From: Andrew Pinski Date: Sun, 27 Oct 2024 03:37:36 +0000 (-0700) Subject: phiopt: Move check for maybe_undef_p slightly earlier X-Git-Tag: basepoints/gcc-16~4839 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3f2739e4664fbb1026ff1ef9db2e8262d5f58cc2;p=thirdparty%2Fgcc.git phiopt: Move check for maybe_undef_p slightly earlier This moves the check for maybe_undef_p in match_simplify_replacement slightly earlier before figuring out the true/false arg using arg0/arg1 instead. In most cases this is no difference in compile time; just in the case there is an undef in the args there would be a slight compile time improvement as there is no reason to figure out which arg corresponds to the true/false side of the conditional. Bootstrapped and tested on x86_64-linux-gnu. gcc/ChangeLog: * tree-ssa-phiopt.cc (match_simplify_replacement): Move check for maybe_undef_p earlier. Signed-off-by: Andrew Pinski --- diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc index f8b119ea8361..cffafe101a43 100644 --- a/gcc/tree-ssa-phiopt.cc +++ b/gcc/tree-ssa-phiopt.cc @@ -943,6 +943,13 @@ match_simplify_replacement (basic_block cond_bb, basic_block middle_bb, stmt_to_move_alt)) return false; + /* Do not make conditional undefs unconditional. */ + if ((TREE_CODE (arg0) == SSA_NAME + && ssa_name_maybe_undef_p (arg0)) + || (TREE_CODE (arg1) == SSA_NAME + && ssa_name_maybe_undef_p (arg1))) + return false; + /* At this point we know we have a GIMPLE_COND with two successors. One successor is BB, the other successor is an empty block which falls through into BB. @@ -982,13 +989,6 @@ match_simplify_replacement (basic_block cond_bb, basic_block middle_bb, arg_false = arg0; } - /* Do not make conditional undefs unconditional. */ - if ((TREE_CODE (arg_true) == SSA_NAME - && ssa_name_maybe_undef_p (arg_true)) - || (TREE_CODE (arg_false) == SSA_NAME - && ssa_name_maybe_undef_p (arg_false))) - return false; - tree type = TREE_TYPE (gimple_phi_result (phi)); { auto_flow_sensitive s1(stmt_to_move);