From f6664feec514b2e3b3f36fb59c9b1b14dc5a52fc Mon Sep 17 00:00:00 2001 From: hubicka Date: Mon, 18 Jun 2001 15:35:47 +0000 Subject: * unroll.c: Include predict.h. (unroll_loop): Drop prediction notes on preconditioning. * predict.def (PRED_LOOP_PRECONDITIONG, PRED_LOOP_CONDITION): New; add comments on the others. * Makefile.in: (unroll.o): Add dependancy on predict.h. * loop.c (strength_reduce): Fix branch prediction. * stmt.c (emit_case_nodes): Optimize test whether index is in given interval. * predict.c (estimate_probability): Do not bail out early when note is present. (combine_predictions_for_insn): Fix note removal code. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@43441 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/predict.def | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'gcc/predict.def') diff --git a/gcc/predict.def b/gcc/predict.def index 01d87a4c3f0..ff8171bcc68 100644 --- a/gcc/predict.def +++ b/gcc/predict.def @@ -36,15 +36,47 @@ Boston, MA 02111-1307, USA. */ REG_BR_PROB_BASE / 2). */ +/* An combined heuristics using probability determined by first + matching heuristics from this list. */ DEF_PREDICTOR (PRED_FIRST_MATCH, "first match", PROB_ALWAYS) + +/* Mark unconditional jump as taken. */ DEF_PREDICTOR (PRED_UNCONDITIONAL, "unconditional jump", PROB_ALWAYS) + +/* Use number of loop iterations determined by loop unroller to set + probability. */ DEF_PREDICTOR (PRED_LOOP_ITERATIONS, "loop iterations", PROB_ALWAYS) + +/* Hints dropped by user via __builtin_expect feature. */ DEF_PREDICTOR (PRED_BUILTIN_EXPECT, "__builtin_expect", PROB_VERY_LIKELY) + +/* Branch to basic block containing call marked by noreturn attribute. */ DEF_PREDICTOR (PRED_NORETURN, "noreturn call", PROB_ALWAYS) + +/* Loopback edge is taken. */ DEF_PREDICTOR (PRED_LOOP_BRANCH, "loop branch", PROB_VERY_LIKELY) + +/* Edge causing loop to terminate is probably not taken. */ DEF_PREDICTOR (PRED_LOOP_EXIT, "loop exit", PROB_LIKELY) + +/* Condition emitted by preconditiong code to ensure that variable + setting number of iterations is greater than initial value of iterator. */ +DEF_PREDICTOR (PRED_LOOP_CONDITION, "loop condition", PROB_VERY_LIKELY) + +/* Preconditioning makes linear list of branches. */ +DEF_PREDICTOR (PRED_LOOP_PRECONDITIONING, "loop preconditioning", PROB_VERY_LIKELY) + +/* Copied condition for the first iteration of loop is probably true. */ DEF_PREDICTOR (PRED_LOOP_HEADER, "loop header", PROB_LIKELY) + +/* Pointers are usually not NULL. */ DEF_PREDICTOR (PRED_POINTER, "pointer", PROB_LIKELY) + +/* NE is probable, EQ not etc... */ DEF_PREDICTOR (PRED_OPCODE, "opcode", PROB_LIKELY) + +/* Branch guarding call is probably taken. */ DEF_PREDICTOR (PRED_CALL, "call", PROB_LIKELY) + +/* Branch causing function to terminate is probably not taken. */ DEF_PREDICTOR (PRED_ERROR_RETURN, "error return", PROB_LIKELY) -- cgit v1.2.1