Re: [PATCH] [vectorizer] Fixing a bug in tree-vect-patterns.c in GCC vectorizer.
On Fri, Sep 13, 2013 at 8:06 PM, Cong Hou wrote:
> A new test case is added to testsuite/gcc.dg/vect, which will fail
> without this patch and pass with it. Bootstrap also get passed. No
> additional test failure is introduced.
>
> The new test case includes a dot product on two arrays with short and
> int types. The loop will still be vectorized (using punpcklwd on array
> with short type), but should not be recognized as a dot-product
> pattern.
Ok if the patch bootstraps and passes regression tests.
Thanks,
Richard.
>
> thanks,
> Cong
>
>
>
>
>
> Index: gcc/tree-vect-patterns.c
> ===
> --- gcc/tree-vect-patterns.c (revision 202572)
> +++ gcc/tree-vect-patterns.c (working copy)
> @@ -397,7 +397,7 @@ vect_recog_dot_prod_pattern (vec
>|| !promotion)
> return NULL;
>oprnd00 = gimple_assign_rhs1 (def_stmt);
> - if (!type_conversion_p (oprnd0, stmt, true, &half_type1, &def_stmt,
> + if (!type_conversion_p (oprnd1, stmt, true, &half_type1, &def_stmt,
> &promotion)
>|| !promotion)
> return NULL;
> Index: gcc/ChangeLog
> ===
> --- gcc/ChangeLog (revision 202572)
> +++ gcc/ChangeLog (working copy)
> @@ -1,3 +1,9 @@
> +2013-09-13 Cong Hou
> +
> + * tree-vect-patterns.c (vect_recog_dot_prod_pattern): Fix a bug
> + when checking the dot production pattern. The type of rhs operand
> + of multiply is now checked correctly.
> +
> 2013-09-13 Jan Hubicka
>
> PR middle-end/58094
> Index: gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s16c.c
> ===
> --- gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s16c.c (revision 0)
> +++ gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s16c.c (revision 0)
> @@ -0,0 +1,73 @@
> +/* { dg-require-effective-target vect_int } */
> +
> +#include
> +#include "tree-vect.h"
> +
> +#define N 64
> +#define DOT 43680
> +
> +signed short X[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
> +signed int Y[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
> +
> +/* (short, int)->int->int dot product.
> + Not detected as a dot-product pattern. */
> +
> +__attribute__ ((noinline)) int
> +foo (int len)
> +{
> + int i;
> + int result = 0;
> +
> + for (i = 0; i < len; i++)
> +{
> + result += (X[i] * Y[i]);
> +}
> + return result;
> +}
> +
> +
> +/* (int, short)->int->int dot product.
> + Not detected as a dot-product pattern. */
> +
> +__attribute__ ((noinline)) int
> +bar (int len)
> +{
> + int i;
> + int result = 0;
> +
> + for (i = 0; i < len; i++)
> +{
> + result += (Y[i] * X[i]);
> +}
> + return result;
> +}
> +
> +int
> +main (void)
> +{
> + int i;
> + int dot;
> +
> + check_vect ();
> +
> + for (i = 0; i < N; i++)
> +{
> + X[i] = i;
> + Y[i] = N - i;
> + __asm__ volatile ("");
> +}
> +
> + dot = foo (N);
> + if (dot != DOT)
> +abort ();
> +
> + dot = bar (N);
> + if (dot != DOT)
> +abort ();
> +
> + return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 2 "vect" {
> target vect_unpack } } } */
> +/* { dg-final { cleanup-tree-dump "vect" } } */
> +
> Index: gcc/testsuite/ChangeLog
> ===
> --- gcc/testsuite/ChangeLog (revision 202572)
> +++ gcc/testsuite/ChangeLog (working copy)
> @@ -1,3 +1,9 @@
> +2013-09-13 Cong Hou
> +
> + * gcc.dg/vect/vect-reduc-dot-s16c.c: Add a test case with dot product
> + on two arrays with short and int types. This should not be recognized
> + as a dot product pattern.
> +
> 2013-09-13 Kai Tietz
>
> gcc.target/i386/pr57848.c: New file.
