1//===- Assumptions.cpp ------ Collection of helpers for assumptions -------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements helper functions for accessing assumption infomration
10// inside of the "llvm.assume" metadata.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/IR/Assumptions.h"
15#include "llvm/ADT/SetOperations.h"
16#include "llvm/ADT/StringExtras.h"
17#include "llvm/IR/Attributes.h"
18#include "llvm/IR/Function.h"
19#include "llvm/IR/InstrTypes.h"
20
21using namespace llvm;
22
23namespace {
24bool hasAssumption(const Attribute &A,
25 const KnownAssumptionString &AssumptionStr) {
26 if (!A.isValid())
27 return false;
28 assert(A.isStringAttribute() && "Expected a string attribute!");
29
30 SmallVector<StringRef, 8> Strings;
31 A.getValueAsString().split(A&: Strings, Separator: ",");
32
33 return llvm::is_contained(Range&: Strings, Element: AssumptionStr);
34}
35
36DenseSet<StringRef> getAssumptions(const Attribute &A) {
37 if (!A.isValid())
38 return DenseSet<StringRef>();
39 assert(A.isStringAttribute() && "Expected a string attribute!");
40
41 DenseSet<StringRef> Assumptions;
42 SmallVector<StringRef, 8> Strings;
43 A.getValueAsString().split(A&: Strings, Separator: ",");
44
45 for (StringRef Str : Strings)
46 Assumptions.insert(V: Str);
47 return Assumptions;
48}
49
50template <typename AttrSite>
51bool addAssumptionsImpl(AttrSite &Site,
52 const DenseSet<StringRef> &Assumptions) {
53 if (Assumptions.empty())
54 return false;
55
56 DenseSet<StringRef> CurAssumptions = getAssumptions(Site);
57
58 if (!set_union(S1&: CurAssumptions, S2: Assumptions))
59 return false;
60
61 LLVMContext &Ctx = Site.getContext();
62 Site.addFnAttr(llvm::Attribute::get(
63 Context&: Ctx, Kind: llvm::AssumptionAttrKey,
64 Val: llvm::join(Begin: CurAssumptions.begin(), End: CurAssumptions.end(), Separator: ",")));
65
66 return true;
67}
68} // namespace
69
70bool llvm::hasAssumption(const Function &F,
71 const KnownAssumptionString &AssumptionStr) {
72 const Attribute &A = F.getFnAttribute(Kind: AssumptionAttrKey);
73 return ::hasAssumption(A, AssumptionStr);
74}
75
76bool llvm::hasAssumption(const CallBase &CB,
77 const KnownAssumptionString &AssumptionStr) {
78 if (Function *F = CB.getCalledFunction())
79 if (hasAssumption(F: *F, AssumptionStr))
80 return true;
81
82 const Attribute &A = CB.getFnAttr(Kind: AssumptionAttrKey);
83 return ::hasAssumption(A, AssumptionStr);
84}
85
86DenseSet<StringRef> llvm::getAssumptions(const Function &F) {
87 const Attribute &A = F.getFnAttribute(Kind: AssumptionAttrKey);
88 return ::getAssumptions(A);
89}
90
91DenseSet<StringRef> llvm::getAssumptions(const CallBase &CB) {
92 const Attribute &A = CB.getFnAttr(Kind: AssumptionAttrKey);
93 return ::getAssumptions(A);
94}
95
96bool llvm::addAssumptions(Function &F, const DenseSet<StringRef> &Assumptions) {
97 return ::addAssumptionsImpl(Site&: F, Assumptions);
98}
99
100bool llvm::addAssumptions(CallBase &CB,
101 const DenseSet<StringRef> &Assumptions) {
102 return ::addAssumptionsImpl(Site&: CB, Assumptions);
103}
104
105StringSet<> llvm::KnownAssumptionStrings({
106 "omp_no_openmp", // OpenMP 5.1
107 "omp_no_openmp_routines", // OpenMP 5.1
108 "omp_no_parallelism", // OpenMP 5.1
109 "ompx_spmd_amenable", // OpenMPOpt extension
110 "ompx_no_call_asm", // OpenMPOpt extension
111});
112