* [PATCH v2 1/2] match.pd: reassociate multiplications
@ 2017-07-21 15:56 Alexander Monakov
2017-07-21 15:56 ` [PATCH v2 2/2] combine successive multiplications by constants Alexander Monakov
2017-07-25 14:18 ` [PATCH v2 1/2] match.pd: reassociate multiplications Richard Biener
0 siblings, 2 replies; 4+ messages in thread
From: Alexander Monakov @ 2017-07-21 15:56 UTC (permalink / raw)
To: gcc-patches
Previous revision here: https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00889.html
Reassociate (X * CST) * Y to (X * Y) * CST, this pushes constants in
multiplication chains to outermost factors, where they can be combined.
Changed in this revision:
- remove !TYPE_OVERFLOW_SANITIZED and !TYPE_SATURATING checks;
(in previous discussion Richard indicated that introducing false negatives
in UBSAN by concealing signed overflow is not a concern, and saturating
types shouldn't appear here because the constant operand should be FIXED_CST)
The checks for @1 being 0 or -1 remain as they are required for correctness,
but since this rule is ordered after the simpler rules that fold X * {0, -1},
those checks are always false at runtime.
* match.pd ((X * CST) * Y): Reassociate to (X * Y) * CST.
testsuite/
* gcc.dg/tree-ssa/assoc-2.c: New testcase.
---
gcc/match.pd | 8 ++++++++
gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c | 8 ++++++++
2 files changed, 16 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
diff --git a/gcc/match.pd b/gcc/match.pd
index 7f5807c..39e1e5c 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2213,6 +2213,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(mult @0 integer_minus_onep)
(negate @0))
+/* Reassociate (X * CST) * Y to (X * Y) * CST. This does not introduce
+ signed overflow for CST != 0 && CST != -1. */
+(simplify
+ (mult:c (mult:s @0 INTEGER_CST@1) @2)
+ (if (TREE_CODE (@2) != INTEGER_CST
+ && !integer_zerop (@1) && !integer_minus_onep (@1))
+ (mult (mult @0 @2) @1)))
+
/* True if we can easily extract the real and imaginary parts of a complex
number. */
(match compositional_complex
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c b/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
new file mode 100644
index 0000000..a92c882
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-gimple-raw -fdump-tree-optimized-raw" } */
+
+int f0(int a, int b){
+ return a * 33 * b * 55;
+}
+
+/* { dg-final { scan-tree-dump-times "mult_expr" 2 "gimple" } } */
--
1.8.3.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v2 2/2] combine successive multiplications by constants
2017-07-21 15:56 [PATCH v2 1/2] match.pd: reassociate multiplications Alexander Monakov
@ 2017-07-21 15:56 ` Alexander Monakov
2017-07-25 14:19 ` Richard Biener
2017-07-25 14:18 ` [PATCH v2 1/2] match.pd: reassociate multiplications Richard Biener
1 sibling, 1 reply; 4+ messages in thread
From: Alexander Monakov @ 2017-07-21 15:56 UTC (permalink / raw)
To: gcc-patches
Previous revision here: https://gcc.gnu.org/ml/gcc-patches/2017-07/msg01090.html
Reassociate X * CST1 * CST2 to X * (CST1 * CST2).
Changed in this revision:
- remove the check for @2 being 0 or -1
* match.pd ((X * CST1) * CST2): Simplify to X * (CST1 * CST2).
testsuite:
* gcc.dg/tree-ssa/assoc-2.c: Enhance.
* gcc.dg/tree-ssa/slsr-4.c: Adjust.