>
>
>
>
> On Wed, Sep 11, 2013 at 6:55 PM, Xinliang David Li wrote:
>> Can you add a test case to the regression suite?
>>
>> When the type of arguments are unsigned short/unsigned int, GCC does
>> not vectorize the loop anymore -- this is worth a separate bug to
>> track. punpcklwd instruction can be used to do zero extension of the
>> short type.
>>
>> David
>>
>> On Wed, Sep 11, 2013 at 6:16 PM, Cong Hou wrote:
>>> Hi
>>>
>>> There is a bug in the function vect_recog_dot_prod_pattern() in
>>> tree-vect-patterns.c. This function checks if a loop is of dot
>>> production pattern. Specifically, according to the comment of this
>>> function:
>>>
>>> /*
>>> Try to find the following pattern:
>>>
>>> type x_t, y_t;
>>> TYPE1 prod;
>>> TYPE2 sum = init;
>>>loop:
>>> sum_0 = phi
>>> S1 x_t = ...
>>> S2 y_t = ...
>>> S3 x_T = (TYPE1) x_t;
>>> S4 y_T = (TYPE1) y_t;
>>> S5 prod = x_T * y_T;
>>> [S6 prod = (TYPE2) prod; #optional]
>>> S7 sum_1 = prod + sum_0;
>>>
>>>where 'TYPE1' is exactly double the size of type 'type', and
>>> 'TYPE2' is the same size of 'TYPE1' or bigger. This is a special case
>>> of a reduc
Re: [PATCH] [vectorizer] Fixing a bug in tree-vect-patterns.c in GCC vectorizer.
A new test case is added to testsuite/gcc.dg/vect, which will fail
without this patch and pass with it. Bootstrap also get passed. No
additional test failure is introduced.
The new test case includes a dot product on two arrays with short and
int types. The loop will still be vectorized (using punpcklwd on array
with short type), but should not be recognized as a dot-product
pattern.
thanks,
Cong
Index: gcc/tree-vect-patterns.c
===
--- gcc/tree-vect-patterns.c (revision 202572)
+++ gcc/tree-vect-patterns.c (working copy)
@@ -397,7 +397,7 @@ vect_recog_dot_prod_pattern (vec
|| !promotion)
return NULL;
oprnd00 = gimple_assign_rhs1 (def_stmt);
- if (!type_conversion_p (oprnd0, stmt, true, &half_type1, &def_stmt,
+ if (!type_conversion_p (oprnd1, stmt, true, &half_type1, &def_stmt,
&promotion)
|| !promotion)
return NULL;
Index: gcc/ChangeLog
===
--- gcc/ChangeLog (revision 202572)
+++ gcc/ChangeLog (working copy)
@@ -1,3 +1,9 @@
+2013-09-13 Cong Hou
+
+ * tree-vect-patterns.c (vect_recog_dot_prod_pattern): Fix a bug
+ when checking the dot production pattern. The type of rhs operand
+ of multiply is now checked correctly.
+
2013-09-13 Jan Hubicka
PR middle-end/58094
Index: gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s16c.c
===
--- gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s16c.c (revision 0)
+++ gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s16c.c (revision 0)
@@ -0,0 +1,73 @@
+/* { dg-require-effective-target vect_int } */
+
+#include
+#include "tree-vect.h"
+
+#define N 64
+#define DOT 43680
+
+signed short X[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
+signed int Y[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
+
+/* (short, int)->int->int dot product.
+ Not detected as a dot-product pattern. */
+
+__attribute__ ((noinline)) int
+foo (int len)
+{
+ int i;
+ int result = 0;
+
+ for (i = 0; i < len; i++)
+{
+ result += (X[i] * Y[i]);
+}
+ return result;
+}
+
+
+/* (int, short)->int->int dot product.
