From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2100) id 2862E3857C77; Thu, 21 Oct 2021 14:49:30 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2862E3857C77 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Giuliano Belinassi To: gcc-cvs@gcc.gnu.org Subject: [gcc(refs/users/giulianob/heads/pfe_backport_clean)] Backport rs6000: Avoid -fpatchable-function-entry* regressions on powerpc64 be [PR98125] X-Act-Checkin: gcc X-Git-Author: Jakub Jelinek X-Git-Refname: refs/users/giulianob/heads/pfe_backport_clean X-Git-Oldrev: bb8b3f4aee3c81ccd4d884846a4d87f543c6b75b X-Git-Newrev: ca5d90d929e92de3f0ced9204233f92aed68c0f8 Message-Id: <20211021144930.2862E3857C77@sourceware.org> Date: Thu, 21 Oct 2021 14:49:30 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 21 Oct 2021 14:49:30 -0000 https://gcc.gnu.org/g:ca5d90d929e92de3f0ced9204233f92aed68c0f8 commit ca5d90d929e92de3f0ced9204233f92aed68c0f8 Author: Jakub Jelinek Date: Sat Apr 3 10:03:15 2021 +0200 Backport rs6000: Avoid -fpatchable-function-entry* regressions on powerpc64 be [PR98125] The SECTION_LINK_ORDER changes broke powerpc64-linux ELFv1. Seems that the assembler/linker relies on the symbol mentioned for the "awo" section to be in the same section as the symbols mentioned in the relocations in that section (i.e. labels for the patchable area in this case). That is the case for most targets, including powerpc-linux 32-bit or powerpc64 ELFv2 (that one has -fpatchable-function-entry* support broken for other reasons and it doesn't seem to be a regression). But it doesn't work on powerpc64-linux ELFv1. We emit: .section ".opd","aw" .align 3 _Z3foov: .quad .L._Z3foov,.TOC.@tocbase,0 .previous .type _Z3foov, @function .L._Z3foov: .section __patchable_function_entries,"awo",@progbits,_Z3foov .align 3 .8byte .LPFE1 .section .text._Z3foov,"axG",@progbits,_Z3foov,comdat .LPFE1: nop .LFB0: .cfi_startproc and because _Z3foov is in the .opd section rather than the function text section, it doesn't work. I'm afraid I don't know what exactly should be done, whether e.g. it could use .section __patchable_function_entries,"awo",@progbits,.L._Z3foov instead, or whether the linker should be changed to handle it as is, or something else. But because we have a P1 regression that didn't see useful progress over the 4 months since it has been filed and we don't really have much time, below is an attempt to do a targetted reversion of H.J's patch, basically act as if HAVE_GAS_SECTION_LINK_ORDER is never true for powerpc64-linux ELFv1, but for 32-bit or 64-bit ELFv2 keep working as is. This would give us time to resolve it for GCC 12 properly. 2021-04-03 Jakub Jelinek PR testsuite/98125 * targhooks.h (default_print_patchable_function_entry_1): Declare. * targhooks.c (default_print_patchable_function_entry_1): New function, copied from default_print_patchable_function_entry with an added flags argument. (default_print_patchable_function_entry): Rewritten into a small wrapper around default_print_patchable_function_entry_1. * config/rs6000/rs6000.c (TARGET_ASM_PRINT_PATCHABLE_FUNCTION_ENTRY): Redefine. (rs6000_print_patchable_function_entry): New function. * g++.dg/pr93195a.C: Skip on powerpc*-*-* 64-bit. Diff: --- gcc/config/rs6000/rs6000.c | 8 ++++++-- gcc/targhooks.c | 38 ++++++++++++++++++++++++++------------ gcc/targhooks.h | 3 +++ gcc/testsuite/g++.dg/pr93195a.C | 1 + 4 files changed, 36 insertions(+), 14 deletions(-) diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c index af0c7ce1656..ac60d6d39ac 100644 --- a/gcc/config/rs6000/rs6000.c +++ b/gcc/config/rs6000/rs6000.c @@ -1615,6 +1615,10 @@ static const struct attribute_spec rs6000_attribute_table[] = #define TARGET_ASM_ASSEMBLE_VISIBILITY rs6000_assemble_visibility #endif +#undef TARGET_ASM_PRINT_PATCHABLE_FUNCTION_ENTRY +#define