diff options
Diffstat (limited to 'lib/Transforms/IPO/IPConstantPropagation.cpp')
| -rw-r--r-- | lib/Transforms/IPO/IPConstantPropagation.cpp | 50 |
1 files changed, 36 insertions, 14 deletions
diff --git a/lib/Transforms/IPO/IPConstantPropagation.cpp b/lib/Transforms/IPO/IPConstantPropagation.cpp index 7d55ebecbf92..7dc4d9ee9e34 100644 --- a/lib/Transforms/IPO/IPConstantPropagation.cpp +++ b/lib/Transforms/IPO/IPConstantPropagation.cpp @@ -1,9 +1,8 @@ //===-- IPConstantPropagation.cpp - Propagate constants through calls -----===// // -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // @@ -62,32 +61,55 @@ static bool PropagateConstantsIntoArguments(Function &F) { // Ignore blockaddress uses. if (isa<BlockAddress>(UR)) continue; - // Used by a non-instruction, or not the callee of a function, do not - // transform. - if (!isa<CallInst>(UR) && !isa<InvokeInst>(UR)) + // If no abstract call site was created we did not understand the use, bail. + AbstractCallSite ACS(&U); + if (!ACS) return false; - CallSite CS(cast<Instruction>(UR)); - if (!CS.isCallee(&U)) + // Mismatched argument count is undefined behavior. Simply bail out to avoid + // handling of such situations below (avoiding asserts/crashes). + unsigned NumActualArgs = ACS.getNumArgOperands(); + if (F.isVarArg() ? ArgumentConstants.size() > NumActualArgs + : ArgumentConstants.size() != NumActualArgs) return false; // Check out all of the potentially constant arguments. Note that we don't // inspect varargs here. - CallSite::arg_iterator AI = CS.arg_begin(); Function::arg_iterator Arg = F.arg_begin(); - for (unsigned i = 0, e = ArgumentConstants.size(); i != e; - ++i, ++AI, ++Arg) { + for (unsigned i = 0, e = ArgumentConstants.size(); i != e; ++i, ++Arg) { // If this argument is known non-constant, ignore it. if (ArgumentConstants[i].second) continue; - Constant *C = dyn_cast<Constant>(*AI); + Value *V = ACS.getCallArgOperand(i); + Constant *C = dyn_cast_or_null<Constant>(V); + + // Mismatched argument type is undefined behavior. Simply bail out to avoid + // handling of such situations below (avoiding asserts/crashes). + if (C && Arg->getType() != C->getType()) + return false; + + // We can only propagate thread independent values through callbacks. + // This is different to direct/indirect call sites because for them we + // know the thread executing the caller and callee is the same. For + // callbacks this is not guaranteed, thus a thread dependent value could + // be different for the caller and callee, making it invalid to propagate. + if (C && ACS.isCallbackCall() && C->isThreadDependent()) { + // Argument became non-constant. If all arguments are non-constant now, + // give up on this function. + if (++NumNonconstant == ArgumentConstants.size()) + return false; + + ArgumentConstants[i].second = true; + continue; + } + if (C && ArgumentConstants[i].first == nullptr) { ArgumentConstants[i].first = C; // First constant seen. } else if (C && ArgumentConstants[i].first == C) { // Still the constant value we think it is. - } else if (*AI == &*Arg) { + } else if (V == &*Arg) { // Ignore recursive calls passing argument down. } else { // Argument became non-constant. If all arguments are non-constant now, |