+ Not detected as a dot-product pattern. */
+
+__attribute__ ((noinline)) int
+bar (int len)
+{
+ int i;
+ int result = 0;
+
+ for (i = 0; i < len; i++)
+{
+ result += (Y[i] * X[i]);
+}
+ return result;
+}
+
+int
+main (void)
+{
+ int i;
+ int dot;
+
+ check_vect ();
+
+ for (i = 0; i < N; i++)
+{
+ X[i] = i;
+ Y[i] = N - i;
+ __asm__ volatile ("");
+}
+
+ dot = foo (N);
+ if (dot != DOT)
+abort ();
+
+ dot = bar (N);
+ if (dot != DOT)
+abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 2 "vect" {
target vect_unpack } } } */
+/* { dg-final { cleanup-tree-dump "vect" } } */
+
Index: gcc/testsuite/ChangeLog
===
--- gcc/testsuite/ChangeLog (revision 202572)
+++ gcc/testsuite/ChangeLog (working copy)
@@ -1,3 +1,9 @@
+2013-09-13 Cong Hou
+
+ * gcc.dg/vect/vect-reduc-dot-s16c.c: Add a test case with dot product
+ on two arrays with short and int types. This should not be recognized
+ as a dot product pattern.
+
2013-09-13 Kai Tietz
gcc.target/i386/pr57848.c: New file.
On Wed, Sep 11, 2013 at 6:55 PM, Xinliang David Li wrote:
> Can you add a test case to the regression suite?
>
> When the type of arguments are unsigned short/unsigned int, GCC does
> not vectorize the loop anymore -- this is worth a separate bug to
> track. punpcklwd instruction can be used to do zero extension of the
> short type.
>
> David
>
> On Wed, Sep 11, 2013 at 6:16 PM, Cong Hou wrote:
>> Hi
>>
>> There is a bug in the function vect_recog_dot_prod_pattern() in
>> tree-vect-patterns.c. This function checks if a loop is of dot
>> production pattern. Specifically, according to the comment of this
>> function:
>>
>> /*
>> Try to find the following pattern:
>>
>> type x_t, y_t;
>> TYPE1 prod;
>> TYPE2 sum = init;
>>loop:
>> sum_0 = phi
>> S1 x_t = ...
>> S2 y_t = ...
>> S3 x_T = (TYPE1) x_t;
>> S4 y_T = (TYPE1) y_t;
>> S5 prod = x_T * y_T;
>> [S6 prod = (TYPE2) prod; #optional]
>> S7 sum_1 = prod + sum_0;
>>
>>where 'TYPE1' is exactly double the size of type 'type', and
>> 'TYPE2' is the same size of 'TYPE1' or bigger. This is a special case
>> of a reduction computation.
>> */
>>
>> This function should check if x_t and y_t have the same type (type)
>> which has the half size of TYPE1. The corresponding code is shown
>> below:
>>
>> oprnd0 = gimple_assign_rhs1 (stmt);
>> oprnd1 = gimple_assign_rhs2 (stmt);
>> if (!types_compatible_p (TREE_TYPE (oprnd0), prod_type) ||
>> !types_compatible_p (TREE_TYPE (oprnd1), prod_type))
>> return NULL;
>> if
Re: [PATCH] [vectorizer] Fixing a bug in tree-vect-patterns.c in GCC vectorizer.
On Thu, Sep 12, 2013 at 3:16 AM, Cong Hou wrote:
> Hi
>
> There is a bug in the function vect_recog_dot_prod_pattern() in
> tree-vect-patterns.c. This function checks if a loop is of dot
> production pattern. Specifically, according to the comment of this
> function:
>
> /*
> Try to find the following pattern:
>
> type x_t, y_t;
> TYPE1 prod;
> TYPE2 sum = init;
>loop:
> sum_0 = phi
> S1 x_t = ...
> S2 y_t = ...
> S3 x_T = (TYPE1) x_t;
> S4 y_T = (TYPE1) y_t;
> S5 prod = x_T * y_T;
> [S6 prod = (TYPE2) prod; #optional]
> S7 sum_1 = prod + sum_0;
>
>where 'TYPE1' is exactly double the size of type 'type', and
> 'TYPE2' is the same size of 'TYPE1' or bigger. This is a special case
> of a reduction computation.
