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re PR tree-optimization/60505 (Warning caused by GCC vectorizer.) 

2014-04-03  Cong Hou  <congh@google.com>

PR tree-optimization/60505
    * tree-vectorizer.h (struct _stmt_vec_info): Add th field as the
    threshold of number of iterations below which no vectorization will be
    done.
    * tree-vect-loop.c (new_loop_vec_info):
    Initialize LOOP_VINFO_COST_MODEL_THRESHOLD.
    * tree-vect-loop.c (vect_analyze_loop_operations):
    Set LOOP_VINFO_COST_MODEL_THRESHOLD.
    * tree-vect-loop.c (vect_transform_loop):
    Use LOOP_VINFO_COST_MODEL_THRESHOLD.
    * tree-vect-loop.c (vect_analyze_loop_2): Check the maximum number
    of iterations of the loop and see if we should build the epilogue.

2014-04-03  Cong Hou  <congh@google.com>

    PR tree-optimization/60505
    * gcc.dg/vect/pr60505.c: New test.

From-SVN: r209065
This commit is contained in:
Cong Hou 2014-04-03 19:05:42 -04:00 committed by Cong Hou
parent bdc67fd6a4
commit 090cd8dc70
5 changed files with 55 additions and 4 deletions
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15
gcc/ChangeLog
View File

@ -1,3 +1,18 @@
2014-04-03 Cong Hou <congh@google.com>
PR tree-optimization/60505
* tree-vectorizer.h (struct _stmt_vec_info): Add th field as the
threshold of number of iterations below which no vectorization will be
done.
* tree-vect-loop.c (new_loop_vec_info):
Initialize LOOP_VINFO_COST_MODEL_THRESHOLD.
* tree-vect-loop.c (vect_analyze_loop_operations):
Set LOOP_VINFO_COST_MODEL_THRESHOLD.
* tree-vect-loop.c (vect_transform_loop):
Use LOOP_VINFO_COST_MODEL_THRESHOLD.
* tree-vect-loop.c (vect_analyze_loop_2): Check the maximum number
of iterations of the loop and see if we should build the epilogue.
2014-04-03 Richard Biener <rguenther@suse.de>
* tree-streamer.h (struct streamer_tree_cache_d): Add next_idx

5
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,8 @@
2014-04-03 Cong Hou <congh@google.com>
PR tree-optimization/60505
* gcc.dg/vect/pr60505.c: New test.
2014-04-03 Richard Biener <rguenther@suse.de>
PR tree-optimization/60740

12
gcc/testsuite/gcc.dg/vect/pr60505.c Normal file
View File

@ -0,0 +1,12 @@
/* { dg-do compile } */
/* { dg-additional-options "-Wall -Werror" } */
void foo(char *in, char *out, int num)
{
int i;
char ovec[16] = {0};
for(i = 0; i < num ; ++i)
out[i] = (ovec[i] = in[i]);
out[num] = ovec[num/2];
}

21
gcc/tree-vect-loop.c
View File

@ -933,6 +933,7 @@ new_loop_vec_info (struct loop *loop)
LOOP_VINFO_NITERS (res) = NULL;
LOOP_VINFO_NITERS_UNCHANGED (res) = NULL;
LOOP_VINFO_COST_MODEL_MIN_ITERS (res) = 0;
LOOP_VINFO_COST_MODEL_THRESHOLD (res) = 0;
LOOP_VINFO_VECTORIZABLE_P (res) = 0;
LOOP_VINFO_PEELING_FOR_ALIGNMENT (res) = 0;
LOOP_VINFO_VECT_FACTOR (res) = 0;
@ -1579,6 +1580,8 @@ vect_analyze_loop_operations (loop_vec_info loop_vinfo, bool slp)
|| min_profitable_iters > min_scalar_loop_bound))
th = (unsigned) min_profitable_iters;
LOOP_VINFO_COST_MODEL_THRESHOLD (loop_vinfo) = th;
if (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)
&& LOOP_VINFO_INT_NITERS (loop_vinfo) <= th)
{
@ -1625,6 +1628,7 @@ vect_analyze_loop_2 (loop_vec_info loop_vinfo)
bool ok, slp = false;
int max_vf = MAX_VECTORIZATION_FACTOR;
int min_vf = 2;
unsigned int th;
/* Find all data references in the loop (which correspond to vdefs/vuses)
and analyze their evolution in the loop. Also adjust the minimal
@ -1769,6 +1773,10 @@ vect_analyze_loop_2 (loop_vec_info loop_vinfo)
/* Decide whether we need to create an epilogue loop to handle
remaining scalar iterations. */
th = ((LOOP_VINFO_COST_MODEL_THRESHOLD (loop_vinfo) + 1)
/ LOOP_VINFO_VECT_FACTOR (loop_vinfo))
* LOOP_VINFO_VECT_FACTOR (loop_vinfo);
if (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)
&& LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) > 0)
{
@ -1779,7 +1787,14 @@ vect_analyze_loop_2 (loop_vec_info loop_vinfo)
}
else if (LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo)
|| (tree_ctz (LOOP_VINFO_NITERS (loop_vinfo))
< (unsigned)exact_log2 (LOOP_VINFO_VECT_FACTOR (loop_vinfo))))
< (unsigned)exact_log2 (LOOP_VINFO_VECT_FACTOR (loop_vinfo))
/* In case of versioning, check if the maximum number of
iterations is greater than th. If they are identical,
the epilogue is unnecessary. */
&& ((!LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo)
&& !LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT (loop_vinfo))
|| (unsigned HOST_WIDE_INT)max_stmt_executions_int
(LOOP_VINFO_LOOP (loop_vinfo)) > th)))
LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo) = true;
/* If an epilogue loop is required make sure we can create one. */
@ -5775,9 +5790,7 @@ vect_transform_loop (loop_vec_info loop_vinfo)
by our caller. If the threshold makes all loops profitable that
run at least the vectorization factor number of times checking
is pointless, too. */
th = ((PARAM_VALUE (PARAM_MIN_VECT_LOOP_BOUND)
* LOOP_VINFO_VECT_FACTOR (loop_vinfo)) - 1);
th = MAX (th, LOOP_VINFO_COST_MODEL_MIN_ITERS (loop_vinfo));
th = LOOP_VINFO_COST_MODEL_THRESHOLD (loop_vinfo);
if (th >= LOOP_VINFO_VECT_FACTOR (loop_vinfo) - 1
&& !LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo))
{

6
gcc/tree-vectorizer.h
View File

@ -264,6 +264,11 @@ typedef struct _loop_vec_info {
values unknown at compile time. */
int min_profitable_iters;
/* Threshold of number of iterations below which vectorzation will not be
performed. It is calculated from MIN_PROFITABLE_ITERS and
PARAM_MIN_VECT_LOOP_BOUND. */
unsigned int th;
/* Is the loop vectorizable? */
bool vectorizable;
@ -382,6 +387,7 @@ typedef struct _loop_vec_info {
cost model. */
#define LOOP_VINFO_NITERS_UNCHANGED(L) (L)->num_iters_unchanged
#define LOOP_VINFO_COST_MODEL_MIN_ITERS(L) (L)->min_profitable_iters
#define LOOP_VINFO_COST_MODEL_THRESHOLD(L) (L)->th
#define LOOP_VINFO_VECTORIZABLE_P(L) (L)->vectorizable
#define LOOP_VINFO_VECT_FACTOR(L) (L)->vectorization_factor
#define LOOP_VINFO_PTR_MASK(L) (L)->ptr_mask