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authorDimitry Andric <dim@FreeBSD.org>2019-12-20 19:53:05 +0000
committerDimitry Andric <dim@FreeBSD.org>2019-12-20 19:53:05 +0000
commit0b57cec536236d46e3dba9bd041533462f33dbb7 (patch)
tree56229dbdbbf76d18580f72f789003db17246c8d9 /contrib/llvm/tools/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptx86ABIFixups.cpp
parent718ef55ec7785aae63f98f8ca05dc07ed399c16d (diff)
Notes
Diffstat (limited to 'contrib/llvm/tools/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptx86ABIFixups.cpp')
-rw-r--r--contrib/llvm/tools/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptx86ABIFixups.cpp281
1 files changed, 0 insertions, 281 deletions
diff --git a/contrib/llvm/tools/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptx86ABIFixups.cpp b/contrib/llvm/tools/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptx86ABIFixups.cpp
deleted file mode 100644
index 4725e8c5b0eb..000000000000
--- a/contrib/llvm/tools/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptx86ABIFixups.cpp
+++ /dev/null
@@ -1,281 +0,0 @@
-//===-- RenderScriptx86ABIFixups.cpp ----------------------------*- C++ -*-===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-#include <set>
-
-#include "llvm/ADT/StringRef.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IRReader/IRReader.h"
-#include "llvm/Pass.h"
-
-#include "lldb/Target/Process.h"
-#include "lldb/Utility/Log.h"
-
-using namespace lldb_private;
-namespace {
-
-bool isRSAPICall(llvm::Module &module, llvm::CallInst *call_inst) {
- // TODO get the list of renderscript modules from lldb and check if
- // this llvm::Module calls into any of them.
- (void)module;
- const auto func_name = call_inst->getCalledFunction()->getName();
- if (func_name.startswith("llvm") || func_name.startswith("lldb"))
- return false;
-
- if (call_inst->getCalledFunction()->isIntrinsic())
- return false;
-
- return true;
-}
-
-bool isRSLargeReturnCall(llvm::Module &module, llvm::CallInst *call_inst) {
- // i686 and x86_64 returns for large vectors in the RenderScript API are not
- // handled as normal register pairs, but as a hidden sret type. This is not
- // reflected in the debug info or mangled symbol name, and the android ABI
- // for x86 and x86_64, (as well as the emulators) specifies there is no AVX,
- // so bcc generates an sret function because we cannot natively return
- // 256 bit vectors.
- // This function simply checks whether a function has a > 128bit return type.
- // It is perhaps an unreliable heuristic, and relies on bcc not generating
- // AVX code, so if the android ABI one day provides for AVX, this function
- // may go out of fashion.
- (void)module;
- if (!call_inst || !call_inst->getCalledFunction())
- return false;
-
- return call_inst->getCalledFunction()
- ->getReturnType()
- ->getPrimitiveSizeInBits() > 128;
-}
-
-bool isRSAllocationPtrTy(const llvm::Type *type) {
- if (!type->isPointerTy())
- return false;
- auto ptr_type = type->getPointerElementType();
-
- return ptr_type->isStructTy() &&
- ptr_type->getStructName().startswith("struct.rs_allocation");
-}
-
-bool isRSAllocationTyCallSite(llvm::Module &module, llvm::CallInst *call_inst) {
- (void)module;
- if (!call_inst->hasByValArgument())
- return false;
- for (const auto &param : call_inst->operand_values())
- if (isRSAllocationPtrTy(param->getType()))
- return true;
- return false;
-}
-
-llvm::FunctionType *cloneToStructRetFnTy(llvm::CallInst *call_inst) {
- // on x86 StructReturn functions return a pointer to the return value, rather
- // than the return value itself
- // [ref](http://www.agner.org/optimize/calling_conventions.pdf section 6). We
- // create a return type by getting the pointer type of the old return type,
- // and inserting a new initial argument of pointer type of the original
- // return type.
