Drop Z from X + Z < Y + Z

2017-04-28  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* match.pd (X+Z OP Y+Z, X-Z OP Y-Z, Z-X OP Z-Y): New transformations.

gcc/testsuite/
	* gcc.dg/tree-ssa/cmpexactdiv-2.c: Update for X-Z OP Y-Z.

From-SVN: r247398
This commit is contained in:
Marc Glisse 2017-04-28 22:51:05 +02:00 committed by Marc Glisse
parent 0c90d48b34
commit d35256b6c1
4 changed files with 58 additions and 2 deletions

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@ -1,3 +1,7 @@
2017-04-28 Marc Glisse <marc.glisse@inria.fr>
* match.pd (X+Z OP Y+Z, X-Z OP Y-Z, Z-X OP Z-Y): New transformations.
2017-04-28 Bernd Edlinger <bernd.edlinger@hotmail.de>
* configure.ac (SYSTEM_HEADER_DIR, BUILD_SYSTEM_HEADER_DIR,

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@ -1042,6 +1042,54 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(if (wi::gt_p(@2, 0, TYPE_SIGN (TREE_TYPE (@2))))
(cmp @0 @1))))
/* X + Z < Y + Z is the same as X < Y when there is no overflow. */
(for op (lt le ge gt)
(simplify
(op (plus:c @0 @2) (plus:c @1 @2))
(if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
&& TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
(op @0 @1))))
/* For equality and subtraction, this is also true with wrapping overflow. */
(for op (eq ne minus)
(simplify
(op (plus:c @0 @2) (plus:c @1 @2))
(if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
&& (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))
|| TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))))
(op @0 @1))))
/* X - Z < Y - Z is the same as X < Y when there is no overflow. */
(for op (lt le ge gt)
(simplify
(op (minus @0 @2) (minus @1 @2))
(if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
&& TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
(op @0 @1))))
/* For equality and subtraction, this is also true with wrapping overflow. */
(for op (eq ne minus)
(simplify
(op (minus @0 @2) (minus @1 @2))
(if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
&& (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))
|| TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))))
(op @0 @1))))
/* Z - X < Z - Y is the same as Y < X when there is no overflow. */
(for op (lt le ge gt)
(simplify
(op (minus @2 @0) (minus @2 @1))
(if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
&& TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
(op @1 @0))))
/* For equality and subtraction, this is also true with wrapping overflow. */
(for op (eq ne minus)
(simplify
(op (minus @2 @0) (minus @2 @1))
(if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
&& (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))
|| TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))))
(op @1 @0))))
/* ((X inner_op C0) outer_op C1)
With X being a tree where value_range has reasoned certain bits to always be
zero throughout its computed value range,

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@ -1,3 +1,7 @@
2017-04-28 Marc Glisse <marc.glisse@inria.fr>
* gcc.dg/tree-ssa/cmpexactdiv-2.c: Update for X-Z OP Y-Z.
2017-04-28 Tom de Vries <tom@codesourcery.com>
* g++.dg/abi/bitfield3.C: Remove superfluous "" in

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@ -1,5 +1,5 @@
/* { dg-do compile } */
/* { dg-options "-O -fdump-tree-optimized-raw" } */
/* { dg-options "-O -fstrict-overflow -fdump-tree-optimized-raw" } */
int f (long *a, long *b, long *c) {
__PTRDIFF_TYPE__ l1 = b - a;
@ -7,5 +7,5 @@ int f (long *a, long *b, long *c) {
return l1 < l2;
}
/* Eventually we also want to remove all minus_expr. */
/* { dg-final { scan-tree-dump-not "minus_expr" "optimized" } } */
/* { dg-final { scan-tree-dump-not "exact_div_expr" "optimized" } } */