---
gcc/match.pd | 13 +++++++++++++
gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c | 13 ++++++++++++-
gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c | 8 ++------
3 files changed, 27 insertions(+), 7 deletions(-)
diff --git a/gcc/match.pd b/gcc/match.pd
index 39e1e5c..732b80c 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -284,6 +284,19 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
|| mul != wi::min_value (TYPE_PRECISION (type), SIGNED))
{ build_zero_cst (type); })))))
+/* Combine successive multiplications. Similar to above, but handling
+ overflow is different. */
+(simplify
+ (mult (mult @0 INTEGER_CST@1) INTEGER_CST@2)
+ (with {
+ bool overflow_p;
+ wide_int mul = wi::mul (@1, @2, TYPE_SIGN (type), &overflow_p);
+ }
+ /* Skip folding on overflow: the only special case is @1 * @2 == -INT_MIN,
+ otherwise undefined overflow implies that @0 must be zero. */
+ (if (!overflow_p || TYPE_OVERFLOW_WRAPS (type))
+ (mult @0 { wide_int_to_tree (type, mul); }))))
+
/* Optimize A / A to 1.0 if we don't care about
NaNs or Infinities. */
(simplify
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c b/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
index a92c882..cc0e9d4 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
@@ -5,4 +5,15 @@ int f0(int a, int b){
return a * 33 * b * 55;
}
-/* { dg-final { scan-tree-dump-times "mult_expr" 2 "gimple" } } */
+int f1(int a){
+ a *= 33;
+ return a * 55;
+}
+
+int f2(int a, int b){
+ a *= 33;
+ return a * b * 55;
+}
+
+/* { dg-final { scan-tree-dump-times "mult_expr" 7 "gimple" } } */
+/* { dg-final { scan-tree-dump-times "mult_expr" 5 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c b/gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c
index 17d7b4c..1e943b7 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c
@@ -23,13 +23,9 @@ f (int i)
foo (y);
}
-/* { dg-final { scan-tree-dump-times "\\* 4" 1 "slsr" } } */
-/* { dg-final { scan-tree-dump-times "\\* 10" 1 "slsr" } } */
-/* { dg-final { scan-tree-dump-times "\\+ 20;" 1 "slsr" } } */
+/* { dg-final { scan-tree-dump-times "\\* 40" 1 "slsr" } } */
/* { dg-final { scan-tree-dump-times "\\+ 200" 1 "slsr" } } */
-/* { dg-final { scan-tree-dump-times "\\- 16;" 1 "slsr" } } */
/* { dg-final { scan-tree-dump-times "\\- 160" 1 "slsr" } } */
-/* { dg-final { scan-tree-dump-times "\\* 4" 1 "optimized" } } */
-/* { dg-final { scan-tree-dump-times "\\* 10" 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "\\* 40" 1 "optimized" } } */
/* { dg-final { scan-tree-dump-times "\\+ 200" 1 "optimized" } } */
/* { dg-final { scan-tree-dump-times "\\+ 40" 1 "optimized" } } */
--
1.8.3.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 1/2] match.pd: reassociate multiplications
2017-07-21 15:56 [PATCH v2 1/2] match.pd: reassociate multiplications Alexander Monakov
2017-07-21 15:56 ` [PATCH v2 2/2] combine successive multiplications by constants Alexander Monakov
@ 2017-07-25 14:18 ` Richard Biener
1 sibling, 0 replies; 4+ messages in thread
From: Richard Biener @ 2017-07-25 14:18 UTC (permalink / raw)
To: Alexander Monakov; +Cc: GCC Patches
On Fri, Jul 21, 2017 at 5:55 PM, Alexander Monakov <amonakov@ispras.ru> wrote:
> Previous revision here: https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00889.html
>
> Reassociate (X * CST) * Y to (X * Y) * CST, this pushes constants in
> multiplication chains to outermost factors, where they can be combined.
>
> Changed in this revision:
> - remove !TYPE_OVERFLOW_SANITIZED and !TYPE_SATURATING checks;
> (in previous discussion Richard indicated that introducing false negatives
> in UBSAN by concealing signed overflow is not a concern, and saturating
> types shouldn't appear here because the constant operand should be FIXED_CST)
>
> The checks for @1 being 0 or -1 remain as they are required for correctness,
> but since this rule is ordered after the simpler rules that fold X * {0, -1},
> those checks are always false at runtime.
Ok.
Thanks,
Richard.
>
> * match.pd ((X * CST) * Y): Reassociate to (X * Y) * CST.
> testsuite/
> * gcc.dg/tree-ssa/assoc-2.c: New testcase.
