Fix code emission for FAIL_ALLOC predictor

From 35ba97e0139d955c04e67ca157f8899bbb468bf1 Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Thu, 9 Jun 2016 17:51:38 +0200
Subject: [PATCH] Fix code emission for FAIL_ALLOC predictor

gcc/ChangeLog:

2016-06-13  Martin Liska  <mliska@suse.cz>

	* predict.def: Define a new predictor.

gcc/fortran/ChangeLog:

2016-06-13  Martin Liska  <mliska@suse.cz>

	* trans-array.c (gfc_array_allocate): Do not generate expect
	stmt.
	* trans.c (gfc_allocate_using_malloc): Properly set FAIL_ALLOC
	predictor for malloc return value.
	(gfc_allocate_allocatable): Use REALLOC predictor instead of
	FAIL_ALLOC.
	(gfc_deallocate_with_status): Likewise.
---
 gcc/fortran/trans-array.c |  2 +-
 gcc/fortran/trans.c       | 10 ++++------
 gcc/predict.def           | 15 +++++++++------
 3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/gcc/fortran/trans-array.c b/gcc/fortran/trans-array.c
index 403ce3a..e95c8dd 100644
--- a/gcc/fortran/trans-array.c
+++ b/gcc/fortran/trans-array.c
@@ -5553,7 +5553,7 @@  gfc_array_allocate (gfc_se * se, gfc_expr * expr, tree status, tree errmsg,
 			  build_int_cst (TREE_TYPE (status), 0));
       gfc_add_expr_to_block (&se->pre,
 		 fold_build3_loc (input_location, COND_EXPR, void_type_node,
-				  gfc_likely (cond, PRED_FORTRAN_FAIL_ALLOC),
+				  cond,
 				  set_descriptor,
 				  build_empty_stmt (input_location)));
     }
diff --git a/gcc/fortran/trans.c b/gcc/fortran/trans.c
index c6688d3..d6b4a56 100644
--- a/gcc/fortran/trans.c
+++ b/gcc/fortran/trans.c
@@ -672,9 +672,6 @@  gfc_allocate_using_malloc (stmtblock_t * block, tree pointer,
   gfc_start_block (&on_error);
   if (status != NULL_TREE)
     {
-      gfc_add_expr_to_block (&on_error,
-			     build_predict_expr (PRED_FORTRAN_FAIL_ALLOC,
-						 NOT_TAKEN));
       tmp = fold_build2_loc (input_location, MODIFY_EXPR, status_type, status,
 			     build_int_cst (status_type, LIBERROR_ALLOCATION));
       gfc_add_expr_to_block (&on_error, tmp);
@@ -693,7 +690,8 @@  gfc_allocate_using_malloc (stmtblock_t * block, tree pointer,
 				boolean_type_node, pointer,
 				build_int_cst (prvoid_type_node, 0));
   tmp = fold_build3_loc (input_location, COND_EXPR, void_type_node,
-			 error_cond, gfc_finish_block (&on_error),
+			 gfc_unlikely (error_cond, PRED_FORTRAN_FAIL_ALLOC),
+			 gfc_finish_block (&on_error),
 			 build_empty_stmt (input_location));
 
   gfc_add_expr_to_block (block, tmp);
@@ -796,7 +794,7 @@  gfc_allocate_allocatable (stmtblock_t * block, tree mem, tree size, tree token,
   null_mem = gfc_unlikely (fold_build2_loc (input_location, NE_EXPR,
 					    boolean_type_node, mem,
 					    build_int_cst (type, 0)),
-			   PRED_FORTRAN_FAIL_ALLOC);
+			   PRED_FORTRAN_REALLOC);
 
   /* If mem is NULL, we call gfc_allocate_using_malloc or
      gfc_allocate_using_lib.  */
@@ -1385,7 +1383,7 @@  gfc_deallocate_with_status (tree pointer, tree status, tree errmsg,
 	  cond2 = fold_build2_loc (input_location, NE_EXPR, boolean_type_node,
 				   stat, build_zero_cst (TREE_TYPE (stat)));
 	  tmp = fold_build3_loc (input_location, COND_EXPR, void_type_node,
-				 gfc_unlikely (cond2, PRED_FORTRAN_FAIL_ALLOC),
+				 gfc_unlikely (cond2, PRED_FORTRAN_REALLOC),
 				 tmp, build_empty_stmt (input_location));
 	  gfc_add_expr_to_block (&non_null, tmp);
 	}
diff --git a/gcc/predict.def b/gcc/predict.def
index c0a3f36..da4f9ab 100644
--- a/gcc/predict.def
+++ b/gcc/predict.def
@@ -163,12 +163,15 @@  DEF_PREDICTOR (PRED_FORTRAN_OVERFLOW, "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.
-   FIXME: the hitrate really ought to be close to 100%.  */
-DEF_PREDICTOR (PRED_FORTRAN_FAIL_ALLOC, "fail alloc", HITRATE (62), 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, "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, "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
-- 
2.8.3