c7cb9beca1
This is a reland offbfa9bf4ecThe arm64 was missing proper codegen for CFI, thus sizes were off. Original change's description: > Reland "[deoptimizer] Change deopt entries into builtins" > > This is a reland of7f58ced72e> > It fixes the different exit size emitted on x64/Atom CPUs due to > performance tuning in TurboAssembler::Call. Additionally, add > cctests to verify the fixed size exits. > > Original change's description: > > [deoptimizer] Change deopt entries into builtins > > > > While the overall goal of this commit is to change deoptimization > > entries into builtins, there are multiple related things happening: > > > > - Deoptimization entries, formerly stubs (i.e. Code objects generated > > at runtime, guaranteed to be immovable), have been converted into > > builtins. The major restriction is that we now need to preserve the > > kRootRegister, which was formerly used on most architectures to pass > > the deoptimization id. The solution differs based on platform. > > - Renamed DEOPT_ENTRIES_OR_FOR_TESTING code kind to FOR_TESTING. > > - Removed heap/ support for immovable Code generation. > > - Removed the DeserializerData class (no longer needed). > > - arm64: to preserve 4-byte deopt exits, introduced a new optimization > > in which the final jump to the deoptimization entry is generated > > once per Code object, and deopt exits can continue to emit a > > near-call. > > - arm,ia32,x64: change to fixed-size deopt exits. This reduces exit > > sizes by 4/8, 5, and 5 bytes, respectively. > > > > On arm the deopt exit size is reduced from 12 (or 16) bytes to 8 bytes > > by using the same strategy as on arm64 (recalc deopt id from return > > address). Before: > > > > e300a002 movw r10, <id> > > e59fc024 ldr ip, [pc, <entry offset>] > > e12fff3c blx ip > > > > After: > > > > e59acb35 ldr ip, [r10, <entry offset>] > > e12fff3c blx ip > > > > On arm64 the deopt exit size remains 4 bytes (or 8 bytes in same cases > > with CFI). Additionally, up to 4 builtin jumps are emitted per Code > > object (max 32 bytes added overhead per Code object). Before: > > > > 9401cdae bl <entry offset> > > > > After: > > > > # eager deoptimization entry jump. > > f95b1f50 ldr x16, [x26, <eager entry offset>] > > d61f0200 br x16 > > # lazy deoptimization entry jump. > > f95b2b50 ldr x16, [x26, <lazy entry offset>] > > d61f0200 br x16 > > # the deopt exit. > > 97fffffc bl <eager deoptimization entry jump offset> > > > > On ia32 the deopt exit size is reduced from 10 to 5 bytes. Before: > > > > bb00000000 mov ebx,<id> > > e825f5372b call <entry> > > > > After: > > > > e8ea2256ba call <entry> > > > > On x64 the deopt exit size is reduced from 12 to 7 bytes. Before: > > > > 49c7c511000000 REX.W movq r13,<id> > > e8ea2f0700 call <entry> > > > > After: > > > > 41ff9560360000 call [r13+<entry offset>] > > > > Bug: v8:8661,v8:8768 > > Change-Id: I13e30aedc360474dc818fecc528ce87c3bfeed42 > > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2465834 > > Commit-Queue: Jakob Gruber <jgruber@chromium.org> > > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org> > > Reviewed-by: Tobias Tebbi <tebbi@chromium.org> > > Reviewed-by: Ulan Degenbaev <ulan@chromium.org> > > Cr-Commit-Position: refs/heads/master@{#70597} > > Tbr: ulan@chromium.org, tebbi@chromium.org, rmcilroy@chromium.org > Bug: v8:8661,v8:8768,chromium:1140165 > Change-Id: Ibcd5c39c58a70bf2b2ac221aa375fc68d495e144 > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485506 > Reviewed-by: Jakob Gruber <jgruber@chromium.org> > Reviewed-by: Tobias Tebbi <tebbi@chromium.org> > Commit-Queue: Jakob Gruber <jgruber@chromium.org> > Cr-Commit-Position: refs/heads/master@{#70655} Tbr: ulan@chromium.org, tebbi@chromium.org, rmcilroy@chromium.org Bug: v8:8661 Bug: v8:8768 Bug: chromium:1140165 Change-Id: I471cc94fc085e527dc9bfb5a84b96bd907c2333f Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2488682 Reviewed-by: Jakob Gruber <jgruber@chromium.org> Commit-Queue: Jakob Gruber <jgruber@chromium.org> Cr-Commit-Position: refs/heads/master@{#70672}
34 lines
859 B
C++
34 lines
859 B
C++
// Copyright 2017 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "test/cctest/assembler-helper-arm.h"
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#include "src/codegen/macro-assembler.h"
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#include "src/execution/isolate-inl.h"
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#include "src/init/v8.h"
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#include "test/cctest/cctest.h"
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namespace v8 {
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namespace internal {
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Handle<Code> AssembleCodeImpl(std::function<void(MacroAssembler&)> assemble) {
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Isolate* isolate = CcTest::i_isolate();
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MacroAssembler assm(isolate, CodeObjectRequired::kYes);
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assemble(assm);
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assm.bx(lr);
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CodeDesc desc;
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assm.GetCode(isolate, &desc);
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Handle<Code> code =
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Factory::CodeBuilder(isolate, desc, CodeKind::FOR_TESTING).Build();
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if (FLAG_print_code) {
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code->Print();
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}
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return code;
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}
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} // namespace internal
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} // namespace v8
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