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| author | guojiufu <guojiufu@linux.ibm.com> | 2020-11-17 19:49:03 +0800 |
|---|---|---|
| committer | guojiufu <guojiufu@linux.ibm.com> | 2020-11-18 13:29:14 +0800 |
| commit | d87ee7f1c9cd2ffa6302cdfd0686d72e5bb7463b (patch) | |
| tree | c4f1dda5d267c73b2a7a7e1cceffc5b13bdbe7ab /gcc | |
| parent | 397654d66a4f84d4439e046cd330d9968af3b62b (diff) | |
| download | gcc-d87ee7f1c9cd2ffa6302cdfd0686d72e5bb7463b.zip gcc-d87ee7f1c9cd2ffa6302cdfd0686d72e5bb7463b.tar.gz gcc-d87ee7f1c9cd2ffa6302cdfd0686d72e5bb7463b.tar.bz2 | |
Clean up loop-closed PHIs after loop finalize
This patch propagates loop-closed PHIs them out at
loop_optimizer_finalize. For some cases, to clean up loop-closed PHIs
would save efforts of optimization passes after loopdone.
Thanks,
Jiufu Guo.
gcc/ChangeLog:
2020-10-18 Jiufu Guo <guojiufu@linux.ibm.com>
* cfgloop.h (loop_optimizer_finalize): Add flag argument.
* loop-init.c (loop_optimizer_finalize): Call clean_up_loop_closed_phi.
* tree-cfgcleanup.h (clean_up_loop_closed_phi): New declare.
* tree-ssa-loop.c (tree_ssa_loop_done): Call loop_optimizer_finalize
with flag argument.
* tree-ssa-propagate.c (clean_up_loop_closed_phi): New function.
gcc/testsuite/ChangeLog:
2020-10-18 Jiufu Guo <guojiufu@linux.ibm.com>
* gcc.dg/tree-ssa/loopclosedphi.c: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/cfgloop.h | 2 | ||||
| -rw-r--r-- | gcc/loop-init.c | 9 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c | 21 | ||||
| -rw-r--r-- | gcc/tree-cfgcleanup.h | 1 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop.c | 2 | ||||
| -rw-r--r-- | gcc/tree-ssa-propagate.c | 72 |
6 files changed, 104 insertions, 3 deletions
diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h index d14689d..438b1f7 100644 --- a/gcc/cfgloop.h +++ b/gcc/cfgloop.h @@ -824,7 +824,7 @@ extern void init_set_costs (void); /* Loop optimizer initialization. */ extern void loop_optimizer_init (unsigned); -extern void loop_optimizer_finalize (function *); +extern void loop_optimizer_finalize (function *, bool = false); inline void loop_optimizer_finalize () { diff --git a/gcc/loop-init.c b/gcc/loop-init.c index 401e528..ac87daf 100644 --- a/gcc/loop-init.c +++ b/gcc/loop-init.c @@ -33,6 +33,7 @@ along with GCC; see the file COPYING3. If not see #include "tree-ssa-loop-niter.h" #include "loop-unroll.h" #include "tree-scalar-evolution.h" +#include "tree-cfgcleanup.h" /* Apply FLAGS to the loop state. */ @@ -133,13 +134,19 @@ loop_optimizer_init (unsigned flags) /* Finalize loop structures. */ void -loop_optimizer_finalize (struct function *fn) +loop_optimizer_finalize (struct function *fn, bool clean_loop_closed_phi) { class loop *loop; basic_block bb; timevar_push (TV_LOOP_FINI); + if (clean_loop_closed_phi && loops_state_satisfies_p (fn, LOOP_CLOSED_SSA)) + { + clean_up_loop_closed_phi (fn); + loops_state_clear (fn, LOOP_CLOSED_SSA); + } + if (loops_state_satisfies_p (fn, LOOPS_HAVE_RECORDED_EXITS)) release_recorded_exits (fn); diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c b/gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c new file mode 100644 index 0000000..d71b757 