JezK
Edit File: test-fast-dtoa.cc
// Copyright 2006-2008 the V8 project authors. All rights reserved. #include <stdlib.h> #include "v8.h" #include "platform.h" #include "cctest.h" #include "diy-fp.h" #include "double.h" #include "fast-dtoa.h" #include "gay-precision.h" #include "gay-shortest.h" using namespace v8::internal; static const int kBufferSize = 100; // Removes trailing '0' digits. static void TrimRepresentation(Vector<char> representation) { int len = StrLength(representation.start()); int i; for (i = len - 1; i >= 0; --i) { if (representation[i] != '0') break; } representation[i + 1] = '\0'; } TEST(FastDtoaShortestVariousDoubles) { char buffer_container[kBufferSize]; Vector<char> buffer(buffer_container, kBufferSize); int length; int point; int status; double min_double = 5e-324; status = FastDtoa(min_double, FAST_DTOA_SHORTEST, 0, buffer, &length, &point); CHECK(status); CHECK_EQ("5", buffer.start()); CHECK_EQ(-323, point); double max_double = 1.7976931348623157e308; status = FastDtoa(max_double, FAST_DTOA_SHORTEST, 0, buffer, &length, &point); CHECK(status); CHECK_EQ("17976931348623157", buffer.start()); CHECK_EQ(309, point); status = FastDtoa(4294967272.0, FAST_DTOA_SHORTEST, 0, buffer, &length, &point); CHECK(status); CHECK_EQ("4294967272", buffer.start()); CHECK_EQ(10, point); status = FastDtoa(4.1855804968213567e298, FAST_DTOA_SHORTEST, 0, buffer, &length, &point); CHECK(status); CHECK_EQ("4185580496821357", buffer.start()); CHECK_EQ(299, point); status = FastDtoa(5.5626846462680035e-309, FAST_DTOA_SHORTEST, 0, buffer, &length, &point); CHECK(status); CHECK_EQ("5562684646268003", buffer.start()); CHECK_EQ(-308, point); status = FastDtoa(2147483648.0, FAST_DTOA_SHORTEST, 0, buffer, &length, &point); CHECK(status); CHECK_EQ("2147483648", buffer.start()); CHECK_EQ(10, point); status = FastDtoa(3.5844466002796428e+298, FAST_DTOA_SHORTEST, 0, buffer, &length, &point); if (status) { // Not all FastDtoa variants manage to compute this number. CHECK_EQ("35844466002796428", buffer.start()); CHECK_EQ(299, point); } uint64_t smallest_normal64 = V8_2PART_UINT64_C(0x00100000, 00000000); double v = Double(smallest_normal64).value(); status = FastDtoa(v, FAST_DTOA_SHORTEST, 0, buffer, &length, &point); if (status) { CHECK_EQ("22250738585072014", buffer.start()); CHECK_EQ(-307, point); } uint64_t largest_denormal64 = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF); v = Double(largest_denormal64).value(); status = FastDtoa(v, FAST_DTOA_SHORTEST, 0, buffer, &length, &point); if (status) { CHECK_EQ("2225073858507201", buffer.start()); CHECK_EQ(-307, point); } } TEST(FastDtoaPrecisionVariousDoubles) { char buffer_container[kBufferSize]; Vector<char> buffer(buffer_container, kBufferSize); int length; int point; int status; status = FastDtoa(1.0, FAST_DTOA_PRECISION, 3, buffer, &length, &point); CHECK(status); CHECK_GE(3, length); TrimRepresentation(buffer); CHECK_EQ("1", buffer.start()); CHECK_EQ(1, point); status = FastDtoa(1.5, FAST_DTOA_PRECISION, 10, buffer, &length, &point); if (status) { CHECK_GE(10, length); TrimRepresentation(buffer); CHECK_EQ("15", buffer.start()); CHECK_EQ(1, point); } double min_double = 5e-324; status = FastDtoa(min_double, FAST_DTOA_PRECISION, 5, buffer, &length, &point); CHECK(status); CHECK_EQ("49407", buffer.start()); CHECK_EQ(-323, point); double