diff options
| -rw-r--r-- | gcc/ChangeLog | 15 | ||||
| -rw-r--r-- | gcc/common.opt | 4 | ||||
| -rw-r--r-- | gcc/ddg.c | 78 | ||||
| -rw-r--r-- | gcc/doc/invoke.texi | 9 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/sms-antideps.c | 37 |
6 files changed, 110 insertions, 38 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index fa456299626..3e7dab0c346 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,18 @@ +2007-08-05 Vladimir Yanovsky <yanov@il.ibm.com> + Revital Eres <eres@il.ibm.com> + + * doc/invoke.texi (-fmodulo-sched-allow-regmoves): Document new + flag. + * ddg.c (create_ddg_dependence): Rename to... + (create_ddg_dep_from_intra_loop_link): This. Do not check + for interloop edges. Do not create anti dependence edge when + a true dependence edge exists in the opposite direction and + -fmodulo-sched-allow-regmoves is set. + (build_intra_loop_deps): Call create_ddg_dep_from_intra_loop_link. + (add_cross_iteration_register_deps): Create anti dependence edge + when -fno-modulo-sched-allow-regmoves is set. + * common.opt (-fmodulo-sched-allow-regmoves): New flag. + 2007-08-04 Richard Sandiford <richard@codesourcery.com> * config/arm/arm.md (movsi): Add braces. diff --git a/gcc/common.opt b/gcc/common.opt index 2d8a1979bb3..4e59e17fe0e 100644 --- a/gcc/common.opt +++ b/gcc/common.opt @@ -651,6 +651,10 @@ fmodulo-sched Common Report Var(flag_modulo_sched) Optimization Perform SMS based modulo scheduling before the first scheduling pass +fmodulo-sched-allow-regmoves +Common Report Var(flag_modulo_sched_allow_regmoves) +Perform SMS based modulo scheduling with register moves allowed + fmove-loop-invariants Common Report Var(flag_move_loop_invariants) Init(1) Optimization Move loop invariant computations out of loops diff --git a/gcc/ddg.c b/gcc/ddg.c index b28bdfdc828..def8e0ee6d9 100644 --- a/gcc/ddg.c +++ b/gcc/ddg.c @@ -51,7 +51,8 @@ enum edge_flag {NOT_IN_SCC = 0, IN_SCC}; static void add_backarc_to_ddg (ddg_ptr, ddg_edge_ptr); static void add_backarc_to_scc (ddg_scc_ptr, ddg_edge_ptr); static void add_scc_to_ddg (ddg_all_sccs_ptr, ddg_scc_ptr); -static void create_ddg_dependence (ddg_ptr, ddg_node_ptr, ddg_node_ptr, dep_t); +static void create_ddg_dep_from_intra_loop_link (ddg_ptr, ddg_node_ptr, + ddg_node_ptr, dep_t); static void create_ddg_dep_no_link (ddg_ptr, ddg_node_ptr, ddg_node_ptr, dep_type, dep_data_type, int); static ddg_edge_ptr create_ddg_edge (ddg_node_ptr, ddg_node_ptr, dep_type, @@ -145,22 +146,16 @@ mem_access_insn_p (rtx insn) /* Computes the dependence parameters (latency, distance etc.), creates a ddg_edge and adds it to the given DDG. */ static void -create_ddg_dependence (ddg_ptr g, ddg_node_ptr src_node, - ddg_node_ptr dest_node, dep_t link) +create_ddg_dep_from_intra_loop_link (ddg_ptr g, ddg_node_ptr src_node, + ddg_node_ptr dest_node, dep_t link) { ddg_edge_ptr e; int latency, distance = 0; - int interloop = (src_node->cuid >= dest_node->cuid); 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); - - /* For now we don't have an exact calculation of the distance, - so assume 1 conservatively. */ - if (interloop) - distance = 1; - + gcc_assert (src_node->cuid < dest_node->cuid); gcc_assert (link); /* Note: REG_DEP_ANTI applies to MEM ANTI_DEP as well!! */ @@ -168,27 +163,34 @@ create_ddg_dependence (ddg_ptr g, ddg_node_ptr src_node, t = ANTI_DEP; else if (DEP_KIND (link) == REG_DEP_OUTPUT) t = OUTPUT_DEP; - latency = dep_cost (link); - e = create_ddg_edge (src_node, dest_node, t, dt, latency, distance); - - if (interloop) + /* We currently choose not to create certain anti-deps edges and + compensate for that by generating reg-moves based on the life-range + analysis. The anti-deps that will be deleted are the ones which + have true-deps edges in the opposite direction (in other words + the kernel has only one def of the relevant register). 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)) { - /* Some interloop dependencies are relaxed: - 1. Every insn is output dependent on itself; ignore such deps. - 2. Every true/flow dependence is an anti dependence in the - opposite direction with distance 1; such register deps - will be removed by renaming if broken --- ignore them. */ - if (!(t == OUTPUT_DEP && src_node == dest_node) - && !