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[ia32] Enable restricted register allocation for CSA-generated builtins

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This switches on a restricted register allocation for all
CSA-generated builtins on ia32, which treats the kRootRegister (=ebx)
as unallocatable.

A few builtins are explicitly excluded. These still need to be fixed
in follow-up CLs. But I'd like to bake this in now to ensure we don't
add more code that cannot handle restricted allocation.

All of this is still behind the (disabled-by-default on ia32)
v8_embedded_builtins configuration.

Bug: v8:6666
Change-Id: If5268aa00439406e1f4e0f7ee18496715a95fdd2
Reviewed-on: https://chromium-review.googlesource.com/1206874
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55654}
This commit is contained in:
jgruber 2018-09-05 16:01:01 +02:00 committed by Commit Bot
parent 34625fdb5a
commit 2b1ca9781a
1 changed files with 11 additions and 2 deletions
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13
src/compiler/pipeline.cc
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@ -2441,7 +2441,16 @@ bool PipelineImpl::SelectInstructions(Linkage* linkage) {
AllocateRegisters(RegisterConfiguration::Poisoning(), call_descriptor,
run_verifier);
#if defined(V8_TARGET_ARCH_IA32) && defined(V8_EMBEDDED_BUILTINS)
} else if (data_->assembler_options().isolate_independent_code) {
// TODO(v8:6666): For explicitly listed builtins, register allocation fails
// due to register pressure when kRootRegister is not allocatable. Either
// refactor these builtins or fix register allocation in these cases.
} else if (Builtins::IsBuiltinId(data->info()->builtin_index()) &&
data->info()->builtin_index() != Builtins::kWasmArgumentsAdaptor &&
data->info()->builtin_index() != Builtins::kCopyFromTempArray &&
data->info()->builtin_index() != Builtins::kCopyWithinSortArray &&
data->info()->builtin_index() != Builtins::kBinaryInsertionSort &&
data->info()->builtin_index() != Builtins::kMergeAt &&
data->info()->builtin_index() != Builtins::kArrayTimSort) {
// TODO(v8:6666): Extend support to user code. Ensure that
// it is mutually exclusive with the Poisoning configuration above; and that
// it cooperates with restricted allocatable registers above.
@ -2451,7 +2460,7 @@ bool PipelineImpl::SelectInstructions(Linkage* linkage) {
CHECK_IMPLIES(FLAG_embedded_builtins, !FLAG_untrusted_code_mitigations);
AllocateRegisters(RegisterConfiguration::PreserveRootIA32(),
call_descriptor, run_verifier);
#endif // V8_TARGET_ARCH_IA32
#endif // defined(V8_TARGET_ARCH_IA32) && defined(V8_EMBEDDED_BUILTINS)
} else {
AllocateRegisters(RegisterConfiguration::Default(), call_descriptor,
run_verifier);