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-rw-r--r--gcc/predict.def32
1 files changed, 32 insertions, 0 deletions
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)