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| author | Jan Hubicka <hubicka@gcc.gnu.org> | 2001-06-12 10:22:22 +0000 |
|---|---|---|
| committer | Jan Hubicka <hubicka@gcc.gnu.org> | 2001-06-12 10:22:22 +0000 |
| commit | aa18f20e7406ee235e94d6360bf4b3e349088544 (patch) | |
| tree | 487d80a5d58a9011b3ff04980963adc35c2b444a /gcc | |
| parent | 7bdcf888aaa78808dc2dd4e16e70458244a607be (diff) | |
| download | gcc-aa18f20e7406ee235e94d6360bf4b3e349088544.zip gcc-aa18f20e7406ee235e94d6360bf4b3e349088544.tar.gz gcc-aa18f20e7406ee235e94d6360bf4b3e349088544.tar.bz2 | |
loop.c: Include predict.h
* loop.c: Include predict.h
(strength_reduce): Drop branch prediction note in case
number of iterations is known.
* predict.def (PRED_LOOP_ITERATIONS): new.
* Makefile.in (loop.o): Add dependancy on predict.h
From-SVN: r43251
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/Makefile.in | 2 | ||||
| -rw-r--r-- | gcc/loop.c | 13 | ||||
| -rw-r--r-- | gcc/predict.def | 1 |
3 files changed, 15 insertions, 1 deletions
diff --git a/gcc/Makefile.in b/gcc/Makefile.in index a9af1e1..6ed6e3f 100644 --- a/gcc/Makefile.in +++ b/gcc/Makefile.in @@ -1438,7 +1438,7 @@ profile.o : profile.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) $(TREE_H) flags.h \ insn-config.h output.h $(REGS_H) $(EXPR_H) function.h \ gcov-io.h toplev.h $(GGC_H) hard-reg-set.h $(BASIC_BLOCK_H) loop.o : loop.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) flags.h $(LOOP_H) insn-config.h \ - $(REGS_H) hard-reg-set.h $(RECOG_H) $(EXPR_H) real.h \ + $(REGS_H) hard-reg-set.h $(RECOG_H) $(EXPR_H) real.h $(PREDICT_H) \ $(BASIC_BLOCK_H) function.h toplev.h varray.h except.h cselib.h $(TM_P_H) doloop.o : doloop.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) flags.h $(LOOP_H) \ $(EXPR_H) hard-reg-set.h $(BASIC_BLOCK_H) $(TM_P_H) toplev.h @@ -52,6 +52,7 @@ Boston, MA 02111-1307, USA. */ #include "cselib.h" #include "except.h" #include "toplev.h" +#include "predict.h" #define LOOP_REG_LIFETIME(LOOP, REGNO) \ ((REGNO_LAST_LUID (REGNO) - REGNO_FIRST_LUID (REGNO))) @@ -4498,6 +4499,18 @@ strength_reduce (loop, flags) doloop_optimize (loop); #endif /* HAVE_doloop_end */ + /* In case number of iterations is known, drop branch prediction note + in the branch. Do that only in second loop pass, as loop unrolling + may change the number of iterations performed. */ + if ((flags & LOOP_BCT) + && loop_info->n_iterations / loop_info->unroll_number > 1) + { + int n = loop_info->n_iterations / loop_info->unroll_number - 1; + predict_insn (PREV_INSN (loop->end), + PRED_LOOP_ITERATIONS, + REG_BR_PROB_BASE - REG_BR_PROB_BASE / n); + } + if (loop_dump_stream) fprintf (loop_dump_stream, "\n"); diff --git a/gcc/predict.def b/gcc/predict.def index f910f3b..01d87a4 100644 --- a/gcc/predict.def +++ b/gcc/predict.def @@ -38,6 +38,7 @@ Boston, MA 02111-1307, USA. */ DEF_PREDICTOR (PRED_FIRST_MATCH, "first match", PROB_ALWAYS) DEF_PREDICTOR (PRED_UNCONDITIONAL, "unconditional jump", PROB_ALWAYS) +DEF_PREDICTOR (PRED_LOOP_ITERATIONS, "loop iterations", PROB_ALWAYS) DEF_PREDICTOR (PRED_BUILTIN_EXPECT, "__builtin_expect", PROB_VERY_LIKELY) DEF_PREDICTOR (PRED_NORETURN, "noreturn call", PROB_ALWAYS) DEF_PREDICTOR (PRED_LOOP_BRANCH, "loop branch", PROB_VERY_LIKELY) |