Revision 5e8279050bfeac11ff7b6596e927d76e321dcc3c authored by Keno Fischer on 04 August 2020, 00:46:38 UTC, committed by GitHub on 04 August 2020, 00:46:38 UTC
When inlining declines to inline something, it instead turns them into :invoke statements. These are then turned into direct (non-inlined) calls by codegen or otherwise receive a fast path at runtime. While inlining has evolved quite a bit, this code has stayed much the same since it was introduced four years ago and doesn't seem to make much sense as is. In particular: 1. For the non-`invoke()` case we were doing an extra method look that seems entirely superfluous, because we already had to do the very same method lookup just to reach this point. The only thing this path was doing at that point was creating a "compilable" specialization (which might use a slightly different signature). We might as well do that directly. 2. For the invoke case, we were pro-actively adding the specialization to the `->invokes` dispatch cache. However, this doesn't make much sense a priori either, because the bail path does not go through the runtime `invoke()` code that uses that cache (it did many years ago when this code was introduced, but hasn't in a long time). There does not seem to be a good reason to believe that this signature will be any more likely than any other to be invoked using the runtime mechanism. This cleans up that path by getting rid of both the superfluous method lookup and the superfluous addition to the `->invokes` cache. There should be a slight performance improvement as well from avoiding this superfluous work, but the bail path is less common than one might expect (the vast majority of call sites are inlined) and in measurements the effect seems to be in the noise. Nevertheless, it seems like a nice simplification and is conceptually clearer.
1 parent ea07765
abi_llvm.cpp
//===-- abi_llvm.cpp - LLVM Target ABI description --------------*- C++ -*-===//
//
// LDC – the LLVM D compiler
//
// This file is distributed under the BSD-style LDC license:
//
// Copyright (c) 2007-2012 LDC Team.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of the LDC Team nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
// ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//===----------------------------------------------------------------------===//
//
// This ABI implementation does whatever LLVM decides is fine.
// It can be useful when first porting Julia to a new platform
// (until a platform-specific implementation can be developed).
//
//===----------------------------------------------------------------------===//
struct ABI_LLVMLayout : AbiLayout {
bool use_sret(jl_datatype_t *ty) override
{
return false;
}
bool needPassByRef(jl_datatype_t *ty, AttrBuilder &ab) override
{
return false;
}
Type *preferred_llvm_type(jl_datatype_t *ty, bool isret) const override
{
return NULL;
}
};
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