a5f3d1a803
As part of the effort to refactor old error handling code that would directly call exit(1), in this patch we change the interface to `BinaryFunctionPass` to return an Error on `runOnFunctions()`. This gives passes the ability to report a serious problem to the caller (RewriteInstance class), so the caller may decide how to best handle the exceptional situation. Co-authored-by: Rafael Auler <rafaelauler@fb.com> Test Plan: NFC
60 lines
1.3 KiB
C++
60 lines
1.3 KiB
C++
//===- bolt/Passes/LoopInversionPass.h --------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef BOLT_PASSES_LOOPINVERSION_H
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#define BOLT_PASSES_LOOPINVERSION_H
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#include "bolt/Passes/BinaryPasses.h"
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// This pass founds cases when BBs have layout:
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// #BB0:
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// ....
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// #BB1:
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// cmp
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// cond_jmp #BB3
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// #BB2:
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// <loop body>
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// jmp #BB1
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// #BB3:
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// <loop exit>
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//
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// And swaps BB1 and BB2:
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// #BB0:
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// ....
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// jmp #BB1
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// #BB2:
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// <loop body>
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// #BB1:
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// cmp
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// cond_njmp #BB2
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// #BB3:
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// <loop exit>
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//
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// And vice versa depending on the profile information.
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// The advantage is that the loop uses only one conditional jump,
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// the unconditional jump is only used once on the loop start.
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namespace llvm {
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namespace bolt {
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class LoopInversionPass : public BinaryFunctionPass {
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public:
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explicit LoopInversionPass() : BinaryFunctionPass(false) {}
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const char *getName() const override { return "loop-inversion-opt"; }
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/// Pass entry point
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Error runOnFunctions(BinaryContext &BC) override;
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bool runOnFunction(BinaryFunction &Function);
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};
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} // namespace bolt
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} // namespace llvm
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#endif
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