ca9ba76481
Summary: Extends the multivalue call infrastructure to tail calls, removes all legacy calls specialized for particular result types, and removes the CallIndirectFixup pass, since all indirect call arguments are now fixed up directly in the post-insertion hook. In order to keep supporting pretty-printed defs and uses in test expectations, MCInstLower now inserts an immediate containing the number of defs for each call and call_indirect. The InstPrinter is updated to query this immediate if it is present and determine which MCOperands are defs and uses accordingly. Depends on D72902. Reviewers: aheejin Subscribers: dschuff, mgorny, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D74192
99 lines
3.4 KiB
C++
99 lines
3.4 KiB
C++
//===-- WebAssemblyUtilities.cpp - WebAssembly Utility Functions ----------===//
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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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///
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/// \file
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/// This file implements several utility functions for WebAssembly.
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///
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//===----------------------------------------------------------------------===//
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#include "WebAssemblyUtilities.h"
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#include "WebAssemblyMachineFunctionInfo.h"
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#include "llvm/CodeGen/MachineInstr.h"
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#include "llvm/CodeGen/MachineLoopInfo.h"
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using namespace llvm;
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const char *const WebAssembly::ClangCallTerminateFn = "__clang_call_terminate";
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const char *const WebAssembly::CxaBeginCatchFn = "__cxa_begin_catch";
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const char *const WebAssembly::CxaRethrowFn = "__cxa_rethrow";
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const char *const WebAssembly::StdTerminateFn = "_ZSt9terminatev";
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const char *const WebAssembly::PersonalityWrapperFn =
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"_Unwind_Wasm_CallPersonality";
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/// Test whether MI is a child of some other node in an expression tree.
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bool WebAssembly::isChild(const MachineInstr &MI,
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const WebAssemblyFunctionInfo &MFI) {
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if (MI.getNumOperands() == 0)
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return false;
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const MachineOperand &MO = MI.getOperand(0);
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if (!MO.isReg() || MO.isImplicit() || !MO.isDef())
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return false;
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Register Reg = MO.getReg();
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return Register::isVirtualRegister(Reg) && MFI.isVRegStackified(Reg);
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}
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bool WebAssembly::mayThrow(const MachineInstr &MI) {
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switch (MI.getOpcode()) {
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case WebAssembly::THROW:
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case WebAssembly::THROW_S:
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case WebAssembly::RETHROW:
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case WebAssembly::RETHROW_S:
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return true;
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}
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if (isCallIndirect(MI.getOpcode()))
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return true;
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if (!MI.isCall())
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return false;
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const MachineOperand &MO = getCalleeOp(MI);
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assert(MO.isGlobal() || MO.isSymbol());
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if (MO.isSymbol()) {
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// Some intrinsics are lowered to calls to external symbols, which are then
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// lowered to calls to library functions. Most of libcalls don't throw, but
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// we only list some of them here now.
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// TODO Consider adding 'nounwind' info in TargetLowering::CallLoweringInfo
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// instead for more accurate info.
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const char *Name = MO.getSymbolName();
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if (strcmp(Name, "memcpy") == 0 || strcmp(Name, "memmove") == 0 ||
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strcmp(Name, "memset") == 0)
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return false;
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return true;
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}
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const auto *F = dyn_cast<Function>(MO.getGlobal());
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if (!F)
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return true;
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if (F->doesNotThrow())
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return false;
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// These functions never throw
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if (F->getName() == CxaBeginCatchFn || F->getName() == PersonalityWrapperFn ||
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F->getName() == ClangCallTerminateFn || F->getName() == StdTerminateFn)
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return false;
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// TODO Can we exclude call instructions that are marked as 'nounwind' in the
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// original LLVm IR? (Even when the callee may throw)
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return true;
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}
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const MachineOperand &WebAssembly::getCalleeOp(const MachineInstr &MI) {
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switch (MI.getOpcode()) {
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case WebAssembly::CALL:
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case WebAssembly::CALL_S:
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case WebAssembly::RET_CALL:
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case WebAssembly::RET_CALL_S:
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return MI.getOperand(MI.getNumExplicitDefs());
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case WebAssembly::CALL_INDIRECT:
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case WebAssembly::CALL_INDIRECT_S:
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case WebAssembly::RET_CALL_INDIRECT:
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case WebAssembly::RET_CALL_INDIRECT_S:
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return MI.getOperand(MI.getNumOperands() - 1);
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default:
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llvm_unreachable("Not a call instruction");
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}
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}
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