/* Definitions for the branch prediction routines in the GNU compiler.
- Copyright (C) 2001-2014 Free Software Foundation, Inc.
+ Copyright (C) 2001-2016 Free Software Foundation, Inc.
This file is part of GCC.
DEF_PREDICTOR (PRED_LOOP_ITERATIONS_GUESSED, "guessed loop iterations",
PROB_ALWAYS, PRED_FLAG_FIRST_MATCH)
+/* Use number of loop iterations guessed by the contents of the loop. */
+DEF_PREDICTOR (PRED_LOOP_ITERATIONS_MAX, "guessed loop iterations",
+ PROB_ALWAYS, PRED_FLAG_FIRST_MATCH)
+
/* Branch containing goto is probably not taken. */
-DEF_PREDICTOR (PRED_CONTINUE, "continue", HITRATE (50), 0)
+DEF_PREDICTOR (PRED_CONTINUE, "continue", HITRATE (67), 0)
/* Branch to basic block containing call marked by noreturn attribute. */
DEF_PREDICTOR (PRED_NORETURN, "noreturn call", PROB_VERY_LIKELY,
DEF_PREDICTOR (PRED_COLD_FUNCTION, "cold function call", PROB_VERY_LIKELY,
PRED_FLAG_FIRST_MATCH)
-/* Loopback edge is taken. */
-DEF_PREDICTOR (PRED_LOOP_BRANCH, "loop branch", HITRATE (86),
+/* Edge causing loop to terminate is probably not taken. */
+DEF_PREDICTOR (PRED_LOOP_EXIT, "loop exit", HITRATE (85),
PRED_FLAG_FIRST_MATCH)
-/* Edge causing loop to terminate is probably not taken. */
-DEF_PREDICTOR (PRED_LOOP_EXIT, "loop exit", HITRATE (91),
+/* Edge causing loop to terminate by computing value used by later
+ conditional. */
+DEF_PREDICTOR (PRED_LOOP_EXTRA_EXIT, "extra loop exit", HITRATE (83),
PRED_FLAG_FIRST_MATCH)
/* Pointers are usually not NULL. */
-DEF_PREDICTOR (PRED_POINTER, "pointer", HITRATE (85), 0)
-DEF_PREDICTOR (PRED_TREE_POINTER, "pointer (on trees)", HITRATE (85), 0)
+DEF_PREDICTOR (PRED_POINTER, "pointer", HITRATE (70), 0)
+DEF_PREDICTOR (PRED_TREE_POINTER, "pointer (on trees)", HITRATE (70), 0)
/* NE is probable, EQ not etc... */
-DEF_PREDICTOR (PRED_OPCODE_POSITIVE, "opcode values positive", HITRATE (79), 0)
-DEF_PREDICTOR (PRED_OPCODE_NONEQUAL, "opcode values nonequal", HITRATE (71), 0)
+DEF_PREDICTOR (PRED_OPCODE_POSITIVE, "opcode values positive", HITRATE (64), 0)
+DEF_PREDICTOR (PRED_OPCODE_NONEQUAL, "opcode values nonequal", HITRATE (66), 0)
DEF_PREDICTOR (PRED_FPOPCODE, "fp_opcode", HITRATE (90), 0)
-DEF_PREDICTOR (PRED_TREE_OPCODE_POSITIVE, "opcode values positive (on trees)", HITRATE (73), 0)
-DEF_PREDICTOR (PRED_TREE_OPCODE_NONEQUAL, "opcode values nonequal (on trees)", HITRATE (72), 0)
+DEF_PREDICTOR (PRED_TREE_OPCODE_POSITIVE, "opcode values positive (on trees)", HITRATE (64), 0)
+DEF_PREDICTOR (PRED_TREE_OPCODE_NONEQUAL, "opcode values nonequal (on trees)", HITRATE (66), 0)
DEF_PREDICTOR (PRED_TREE_FPOPCODE, "fp_opcode (on trees)", HITRATE (90), 0)
/* Branch guarding call is probably taken. */
-DEF_PREDICTOR (PRED_CALL, "call", HITRATE (71), 0)
-
-/* Branch causing function to terminate is probably not taken. */
-DEF_PREDICTOR (PRED_TREE_EARLY_RETURN, "early return (on trees)", HITRATE (61), 0)
-
-/* Branch containing goto is probably not taken. */
+DEF_PREDICTOR (PRED_CALL, "call", HITRATE (67), 0)
+
+/* Recursive calls are usually not taken or the function will recurse indefinitely. */
+DEF_PREDICTOR (PRED_RECURSIVE_CALL, "recursive call", HITRATE (75), 0)
+
+/* Branch causing function to terminate is probably not taken.
+ FIXME: early return currently predicts code:
+ int foo (int a)
+ {
+ if (a)
+ bar();
+ else
+ bar2();
+ }
+ even though there is no return statement involved. We probably want to track
+ this from FE or retire the predictor. */
+DEF_PREDICTOR (PRED_TREE_EARLY_RETURN, "early return (on trees)", HITRATE (54), 0)
+
+/* Branch containing goto is probably not taken.
