On 5/20/20 12:28 PM, Leif Lindholm via groups.io wrote:
On Wed, May 20, 2020 at 12:05:03 +0200, Ard Biesheuvel wrote:Gary reports that GCC 10 will emit calls to atomics intrinsics routines unless -mno-outline-atomics is specified. This means GCC-10 introduces new intrinsics, and even though it would be possible to work around this by specifying the command line option, this would require a new GCC10 toolchain profile to be created, which we prefer to avoid.So instead, add the new intrinsics to our library so they are provided when necessary. Link: https://bugzilla.tianocore.org/show_bug.cgi?id=2723 Signed-off-by: Ard Biesheuvel <ard.biesheu...@arm.com>1) Thanks!
Note that there's a bug below - missing .globl
2) My head hurts. Is there any chance we could merge the
macro-expanded version?
GAS macros don't work like that, unfortunately.
Of course, this isn't somewhere we expect churn, and this is probably real handy if we end up having to add more variants, but it feels a bit write-only at the moment. If we keep this form, could we sprinkle it with comments a bit? I can sort of see what it does, but I definitely can't follow it.
Sure.
--- ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf | 3 + ArmPkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S | 91 ++++++++++++++++++++ 2 files changed, 94 insertions(+) diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf b/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf index d5bad9467758..fcf48c678119 100644 --- a/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf +++ b/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf @@ -79,6 +79,9 @@ [Sources.ARM] Arm/ldivmod.asm | MSFT Arm/llsr.asm | MSFT+[Sources.AARCH64]+ AArch64/Atomics.S | GCC + [Packages] MdePkg/MdePkg.dec ArmPkg/ArmPkg.dec diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S b/ArmPkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S new file mode 100644 index 000000000000..5846131ab19e --- /dev/null +++ b/ArmPkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S @@ -0,0 +1,91 @@ +#------------------------------------------------------------------------------ +# +# Copyright (c) 2020, Arm, Limited. All rights reserved.<BR> +# +# SPDX-License-Identifier: BSD-2-Clause-Patent +# +#------------------------------------------------------------------------------ + + .arch armv8-a + + .macro reg_alias, pfx, sz + r0_\sz .req \pfx\()0 + r1_\sz .req \pfx\()1 + tmp0_\sz .req \pfx\()16 + tmp1_\sz .req \pfx\()17 + .endm + + .macro fn_start, name:req + .section .text.\name + .type \name, %function
Note: missing .global \name here
+\name\(): + .endm + + .macro emit_ld_sz, sz:req, insn:req, opc:req, model:req, s, a, l + fn_start __aarch64_\insn\()\sz\()\model + mov tmp0_\sz, r0_\sz +0: ld\a\()xr\s r0_\sz, [x1] + .ifnc \insn, swp + \opc tmp1_\sz, r0_\sz, tmp0_\sz + .else + \opc tmp1_\sz, tmp0_\sz + .endif + st\l\()xr\s w15, tmp1_\sz, [x1] + cbnz w15, 0b + ret + .endm + + .macro emit_ld, insn:req, opc:req, model:req, a, l + emit_ld_sz 1, \insn, \opc, \model, b, \a, \l + emit_ld_sz 2, \insn, \opc, \model, h, \a, \l + emit_ld_sz 4, \insn, \opc, \model, , \a, \l + emit_ld_sz 8, \insn, \opc, \model, , \a, \l + .endm + + .macro emit_cas_sz, sz:req, model:req, uxt:req, s, a, l + fn_start __aarch64_cas\sz\()\model + \uxt tmp0_\sz, r0_\sz +0: ld\a\()xr\s r0_\sz, [x2] + cmp r0_\sz, tmp0_\sz + bne 1f + st\l\()xr\s w15, r1_\sz, [x2] + cbnz w15, 0b +1: ret + .endm + + .macro emit_cas, model:req, a, l + emit_cas_sz 1, \model, uxtb, b, \a, \l + emit_cas_sz 2, \model, uxth, h, \a, \l + emit_cas_sz 4, \model, mov , , \a, \l + emit_cas_sz 8, \model, mov , , \a, \l + + fn_start __aarch64_cas16\model + mov x16, x0 + mov x17, x1 +0: ld\a\()xp x0, x1, [x4] + cmp x0, x16 + ccmp x1, x17, #0, eq + bne 1f + st\l\()xp w15, x16, x17, [x4] + cbnz w15, 0b +1: ret + .endm + + .macro emit_model, model:req, a, l + emit_ld ldadd, add, \model, \a, \l + emit_ld ldclr, bic, \model, \a, \l + emit_ld ldeor, eor, \model, \a, \l + emit_ld ldset, orr, \model, \a, \l + emit_ld swp, mov, \model, \a, \l + emit_cas \model, \a, \l + .endm + + reg_alias w, 1 + reg_alias w, 2 + reg_alias w, 4 + reg_alias x, 8 + + emit_model _relax + emit_model _acq, a + emit_model _rel,, l + emit_model _acq_rel, a, l -- 2.17.1
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