>
> ---
> gcc/match.pd | 8 ++++++++
> gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c | 8 ++++++++
> 2 files changed, 16 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 7f5807c..39e1e5c 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -2213,6 +2213,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (mult @0 integer_minus_onep)
> (negate @0))
>
> +/* Reassociate (X * CST) * Y to (X * Y) * CST. This does not introduce
> + signed overflow for CST != 0 && CST != -1. */
> +(simplify
> + (mult:c (mult:s @0 INTEGER_CST@1) @2)
> + (if (TREE_CODE (@2) != INTEGER_CST
> + && !integer_zerop (@1) && !integer_minus_onep (@1))
> + (mult (mult @0 @2) @1)))
> +
> /* True if we can easily extract the real and imaginary parts of a complex
> number. */
> (match compositional_complex
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c b/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
> new file mode 100644
> index 0000000..a92c882
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-gimple-raw -fdump-tree-optimized-raw" } */
> +
> +int f0(int a, int b){
> + return a * 33 * b * 55;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "mult_expr" 2 "gimple" } } */
> --
> 1.8.3.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 2/2] combine successive multiplications by constants
2017-07-21 15:56 ` [PATCH v2 2/2] combine successive multiplications by constants Alexander Monakov
@ 2017-07-25 14:19 ` Richard Biener
0 siblings, 0 replies; 4+ messages in thread
From: Richard Biener @ 2017-07-25 14:19 UTC (permalink / raw)
To: Alexander Monakov; +Cc: GCC Patches
On Fri, Jul 21, 2017 at 5:55 PM, Alexander Monakov <amonakov@ispras.ru> wrote:
> Previous revision here: https://gcc.gnu.org/ml/gcc-patches/2017-07/msg01090.html
>
> Reassociate X * CST1 * CST2 to X * (CST1 * CST2).
>
> Changed in this revision:
> - remove the check for @2 being 0 or -1
Ok.
Thanks,
Richard.
> * match.pd ((X * CST1) * CST2): Simplify to X * (CST1 * CST2).
> testsuite:
> * gcc.dg/tree-ssa/assoc-2.c: Enhance.
> * gcc.dg/tree-ssa/slsr-4.c: Adjust.
>
> ---
> gcc/match.pd | 13 +++++++++++++
> gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c | 13 ++++++++++++-
> gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c | 8 ++------
> 3 files changed, 27 insertions(+), 7 deletions(-)
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 39e1e5c..732b80c 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -284,6 +284,19 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> || mul != wi::min_value (TYPE_PRECISION (type), SIGNED))
> { build_zero_cst (type); })))))
>
> +/* Combine successive multiplications. Similar to above, but handling
> + overflow is different. */
> +(simplify
> + (mult (mult @0 INTEGER_CST@1) INTEGER_CST@2)
> + (with {
> + bool overflow_p;
> + wide_int mul = wi::mul (@1, @2, TYPE_SIGN (type), &overflow_p);
> + }
> + /* Skip folding on overflow: the only special case is @1 * @2 == -INT_MIN,
> + otherwise undefined overflow implies that @0 must be zero. */
> + (if (!overflow_p || TYPE_OVERFLOW_WRAPS (type))
> + (mult @0 { wide_int_to_tree (type, mul); }))))
> +
> /* Optimize A / A to 1.0 if we don't care about
> NaNs or Infinities. */
> (simplify
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c b/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
> index a92c882..cc0e9d4 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c
> @@ -5,4 +5,15 @@ int f0(int a, int b){
> return a * 33 * b * 55;
> }
>
> -/* { dg-final { scan-tree-dump-times "mult_expr" 2 "gimple" } } */
> +int f1(int a){
> + a *= 33;
> + return a * 55;
> +}
> +
> +int f2(int a, int b){
> + a *= 33;
> + return a * b * 55;
> +}
> +
> +/* { dg-final { scan-tree-dump-times "mult_expr" 7 "gimple" } } */
> +/* { dg-final { scan-tree-dump-times "mult_expr" 5 "optimized" } } */
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c b/gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c
> index 17d7b4c..1e943b7 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c
> @@ -23,13 +23,9 @@ f (int i)
> foo (y);
> }
>
> -/* { dg-final { scan-tree-dump-times "\\* 4" 1 "slsr" } } */
> -/* { dg-final { scan-tree-dump-times "\\* 10" 1 "slsr" } } */
> -/* { dg-final { scan-tree-dump-times "\\+ 20;" 1 "slsr" } } */
> +/* { dg-final { scan-tree-dump-times "\\* 40" 1 "slsr" } } */
> /* { dg-final { scan-tree-dump-times "\\+ 200" 1 "slsr" } } */
> -/* { dg-final { scan-tree-dump-times "\\- 16;" 1 "slsr" } } */
> /* { dg-final { scan-tree-dump-times "\\- 160" 1 "slsr" } } */
> -/* { dg-final { scan-tree-dump-times "\\* 4" 1 "optimized" } } */
> -/* { dg-final { scan-tree-dump-times "\\* 10" 1 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "\\* 40" 1 "optimized" } } */
> /* { dg-final { scan-tree-dump-times "\\+ 200" 1 "optimized" } } */
> /* { dg-final { scan-tree-dump-times "\\+ 40" 1 "optimized" } } */
> --
> 1.8.3.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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