qzdoom/tools/drawergen/ssa/ssa_for_block.cpp
2016-11-28 17:31:56 +01:00

62 lines
2.6 KiB
C++

/*
** LLVM for loop branching
** Copyright (c) 2016 Magnus Norddahl
**
** This software is provided 'as-is', without any express or implied
** warranty. In no event will the authors be held liable for any damages
** arising from the use of this software.
**
** Permission is granted to anyone to use this software for any purpose,
** including commercial applications, and to alter it and redistribute it
** freely, subject to the following restrictions:
**
** 1. The origin of this software must not be misrepresented; you must not
** claim that you wrote the original software. If you use this software
** in a product, an acknowledgment in the product documentation would be
** appreciated but is not required.
** 2. Altered source versions must be plainly marked as such, and must not be
** misrepresented as being the original software.
** 3. This notice may not be removed or altered from any source distribution.
**
*/
#include "precomp.h"
#include "ssa_for_block.h"
#include "ssa_scope.h"
SSAForBlock::SSAForBlock()
: if_basic_block(0), loop_basic_block(0), end_basic_block(0)
{
if_basic_block = llvm::BasicBlock::Create(SSAScope::context(), "forbegin", SSAScope::builder().GetInsertBlock()->getParent());
loop_basic_block = llvm::BasicBlock::Create(SSAScope::context(), "forloop", SSAScope::builder().GetInsertBlock()->getParent());
end_basic_block = llvm::BasicBlock::Create(SSAScope::context(), "forend", SSAScope::builder().GetInsertBlock()->getParent());
SSAScope::builder().CreateBr(if_basic_block);
SSAScope::builder().SetInsertPoint(if_basic_block);
}
void SSAForBlock::loop_block(SSABool true_condition, int unroll_count)
{
auto branch = SSAScope::builder().CreateCondBr(true_condition.v, loop_basic_block, end_basic_block);
#if LLVM_VERSION_MAJOR > 3 || (LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR >= 9)
if (unroll_count > 0)
{
using namespace llvm;
auto md_unroll_enable = MDNode::get(SSAScope::context(), {
MDString::get(SSAScope::context(), "llvm.loop.unroll.enable")
});
auto md_unroll_count = MDNode::get(SSAScope::context(), {
MDString::get(SSAScope::context(), "llvm.loop.unroll.count"),
ConstantAsMetadata::get(ConstantInt::get(SSAScope::context(), APInt(32, unroll_count)))
});
auto md_loop = MDNode::getDistinct(SSAScope::context(), { md_unroll_enable, md_unroll_count });
branch->setMetadata(LLVMContext::MD_loop, md_loop);
}
#endif
SSAScope::builder().SetInsertPoint(loop_basic_block);
}
void SSAForBlock::end_block()
{
SSAScope::builder().CreateBr(if_basic_block);
SSAScope::builder().SetInsertPoint(end_basic_block);
}