Skip to content

Commit 4667371

Browse files
bongjunjbongjunj
authored
Create targetline.expected
1 parent 082a068 commit 4667371

File tree

1 file changed

+146
-0
lines changed

1 file changed

+146
-0
lines changed

‎tools/targetline.expected‎

Lines changed: 146 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,146 @@
1+
===== Human =====
2+
3+
Your task is to read a code change from a commit and (1) determine the target lines for a directed compiler fuzzer to aim at, and (2) categorize the code change.
4+
5+
First, you determine the target lines.
6+
The source code is from the LLVM project and implements mid-end optimizations in C++, including InstCombine, VectorCombine, GVN, SLPVectorizer, and others.
7+
The directed compiler fuzzer, Optimuzz, generates input programs that satisfy the optimization conditions in the source code to reach the target line and trigger the optimization.
8+
The target line is the line at which the optimization happens after the optimization condition checks and the code transformation is applied.
9+
For example, LLVM InstCombine pass returns a newly created instruction when the optimization is applied,
10+
and the return statement is usually located at the target line.
11+
12+
The code change is typically one of the following three types:
13+
(A) A new optimization is added to the compiler.
14+
```c++
15+
1 Instruction *foldX() {
16+
2 if (A)
17+
3 return Inst();
18+
4 if (C)
19+
5 ...
20+
6 }
21+
```
22+
In the example, a new optimization is added with the optimization condition `A`.
23+
In this case, the target line is 3, where the new instruction `Inst()` is created and returned.
24+
This is because we want to generate input programs that test the optimization `Inst()`.
25+
(B) Optimization condition is weakened.
26+
```c++
27+
1 Instruction *foldX() {
28+
2 if (A)
29+
3 + if (B)
30+
4 return nullptr;
31+
5 if (C)
32+
6 return Opt1();
33+
7 return nullptr;
34+
8 }
35+
```
36+
In the example, the optimization condition `B` is added,
37+
then the optimization condition of `Opt1` is weakened since both `A` and `B` are required to be true to prevent the optimization.
38+
In this case, the target line is 6, where the optimization `Opt1` is applied.
39+
(C) Optimization condition is strengthened.
40+
```c++
41+
1 Instruction *foldX() {
42+
2 if (A)
43+
3 + if (B)
44+
4 return Opt1();
45+
5 if (C)
46+
6 return Opt2();
47+
7 return nullptr;
48+
8 }
49+
```
50+
In the example, the optimization condition `B` is added to the optimization `Opt1`.
51+
In this case, the target lines are 4 and 6, where the optimization `Opt1` is applied and the optimization `Opt2` is applied.
52+
Since the optimization condition of `Opt2` is weakend, we also target the line of `Opt2`.
53+
54+
Second, you categorize the code change.
55+
A code change is typically one of the following three types:
56+
57+
1. A new optimization is added to the compiler. Then you should answer `new`. The code change usually follows the pattern of (A) above.
58+
2. An optimization condition is weakened. Then you should answer `weakened`. The code change usually follows the pattern of (B) above.
59+
3. An optimization condition is strengthened. Then you should answer `strengthened`. The code change usually follows the pattern of (C) above.
60+
61+
The commit message is:
62+
[InstCombine] Preserve the sign bit of NaN in `SimplifyDemandedUseFPClass` (#137287)
63+
64+
Alive2: https://alive2.llvm.org/ce/z/uiUzEf
65+
66+
Closes https://github.com/llvm/llvm-project/issues/137196.
67+
68+
Note: To avoid regression in
69+
`ret_nofpclass_nopositives_copysign_nnan_flag`, the second commit takes
70+
FMF into account.
71+
72+
The code change is as follows:
73+
74+
File: llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
75+
Status: modified
76+
Patch:
77+
```
78+
--- | @@ -1959,9 +1959,11 @@ static Constant *getFPClassConstant(Type *Ty, FPClassTest Mask) {
79+
1959 | }
80+
1960 | }
81+
1961 |
82+
--- | -Value *InstCombinerImpl::SimplifyDemandedUseFPClass(
83+
--- | - Value *V, const FPClassTest DemandedMask, KnownFPClass &Known,
84+
--- | - unsigned Depth, Instruction *CxtI) {
85+
1962 | +Value *InstCombinerImpl::SimplifyDemandedUseFPClass(Value *V,
86+
1963 | + FPClassTest DemandedMask,
87+
1964 | + KnownFPClass &Known,
88+
1965 | + unsigned Depth,
89+
1966 | + Instruction *CxtI) {
90+
1967 | assert(Depth <= MaxAnalysisRecursionDepth && "Limit Search Depth");
91+
1968 | Type *VTy = V->getType();
92+
1969 |
93+
--- | @@ -1985,7 +1987,12 @@ Value *InstCombinerImpl::SimplifyDemandedUseFPClass(
94+
1987 | if (!I->hasOneUse())
95+
1988 | return nullptr;
96+
1989 |
97+
--- | - // TODO: Should account for nofpclass/FastMathFlags on current instruction
98+
1990 | + if (auto *FPOp = dyn_cast<FPMathOperator>(I)) {
99+
1991 | + if (FPOp->hasNoNaNs())
100+
1992 | + DemandedMask &= ~fcNan;
101+
1993 | + if (FPOp->hasNoInfs())
102+
1994 | + DemandedMask &= ~fcInf;
103+
1995 | + }
104+
1996 | switch (I->getOpcode()) {
105+
1997 | case Instruction::FNeg: {
106+
1998 | if (SimplifyDemandedFPClass(I, 0, llvm::fneg(DemandedMask), Known,
107+
--- | @@ -2013,13 +2020,13 @@ Value *InstCombinerImpl::SimplifyDemandedUseFPClass(
108+
2020 | if (SimplifyDemandedFPClass(I, 0, DemandedMaskAnySign, Known, Depth + 1))
109+
2021 | return I;
110+
2022 |
111+
--- | - if ((DemandedMask & fcPositive) == fcNone) {
112+
2023 | + if ((DemandedMask & fcNegative) == DemandedMask) {
113+
2024 | // Roundabout way of replacing with fneg(fabs)
114+
2025 | I->setOperand(1, ConstantFP::get(VTy, -1.0));
115+
2026 | return I;
116+
2027 | }
117+
2028 |
118+
--- | - if ((DemandedMask & fcNegative) == fcNone) {
119+
2029 | + if ((DemandedMask & fcPositive) == DemandedMask) {
120+
2030 | // Roundabout way of replacing with fabs
121+
2031 | I->setOperand(1, ConstantFP::getZero(VTy));
122+
2032 | return I;
123+
124+
```
125+
Now you should answer the following question:
126+
127+
(1) Which target line should Optimuzz aim at? Provide your best suggestion of the target line.
128+
(2) What is the type of the code change? You can answer one of the following four types: `new`, `bug fix`, `weakened`, `removed`.
129+
130+
You answer should follow the JSON format:
131+
```json
132+
{
133+
"target_file": "<target_file>",
134+
"target_line": <target_line>,
135+
"type": "<type>"
136+
}
137+
```
138+
139+
===== AI =====
140+
```json
141+
{
142+
"target_file": "llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp",
143+
"target_line": 2026,
144+
"type": "strengthened"
145+
}
146+
```

0 commit comments

Comments
 (0)