(t == ANTI_DEP && dt == REG_DEP)) - add_backarc_to_ddg (g, e); - else - free (e); + rtx set; + + set = single_set (dest_node->insn); + if (set) + { + int regno = REGNO (SET_DEST (set)); + struct df_ref *first_def = + df_bb_regno_first_def_find (g->bb, regno); + struct df_rd_bb_info *bb_info = DF_RD_BB_INFO (g->bb); + + if (bitmap_bit_p (bb_info->gen, first_def->id)) + return; + } } - else if (t == ANTI_DEP && dt == REG_DEP) - free (e); /* We can fix broken anti register deps using reg-moves. */ - else - add_edge_to_ddg (g, e); + + latency = dep_cost (link); + e = create_ddg_edge (src_node, dest_node, t, dt, latency, distance); + add_edge_to_ddg (g, e); } /* The same as the above function, but it doesn't require a link parameter. */ @@ -247,6 +249,11 @@ add_cross_iteration_register_deps (ddg_ptr g, struct df_ref *last_def) gcc_assert (last_def_node); gcc_assert (first_def); +#ifdef ENABLE_CHECKING + if (last_def->id != first_def->id) + gcc_assert (!bitmap_bit_p (bb_info->gen, first_def->id)); +#endif + /* Create inter-loop true dependences and anti dependences. */ for (r_use = DF_REF_CHAIN (last_def); r_use != NULL; r_use = r_use->next) { @@ -280,14 +287,11 @@ add_cross_iteration_register_deps (ddg_ptr g, struct df_ref *last_def) gcc_assert (first_def_node); - if (last_def->id != first_def->id) - { -#ifdef ENABLE_CHECKING - gcc_assert (!bitmap_bit_p (bb_info->gen, first_def->id)); -#endif - create_ddg_dep_no_link (g, use_node, first_def_node, ANTI_DEP, - REG_DEP, 1); - } + if (last_def->id != first_def->id + || !flag_modulo_sched_allow_regmoves) + create_ddg_dep_no_link (g, use_node, first_def_node, ANTI_DEP, + REG_DEP, 1); + } } /* Create an inter-loop output dependence between LAST_DEF (which is the @@ -392,7 +396,7 @@ build_intra_loop_deps (ddg_ptr g) continue; add_forw_dep (link); - create_ddg_dependence (g, src_node, dest_node, dep); + 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 diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index d5974ee195f..5a13c42501b 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -328,7 +328,7 @@ Objective-C and Objective-C++ Dialects}. -finline-functions -finline-functions-called-once @gol -finline-limit=@var{n} -fkeep-inline-functions @gol -fkeep-static-consts -fmerge-constants -fmerge-all-constants @gol --fmodulo-sched -fno-branch-count-reg @gol +-fmodulo-sched -fmodulo-sched-allow-regmoves -fno-branch-count-reg @gol -fno-default-inline -fno-defer-pop -fmove-loop-invariants @gol -fno-function-cse -fno-guess-branch-probability @gol -fno-inline -fno-math-errno -fno-peephole -fno-peephole2 @gol @@ -5265,6 +5265,13 @@ Perform swing modulo scheduling immediately before the first scheduling pass. This pass looks at innermost loops and reorders their instructions by overlapping different iterations. +@item -fmodulo-sched-allow-regmoves +@opindex fmodulo-sched-allow-regmoves +Perform more aggressive SMS based modulo scheduling with register moves +allowed. By setting this flag certain anti-dependences edges will be +deleted which will trigger the generation of reg-moves based on the +life-range analysis. + @item -fno-branch-count-reg @opindex fno-branch-count-reg Do not use ``decrement and branch'' instructions on a count register, diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 3dabc56d37c..b5f183e68c7 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2007-08-05 Vladimir Yanovsky <yanov@il.ibm.com> + Revital Eres <eres@il.ibm.com> + + * gcc.dg/sms-antideps.c: New test. + 2007-08-04 Paul Thomas <pault@gcc.gnu.org> PR fortran/31214 diff --git a/gcc/testsuite/gcc.dg/sms-antideps.c b/gcc/testsuite/gcc.dg/sms-antideps.c new file mode 100644 index 00000000000..e973261999a --- /dev/null +++ b/gcc/testsuite/gcc.dg/sms-antideps.c @@ -0,0 +1,37 @@ +/* This test is a reduced test case for a bug that caused + bootstrapping with -fmodulo-sched. Related to a broken anti-dep + that was not fixed by reg-moves. */ + + /* { dg-do run } */ + /* { dg-options "-O2 -fmodulo-sched -fmodulo-sched-allow-regmoves" } */ + +#include <stdlib.h> + +unsigned long long +foo (long long ixi, unsigned ctr) +{ + unsigned long long irslt = 1; + long long ix = ixi; + + for (; ctr; ctr--) + { + irslt *= ix; + ix *= ix; + } + + if (irslt != 14348907) + abort (); + return irslt; +} + + +int +main () +{ + unsigned long long res; + + res = foo (3, 4); +} + + + |