+2017-05-02 Richard Biener <rguenther@suse.de>
+
+ * common.opt (fstrict-overflow): Alias negative to fwrapv.
+ * doc/invoke.texi (fstrict-overflow): Remove all traces of
+ -fstrict-overflow documentation.
+ * tree.h (TYPE_OVERFLOW_UNDEFINED): Do not test flag_strict_overflow.
+ (POINTER_TYPE_OVERFLOW_UNDEFINED): Test !flag_wrapv instead of
+ flag_strict_overflow.
+ * ipa-inline.c (can_inline_edge_p): Do not test flag_strict_overflow.
+ * lto-opts.c (lto_write_options): Do not stream it.
+ * lto-wrapper.c (merge_and_complain): Do not handle it.
+ * opts.c (default_options_table): Do not set -fstrict-overflow.
+ (finish_options): Likewise do not clear it when sanitizing.
+ * simplify-rtx.c (simplify_const_relational_operation): Do not
+ test flag_strict_overflow.
+
2017-05-02 Uros Bizjak <ubizjak@gmail.com>
* config/alpha/alpha.md (*add<mode>3_ieee): Merge to add<mode>3
+2017-05-02 Richard Biener <rguenther@suse.de>
+
+ * gcc-interface/misc.c (gnat_post_options): Do not set
+ -fstrict-overflow.
+
2017-05-02 Eric Botcazou <ebotcazou@adacore.com>
* gcc-interface/trans.c (assoc_to_constructor): Make sure
if (!global_options_set.x_flag_diagnostics_show_caret)
global_dc->show_caret = false;
- /* Set strict overflow by default for Ada. */
- if (!global_options_set.x_flag_strict_overflow)
- global_options.x_flag_strict_overflow = true;
-
/* Warn only if STABS is not the default: we don't want to emit a warning if
the user did not use a -gstabs option. */
if (PREFERRED_DEBUGGING_TYPE != DBX_DEBUG && write_symbols == DBX_DEBUG)
Assume strict aliasing rules apply.
fstrict-overflow
-Common Report Var(flag_strict_overflow) Optimization
-Treat signed overflow as undefined.
+Common NegativeAlias Alias(fwrapv)
+Treat signed overflow as undefined. Negated as -fwrapv.
fsync-libcalls
Common Report Var(flag_sync_libcalls) Init(1)
-fsplit-paths @gol
-fsplit-wide-types -fssa-backprop -fssa-phiopt @gol
-fstdarg-opt -fstore-merging -fstrict-aliasing @gol
--fstrict-overflow -fthread-jumps -ftracer -ftree-bit-ccp @gol
+-fthread-jumps -ftracer -ftree-bit-ccp @gol
-ftree-builtin-call-dce -ftree-ccp -ftree-ch @gol
-ftree-coalesce-vars -ftree-copy-prop -ftree-dce -ftree-dominator-opts @gol
-ftree-dse -ftree-forwprop -ftree-fre -fcode-hoisting @gol
@itemx -Wstrict-overflow=@var{n}
@opindex Wstrict-overflow
@opindex Wno-strict-overflow
-This option is only active when @option{-fstrict-overflow} is active.
+This option is only active when signed overflow is undefined.
It warns about cases where the compiler optimizes based on the
assumption that signed overflow does not occur. Note that it does not
warn about all cases where the code might overflow: it only warns
@table @gcctabopt
@item -Wstrict-overflow=1
Warn about cases that are both questionable and easy to avoid. For
-example, with @option{-fstrict-overflow}, the compiler simplifies
+example the compiler simplifies
@code{x + 1 > x} to @code{1}. This level of
@option{-Wstrict-overflow} is enabled by @option{-Wall}; higher levels
are not, and must be explicitly requested.
@item -Wstrict-overflow=2
Also warn about other cases where a comparison is simplified to a
constant. For example: @code{abs (x) >= 0}. This can only be
-simplified when @option{-fstrict-overflow} is in effect, because
+simplified when signed integer overflow is undefined, because
@code{abs (INT_MIN)} overflows to @code{INT_MIN}, which is less than
zero. @option{-Wstrict-overflow} (with no level) is the same as
@option{-Wstrict-overflow=2}.
-fsched-interblock -fsched-spec @gol
-fschedule-insns -fschedule-insns2 @gol
-fstore-merging @gol
--fstrict-aliasing -fstrict-overflow @gol
+-fstrict-aliasing @gol
-ftree-builtin-call-dce @gol
-ftree-switch-conversion -ftree-tail-merge @gol
-fcode-hoisting @gol
The @option{-fstrict-aliasing} option is enabled at levels
@option{-O2}, @option{-O3}, @option{-Os}.
-@item -fstrict-overflow
-@opindex fstrict-overflow
-Allow the compiler to assume strict signed overflow rules, depending
-on the language being compiled. For C (and C++) this means that
-overflow when doing arithmetic with signed numbers is undefined, which
-means that the compiler may assume that it does not happen. This
-permits various optimizations. For example, the compiler assumes
-that an expression like @code{i + 10 > i} is always true for
-signed @code{i}. This assumption is only valid if signed overflow is
-undefined, as the expression is false if @code{i + 10} overflows when
-using twos complement arithmetic. When this option is in effect any
-attempt to determine whether an operation on signed numbers
-overflows must be written carefully to not actually involve overflow.
-
-This option also allows the compiler to assume strict pointer
-semantics: given a pointer to an object, if adding an offset to that
-pointer does not produce a pointer to the same object, the addition is
-undefined. This permits the compiler to conclude that @code{p + u >
-p} is always true for a pointer @code{p} and unsigned integer
-@code{u}. This assumption is only valid because pointer wraparound is
-undefined, as the expression is false if @code{p + u} overflows using
-twos complement arithmetic.