+ FIXME: Currently not used. */
DEF_PREDICTOR (PRED_GOTO, "goto", HITRATE (70), 0)
/* Branch ending with return constant is probably not taken. */
-DEF_PREDICTOR (PRED_CONST_RETURN, "const return", HITRATE (67), 0)
+DEF_PREDICTOR (PRED_CONST_RETURN, "const return", HITRATE (69), 0)
/* Branch ending with return negative constant is probably not taken. */
-DEF_PREDICTOR (PRED_NEGATIVE_RETURN, "negative return", HITRATE (96), 0)
+DEF_PREDICTOR (PRED_NEGATIVE_RETURN, "negative return", HITRATE (98), 0)
/* Branch ending with return; is probably not taken */
-DEF_PREDICTOR (PRED_NULL_RETURN, "null return", HITRATE (90), 0)
+DEF_PREDICTOR (PRED_NULL_RETURN, "null return", HITRATE (91), 0)
/* Branches to compare induction variable to a loop bound is
extremely likely. */
DEF_PREDICTOR (PRED_LOOP_IV_COMPARE_GUESS, "guess loop iv compare",
- PROB_VERY_LIKELY, 0)
+ HITRATE (98), 0)
/* Use number of loop iterations determined by # of iterations analysis
to set probability of branches that compares IV to loop bound variable. */
/* The following predictors are used in Fortran. */
/* Branch leading to an integer overflow are extremely unlikely. */
-DEF_PREDICTOR (PRED_FORTRAN_OVERFLOW, "overflow", PROB_ALWAYS,
+DEF_PREDICTOR (PRED_FORTRAN_OVERFLOW, "Fortran overflow", PROB_ALWAYS,
PRED_FLAG_FIRST_MATCH)
/* Branch leading to a failure status are unlikely. This can occur for out
- of memory or when trying to allocate an already allocated allocated or
- deallocating an already deallocated allocatable. This predictor only
- occurs when the user explicitly asked for a return status. By default,
- the code aborts, which is handled via PRED_NORETURN. */
-DEF_PREDICTOR (PRED_FORTRAN_FAIL_ALLOC, "fail alloc", PROB_VERY_LIKELY, 0)
+ of memory. This predictor only occurs when the user explicitly asked
+ for a return status. By default, the code aborts,
+ which is handled via PRED_NORETURN. */
+DEF_PREDICTOR (PRED_FORTRAN_FAIL_ALLOC, "Fortran fail alloc", PROB_VERY_LIKELY, 0)
+
+/* Predictor is used for an allocation of an already allocated memory or
+ deallocating an already deallocated allocatable. */
+DEF_PREDICTOR (PRED_FORTRAN_REALLOC, \
+ "Fortran repeated allocation/deallocation", PROB_LIKELY, 0)
/* Branch leading to an I/O failure status are unlikely. This predictor is
used for I/O failures such as for invalid unit numbers. This predictor
only occurs when the user explicitly asked for a return status. By default,
the code aborts, which is handled via PRED_NORETURN. */
-DEF_PREDICTOR (PRED_FORTRAN_FAIL_IO, "fail alloc", HITRATE(85), 0)
+DEF_PREDICTOR (PRED_FORTRAN_FAIL_IO, "Fortran fail IO", HITRATE (85), 0)
/* Branch leading to a run-time warning message which is printed only once
are unlikely. The print-warning branch itself can be likely or unlikely. */
-DEF_PREDICTOR (PRED_FORTRAN_WARN_ONCE, "warn once", HITRATE (75), 0)
+DEF_PREDICTOR (PRED_FORTRAN_WARN_ONCE, "Fortran warn once", HITRATE (75), 0)
/* Branch belonging to a zero-sized array. */
-DEF_PREDICTOR (PRED_FORTRAN_SIZE_ZERO, "zero-sized array", HITRATE(70), 0)
+DEF_PREDICTOR (PRED_FORTRAN_SIZE_ZERO, "Fortran zero-sized array", \
+ HITRATE (99), 0)
/* Branch belonging to an invalid bound index, in a context where it is
standard conform and well defined but rather pointless and, hence, rather
unlikely to occur. */
-DEF_PREDICTOR (PRED_FORTRAN_INVALID_BOUND, "zero-sized array", HITRATE(90), 0)
+DEF_PREDICTOR (PRED_FORTRAN_INVALID_BOUND, "Fortran invalid bound", \
+ HITRATE (90), 0)
/* Branch belonging to the handling of absent optional arguments. This
predictor is used when an optional dummy argument, associated with an
absent argument, is passed on as actual argument to another procedure,
which in turn has an optional argument. */
-DEF_PREDICTOR (PRED_FORTRAN_ABSENT_DUMMY, "absent dummy", HITRATE(60), 0)
+DEF_PREDICTOR (PRED_FORTRAN_ABSENT_DUMMY, "Fortran absent dummy", \
+ HITRATE (60), 0)
+
+/* Fortran DO statement generates a pre-header guard:
+ empty = (step > 0 ? to < from : to > from), which can be predicted
+ to be very likely. */
+DEF_PREDICTOR (PRED_FORTRAN_LOOP_PREHEADER, "Fortran loop preheader", \
+ HITRATE (99), 0)
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