> */
>
> This function should check if x_t and y_t have the same type (type)
> which has the half size of TYPE1. The corresponding code is shown
> below:
>
> oprnd0 = gimple_assign_rhs1 (stmt);
> oprnd1 = gimple_assign_rhs2 (stmt);
> if (!types_compatible_p (TREE_TYPE (oprnd0), prod_type) ||
> !types_compatible_p (TREE_TYPE (oprnd1), prod_type))
> return NULL;
> if (!type_conversion_p (oprnd0, stmt, true, &half_type0,
> &def_stmt, &promotion) || !promotion)
> return NULL;
> oprnd00 = gimple_assign_rhs1 (def_stmt);
>
> /*==V see here! */
> if (!type_conversion_p (oprnd0, stmt, true, &half_type1,
> &def_stmt, &promotion) || !promotion)
> return NULL;
> oprnd01 = gimple_assign_rhs1 (def_stmt);
> if (!types_compatible_p (half_type0, half_type1))
> return NULL;
> if (TYPE_PRECISION (prod_type) != TYPE_PRECISION (half_type0) * 2)
> return NULL;
>
> Here the function uses x_T (oprnd0) to check the type of y_t, which is
> incorrect. The fix is simple: just replace it by oprnd1.
>
> The failed test case for this bug is shown below:
>
> int foo(short *a, int *b, int n) {
> int sum = 0;
> for (int i = 0; i < n; ++i)
> sum += a[i] * b[i];
> return sum;
> }
Bootstrapped and tested on ... ?
Please add a testcase that fails at runtime without the patch and
succeeds with it.
Thanks,
Richard.
>
> thanks,
> Cong
>
>
> Index: gcc/tree-vect-patterns.c
> ===
> --- gcc/tree-vect-patterns.c (revision 200988)
> +++ gcc/tree-vect-patterns.c (working copy)
> @@ -397,7 +397,7 @@ vect_recog_dot_prod_pattern (vec
>|| !promotion)
> return NULL;
>oprnd00 = gimple_assign_rhs1 (def_stmt);
> - if (!type_conversion_p (oprnd0, stmt, true, &half_type1, &def_stmt,
> + if (!type_conversion_p (oprnd1, stmt, true, &half_type1, &def_stmt,
> &promotion)
>|| !promotion)
> return NULL;
Re: [PATCH] [vectorizer] Fixing a bug in tree-vect-patterns.c in GCC vectorizer.
Can you add a test case to the regression suite?
When the type of arguments are unsigned short/unsigned int, GCC does
not vectorize the loop anymore -- this is worth a separate bug to
track. punpcklwd instruction can be used to do zero extension of the
short type.
David
On Wed, Sep 11, 2013 at 6:16 PM, Cong Hou wrote:
> Hi
>
> There is a bug in the function vect_recog_dot_prod_pattern() in
> tree-vect-patterns.c. This function checks if a loop is of dot
> production pattern. Specifically, according to the comment of this
> function:
>
> /*
> Try to find the following pattern:
>
> type x_t, y_t;
> TYPE1 prod;
> TYPE2 sum = init;
>loop:
> sum_0 = phi
> S1 x_t = ...
> S2 y_t = ...
> S3 x_T = (TYPE1) x_t;
> S4 y_T = (TYPE1) y_t;
> S5 prod = x_T * y_T;
> [S6 prod = (TYPE2) prod; #optional]
> S7 sum_1 = prod + sum_0;
>
>where 'TYPE1' is exactly double the size of type 'type', and
> 'TYPE2' is the same size of 'TYPE1' or bigger. This is a special case
> of a reduction computation.
> */
>
> This function should check if x_t and y_t have the same type (type)
> which has the half size of TYPE1. The corresponding code is shown
> below:
>
> oprnd0 = gimple_assign_rhs1 (stmt);
> oprnd1 = gimple_assign_rhs2 (stmt);
> if (!types_compatible_p (TREE_TYPE (oprnd0), prod_type) ||
> !types_compatible_p (TREE_TYPE (oprnd1), prod_type))
> return NULL;
> if (!type_conversion_p (oprnd0, stmt, true, &half_type0,
> &def_stmt, &promotion) || !promotion)
> return NULL;
> oprnd00 = gimple_assign_rhs1 (def_stmt);
>
> /*==V see here! */
> if (!type_conversion_p (oprnd0, stmt, true, &half_type1,
> &def_stmt, &promotion) || !promotion)
> return NULL;
> oprnd01 = gimple_assign_rhs1 (def_stmt);
> if (!types_compatible_p (half_type0, half_type1))
> return NULL;
> if (TYPE_PRECISION (prod_type) != TYPE_PRECISION (half_type0) * 2)
> return NULL;
>
> Here the function uses x_T (oprnd0) to check the type of y_t, which is
> incorrect. The fix is simple: just replace it by oprnd1.