- Log *log(
- GetLogIfAnyCategoriesSet(LIBLLDB_LOG_LANGUAGE | LIBLLDB_LOG_EXPRESSIONS));
-
- assert(call_inst && "no CallInst");
- llvm::Function *orig = call_inst->getCalledFunction();
- assert(orig && "CallInst has no called function");
- llvm::FunctionType *orig_type = orig->getFunctionType();
- auto name = orig->getName();
- if (log)
- log->Printf("%s - cloning to StructRet function for '%s'", __FUNCTION__,
- name.str().c_str());
-
- unsigned num_params = orig_type->getNumParams();
- std::vector<llvm::Type *> new_params{num_params + 1, nullptr};
- std::vector<llvm::Type *> params{orig_type->param_begin(),
- orig_type->param_end()};
-
- // This may not work if the function is somehow declared void as llvm is
- // strongly typed and represents void* with i8*
- assert(!orig_type->getReturnType()->isVoidTy() &&
- "Cannot add StructRet attribute to void function");
- llvm::PointerType *return_type_ptr_type =
- llvm::PointerType::getUnqual(orig->getReturnType());
- assert(return_type_ptr_type &&
- "failed to get function return type PointerType");
- if (!return_type_ptr_type)
- return nullptr;
-
- if (log)
- log->Printf("%s - return type pointer type for StructRet clone @ '0x%p':\n",
- __FUNCTION__, (void *)return_type_ptr_type);
- // put the sret pointer argument in place at the beginning of the
- // argument list.
- params.emplace(params.begin(), return_type_ptr_type);
- assert(params.size() == num_params + 1);
- return llvm::FunctionType::get(return_type_ptr_type, params,
- orig->isVarArg());
-}
-
-bool findRSCallSites(llvm::Module &module,
- std::set<llvm::CallInst *> &rs_callsites,
- bool (*predicate)(llvm::Module &, llvm::CallInst *)) {
- bool found = false;
-
- for (auto &func : module.getFunctionList())
- for (auto &block : func.getBasicBlockList())
- for (auto &inst : block) {
- llvm::CallInst *call_inst =
- llvm::dyn_cast_or_null<llvm::CallInst>(&inst);
- if (!call_inst || !call_inst->getCalledFunction())
- // This is not the call-site you are looking for...
- continue;
- if (isRSAPICall(module, call_inst) && predicate(module, call_inst)) {
- rs_callsites.insert(call_inst);
- found = true;
- }
- }
- return found;
-}
-
-bool fixupX86StructRetCalls(llvm::Module &module) {
- bool changed = false;
- // changing a basic block while iterating over it seems to have some
- // undefined behaviour going on so we find all RS callsites first, then fix
- // them up after consuming the iterator.
- std::set<llvm::CallInst *> rs_callsites;
- if (!findRSCallSites(module, rs_callsites, isRSLargeReturnCall))
- return false;
-
- for (auto call_inst : rs_callsites) {
- llvm::FunctionType *new_func_type = cloneToStructRetFnTy(call_inst);
- assert(new_func_type &&
- "failed to clone functionType for Renderscript ABI fixup");
-
- llvm::CallSite call_site(call_inst);
- llvm::Function *func = call_inst->getCalledFunction();
- assert(func && "cannot resolve function in RenderScriptRuntime");
- // Copy the original call arguments
- std::vector<llvm::Value *> new_call_args(call_site.arg_begin(),
- call_site.arg_end());
-
- // Allocate enough space to store the return value of the original function
- // we pass a pointer to this allocation as the StructRet param, and then
- // copy its value into the lldb return value
- const llvm::DataLayout &DL = module.getDataLayout();
- llvm::AllocaInst *return_value_alloc = new llvm::AllocaInst(
- func->getReturnType(), DL.getAllocaAddrSpace(), "var_vector_return_alloc",
- call_inst);
- // use the new allocation as the new first argument
- new_call_args.emplace(new_call_args.begin(),
- llvm::cast<llvm::Value>(return_value_alloc));
- llvm::PointerType *new_func_ptr_type =
- llvm::PointerType::get(new_func_type, 0);
- // Create the type cast from the old function type to the new one
