1 /*========================== begin_copyright_notice ============================
2
3 Copyright (C) 2017-2021 Intel Corporation
4
5 SPDX-License-Identifier: MIT
6
7 ============================= end_copyright_notice ===========================*/
8
9 #include "Compiler/IGCPassSupport.h"
10 #include "common/LLVMWarningsPush.hpp"
11 #include "llvm/IR/InstIterator.h"
12 #include "common/LLVMWarningsPop.hpp"
13 #include "GenISAIntrinsics/GenIntrinsicInst.h"
14 #include "Compiler/CodeGenPublicEnums.h"
15 #include "Compiler/CISACodeGen/helper.h"
16
17 #include <llvm/IR/PassManager.h>
18
19 using namespace IGC;
20 using namespace llvm;
21
22 class RemoveNonPositionOutput : public llvm::FunctionPass
23 {
24 public:
25 static char ID;
26
27 RemoveNonPositionOutput();
28
~RemoveNonPositionOutput()29 ~RemoveNonPositionOutput() {}
30
getAnalysisUsage(llvm::AnalysisUsage & AU) const31 virtual void getAnalysisUsage(llvm::AnalysisUsage& AU) const override
32 {
33 AU.setPreservesCFG();
34 }
35
36 virtual bool runOnFunction(llvm::Function& F) override;
37
getPassName() const38 virtual llvm::StringRef getPassName() const override
39 {
40 return "remove non-position output in vertex shader";
41 }
42 };
43
createRemoveNonPositionOutputPass()44 llvm::FunctionPass* createRemoveNonPositionOutputPass()
45 {
46 return new RemoveNonPositionOutput();
47 }
48
49 // Register pass to igc-opt
50 #define PASS_FLAG_POSH "igc-remove-nonposition-output"
51 #define PASS_DESCRIPTION_POSH "Custom Pass for Position-Only Shader"
52 #define PASS_CFG_ONLY_POSH false
53 #define PASS_ANALYSIS_POSH false
54 IGC_INITIALIZE_PASS_BEGIN(RemoveNonPositionOutput, PASS_FLAG_POSH, PASS_DESCRIPTION_POSH, PASS_CFG_ONLY_POSH, PASS_ANALYSIS_POSH)
55 IGC_INITIALIZE_PASS_END(RemoveNonPositionOutput, PASS_FLAG_POSH, PASS_DESCRIPTION_POSH, PASS_CFG_ONLY_POSH, PASS_ANALYSIS_POSH)
56
57 char RemoveNonPositionOutput::ID = 0;
58
RemoveNonPositionOutput()59 RemoveNonPositionOutput::RemoveNonPositionOutput() : FunctionPass(ID)
60 {
61 initializeRemoveNonPositionOutputPass(*PassRegistry::getPassRegistry());
62 }
63
runOnFunction(Function & F)64 bool RemoveNonPositionOutput::runOnFunction(Function& F)
65 {
66 // Initialize the worklist to all of the instructions ready to process...
67 SmallVector<Instruction*, 10> instructionToRemove;
68 for (inst_iterator II = inst_begin(F), E = inst_end(F); II != E; ++II)
69 {
70 if (GenIntrinsicInst * inst = dyn_cast<GenIntrinsicInst>(&*II))
71 {
72 if (inst->getIntrinsicID() == GenISAIntrinsic::GenISA_OUTPUT)
73 {
74 const ShaderOutputType usage = static_cast<ShaderOutputType>(
75 llvm::cast<llvm::ConstantInt>(inst->getOperand(4))->getZExtValue());
76 if (usage != SHADER_OUTPUT_TYPE_POSITION &&
77 usage != SHADER_OUTPUT_TYPE_POINTWIDTH &&
78 usage != SHADER_OUTPUT_TYPE_VIEWPORT_ARRAY_INDEX &&
79 usage != SHADER_OUTPUT_TYPE_CLIPDISTANCE_LO &&
80 usage != SHADER_OUTPUT_TYPE_CLIPDISTANCE_HI)
81 {
82 instructionToRemove.push_back(inst);
83 }
84 }
85 }
86 }
87 bool changed = false;
88 uint num = instructionToRemove.size();
89 for (uint i = 0; i < num; ++i)
90 {
91 instructionToRemove[i]->eraseFromParent();
92 changed = true;
93 }
94 return changed;
95 }
96