Hi!
The following testcase FAILs because the always_inline function can't
be inlined.
The rs6000 backend has similarly to other targets a hook which rejects
inlining which would bring in new ISAs which aren't there in the caller.
And this hook rejects this because of OPTION_MASK_SAVE_TOC_INDIRECT
differences.
This flag is set if explicitly requested or by default depending on
whether the current function looks hot (or at least not cold):
if ((rs6000_isa_flags_explicit & OPTION_MASK_SAVE_TOC_INDIRECT) == 0
&& flag_shrink_wrap_separate
&& optimize_function_for_speed_p (cfun))
rs6000_isa_flags |= OPTION_MASK_SAVE_TOC_INDIRECT;
The target nodes that are being compared here are actually the default
target node (which was created when cfun was NULL) vs. one that was
created for the always_inline function when it wasn't NULL, so one
doesn't have it, the other does.
In any case, this flag feels like a tuning decision rather than hard
ISA requirement and I see no problems why we couldn't inline
even explicit -msave-toc-indirect function into -mno-save-toc-indirect
or vice versa.
We already ignore OPTION_MASK_P{8,10}_FUSION which are also more
like tuning flags.
Bootstrapped/regtested on powerpc64le-linux, ok for trunk?
2025-03-26 Jakub Jelinek <ja...@redhat.com>
PR target/119327
* config/rs6000/rs6000.cc (rs6000_can_inline_p): Ignore also
OPTION_MASK_SAVE_TOC_INDIRECT differences.
* g++.dg/opt/pr119327.C: New test.
--- gcc/config/rs6000/rs6000.cc.jj 2025-03-18 14:56:37.990023768 +0100
+++ gcc/config/rs6000/rs6000.cc 2025-03-25 13:21:33.174568536 +0100
@@ -25765,10 +25765,13 @@ rs6000_can_inline_p (tree caller, tree c
}
}
- /* Ignore -mpower8-fusion and -mpower10-fusion options for inlining
- purposes. */
- callee_isa &= ~(OPTION_MASK_P8_FUSION | OPTION_MASK_P10_FUSION);
- explicit_isa &= ~(OPTION_MASK_P8_FUSION | OPTION_MASK_P10_FUSION);
+ /* Ignore -mpower8-fusion, -mpower10-fusion and -msave-toc-indirect options
+ for inlining purposes. */
+ HOST_WIDE_INT ignored_isas = (OPTION_MASK_P8_FUSION
+ | OPTION_MASK_P10_FUSION
+ | OPTION_MASK_SAVE_TOC_INDIRECT);
+ callee_isa &= ~ignored_isas;
+ explicit_isa &= ~ignored_isas;
/* The callee's options must be a subset of the caller's options, i.e.
a vsx function may inline an altivec function, but a no-vsx function
--- gcc/testsuite/g++.dg/opt/pr119327.C.jj 2025-03-25 13:24:45.129988649
+0100
+++ gcc/testsuite/g++.dg/opt/pr119327.C 2025-03-25 13:25:09.513661266 +0100
@@ -0,0 +1,16 @@
+// PR target/119327
+// { dg-do compile { target c++11 } }
+// { dg-options "-Os" }
+
+#pragma GCC optimize "fp-contract=off"
+
+template <class T>
+void
+foo (T f)
+{
+ f ();
+}
+
+struct S {
+ S () { [] {}; foo ([] __attribute__((always_inline)) {}); }
+} s;
Jakub
