcc_assert (g->closing_branch); + return g; +} +/* Add the edges to a DDG that was previously created by create_ddg. + This function relies on scheduler dependencies. */ - /* Build the data dependency graph. */ +void +add_edges_to_ddg (ddg_ptr g) +{ build_intra_loop_deps (g); build_inter_loop_deps (g); - return g; + build_memory_deps (g); } /* Free all the memory allocated for the DDG. */ Index: gcc/modulo-sched.c =================================================================== --- gcc/modulo-sched.c 2011-12-30 13:13:45.077544981 +0000 +++ gcc/modulo-sched.c 2011-12-30 13:24:57.327195816 +0000 @@ -345,6 +345,38 @@ ps_num_consecutive_stages (partial_sched return ps_reg_move (ps, id)->num_consecutive_stages; } +/* Perform a saturating multiplication of nonnegative values A and B. */ + +static inline int +sat_mulpp (unsigned int a, unsigned int b) +{ + if ((unsigned int) INT_MAX / b <= a) + return INT_MAX; + else + return a * b; +} + +/* Perform a saturating addition of signed value A and nonnegative value B. */ + +static inline int +sat_addsp (int a, int b) +{ + if (INT_MAX - b <= a) + return INT_MAX; + return a + b; +} + +/* Perform a saturating subtraction of signed value A and nonnegative + value B. */ + +static inline int +sat_subsp (int a, int b) +{ + if (INT_MIN + b >= a) + return INT_MIN; + return a - b; +} + /* Given HEAD and TAIL which are the first and last insns in a loop; return the register which controls the loop. Return zero if it has more than one occurrence in the loop besides the control part or the @@ -709,7 +741,9 @@ schedule_reg_moves (partial_schedule_ptr ranges started at u (excluding self-loops). */ distances[0] = distances[1] = false; for (e = u->out; e; e = e->next_out) - if (e->type == TRUE_DEP && e->dest != e->src) + if (e->data_type == REG_DEP + && e->type == TRUE_DEP + && e->dest != e->src) { int nreg_moves4e = (SCHED_TIME (e->dest->cuid) - SCHED_TIME (e->src->cuid)) / ii; @@ -781,7 +815,9 @@ schedule_reg_moves (partial_schedule_ptr copy of this register, depending on the time the use is scheduled. Record which uses require which move results. */ for (e = u->out; e; e = e->next_out) - if (e->type == TRUE_DEP && e->dest != e->src) + if (e->data_type == REG_DEP + && e->type == TRUE_DEP + && e->dest != e->src) { int dest_copy = (SCHED_TIME (e->dest->cuid) - SCHED_TIME (e->src->cuid)) / ii; @@ -1355,6 +1391,7 @@ sms_schedule (void) basic_block condition_bb = NULL; edge latch_edge; gcov_type trip_count = 0; + int num_ddgs; loop_optimizer_init (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_RECORDED_EXITS); @@ -1364,34 +1401,19 @@ sms_schedule (void) return; /* There are no loops to schedule. */ } - /* Initialize issue_rate. */ - if (targetm.sched.issue_rate) - { - int temp = reload_completed; - - reload_completed = 1; - issue_rate = targetm.sched.issue_rate (); - reload_completed = temp; - } - else - issue_rate = 1; - - /* Initialize the scheduler. */ - setup_sched_infos (); - haifa_sched_init (); - /* Allocate memory to hold the DDG array one entry for each loop. We use loop->num as index into this array. */ g_arr = XCNEWVEC (ddg_ptr, number_of_loops ()); if (dump_file) - { - fprintf (dump_file, "\n\nSMS analysis phase\n"); - fprintf (dump_file, "===================\n\n"); - } + { + fprintf (dump_file, "\n\nSMS loop discovery phase\n"); + fprintf (dump_file, "========================\n\n"); + } /* Build DDGs for all the relevant loops and hold them in G_ARR indexed by the loop index. */ + num_ddgs = 0; FOR_EACH_LOOP (li, loop, 0) { rtx head, tail; @@ -1512,7 +1534,7 @@ sms_schedule (void) instructions. The branch is rotated to be in row ii-1 