Hi,
this is a variant of patch I backported to GCC 4.9. It also includes the
earlier
for for -fstrict-aliasing boundary.
Honza
Index: ChangeLog
===================================================================
--- ChangeLog (revision 223269)
+++ ChangeLog (working copy)
@@ -1,3 +1,10 @@
+2015-04-16 Jan Hubicka <hubi...@ucw.cz>
+
+ PR ipa/65873
+ * ipa-inline.c (can_inline_edge_p): Allow early inlining of always
+ inlines across optimization boundary; be tolerant about COMDAT;
+ allow inlining across -fstrict-aliasing boundary.
+
2015-05-16 Segher Boessenkool <seg...@kernel.crashing.org>
Backport from mainline
Index: ipa-inline.c
===================================================================
--- ipa-inline.c (revision 223252)
+++ ipa-inline.c (working copy)
@@ -427,49 +427,55 @@ can_inline_edge_p (struct cgraph_edge *e
&& lookup_attribute ("always_inline",
DECL_ATTRIBUTES (callee->decl)));
+ /* Until GCC 4.9 we did not check the semantics alterning flags
+ bellow and inline across optimization boundry.
+ Enabling checks bellow breaks several packages by refusing
+ to inline library always_inline functions. See PR65873.
+ Disable the check for early inlining for now until better solution
+ is found. */
+ if (always_inline && early)
+ ;
/* 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. */
- 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)
- || check_match (flag_trapv)
- /* Strictly speaking only when the callee contains memory
- accesses that are not using alias-set zero anyway. */
- || check_maybe_down (flag_strict_aliasing)
- /* Strictly speaking only when the callee uses FP math. */
- || check_maybe_up (flag_rounding_math)
- || check_maybe_up (flag_trapping_math)
- || check_maybe_down (flag_unsafe_math_optimizations)
- || check_maybe_down (flag_finite_math_only)
- || check_maybe_up (flag_signaling_nans)
- || check_maybe_down (flag_cx_limited_range)
- || check_maybe_up (flag_signed_zeros)
- || check_maybe_down (flag_associative_math)
- || check_maybe_down (flag_reciprocal_math)
- /* We do not want to make code compiled with exceptions to be brought
- into a non-EH function unless we know that the callee does not
- throw. This is tracked by DECL_FUNCTION_PERSONALITY. */
- || (check_match (flag_non_call_exceptions)
- /* TODO: We also may allow bringing !flag_non_call_exceptions
- to flag_non_call_exceptions function, but that may need
- extra work in tree-inline to add the extra EH edges. */
- && (!opt_for_fn (callee->decl, flag_non_call_exceptions)
- || DECL_FUNCTION_PERSONALITY (callee->decl)))
- || (check_maybe_up (flag_exceptions)
- && DECL_FUNCTION_PERSONALITY (callee->decl))
- /* Strictly speaking only when the callee contains function
- calls that may end up setting errno. */
- || check_maybe_up (flag_errno_math)
- /* When devirtualization is diabled for callee, it is not safe
- to inline it as we possibly mangled the type info.
- Allow early inlining of always inlines. */
- || (!early && check_maybe_down (flag_devirtualize)))
+ 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)
+ || check_match (flag_trapv)
+ /* Strictly speaking only when the callee uses FP math. */
+ || check_maybe_up (flag_rounding_math)
+ || check_maybe_up (flag_trapping_math)
+ || check_maybe_down (flag_unsafe_math_optimizations)
+ || check_maybe_down (flag_finite_math_only)
+ || check_maybe_up (flag_signaling_nans)
+ || check_maybe_down (flag_cx_limited_range)
+ || check_maybe_up (flag_signed_zeros)
+ || check_maybe_down (flag_associative_math)
+ || check_maybe_down (flag_reciprocal_math)
+ /* We do not want to make code compiled with exceptions to be
+ brought into a non-EH function unless we know that the callee
+ does not throw.
+ This is tracked by DECL_FUNCTION_PERSONALITY. */
+ || (check_match (flag_non_call_exceptions)
+ /* TODO: We also may allow bringing !flag_non_call_exceptions
+ to flag_non_call_exceptions function, but that may need
+ extra work in tree-inline to add the extra EH edges. */
+ && (!opt_for_fn (callee->decl, flag_non_call_exceptions)
+ || DECL_FUNCTION_PERSONALITY (callee->decl)))
+ || (check_maybe_up (flag_exceptions)
+ && DECL_FUNCTION_PERSONALITY (callee->decl))
+ /* Strictly speaking only when the callee contains function
+ calls that may end up setting errno. */
+ || check_maybe_up (flag_errno_math)
+ /* When devirtualization is diabled for callee, it is not safe
+ to inline it as we possibly mangled the type info.
+ Allow early inlining of always inlines. */
+ || (!early && check_maybe_down (flag_devirtualize)))
{
e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
inlinable = false;
@@ -484,6 +490,17 @@ can_inline_edge_p (struct cgraph_edge *e
e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
inlinable = false;
}
+ /* If explicit optimize attribute are not used, the mismatch is caused
+ by different command line options used to build different units.
+ Do not care about COMDAT functions - those are intended to be
+ optimized with the optimization flags of module they are used in.
+ Also do not care about mixing up size/speed optimization when
+ DECL_DISREGARD_INLINE_LIMITS is set. */
+ else if ((callee->merged
+ && !lookup_attribute ("optimize",
+ DECL_ATTRIBUTES (caller->decl)))
+ || DECL_DISREGARD_INLINE_LIMITS (callee->decl))
+ ;
/* If mismatch is caused by merging two LTO units with different
optimizationflags we want to be bit nicer. However never inline
if one of functions is not optimized at all. */
@@ -515,7 +532,7 @@ can_inline_edge_p (struct cgraph_edge *e
else if (opt_for_fn (callee->decl, optimize_size)
< opt_for_fn (caller->decl, optimize_size)
|| (opt_for_fn (callee->decl, optimize)
- >= opt_for_fn (caller->decl, optimize)))
+ > opt_for_fn (caller->decl, optimize)))
{
if (estimate_edge_time (e)
>= 20 + inline_edge_summary (e)->call_stmt_time)
