On 6/27/21 5:24 PM, apinski--- via Gcc-patches wrote:
From: Andrew Pinski <apin...@marvell.com>To move a few things more to match-and-simplify from phiopt, we need to allow match_simplify_replacement to run in early phiopt. To do this we add a replacement for gimple_simplify that is explictly for phiopt. OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. gcc/ChangeLog: * tree-ssa-phiopt.c (match_simplify_replacement): Add early_p argument. Call gimple_simplify_phiopt instead of gimple_simplify. (tree_ssa_phiopt_worker): Update call to match_simplify_replacement and allow unconditionally. (phiopt_early_allow): New function. (gimple_simplify_phiopt): New function. --- gcc/tree-ssa-phiopt.c | 89 ++++++++++++++++++++++++++++++++++--------- 1 file changed, 70 insertions(+), 19 deletions(-) diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c index ab12e85569d..17bc597851b 100644 --- a/gcc/tree-ssa-phiopt.c +++ b/gcc/tree-ssa-phiopt.c @@ -50,12 +50,13 @@ along with GCC; see the file COPYING3. If not see #include "gimple-fold.h" #include "internal-fn.h" #include "gimple-range.h" +#include "gimple-match.h"static unsigned int tree_ssa_phiopt_worker (bool, bool, bool);static bool two_value_replacement (basic_block, basic_block, edge, gphi *, tree, tree); static bool match_simplify_replacement (basic_block, basic_block, - edge, edge, gphi *, tree, tree); + edge, edge, gphi *, tree, tree, bool); static gphi *factor_out_conditional_conversion (edge, edge, gphi *, tree, tree, gimple *); static int value_replacement (basic_block, basic_block, @@ -345,9 +346,9 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p) /* Do the replacement of conditional if it can be done. */ if (!early_p && two_value_replacement (bb, bb1, e2, phi, arg0, arg1)) cfgchanged = true; - else if (!early_p - && match_simplify_replacement (bb, bb1, e1, e2, phi, - arg0, arg1)) + else if (match_simplify_replacement (bb, bb1, e1, e2, phi, + arg0, arg1, + early_p)) cfgchanged = true; else if (abs_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) cfgchanged = true; @@ -811,6 +812,67 @@ two_value_replacement (basic_block cond_bb, basic_block middle_bb, return true; }+/* Return TRUE if CODE should be allowed during early phiopt.+ Currently this is to allow MIN/MAX and ABS/NEGATE. */ +static bool +phiopt_early_allow (enum tree_code code) +{ + switch (code) + { + case MIN_EXPR: + case MAX_EXPR: + case ABS_EXPR: + case ABSU_EXPR: + case NEGATE_EXPR: + case SSA_NAME: + return true; + default: + return false; + } +} + +/* gimple_simplify_phiopt is like gimple_simplify but designed for PHIOPT. + Return NULL if nothing can be simplified or the resulting simplified value + with parts pushed if EARLY_P was true. Also rejects non allowed tree code + if EARLY_P is set. + Takes the comparison from COMP_STMT and two args, ARG0 and ARG1 and tries + to simplify CMP ? ARG0 : ARG1. */ +static tree +gimple_simplify_phiopt (bool early_p, tree type, gimple *comp_stmt, + tree arg0, tree arg1, + gimple_seq *seq) +{ + tree result; + enum tree_code comp_code = gimple_cond_code (comp_stmt); + location_t loc = gimple_location (comp_stmt); + tree cmp0 = gimple_cond_lhs (comp_stmt); + tree cmp1 = gimple_cond_rhs (comp_stmt); + /* To handle special cases like floating point comparison, it is easier and + less error-prone to build a tree and gimplify it on the fly though it is + less efficient. + Don't use fold_build2 here as that might create (bool)a instead of just + "a != 0". */ + tree cond = build2_loc (loc, comp_code, boolean_type_node, + cmp0, cmp1); + gimple_match_op op (gimple_match_cond::UNCOND, + COND_EXPR, type, cond, arg0, arg1); + + if (op.resimplify (early_p ? NULL : seq, follow_all_ssa_edges)) + { + /* Early we want only to allow some generated tree codes. */ + if (!early_p + || op.code.is_tree_code () + || phiopt_early_allow ((tree_code)op.code)) + { + result = maybe_push_res_to_seq (&op, seq); + if (result) + return result;
It looks to me like the last if statement is redundant and could be replaced by return maybe_push_res_to_seq (&op, seq); thus also making the result variable redundant, further simplifying the code. Martin
+ } + } + + return NULL; +} + /* The function match_simplify_replacement does the main work of doing the replacement using match and simplify. Return true if the replacement is done. Otherwise return false. @@ -820,10 +882,9 @@ two_value_replacement (basic_block cond_bb, basic_block middle_bb, static bool match_simplify_replacement (basic_block cond_bb, basic_block middle_bb, edge e0, edge e1, gphi *phi, - tree arg0, tree arg1) + tree arg0, tree arg1, bool early_p) { gimple *stmt; - tree cond; gimple_stmt_iterator gsi; edge true_edge, false_edge; gimple_seq seq = NULL; @@ -884,15 +945,6 @@ match_simplify_replacement (basic_block cond_bb, basic_block middle_bb,stmt = last_stmt (cond_bb); - /* To handle special cases like floating point comparison, it is easier and- less error-prone to build a tree and gimplify it on the fly though it is - less efficient. - Don't use fold_build2 here as that might create (bool)a instead of just - "a != 0". */ - cond = build2_loc (gimple_location (stmt), - gimple_cond_code (stmt), boolean_type_node, - gimple_cond_lhs (stmt), gimple_cond_rhs (stmt)); - /* We need to know which is the true edge and which is the false edge so that we know when to invert the condition below. */ extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); @@ -900,10 +952,9 @@ match_simplify_replacement (basic_block cond_bb, basic_block middle_bb, std::swap (arg0, arg1);tree type = TREE_TYPE (gimple_phi_result (phi));- result = gimple_simplify (COND_EXPR, type, - cond, - arg0, arg1, - &seq, NULL); + result = gimple_simplify_phiopt (early_p, type, stmt, + arg0, arg1, + &seq); if (!result) return false;