-
-See also the @option{-fwrapv} option. Using @option{-fwrapv} means
-that integer signed overflow is fully defined: it wraps. When
-@option{-fwrapv} is used, there is no difference between
-@option{-fstrict-overflow} and @option{-fno-strict-overflow} for
-integers. With @option{-fwrapv} certain types of overflow are
-permitted. For example, if the compiler gets an overflow when doing
-arithmetic on constants, the overflowed value can still be used with
-@option{-fwrapv}, but not otherwise.
-
-The @option{-fstrict-overflow} option is enabled at levels
-@option{-O2}, @option{-O3}, @option{-Os}.
-
@item -falign-functions
@itemx -falign-functions=@var{n}
@opindex falign-functions
/* There are some options that change IL semantics which means
we cannot inline in these cases for correctness reason.
Not even for always_inline declared functions. */
- /* Strictly speaking only when the callee contains signed integer
- math where overflow is undefined. */
- else if ((check_maybe_up (flag_strict_overflow)
- /* this flag is set by optimize. Allow inlining across
- optimize boundary. */
- && (!opt_for_fn (caller->decl, optimize)
- == !opt_for_fn (callee->decl, optimize) || !always_inline))
- || check_match (flag_wrapv)
+ else if (check_match (flag_wrapv)
|| check_match (flag_trapv)
/* When caller or callee does FP math, be sure FP codegen flags
compatible. */
if (!global_options_set.x_flag_trapv
&& !global_options.x_flag_trapv)
append_to_collect_gcc_options (&temporary_obstack, &first_p, "-fno-trapv");
- if (!global_options_set.x_flag_strict_overflow
- && !global_options.x_flag_strict_overflow)
- append_to_collect_gcc_options (&temporary_obstack, &first_p,
- "-fno-strict-overflow");
if (!global_options_set.x_flag_openmp
&& !global_options.x_flag_openmp)
break;
case OPT_ftrapv:
- case OPT_fstrict_overflow:
case OPT_ffp_contract_:
/* For selected options we can merge conservatively. */
for (j = 0; j < *decoded_options_count; ++j)
case OPT_fopenacc_dim_:
case OPT_fcilkplus:
case OPT_ftrapv:
- case OPT_fstrict_overflow:
case OPT_foffload_abi_:
case OPT_O:
case OPT_Ofast:
{ OPT_LEVELS_2_PLUS, OPT_fschedule_insns2, NULL, 1 },
#endif
{ OPT_LEVELS_2_PLUS, OPT_fstrict_aliasing, NULL, 1 },
- { OPT_LEVELS_2_PLUS, OPT_fstrict_overflow, NULL, 1 },
{ OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_freorder_blocks_algorithm_, NULL,
REORDER_BLOCKS_ALGORITHM_STC },
{ OPT_LEVELS_2_PLUS, OPT_freorder_functions, NULL, 1 },
/* Aggressive compiler optimizations may cause false negatives. */
if (opts->x_flag_sanitize & ~(SANITIZE_LEAK | SANITIZE_UNREACHABLE))
- {
- opts->x_flag_aggressive_loop_optimizations = 0;
- opts->x_flag_strict_overflow = 0;
- }
+ opts->x_flag_aggressive_loop_optimizations = 0;
/* Enable -fsanitize-address-use-after-scope if address sanitizer is
enabled. */
/* Optimize abs(x) < 0.0. */
if (!HONOR_SNANS (mode)
&& (!INTEGRAL_MODE_P (mode)
- || (!flag_wrapv && !flag_trapv && flag_strict_overflow)))
+ || (!flag_wrapv && !flag_trapv)))
{
if (INTEGRAL_MODE_P (mode)
&& (issue_strict_overflow_warning
/* Optimize abs(x) >= 0.0. */
if (!HONOR_NANS (mode)
&& (!INTEGRAL_MODE_P (mode)
- || (!flag_wrapv && !flag_trapv && flag_strict_overflow)))
+ || (!flag_wrapv && !flag_trapv)))
{
if (INTEGRAL_MODE_P (mode)
&& (issue_strict_overflow_warning
+2017-05-02 Richard Biener <rguenther@suse.de>
+
+ * c-c++-common/Wlogical-op-1.c: Add -fwrapv to restore previous
+ behavior.
+ * gcc.target/i386/pr46253.c: Make i unsigned to avoid warning.
+
2017-05-02 Richard Biener <rguenther@suse.de>
PR tree-optimization/80591
/* PR c/63357 */
/* { dg-do compile } */
-/* { dg-options "-Wlogical-op" } */
+/* For -fwrapv see PR80525, xfailing the subtest isn't possible as it passes
+ with the C++ FE which doesn't have maybe_const_expr. */
+/* { dg-options "-fwrapv -Wlogical-op" } */
#ifndef __cplusplus
# define bool _Bool
__m256i bar (void);
void foo (void)
{
- int i = 0;
+ unsigned int i = 0;
bar ();
__builtin_ia32_vzeroupper ();
while (++i);
caller decide whether a warning is appropriate or not. */
#define TYPE_OVERFLOW_UNDEFINED(TYPE) \
(!ANY_INTEGRAL_TYPE_CHECK(TYPE)->base.u.bits.unsigned_flag \
- && !flag_wrapv && !flag_trapv && flag_strict_overflow)
+ && !flag_wrapv && !flag_trapv)
/* True if overflow for the given integral type should issue a
trap. */
&& (flag_sanitize & SANITIZE_SI_OVERFLOW))
/* True if pointer types have undefined overflow. */
-#define POINTER_TYPE_OVERFLOW_UNDEFINED (flag_strict_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.
projects / gcc.git / commitdiff