From 1447bf0556ad0cb300aabd1b883fedee314b6fca Mon Sep 17 00:00:00 2001 From: Richard Guenther Date: Tue, 29 Apr 2008 15:59:43 +0000 Subject: [PATCH] re PR tree-optimization/15255 ([tree-ssa] a * 2 + a * 2 is not converted to a * 4) 2008-04-29 Richard Guenther PR middle-end/15255 * fold-const.c (fold_binary): Fold (A + A) * C to A * 2*C. * gcc.dg/fold-plusmult.c: New testcase. From-SVN: r134798 --- gcc/ChangeLog | 5 +++++ gcc/fold-const.c | 11 +++++++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/fold-plusmult.c | 15 +++++++++++++++ 4 files changed, 36 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/fold-plusmult.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index e261305f13f..b5ae15e141b 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2008-04-29 Richard Guenther + + PR middle-end/15255 + * fold-const.c (fold_binary): Fold (A + A) * C to A * 2*C. + 2008-04-29 Richard Guenther * tree-ssa-alias.c (finalize_ref_all_pointers): Remove. diff --git a/gcc/fold-const.c b/gcc/fold-const.c index aae20377728..b4645ca256e 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -10154,6 +10154,17 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1) return fold_build2 (LSHIFT_EXPR, type, op1, TREE_OPERAND (arg0, 1)); + /* (A + A) * C -> A * 2 * C */ + if (TREE_CODE (arg0) == PLUS_EXPR + && TREE_CODE (arg1) == INTEGER_CST + && operand_equal_p (TREE_OPERAND (arg0, 0), + TREE_OPERAND (arg0, 1), 0)) + return fold_build2 (MULT_EXPR, type, + omit_one_operand (type, TREE_OPERAND (arg0, 0), + TREE_OPERAND (arg0, 1)), + fold_build2 (MULT_EXPR, type, + build_int_cst (type, 2) , arg1)); + strict_overflow_p = false; if (TREE_CODE (arg1) == INTEGER_CST && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE, diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index f2b69e90afc..dd8b3aee01c 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2008-04-29 Richard Guenther + + PR middle-end/15255 + * gcc.dg/fold-plusmult.c: New testcase. + 2008-04-29 Richard Guenther PR middle-end/36077 diff --git a/gcc/testsuite/gcc.dg/fold-plusmult.c b/gcc/testsuite/gcc.dg/fold-plusmult.c new file mode 100644 index 00000000000..d584b958874 --- /dev/null +++ b/gcc/testsuite/gcc.dg/fold-plusmult.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-fdump-tree-original" } */ + +int test1 (int a) +{ + return 2*a + 2*a; +} + +int test2 (int a) +{ + return (a + a)*2; +} + +/* { dg-final { scan-tree-dump-times " \\\* 4" 2 "original" } } */ +/* { dg-final { cleanup-tree-dump "original" } } */ -- 2.30.2