>
> The failed test case for this bug is shown below:
>
> int foo(short *a, int *b, int n) {
> int sum = 0;
> for (int i = 0; i < n; ++i)
> sum += a[i] * b[i];
> return sum;
> }
>
>
> thanks,
> Cong
>
>
> Index: gcc/tree-vect-patterns.c
> ===
> --- gcc/tree-vect-patterns.c (revision 200988)
> +++ gcc/tree-vect-patterns.c (working copy)
> @@ -397,7 +397,7 @@ vect_recog_dot_prod_pattern (vec
>|| !promotion)
> return NULL;
>oprnd00 = gimple_assign_rhs1 (def_stmt);
> - if (!type_conversion_p (oprnd0, stmt, true, &half_type1, &def_stmt,
> + if (!type_conversion_p (oprnd1, stmt, true, &half_type1, &def_stmt,
> &promotion)
>|| !promotion)
> return NULL;
[PATCH] [vectorizer] Fixing a bug in tree-vect-patterns.c in GCC vectorizer.
Hi
There is a bug in the function vect_recog_dot_prod_pattern() in
tree-vect-patterns.c. This function checks if a loop is of dot
production pattern. Specifically, according to the comment of this
function:
/*
Try to find the following pattern:
type x_t, y_t;
TYPE1 prod;
TYPE2 sum = init;
loop:
sum_0 = phi
S1 x_t = ...
S2 y_t = ...
S3 x_T = (TYPE1) x_t;
S4 y_T = (TYPE1) y_t;
S5 prod = x_T * y_T;
[S6 prod = (TYPE2) prod; #optional]
S7 sum_1 = prod + sum_0;
where 'TYPE1' is exactly double the size of type 'type', and
'TYPE2' is the same size of 'TYPE1' or bigger. This is a special case
of a reduction computation.
*/
This function should check if x_t and y_t have the same type (type)
which has the half size of TYPE1. The corresponding code is shown
below:
oprnd0 = gimple_assign_rhs1 (stmt);
oprnd1 = gimple_assign_rhs2 (stmt);
if (!types_compatible_p (TREE_TYPE (oprnd0), prod_type) ||
!types_compatible_p (TREE_TYPE (oprnd1), prod_type))
return NULL;
if (!type_conversion_p (oprnd0, stmt, true, &half_type0,
&def_stmt, &promotion) || !promotion)
return NULL;
oprnd00 = gimple_assign_rhs1 (def_stmt);
/*==V see here! */
if (!type_conversion_p (oprnd0, stmt, true, &half_type1,
&def_stmt, &promotion) || !promotion)
return NULL;
oprnd01 = gimple_assign_rhs1 (def_stmt);
if (!types_compatible_p (half_type0, half_type1))
return NULL;
if (TYPE_PRECISION (prod_type) != TYPE_PRECISION (half_type0) * 2)
return NULL;
Here the function uses x_T (oprnd0) to check the type of y_t, which is
incorrect. The fix is simple: just replace it by oprnd1.
The failed test case for this bug is shown below:
int foo(short *a, int *b, int n) {
int sum = 0;
for (int i = 0; i < n; ++i)
sum += a[i] * b[i];
return sum;
}
thanks,
Cong
Index: gcc/tree-vect-patterns.c
===
--- gcc/tree-vect-patterns.c (revision 200988)
+++ gcc/tree-vect-patterns.c (working copy)
@@ -397,7 +397,7 @@ vect_recog_dot_prod_pattern (vec
|| !promotion)
return NULL;
oprnd00 = gimple_assign_rhs1 (def_stmt);
- if (!type_conversion_p (oprnd0, stmt, true, &half_type1, &def_stmt,
+ if (!type_conversion_p (oprnd1, stmt, true, &half_type1, &def_stmt,
&promotion)
|| !promotion)
return NULL;