at the end of the scheduling procedure to make sure it's the last instruction in the iteration. */ - if (! (g = create_ddg (bb, 1))) + if (! (g = create_ddg (loop, bb, 1))) { if (dump_file) fprintf (dump_file, "SMS create_ddg failed\n"); @@ -1523,12 +1545,38 @@ sms_schedule (void) if (dump_file) fprintf (dump_file, "...OK\n"); + num_ddgs++; + } + iv_analysis_done (); + + if (num_ddgs == 0) + { + if (dump_file) + fprintf (dump_file, "No suitable loops\n"); + goto done; } + + /* Initialize issue_rate. */ + if (targetm.sched.issue_rate) + { + int temp = reload_completed; + + reload_completed = 1; + issue_rate = targetm.sched.issue_rate (); + reload_completed = temp; + } + else + issue_rate = 1; + + /* Initialize the scheduler. */ + setup_sched_infos (); + haifa_sched_init (); + if (dump_file) - { - fprintf (dump_file, "\nSMS transformation phase\n"); - fprintf (dump_file, "=========================\n\n"); - } + { + fprintf (dump_file, "\nSMS transformation phase\n"); + fprintf (dump_file, "=========================\n\n"); + } /* We don't want to perform SMS on new loops - created by versioning. */ FOR_EACH_LOOP (li, loop, 0) @@ -1542,6 +1590,8 @@ sms_schedule (void) if (! (g = g_arr[loop->num])) continue; + add_edges_to_ddg (g); + if (dump_file) { rtx insn = BB_END (loop->header); @@ -1754,10 +1804,12 @@ sms_schedule (void) free_ddg (g); } - free (g_arr); - /* Release scheduler data, needed until now because of DFA. */ haifa_sched_finish (); + + done: + free (g_arr); + loop_optimizer_finalize (); } @@ -1844,6 +1896,7 @@ #define DFA_HISTORY SMS_DFA_HISTORY /* A threshold for the number of repeated unsuccessful attempts to insert an empty row, before we flush the partial schedule and start over. */ #define MAX_SPLIT_NUM 10 + /* Given the partial schedule PS, this function calculates and returns the cycles in which we can schedule the node with the given index I. NOTE: Here we do the backtracking in SMS, in some special cases. We have @@ -1896,7 +1949,7 @@ get_sched_window (partial_schedule_ptr p fprintf (dump_file, "=========== =========== =========== ===========" " =====\n"); } - /* Calculate early_start and limit end. Both bounds are inclusive. */ + /* Calculate early_start and limit start. Both bounds are inclusive. */ if (psp_not_empty) for (e = u_node->in; e != 0; e = e->next_in) { @@ -1905,26 +1958,36 @@ get_sched_window (partial_schedule_ptr p if (TEST_BIT (sched_nodes, v)) { int p_st = SCHED_TIME (v); - int earliest = p_st + e->latency - (e->distance * ii); - int latest = (e->data_type == MEM_DEP ? p_st + ii - 1 : INT_MAX); + int earliest = sat_subsp (sat_addsp (p_st, e->latency), + sat_mulpp (e->distance, ii)); + if (e->data_type == MEM_DEP) + { + start = MAX (start, earliest); + if (dump_file) + fprintf (dump_file, "%11d %11s %11s %11s", + earliest, "", "", ""); + } + else + { + early_start = MAX (early_start, earliest); + if (dump_file) + fprintf (dump_file, "%11s %11d %11s %11s", + "", earliest, "", ""); + } if (dump_file) { - fprintf (dump_file, "%11s %11d %11s %11d %5d", - "", earliest, "", latest, p_st); + fprintf (dump_file, " %5d", p_st); print_ddg_edge (dump_file, e); fprintf (dump_file, "\n"); } - early_start = MAX (early_start, earliest); - end = MIN (end, latest); - if (e->type == TRUE_DEP && e->data_type == REG_DEP) count_preds++; } } - /* Calculate late_start and limit start. Both bounds are inclusive. */ + /* Calculate late_start and limit end. Both bounds are inclusive. */ if (pss_not_empty) for (e = u_node->out; e != 0; e = e->next_out) { @@ -1933,20 +1996,30 @@ get_sched_window (partial_schedule_ptr p if (TEST_BIT (sched_nodes, v)) { int s_st = SCHED_TIME (v); - int earliest = (e->data_type == MEM_DEP ? s_st - ii + 1 : INT_MIN); - int latest = s_st - e->latency + (e->distance * ii); + int latest = sat_addsp (sat_subsp (s_st, e->latency), + sat_mulpp (e->distance, ii)); + if (e->data_type == MEM_DEP) + { + end = MIN (end, latest); + if (dump_file) + fprintf (dump_file, "%11s %11s %11s %11d", + "", "", "", latest); + } + else + { + late_start = MIN (late_start, latest); + if (dump_file) + fprintf (dump_file, "%11s %11s %11d %11s", + "", "", latest, ""); + } if (dump_file) { - fprintf (dump_file, "%11d %11s %11d %11s %5d", - earliest, "", latest, "", s_st); + fprintf (dump_file, " %5d", s_st); print_ddg_edge (dump_file, e); fprintf (dump_file, "\n"); } - start = MAX (start, earliest); - late_start = MIN (late_start, latest); - if (e->type == TRUE_DEP && e->data_type == REG_DEP) count_succs++; } @@ -1963,14 +2036,22 @@ get_sched_window (partial_schedule_ptr p /* Get a target scheduling window no bigger than ii. */ if (early_start == INT_MIN && late_start == INT_MAX) - early_start = NODE_ASAP (u_node); - else if (early_start == INT_MIN) - early_start = late_start - (ii - 1); - late_start = MIN (late_start, early_start + (ii - 1)); - - /* Apply memory dependence limits. */ - start = MAX (start, early_start); - end = MIN (end, late_start); + { + /* The default window (as given in the paper) is based on + the node's ASAP value, but shift or shrink it as necessary + in order to honor memory dependencies. */ + early_start = MIN (NODE_ASAP (u_node), end - (ii - 1)); + start = MAX (early_start, start); + } + else + { + end = MIN (end, late_start); + if (early_start == INT_MIN) + start = MAX (start, end - (ii - 1)); + else + start = MAX (start, early_start); + } + end = MIN (end, start + (ii - 1)); if (dump_file && (psp_not_empty || pss_not_empty)) fprintf (dump_file, "%11s %11d %11d %11s %5s final window\n", @@ -2060,8 +2141,8 @@ calculate_must_precede_follow (ddg_node_ SCHED_TIME (e->src) - (e->distance * ii) == first_cycle_in_window */ for (e = u_node->in; e != 0; e = e->next_in) if (TEST_BIT (sched_nodes, e->src->cuid) - && ((SCHED_TIME (e->src->cuid) - (e->distance * ii)) == - first_cycle_in_window)) + && (sat_subsp (SCHED_TIME (e->src->cuid), sat_mulpp (e->distance, ii)) + == first_cycle_in_window)) { if (dump_file) fprintf (dump_file, "%d ", e->src->cuid); @@ -2371,7 +2452,8 @@ compute_split_row (sbitmap sched_nodes, int v = e->src->cuid; if (TEST_BIT (sched_nodes, v) - && (low == SCHED_TIME (v) + e->latency - (e->distance * ii))) + && low == sat_subsp (sat_addsp (SCHED_TIME (v), e->latency), + sat_mulpp (e->distance, ii))) if (SCHED_TIME (v) > lower) { crit_pred = v;

13 years, 6 months

Update to lp:~rsandifo/+junk/loop-microbenchmarks

by Richard Sandiford

About three months ago, 4.7 stopped being able to optimise things like: int *__restrict x = ...; The (libav) loop microbenchmarks that I'd written used this construct a lot, as an easy way of automatically generating a whole function from a loop kernel. I spent a while testing 4.7 with the restrict patch reverted, while I caught up with my post-holiday email backlog and saw whether the effect on this code was deliberate. I eventually realised it was, so implemented a change that Ira had suggested: splitting out a peak_loop_1 that takes all the restrict pointers as arguments. I just realised that I never pushed that change back up to bzr, so I've done it now. Probably a write-only change, since I doubt anyone's going to be using the benchmark again, but just in case :-) Richard

13 years, 6 months

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

linaro-toolchain