From 288fe52ed1db0510d16a31a0b4cbc8ae0d4e288f Mon Sep 17 00:00:00 2001 From: Alexander Monakov Date: Tue, 25 Jul 2017 17:36:03 +0300 Subject: [PATCH] match.pd: combine successive multiplications by constants * 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. From-SVN: r250524 --- gcc/ChangeLog | 4 ++++ gcc/match.pd | 13 +++++++++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c | 13 ++++++++++++- gcc/testsuite/gcc.dg/tree-ssa/slsr-4.c | 8 ++------ 5 files changed, 36 insertions(+), 7 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 654227cd55d..34bbe013441 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2017-07-25 Alexander Monakov + + * match.pd ((X * CST1) * CST2): Simplify to X * (CST1 * CST2). + 2017-07-25 Alexander Monakov * match.pd ((X * CST) * Y): Reassociate to (X * Y) * CST. diff --git a/gcc/match.pd b/gcc/match.pd index 39e1e5c8384..732b80c04bf 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/ChangeLog b/gcc/testsuite/ChangeLog index a5c00b4e25b..6c25221694f 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-07-25 Alexander Monakov + + * gcc.dg/tree-ssa/assoc-2.c: Enhance. + * gcc.dg/tree-ssa/slsr-4.c: Adjust. + 2017-07-25 Alexander Monakov * gcc.dg/tree-ssa/assoc-2.c: New testcase. diff --git a/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c b/gcc/testsuite/gcc.dg/tree-ssa/assoc-2.c index a92c88226e5..cc0e9d429b4 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 17d7b4c6951..1e943b737b9 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" } } */ -- 2.30.2