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 Assumptions.insert_range(R&: Strings);
46 return Assumptions;
47}
48
49template <typename AttrSite>
50bool addAssumptionsImpl(AttrSite &Site,
51 const DenseSet<StringRef> &Assumptions) {
52 if (Assumptions.empty())
53 return false;
54
55 DenseSet<StringRef> CurAssumptions = getAssumptions(Site);
56
57 if (!set_union(S1&: CurAssumptions, S2: Assumptions))
58 return false;
59
60 LLVMContext &Ctx = Site.getContext();
61 Site.addFnAttr(llvm::Attribute::get(
62 Context&: Ctx, Kind: llvm::AssumptionAttrKey,
63 Val: llvm::join(Begin: CurAssumptions.begin(), End: CurAssumptions.end(), Separator: ",")));
64
65 return true;
66}
67} // namespace
68
69bool llvm::hasAssumption(const Function &F,
70 const KnownAssumptionString &AssumptionStr) {
71 const Attribute &A = F.getFnAttribute(Kind: AssumptionAttrKey);
72 return ::hasAssumption(A, AssumptionStr);
73}
74
75bool llvm::hasAssumption(const CallBase &CB,
76 const KnownAssumptionString &AssumptionStr) {
77 if (Function *F = CB.getCalledFunction())
78 if (hasAssumption(F: *F, AssumptionStr))
79 return true;
80
81 const Attribute &A = CB.getFnAttr(Kind: AssumptionAttrKey);
82 return ::hasAssumption(A, AssumptionStr);
83}
84
85DenseSet<StringRef> llvm::getAssumptions(const Function &F) {
86 const Attribute &A = F.getFnAttribute(Kind: AssumptionAttrKey);
87 return ::getAssumptions(A);
88}
89
90DenseSet<StringRef> llvm::getAssumptions(const CallBase &CB) {
91 const Attribute &A = CB.getFnAttr(Kind: AssumptionAttrKey);
92 return ::getAssumptions(A);
93}
94
95bool llvm::addAssumptions(Function &F, const DenseSet<StringRef> &Assumptions) {
96 return ::addAssumptionsImpl(Site&: F, Assumptions);
97}
98
99bool llvm::addAssumptions(CallBase &CB,
100 const DenseSet<StringRef> &Assumptions) {
101 return ::addAssumptionsImpl(Site&: CB, Assumptions);
102}
103
104StringSet<> llvm::KnownAssumptionStrings({
105 "omp_no_openmp", // OpenMP 5.1
106 "omp_no_openmp_routines", // OpenMP 5.1
107 "omp_no_parallelism", // OpenMP 5.1
108 "omp_no_openmp_constructs", // OpenMP 6.0
109 "ompx_spmd_amenable", // OpenMPOpt extension
110 "ompx_no_call_asm", // OpenMPOpt extension
111 "ompx_aligned_barrier", // OpenMPOpt extension
112});
113