From 5e19d4371e4e2c7e8251f9f560abe4c43208e63a Mon Sep 17 00:00:00 2001 From: Bin Cheng Date: Tue, 1 Aug 2017 09:28:18 +0000 Subject: [PATCH] tree.h (POINTER_TYPE_OVERFLOW_UNDEFINED): Delete. * tree.h (POINTER_TYPE_OVERFLOW_UNDEFINED): Delete. * fold-const.c (fold_comparison, fold_binary_loc): Delete use of above macro. * match.pd: Ditto in address comparison pattern. gcc/testsuite * gcc.dg/no-strict-overflow-7.c: Revise comment and test string. * gcc.dg/tree-ssa/pr81388-1.c: Ditto. From-SVN: r250765 --- gcc/ChangeLog | 7 +++++++ gcc/fold-const.c | 21 ++++++--------------- gcc/match.pd | 9 +-------- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/no-strict-overflow-7.c | 6 +++--- gcc/testsuite/gcc.dg/tree-ssa/pr81388-1.c | 6 ++++-- gcc/tree.h | 3 --- 7 files changed, 26 insertions(+), 31 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9e09d56d2b2..10c10c7089c 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2017-08-01 Bin Cheng + + * tree.h (POINTER_TYPE_OVERFLOW_UNDEFINED): Delete. + * fold-const.c (fold_comparison, fold_binary_loc): Delete use of + above macro. + * match.pd: Ditto in address comparison pattern. + 2017-08-01 Bin Cheng PR tree-optimization/81627 diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 524208ae564..eeeff1ed166 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -8458,14 +8458,9 @@ fold_comparison (location_t loc, enum tree_code code, tree type, { /* We can fold this expression to a constant if the non-constant offset parts are equal. */ - if ((offset0 == offset1 - || (offset0 && offset1 - && operand_equal_p (offset0, offset1, 0))) - && (equality_code - || (indirect_base0 - && (DECL_P (base0) || CONSTANT_CLASS_P (base0))) - || POINTER_TYPE_OVERFLOW_UNDEFINED)) - + if (offset0 == offset1 + || (offset0 && offset1 + && operand_equal_p (offset0, offset1, 0))) { if (!equality_code && bitpos0 != bitpos1 @@ -8500,11 +8495,7 @@ fold_comparison (location_t loc, enum tree_code code, tree type, because pointer arithmetic is restricted to retain within an object and overflow on pointer differences is undefined as of 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */ - else if (bitpos0 == bitpos1 - && (equality_code - || (indirect_base0 - && (DECL_P (base0) || CONSTANT_CLASS_P (base0))) - || POINTER_TYPE_OVERFLOW_UNDEFINED)) + else if (bitpos0 == bitpos1) { /* By converting to signed sizetype we cover middle-end pointer arithmetic which operates on unsigned pointer types of size @@ -9590,7 +9581,7 @@ fold_binary_loc (location_t loc, /* With undefined overflow prefer doing association in a type which wraps on overflow, if that is one of the operand types. */ - if ((POINTER_TYPE_P (type) && POINTER_TYPE_OVERFLOW_UNDEFINED) + if (POINTER_TYPE_P (type) || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type))) { if (INTEGRAL_TYPE_P (TREE_TYPE (arg0)) @@ -9604,7 +9595,7 @@ fold_binary_loc (location_t loc, /* With undefined overflow we can only associate constants with one variable, and constants whose association doesn't overflow. */ - if ((POINTER_TYPE_P (atype) && POINTER_TYPE_OVERFLOW_UNDEFINED) + if (POINTER_TYPE_P (atype) || (INTEGRAL_TYPE_P (atype) && !TYPE_OVERFLOW_WRAPS (atype))) { if (var0 && var1) diff --git a/gcc/match.pd b/gcc/match.pd index 1cabcfc618a..e98db52af84 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -3223,14 +3223,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) || TREE_CODE (base1) == STRING_CST)) equal = (base0 == base1); } - (if (equal == 1 - && (cmp == EQ_EXPR || cmp == NE_EXPR - /* If the offsets are equal we can ignore overflow. */ - || off0 == off1 - || POINTER_TYPE_OVERFLOW_UNDEFINED - /* Or if we compare using pointers to decls or strings. */ - || (POINTER_TYPE_P (TREE_TYPE (@2)) - && (DECL_P (base0) || TREE_CODE (base0) == STRING_CST)))) + (if (equal == 1) (switch (if (cmp == EQ_EXPR) { constant_boolean_node (off0 == off1, type); }) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index a86b281157e..02df696860c 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-08-01 Bin Cheng + + * gcc.dg/no-strict-overflow-7.c: Revise comment and test string. + * gcc.dg/tree-ssa/pr81388-1.c: Ditto. + 2017-08-01 Bin Cheng PR tree-optimization/81627 diff --git a/gcc/testsuite/gcc.dg/no-strict-overflow-7.c b/gcc/testsuite/gcc.dg/no-strict-overflow-7.c index 19e1b55bb12..0e73d486f22 100644 --- a/gcc/testsuite/gcc.dg/no-strict-overflow-7.c +++ b/gcc/testsuite/gcc.dg/no-strict-overflow-7.c @@ -3,8 +3,8 @@ /* Source: Ian Lance Taylor. Dual of strict-overflow-6.c. */ -/* We can only simplify the conditional when using strict overflow - semantics. */ +/* We can simplify the conditional because pointer overflow always has + undefined semantics. */ int foo (char* p) @@ -12,4 +12,4 @@ foo (char* p) return p + 1000 < p; } -/* { dg-final { scan-tree-dump "\[+\]\[ \]*1000" "optimized" } } */ +/* { dg-final { scan-tree-dump "return 0" "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr81388-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr81388-1.c index ecfe12929cc..0beb5109d40 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/pr81388-1.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr81388-1.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O2 -fno-strict-overflow -fdump-tree-ivcanon-details" } */ +/* { dg-options "-O2 -fno-strict-overflow -fdump-tree-tailc-details" } */ void bar(); void foo(char *dst) @@ -11,4 +11,6 @@ void foo(char *dst) } while (dst < end); } -/* { dg-final { scan-tree-dump-times " zero if " 1 "ivcanon" } } */ +/* The loop only iterates once because pointer overflow always has undefined + semantics. As a result, call to bar becomes tail call. */ +/* { dg-final { scan-tree-dump-times "Found tail call " 1 "tailc" } } */ diff --git a/gcc/tree.h b/gcc/tree.h index e9e7931b1ae..d955b58d82a 100644 --- a/gcc/tree.h +++ b/gcc/tree.h @@ -859,9 +859,6 @@ extern void omp_clause_range_check_failed (const_tree, const char *, int, && !TYPE_OVERFLOW_WRAPS (TYPE) \ && (flag_sanitize & SANITIZE_SI_OVERFLOW)) -/* True if pointer types have undefined overflow. */ -#define POINTER_TYPE_OVERFLOW_UNDEFINED (!flag_wrapv) - /* Nonzero in a VAR_DECL or STRING_CST means assembler code has been written. Nonzero in a FUNCTION_DECL means that the function has been compiled. This is interesting in an inline function, since it might not need -- 2.30.2