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-options "-O3 -fno-tree-ch -w -fdump-tree-loopdone-details" } */ + +void +t6 (int qz, int wh) +{ + int jl = wh; + + while (1.0 * qz / wh < 1) + { + qz = wh * (wh + 2); + + while (wh < 1) + jl = 0; + } + + while (qz < 1) + qz = jl * wh; +} + +/* { dg-final { scan-tree-dump-times "Replacing" 2 "loopdone"} } */ diff --git a/gcc/tree-cfgcleanup.h b/gcc/tree-cfgcleanup.h index 6ff6726..9e368d6 100644 --- a/gcc/tree-cfgcleanup.h +++ b/gcc/tree-cfgcleanup.h @@ -26,5 +26,6 @@ extern bool cleanup_tree_cfg (unsigned = 0); extern bool fixup_noreturn_call (gimple *stmt); extern bool delete_unreachable_blocks_update_callgraph (cgraph_node *dst_node, bool update_clones); +extern unsigned clean_up_loop_closed_phi (function *); #endif /* GCC_TREE_CFGCLEANUP_H */ diff --git a/gcc/tree-ssa-loop.c b/gcc/tree-ssa-loop.c index 5e8365d..339a0c5 100644 --- a/gcc/tree-ssa-loop.c +++ b/gcc/tree-ssa-loop.c @@ -529,7 +529,7 @@ tree_ssa_loop_done (void) { free_numbers_of_iterations_estimates (cfun); scev_finalize (); - loop_optimizer_finalize (); + loop_optimizer_finalize (cfun, true); return 0; } diff --git a/gcc/tree-ssa-propagate.c b/gcc/tree-ssa-propagate.c index 87dbf55..354057b 100644 --- a/gcc/tree-ssa-propagate.c +++ b/gcc/tree-ssa-propagate.c @@ -1549,3 +1549,75 @@ propagate_tree_value_into_stmt (gimple_stmt_iterator *gsi, tree val) else gcc_unreachable (); } + +/* Check exits of each loop in FUN, walk over loop closed PHIs in + each exit basic block and propagate degenerate PHIs. */ + +unsigned +clean_up_loop_closed_phi (function *fun) +{ + unsigned i; + edge e; + gphi *phi; + tree rhs; + tree lhs; + gphi_iterator gsi; + struct loop *loop; + + /* Avoid possibly quadratic work when scanning for loop exits across + all loops of a nest. */ + if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) + return 0; + + /* Walk over loop in function. */ + FOR_EACH_LOOP_FN (fun, loop, 0) + { + /* Check each exit edege of loop. */ + auto_vec<edge> exits = get_loop_exit_edges (loop); + FOR_EACH_VEC_ELT (exits, i, e) + if (single_pred_p (e->dest)) + /* Walk over loop-closed PHIs. */ + for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi);) + { + phi = gsi.phi (); + rhs = gimple_phi_arg_def (phi, 0); + lhs = gimple_phi_result (phi); + + if (rhs && may_propagate_copy (lhs, rhs)) + { + /* Dump details. */ + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, " Replacing '"); + print_generic_expr (dump_file, lhs, dump_flags); + fprintf (dump_file, "' with '"); + print_generic_expr (dump_file, rhs, dump_flags); + fprintf (dump_file, "'\n"); + } + + use_operand_p use_p; + imm_use_iterator iter; + gimple *use_stmt; + FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) + { + FOR_EACH_IMM_USE_ON_STMT (use_p, iter) + replace_exp (use_p, rhs); + update_stmt (use_stmt); + + /* Update the invariant flag for ADDR_EXPR if replacing + a variable index with a constant. */ + if (gimple_assign_single_p (use_stmt) + && TREE_CODE (gimple_assign_rhs1 (use_stmt)) + == ADDR_EXPR) + recompute_tree_invariant_for_addr_expr ( + gimple_assign_rhs1 (use_stmt)); + } + remove_phi_node (&gsi, true); + } + else + gsi_next (&gsi); + } + } + + return 0; +} |