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* [Bug c/100357] New: attribute noinit with -fdata-sections unexpected behaviour @ 2021-04-30 13:16 sebastian.huber@embedded-brains.de 2021-04-30 13:20 ` [Bug c/100357] unexpected behaviour of attribute noinit sebastian.huber@embedded-brains.de ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: sebastian.huber@embedded-brains.de @ 2021-04-30 13:16 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100357 Bug ID: 100357 Summary: attribute noinit with -fdata-sections unexpected behaviour Product: gcc Version: 10.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: sebastian.huber@embedded-brains.de Target Milestone: --- Consider the following test code: ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/100357] unexpected behaviour of attribute noinit 2021-04-30 13:16 [Bug c/100357] New: attribute noinit with -fdata-sections unexpected behaviour sebastian.huber@embedded-brains.de @ 2021-04-30 13:20 ` sebastian.huber@embedded-brains.de 2021-09-22 7:20 ` [Bug middle-end/100357] noinit attribute does not work sometimes (small data or with -fdata-sections) pinskia at gcc dot gnu.org 2021-09-22 7:22 ` [Bug middle-end/100357] noinit attribute does not work sometimes (small data) pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: sebastian.huber@embedded-brains.de @ 2021-04-30 13:20 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100357 Sebastian Huber <sebastian.huber@embedded-brains.de> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|attribute noinit with |unexpected behaviour of |-fdata-sections unexpected |attribute noinit |behaviour | --- Comment #1 from Sebastian Huber <sebastian.huber@embedded-brains.de> --- Consider the following test code: __attribute__(( __noinit__ )) int a; __attribute__(( __noinit__ )) int b; On a target with a small data area (e.g. powerpc) this yields: powerpc-rtems6-gcc -O2 -S -o - test.c .file "test.c" .machine ppc .section ".text" .globl B .globl a .section .sbss,"aw",@nobits .align 2 .type B, @object .size B, 4 B: .zero 4 .type a, @object .size a, 4 a: .zero 4 .ident "GCC: (GNU) 10.2.1 20210113 (RTEMS 6, RSB 3d30ecae960152dd5a0e1be55de97dd46486ac53, Newlib 415fdd4)" .section .note.GNU-stack,"",@progbits On arm you get the expected result: arm-rtems6-gcc -O2 -S -o - test.c .cpu arm7tdmi .eabi_attribute 20, 1 .eabi_attribute 21, 1 .eabi_attribute 23, 3 .eabi_attribute 24, 1 .eabi_attribute 25, 1 .eabi_attribute 26, 2 .eabi_attribute 30, 2 .eabi_attribute 34, 0 .eabi_attribute 18, 4 .file "test.c" .text .global B .global a .section .noinit,"aw" .align 2 .type B, %object .size B, 4 B: .space 4 .type a, %object .size a, 4 a: .space 4 .ident "GCC: (GNU) 10.2.1 20210113 (RTEMS 6, RSB 3d30ecae960152dd5a0e1be55de97dd46486ac53, Newlib 415fdd4)" However, with -fdata-sections you get: arm-rtems6-gcc -O2 -S -o - test.c -fdata-sections .cpu arm7tdmi .eabi_attribute 20, 1 .eabi_attribute 21, 1 .eabi_attribute 23, 3 .eabi_attribute 24, 1 .eabi_attribute 25, 1 .eabi_attribute 26, 2 .eabi_attribute 30, 2 .eabi_attribute 34, 0 .eabi_attribute 18, 4 .file "test.c" .text .global B .global a .section .bss.B,"aw",%nobits .align 2 .type B, %object .size B, 4 B: .space 4 .section .bss.a,"aw",%nobits .align 2 .type a, %object .size a, 4 a: .space 4 .ident "GCC: (GNU) 10.2.1 20210113 (RTEMS 6, RSB 3d30ecae960152dd5a0e1be55de97dd46486ac53, Newlib 415fdd4)" ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug middle-end/100357] noinit attribute does not work sometimes (small data or with -fdata-sections) 2021-04-30 13:16 [Bug c/100357] New: attribute noinit with -fdata-sections unexpected behaviour sebastian.huber@embedded-brains.de 2021-04-30 13:20 ` [Bug c/100357] unexpected behaviour of attribute noinit sebastian.huber@embedded-brains.de @ 2021-09-22 7:20 ` pinskia at gcc dot gnu.org 2021-09-22 7:22 ` [Bug middle-end/100357] noinit attribute does not work sometimes (small data) pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-09-22 7:20 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100357 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- -fdata-sections problem was fixed with r11-5246-gb510765dedfec5. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug middle-end/100357] noinit attribute does not work sometimes (small data) 2021-04-30 13:16 [Bug c/100357] New: attribute noinit with -fdata-sections unexpected behaviour sebastian.huber@embedded-brains.de 2021-04-30 13:20 ` [Bug c/100357] unexpected behaviour of attribute noinit sebastian.huber@embedded-brains.de 2021-09-22 7:20 ` [Bug middle-end/100357] noinit attribute does not work sometimes (small data or with -fdata-sections) pinskia at gcc dot gnu.org @ 2021-09-22 7:22 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-09-22 7:22 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100357 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|noinit attribute does not |noinit attribute does not |work sometimes (small data |work sometimes (small data) |or with -fdata-sections) | Ever confirmed|0 |1 Status|UNCONFIRMED |NEW Last reconfirmed| |2021-09-22 --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- The sbss issue can most likely be fixed by: diff --git a/gcc/varasm.c b/gcc/varasm.c index 2d261b353bf..1216e76be53 100644 --- a/gcc/varasm.c +++ b/gcc/varasm.c @@ -7063,7 +7063,7 @@ categorize_decl_for_section (const_tree decl, int reloc) } /* If the target uses small data sections, select it. */ - else if (targetm.in_small_data_p (decl)) + else if (!DECL_NOINIT_P (decl) && targetm.in_small_data_p (decl)) { if (ret == SECCAT_BSS) ret = SECCAT_SBSS; But I have no way to test this patch. Anyways confirmed for small data. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-09-22 7:22 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-04-30 13:16 [Bug c/100357] New: attribute noinit with -fdata-sections unexpected behaviour sebastian.huber@embedded-brains.de 2021-04-30 13:20 ` [Bug c/100357] unexpected behaviour of attribute noinit sebastian.huber@embedded-brains.de 2021-09-22 7:20 ` [Bug middle-end/100357] noinit attribute does not work sometimes (small data or with -fdata-sections) pinskia at gcc dot gnu.org 2021-09-22 7:22 ` [Bug middle-end/100357] noinit attribute does not work sometimes (small data) pinskia at gcc dot gnu.org
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