https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104323
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:fa882c3e3bf642e0ef30772e4b54a2851497db96 commit r12-6974-gfa882c3e3bf642e0ef30772e4b54a2851497db96 Author: Jakub Jelinek <ja...@redhat.com> Date: Tue Feb 1 20:22:14 2022 +0100 rs6000: Fix up PCH on powerpc* [PR104323] As mentioned in the PR and as can be seen on: --- gcc/testsuite/gcc.dg/pch/pr104323-1.c.jj 2022-02-01 13:06:00.163192414 +0100 +++ gcc/testsuite/gcc.dg/pch/pr104323-1.c 2022-02-01 13:13:41.226712735 +0100 @@ -0,0 +1,16 @@ +/* PR target/104323 */ +/* { dg-require-effective-target powerpc_altivec_ok } */ +/* { dg-options "-maltivec" } */ + +#include "pr104323-1.h" + +__vector int a1 = { 100, 200, 300, 400 }; +__vector int a2 = { 500, 600, 700, 800 }; +__vector int r; + +int +main () +{ + r = vec_add (a1, a2); + return 0; +} --- gcc/testsuite/gcc.dg/pch/pr104323-1.hs.jj 2022-02-01 13:06:03.180149978 +0100 +++ gcc/testsuite/gcc.dg/pch/pr104323-1.hs 2022-02-01 13:12:30.175706620 +0100 @@ -0,0 +1,5 @@ +/* PR target/104323 */ +/* { dg-require-effective-target powerpc_altivec_ok } */ +/* { dg-options "-maltivec" } */ + +#include <altivec.h> testcase which I'm not including into testsuite because for some reason the test fails on non-powerpc* targets (is done even on those and fails because of missing altivec.h etc.), PCH is broken on powerpc*-*-* since the new builtin generator has been introduced. The generator contains or emits comments like: /* #### Cannot mark this as a GC root because only pointer types can be marked as GTY((user)) and be GC roots. All trees in here are kept alive by other globals, so not a big deal. Alternatively, we could change the enum fields to ints and cast them in and out to avoid requiring a GTY((user)) designation, but that seems unnecessarily gross. */ Having the fntypes stored in other GC roots can work fine for GC, ggc_collect will then always mark them and so they won't disappear from the tables, but it definitely doesn't work for PCH, which when the arrays with fntype members aren't GTY marked means on PCH write we create copies of those FUNCTION_TYPEs and store in *.gch that the GC roots should be updated, but don't store that rs6000_builtin_info[?].fntype etc. should be updated. When PCH is read again, the blob is read at some other address, GC roots are updated, rs6000_builtin_info[?].fntype contains garbage pointers (GC freed pointers with random data, or random unrelated types or other trees). The following patch fixes that. It stops any user markings because that is totally unnecessary, just skips fields we don't need to mark and adds GTY(()) to the 2 array variables. We can get rid of all those global vars for the fn types, they can be now automatic vars. With the patch we get { &rs6000_instance_info[0].fntype, 1 * (RS6000_INST_MAX), sizeof (rs6000_instance_info[0]), >_ggc_mx_tree_node, >_pch_nx_tree_node }, { &rs6000_builtin_info[0].fntype, 1 * (RS6000_BIF_MAX), sizeof (rs6000_builtin_info[0]), >_ggc_mx_tree_node, >_pch_nx_tree_node }, as the new roots which is exactly what we want and significantly more compact than countless { &uv2di_ftype_pudi_usi, 1, sizeof (uv2di_ftype_pudi_usi), >_ggc_mx_tree_node, >_pch_nx_tree_node }, { &uv2di_ftype_lg_puv2di, 1, sizeof (uv2di_ftype_lg_puv2di), >_ggc_mx_tree_node, >_pch_nx_tree_node }, { &uv2di_ftype_lg_pudi, 1, sizeof (uv2di_ftype_lg_pudi), >_ggc_mx_tree_node, >_pch_nx_tree_node }, { &uv2di_ftype_di_puv2di, 1, sizeof (uv2di_ftype_di_puv2di), >_ggc_mx_tree_node, >_pch_nx_tree_node }, cases (822 of these instead of just those 4 shown). 2022-02-01 Jakub Jelinek <ja...@redhat.com> PR target/104323 * config/rs6000/t-rs6000 (EXTRA_GTYPE_DEPS): Append rs6000-builtins.h rather than $(srcdir)/config/rs6000/rs6000-builtins.def. * config/rs6000/rs6000-gen-builtins.cc (write_decls): Don't use GTY((user)) for struct bifdata and struct ovlddata. Instead add GTY((skip(""))) to members with pointer and enum types that don't need to be tracked. Add GTY(()) to rs6000_builtin_info and rs6000_instance_info declarations. Don't emit gt_ggc_mx and gt_pch_nx declarations. (write_extern_fntype, write_fntype): Remove. (write_fntype_init): Emit the fntype vars as automatic vars instead of file scope ones. (write_header_file): Don't iterate with write_extern_fntype. (write_init_file): Don't iterate with write_fntype. Don't emit gt_ggc_mx and gt_pch_nx definitions.
