1 //===- DemandedBitsTest.cpp - DemandedBits tests --------------------------===//
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 #include "llvm/Analysis/DemandedBits.h"
10 #include "../Support/KnownBitsTest.h"
11 #include "llvm/Support/KnownBits.h"
12 #include "gtest/gtest.h"
13
14 using namespace llvm;
15
16 namespace {
17
18 template <typename Fn1, typename Fn2>
TestBinOpExhaustive(Fn1 PropagateFn,Fn2 EvalFn)19 static void TestBinOpExhaustive(Fn1 PropagateFn, Fn2 EvalFn) {
20 unsigned Bits = 4;
21 unsigned Max = 1 << Bits;
22 ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
23 ForeachKnownBits(Bits, [&](const KnownBits &Known2) {
24 for (unsigned AOut_ = 0; AOut_ < Max; AOut_++) {
25 APInt AOut(Bits, AOut_);
26 APInt AB1 = PropagateFn(0, AOut, Known1, Known2);
27 APInt AB2 = PropagateFn(1, AOut, Known1, Known2);
28 {
29 // If the propagator claims that certain known bits
30 // didn't matter, check it doesn't change its mind
31 // when they become unknown.
32 KnownBits Known1Redacted;
33 KnownBits Known2Redacted;
34 Known1Redacted.Zero = Known1.Zero & AB1;
35 Known1Redacted.One = Known1.One & AB1;
36 Known2Redacted.Zero = Known2.Zero & AB2;
37 Known2Redacted.One = Known2.One & AB2;
38
39 APInt AB1R = PropagateFn(0, AOut, Known1Redacted, Known2Redacted);
40 APInt AB2R = PropagateFn(1, AOut, Known1Redacted, Known2Redacted);
41 EXPECT_EQ(AB1, AB1R);
42 EXPECT_EQ(AB2, AB2R);
43 }
44 ForeachNumInKnownBits(Known1, [&](APInt Value1) {
45 ForeachNumInKnownBits(Known2, [&](APInt Value2) {
46 APInt ReferenceResult = EvalFn((Value1 & AB1), (Value2 & AB2));
47 APInt Result = EvalFn(Value1, Value2);
48 EXPECT_EQ(Result & AOut, ReferenceResult & AOut);
49 });
50 });
51 }
52 });
53 });
54 }
55
TEST(DemandedBitsTest,Add)56 TEST(DemandedBitsTest, Add) {
57 TestBinOpExhaustive(DemandedBits::determineLiveOperandBitsAdd,
58 [](APInt N1, APInt N2) -> APInt { return N1 + N2; });
59 }
60
TEST(DemandedBitsTest,Sub)61 TEST(DemandedBitsTest, Sub) {
62 TestBinOpExhaustive(DemandedBits::determineLiveOperandBitsSub,
63 [](APInt N1, APInt N2) -> APInt { return N1 - N2; });
64 }
65
66 } // anonymous namespace
67