TARGET_ASM_PRINT_PATCHABLE_FUNCTION_ENTRY \ + rs6000_print_patchable_function_entry + #undef TARGET_SET_UP_BY_PROLOGUE #define TARGET_SET_UP_BY_PROLOGUE rs6000_set_up_by_prologue @@ -27933,8 +27937,8 @@ debug_stack_info (rs6000_stack_t *info) fprintf (stderr, "\n"); } -rtx -rs6000_return_addr (int count, rtx frame) +enum rtx_code +rs6000_reverse_condition (machine_mode mode, enum rtx_code code) { /* We can't use get_hard_reg_initial_val for LR when count == 0 if LR is trashed by the prologue, as it is for PIC on ABI_V4 and Darwin. */ diff --git a/gcc/targhooks.c b/gcc/targhooks.c index 8aa610f5cde..958ec4ba6ff 100644 --- a/gcc/targhooks.c +++ b/gcc/targhooks.c @@ -1610,17 +1610,15 @@ default_compare_by_pieces_branch_ratio (machine_mode) return 1; } -/* Write PATCH_AREA_SIZE NOPs into the asm outfile FILE around a function - entry. If RECORD_P is true and the target supports named sections, - the location of the NOPs will be recorded in a special object section - called "__patchable_function_entries". This routine may be called - twice per function to put NOPs before and after the function - entry. */ +/* Helper for default_print_patchable_function_entry and other + print_patchable_function_entry hook implementations. */ void -default_print_patchable_function_entry (FILE *file, - unsigned HOST_WIDE_INT patch_area_size, - bool record_p) +default_print_patchable_function_entry_1 (FILE *file, + unsigned HOST_WIDE_INT + patch_area_size, + bool record_p, + unsigned int flags) { const char *nop_templ = 0; int code_num; @@ -1642,9 +1640,6 @@ default_print_patchable_function_entry (FILE *file, patch_area_number++; ASM_GENERATE_INTERNAL_LABEL (buf, "LPFE", patch_area_number); - unsigned int flags = SECTION_WRITE | SECTION_RELRO; - if (HAVE_GAS_SECTION_LINK_ORDER) - flags |= SECTION_LINK_ORDER; switch_to_section (get_section ("__patchable_function_entries", flags, current_function_decl)); assemble_align (POINTER_SIZE); @@ -1661,6 +1656,25 @@ default_print_patchable_function_entry (FILE *file, output_asm_insn (nop_templ, NULL); } +/* Write PATCH_AREA_SIZE NOPs into the asm outfile FILE around a function + entry. If RECORD_P is true and the target supports named sections, + the location of the NOPs will be recorded in a special object section + called "__patchable_function_entries". This routine may be called + twice per function to put NOPs before and after the function + entry. */ + +void +default_print_patchable_function_entry (FILE *file, + unsigned HOST_WIDE_INT patch_area_size, + bool record_p) +{ + unsigned int flags = SECTION_WRITE | SECTION_RELRO; + if (HAVE_GAS_SECTION_LINK_ORDER) + flags |= SECTION_LINK_ORDER; + default_print_patchable_function_entry_1 (file, patch_area_size, record_p, + flags); +} + bool default_profile_before_prologue (void) { diff --git a/gcc/targhooks.h b/gcc/targhooks.h index 6206fe20823..7b6d2fb9138 100644 --- a/gcc/targhooks.h +++ b/gcc/targhooks.h @@ -203,6 +203,9 @@ extern bool default_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT, bool); extern int default_compare_by_pieces_branch_ratio (machine_mode); +extern void default_print_patchable_function_entry_1 (FILE *, + unsigned HOST_WIDE_INT, + bool, unsigned int); extern void default_print_patchable_function_entry (FILE *, unsigned HOST_WIDE_INT, bool); diff --git a/gcc/testsuite/g++.dg/pr93195a.C b/gcc/testsuite/g++.dg/pr93195a.C index 26d265da74e..b14f1b3e341 100644 --- a/gcc/testsuite/g++.dg/pr93195a.C +++ b/gcc/testsuite/g++.dg/pr93195a.C @@ -1,4 +1,5 @@ /* { dg-do link { target { ! { nvptx*-*-* visium-*-* } } } } */ +/* { dg-skip-if "not supported" { { powerpc*-*-* } && lp64 } } */ // { dg-require-effective-target o_flag_in_section } /* { dg-options "-O0 -fpatchable-function-entry=1" } */ /* { dg-additional-options "-fno-pie" { target sparc*-*-* } } */