binutils-gdb/ld/testsuite/ld-powerpc/callstub-1.d
Alan Modra e10a07b32d Power10 stub selection
This patch better supports mixing of power10 and non-power10 code,
as might be seen in a cpu-optimized library using ifuncs to select
functions optimized for a given cpu.  Using -Wl,--no-power10-stubs
isn't that good in this situation since non-power10 notoc stubs are
slower and larger than the power10 variants, which you'd like to use
on power10 code paths.

With this change, power10 pc-relative code that makes calls marked
@notoc uses power10 stubs if stubs are necessary, and other calls use
non-power10 instructions in stubs.  This will mean that if gcc is
generating code for -mcpu=power10 but with pc-rel disabled then you'll
get the older stubs even on power10 (unless you force with
-Wl,--power10-stubs).  That shouldn't be too big a problem: stubs that
use r2 are reasonable.  It's just the ones that set up addressing
using "mflr 12; bcl 20,31,.+4; mflr 11; mtlr 12" that should be
avoided if possible.

bfd/
	* elf64-ppc.c (struct ppc_link_hash_table): Add has_power10_relocs.
	(select_alt_stub): New function.
	(ppc_get_stub_entry): Use it here.
	(ppc64_elf_check_relocs): Set had_power10_relocs rather than
	power10_stubs.
	(ppc64_elf_size_stubs): Clear power10_stubs here instead.  Don't
	merge notoc stubs with other varieties when power10_stubs is "auto".
	Instead dup the stub hash table entry.
	(plt_stub_size, ppc_build_one_stub, ppc_size_one_stub): Adjust
	tests of power10_stubs.
ld/
	* emultempl/ppc64elf.em (power10-stubs): Accept optional "auto" arg.
	* ld.texi (power10-stubs): Update.
	* testsuite/ld-powerpc/callstub-1.d: Force --power10-stubs.
	* testsuite/ld-powerpc/callstub-2.d: Relax branch offset comparison.
	* testsuite/ld-powerpc/callstub-4.d: New test.
	* testsuite/ld-powerpc/notoc.d: Force --no-power10-stubs.
	* testsuite/ld-powerpc/notoc3.d,
	* testsuite/ld-powerpc/notoc3.s,
	* testsuite/ld-powerpc/notoc3.wf: New test.
	* testsuite/ld-powerpc/powerpc.exp: Run new tests.  Pass
	--no-power10-stubs for notoc link.
2020-07-19 12:27:47 +09:30

30 lines
840 B
Makefile

#as: -a64 -mpower10
#ld: -melf64ppc -shared --plt-align=0 --power10-stubs --hash-style=gnu
#objdump: -dr -Mpower10
.*
Disassembly of section \.text:
.*\.plt_call\.f1>:
.*: (f8 41 00 18|18 00 41 f8) std r2,24\(r1\)
.*: (60 00 00 00|00 00 00 60) nop
.*: (04 10 00 01|01 00 10 04) pld r12,.*
.*: (e5 80 .. ..|.. .. 80 e5)
.*: (7d 89 03 a6|a6 03 89 7d) mtctr r12
.*: (4e 80 04 20|20 04 80 4e) bctr
.*\.plt_call\.f2>:
.*: (04 10 00 01|01 00 10 04) pld r12,.*
.*: (e5 80 .. ..|.. .. 80 e5)
.*: (7d 89 03 a6|a6 03 89 7d) mtctr r12
.*: (4e 80 04 20|20 04 80 4e) bctr
#...
.*<_start>:
.*: (4b ff .. ..|.. .. ff 4b) bl .*\.plt_call\.f1>
.*: (e8 41 00 18|18 00 41 e8) ld r2,24\(r1\)
.*: (4b ff .. ..|.. .. ff 4b) bl .*\.plt_call\.f1\+0x4>
.*: (4b ff .. ..|.. .. ff 4b) bl .*\.plt_call\.f2>
#pass