- llvm::Constant *new_func_cast = llvm::ConstantExpr::getCast(
- llvm::Instruction::BitCast, func, new_func_ptr_type);
- // create an allocation for a new function pointer
- llvm::AllocaInst *new_func_ptr =
- new llvm::AllocaInst(new_func_ptr_type, DL.getAllocaAddrSpace(),
- "new_func_ptr", call_inst);
- // store the new_func_cast to the newly allocated space
- (new llvm::StoreInst(new_func_cast, new_func_ptr, call_inst))
- ->setName("new_func_ptr_load_cast");
- // load the new function address ready for a jump
- llvm::LoadInst *new_func_addr_load =
- new llvm::LoadInst(new_func_ptr, "load_func_pointer", call_inst);
- // and create a callinstruction from it
- llvm::CallInst *new_call_inst =
- llvm::CallInst::Create(new_func_type, new_func_addr_load, new_call_args,
- "new_func_call", call_inst);
- new_call_inst->setCallingConv(call_inst->getCallingConv());
- new_call_inst->setTailCall(call_inst->isTailCall());
- llvm::LoadInst *lldb_save_result_address =
- new llvm::LoadInst(return_value_alloc, "save_return_val", call_inst);
-
- // Now remove the old broken call
- call_inst->replaceAllUsesWith(lldb_save_result_address);
- call_inst->eraseFromParent();
- changed = true;
- }
- return changed;
-}
-
-bool fixupRSAllocationStructByValCalls(llvm::Module &module) {
- // On x86_64, calls to functions in the RS runtime that take an
- // `rs_allocation` type argument are actually handled as by-ref params by
- // bcc, but appear to be passed by value by lldb (the callsite all use
- // `struct byval`). On x86_64 Linux, struct arguments are transferred in
- // registers if the struct size is no bigger than 128bits
- // [ref](http://www.agner.org/optimize/calling_conventions.pdf) section 7.1
- // "Passing and returning objects" otherwise passed on the stack. an object
- // of type `rs_allocation` is actually 256bits, so should be passed on the
- // stack. However, code generated by bcc actually treats formal params of
- // type `rs_allocation` as `rs_allocation *` so we need to convert the
- // calling convention to pass by reference, and remove any hint of byval from
- // formal parameters.
- bool changed = false;
- std::set<llvm::CallInst *> rs_callsites;
- if (!findRSCallSites(module, rs_callsites, isRSAllocationTyCallSite))
- return false;
-
- std::set<llvm::Function *> rs_functions;
-
- // for all call instructions
- for (auto call_inst : rs_callsites) {
- // add the called function to a set so that we can strip its byval
- // attributes in another pass
- rs_functions.insert(call_inst->getCalledFunction());
-
- // get the function attributes
- llvm::AttributeList call_attribs = call_inst->getAttributes();
-
- // iterate over the argument attributes
- for (unsigned I = call_attribs.index_begin(); I != call_attribs.index_end();
- I++) {
- // if this argument is passed by val
- if (call_attribs.hasAttribute(I, llvm::Attribute::ByVal)) {
- // strip away the byval attribute
- call_inst->removeAttribute(I, llvm::Attribute::ByVal);
- changed = true;
- }
- }
- }
-
- // for all called function decls
- for (auto func : rs_functions) {
- // inspect all of the arguments in the call
- for (auto &arg : func->args()) {
- if (arg.hasByValAttr()) {
- arg.removeAttr(llvm::Attribute::ByVal);
- changed = true;
- }
- }
- }
- return changed;
-}
-} // end anonymous namespace
-
-namespace lldb_private {
-namespace lldb_renderscript {
-
-bool fixupX86FunctionCalls(llvm::Module &module) {
- return fixupX86StructRetCalls(module);
-}
-
-bool fixupX86_64FunctionCalls(llvm::Module &module) {
- bool changed = false;
- changed |= fixupX86StructRetCalls(module);
- changed |= fixupRSAllocationStructByValCalls(module);
- return changed;
-}
-
-} // end namespace lldb_renderscript
-} // end namespace lldb_private