From 68aba1f6a863b0fc0fd487a737693787a49845e2 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Tue, 28 Jul 2015 11:53:37 +0000 Subject: [PATCH] match.pd: Add more simplification of address comparisons. 2015-07-28 Richard Biener * match.pd: Add more simplification of address comparisons. From-SVN: r226312 --- gcc/ChangeLog | 4 ++++ gcc/match.pd | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 44 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d81551f6968..fadcb03c5ed 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2015-07-28 Richard Biener + + * match.pd: Add more simplification of address comparisons. + 2015-07-28 Richard Biener * match.pd: Re-order two cases in comparison with max/min diff --git a/gcc/match.pd b/gcc/match.pd index 5aaa8e119aa..b0c6d773f9e 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -1828,6 +1828,46 @@ along with GCC; see the file COPYING3. If not see (if (tree_single_nonzero_warnv_p (@0, NULL)) { constant_boolean_node (cmp == NE_EXPR, type); }))) +/* When the addresses are not directly of decls compare base and offset. + This implements some remaining parts of fold_comparison address + comparisons but still no complete part of it. Still it is good + enough to make fold_stmt not regress when not dispatching to fold_binary. */ +(for cmp (simple_comparison) + (simplify + (cmp (convert? addr@0) (convert? addr@1)) + (with + { + HOST_WIDE_INT off0, off1; + tree base0 = get_addr_base_and_unit_offset (TREE_OPERAND (@0, 0), &off0); + tree base1 = get_addr_base_and_unit_offset (TREE_OPERAND (@1, 0), &off1); + if (base0 && TREE_CODE (base0) == MEM_REF) + { + off0 += mem_ref_offset (base0).to_short_addr (); + base0 = TREE_OPERAND (base0, 0); + } + if (base1 && TREE_CODE (base1) == MEM_REF) + { + off1 += mem_ref_offset (base1).to_short_addr (); + base1 = TREE_OPERAND (base1, 0); + } + } + (if (base0 && base1 + && operand_equal_p (base0, base1, 0) + && (cmp == EQ_EXPR || cmp == NE_EXPR + || POINTER_TYPE_OVERFLOW_UNDEFINED)) + (switch + (if (cmp == EQ_EXPR) + { constant_boolean_node (off0 == off1, type); }) + (if (cmp == NE_EXPR) + { constant_boolean_node (off0 != off1, type); }) + (if (cmp == LT_EXPR) + { constant_boolean_node (off0 < off1, type); }) + (if (cmp == LE_EXPR) + { constant_boolean_node (off0 <= off1, type); }) + (if (cmp == GE_EXPR) + { constant_boolean_node (off0 >= off1, type); }) + (if (cmp == GT_EXPR) + { constant_boolean_node (off0 > off1, type); })))))) /* Non-equality compare simplifications from fold_binary */ (for cmp (lt gt le ge) -- 2.30.2