From 9737f35bba5f6dd73a19b8877ecf5b4fc37b7921 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Wed, 13 Jul 2016 13:57:05 +0000 Subject: [PATCH] re PR tree-optimization/24574 (a!=0?a/10:0 is not reduced to a/10) 2016-07-13 Richard Biener PR tree-optimization/24574 * tree-ssa-phiopt.c (absorbing_element_p): Pass in argument position and add shift, rotate, divison and modulo support for left zero. (value_replacement): Pass in argument position to absorbing_element_p. * gcc.dg/pr24574.c: New testcase. From-SVN: r238299 --- gcc/ChangeLog | 8 ++++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/pr24574.c | 36 ++++++++++++++++++++++++++++++++++ gcc/tree-ssa-phiopt.c | 24 +++++++++++++++++++---- 4 files changed, 69 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/pr24574.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 03dac3322bd..cd416b7d8e9 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2016-07-13 Richard Biener + + PR tree-optimization/24574 + * tree-ssa-phiopt.c (absorbing_element_p): Pass in argument + position and add shift, rotate, divison and modulo support + for left zero. + (value_replacement): Pass in argument position to absorbing_element_p. + 2016-07-13 Ilya Enkovich PR ipa/71633 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index bccd0d8e956..92a7cb63ebf 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-07-13 Richard Biener + + PR tree-optimization/24574 + * gcc.dg/pr24574.c: New testcase. + 2016-07-13 Senthil Kumar Selvaraj * c-c++-common/Wduplicated-cond-3.c (fn10): Use smaller diff --git a/gcc/testsuite/gcc.dg/pr24574.c b/gcc/testsuite/gcc.dg/pr24574.c new file mode 100644 index 00000000000..db0d8692a76 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr24574.c @@ -0,0 +1,36 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt1" } */ + +int f0(int i) +{ + if (i == 0) return 0; + return i/10; +} +int f1(int i) +{ + return i?i/10:0; +} + +int f2(int i) +{ + if (i == 0) return 0; + return i%10; +} +int f3(int i) +{ + return i?i%10:0; +} + +int f4(int i) +{ + if (i == 0) return 0; + return i<<10; +} +int f5(int i) +{ + return i?i<<10:0; +} + +/* We should if-convert all functions to carry out the operation + unconditionally. */ +/* { dg-final { scan-tree-dump-not "= PHI" "phiopt1" } } */ diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c index caf591bc529..dd9aa0195fa 100644 --- a/gcc/tree-ssa-phiopt.c +++ b/gcc/tree-ssa-phiopt.c @@ -812,7 +812,7 @@ neutral_element_p (tree_code code, tree arg, bool right) /* Returns true if ARG is an absorbing element for operation CODE. */ static bool -absorbing_element_p (tree_code code, tree arg) +absorbing_element_p (tree_code code, tree arg, bool right) { switch (code) { @@ -823,6 +823,21 @@ absorbing_element_p (tree_code code, tree arg) case BIT_AND_EXPR: return integer_zerop (arg); + case LSHIFT_EXPR: + case RSHIFT_EXPR: + case LROTATE_EXPR: + case RROTATE_EXPR: + case TRUNC_DIV_EXPR: + case CEIL_DIV_EXPR: + case FLOOR_DIV_EXPR: + case ROUND_DIV_EXPR: + case EXACT_DIV_EXPR: + case TRUNC_MOD_EXPR: + case CEIL_MOD_EXPR: + case FLOOR_MOD_EXPR: + case ROUND_MOD_EXPR: + return !right && integer_zerop (arg); + default: return false; } @@ -994,9 +1009,10 @@ value_replacement (basic_block cond_bb, basic_block middle_bb, && operand_equal_for_phi_arg_p (rhs1, cond_lhs) && neutral_element_p (code_def, cond_rhs, false)) || (operand_equal_for_phi_arg_p (arg1, cond_rhs) - && (operand_equal_for_phi_arg_p (rhs2, cond_lhs) - || operand_equal_for_phi_arg_p (rhs1, cond_lhs)) - && absorbing_element_p (code_def, cond_rhs)))) + && ((operand_equal_for_phi_arg_p (rhs2, cond_lhs) + && absorbing_element_p (code_def, cond_rhs, true)) + || (operand_equal_for_phi_arg_p (rhs1, cond_lhs) + && absorbing_element_p (code_def, cond_rhs, false)))))) { gsi = gsi_for_stmt (cond); if (INTEGRAL_TYPE_P (TREE_TYPE (lhs))) -- 2.30.2