From cc11a171eee059b645870f2e208c530f301239c9 Mon Sep 17 00:00:00 2001 From: Kewen Lin Date: Tue, 21 Sep 2021 19:13:57 -0500 Subject: [PATCH] ipa-fnsummary: Remove inconsistent bp_pack_value There is one inconsistent bit-field streaming out and in. On the side of streaming in: bp_pack_value (&bp, info->inlinable, 1); bp_pack_value (&bp, false, 1); bp_pack_value (&bp, info->fp_expressions, 1); while on the side of the streaming out: info->inlinable = bp_unpack_value (&bp, 1); info->fp_expressions = bp_unpack_value (&bp, 1) The removal of Cilk Plus support r8-4956 missed to remove the streaming out of the bit, instead just change the value for streaming out to be always false. By hacking fp_expression_p to always return true, I can see it reads the wrong fp_expressions value (false) out in wpa. GCC12 adopts commit 63c6446f77b9001d26f973114450d790749f282b which removes the inconsistent streaming out instead. gcc/ChangeLog: * ipa-fnsummary.c (inline_read_section): Unpack a dummy bit to keep consistent with the side of streaming out. --- gcc/ipa-fnsummary.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/gcc/ipa-fnsummary.c b/gcc/ipa-fnsummary.c index 18bbae145b9b..bf635c1f78aa 100644 --- a/gcc/ipa-fnsummary.c +++ b/gcc/ipa-fnsummary.c @@ -4403,13 +4403,20 @@ inline_read_section (struct lto_file_decl_data *file_data, const char *data, bp = streamer_read_bitpack (&ib); if (info) { - info->inlinable = bp_unpack_value (&bp, 1); - info->fp_expressions = bp_unpack_value (&bp, 1); + info->inlinable = bp_unpack_value (&bp, 1); + /* On the side of streaming out, there is still one bit + streamed out between inlinable and fp_expressions bits, + which was used for cilk+ before but now always false. + To remove the bit packing need to bump LTO minor version, + so unpack a dummy bit here to keep consistent instead. */ + bp_unpack_value (&bp, 1); + info->fp_expressions = bp_unpack_value (&bp, 1); } else { - bp_unpack_value (&bp, 1); - bp_unpack_value (&bp, 1); + bp_unpack_value (&bp, 1); + bp_unpack_value (&bp, 1); + bp_unpack_value (&bp, 1); } count2 = streamer_read_uhwi (&ib); -- 2.47.2