max_double = 1.7976931348623157e308; status = FastDtoa(max_double, FAST_DTOA_PRECISION, 7, buffer, &length, &point); CHECK(status); CHECK_EQ("1797693", buffer.start()); CHECK_EQ(309, point); status = FastDtoa(4294967272.0, FAST_DTOA_PRECISION, 14, buffer, &length, &point); if (status) { CHECK_GE(14, length); TrimRepresentation(buffer); CHECK_EQ("4294967272", buffer.start()); CHECK_EQ(10, point); } status = FastDtoa(4.1855804968213567e298, FAST_DTOA_PRECISION, 17, buffer, &length, &point); CHECK(status); CHECK_EQ("41855804968213567", buffer.start()); CHECK_EQ(299, point); status = FastDtoa(5.5626846462680035e-309, FAST_DTOA_PRECISION, 1, buffer, &length, &point); CHECK(status); CHECK_EQ("6", buffer.start()); CHECK_EQ(-308, point); status = FastDtoa(2147483648.0, FAST_DTOA_PRECISION, 5, buffer, &length, &point); CHECK(status); CHECK_EQ("21475", buffer.start()); CHECK_EQ(10, point); status = FastDtoa(3.5844466002796428e+298, FAST_DTOA_PRECISION, 10, buffer, &length, &point); CHECK(status); CHECK_GE(10, length); TrimRepresentation(buffer); CHECK_EQ("35844466", buffer.start()); CHECK_EQ(299, point); uint64_t smallest_normal64 = V8_2PART_UINT64_C(0x00100000, 00000000); double v = Double(smallest_normal64).value(); status = FastDtoa(v, FAST_DTOA_PRECISION, 17, buffer, &length, &point); CHECK(status); CHECK_EQ("22250738585072014", buffer.start()); CHECK_EQ(-307, point); uint64_t largest_denormal64 = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF); v = Double(largest_denormal64).value(); status = FastDtoa(v, FAST_DTOA_PRECISION, 17, buffer, &length, &point); CHECK(status); CHECK_GE(20, length); TrimRepresentation(buffer); CHECK_EQ("22250738585072009", buffer.start()); CHECK_EQ(-307, point); v = 3.3161339052167390562200598e-237; status = FastDtoa(v, FAST_DTOA_PRECISION, 18, buffer, &length, &point); CHECK(status); CHECK_EQ("331613390521673906", buffer.start()); CHECK_EQ(-236, point); v = 7.9885183916008099497815232e+191; status = FastDtoa(v, FAST_DTOA_PRECISION, 4, buffer, &length, &point); CHECK(status); CHECK_EQ("7989", buffer.start()); CHECK_EQ(192, point); } TEST(FastDtoaGayShortest) { char buffer_container[kBufferSize]; Vector<char> buffer(buffer_container, kBufferSize); bool status; int length; int point; int succeeded = 0; int total = 0; bool needed_max_length = false; Vector<const PrecomputedShortest> precomputed = PrecomputedShortestRepresentations(); for (int i = 0; i < precomputed.length(); ++i) { const PrecomputedShortest current_test = precomputed[i]; total++; double v = current_test.v; status = FastDtoa(v, FAST_DTOA_SHORTEST, 0, buffer, &length, &point); CHECK_GE(kFastDtoaMaximalLength, length); if (!status) continue; if (length == kFastDtoaMaximalLength) needed_max_length = true; succeeded++; CHECK_EQ(current_test.decimal_point, point); CHECK_EQ(current_test.representation, buffer.start()); } CHECK_GT(succeeded*1.0/total, 0.99); CHECK(needed_max_length); } TEST(FastDtoaGayPrecision) { char buffer_container[kBufferSize]; Vector<char> buffer(buffer_container, kBufferSize); bool status; int length; int point; int succeeded = 0; int total = 0; // Count separately for entries with less than 15 requested digits. int succeeded_15 = 0; int total_15 = 0; Vector<const PrecomputedPrecision> precomputed = PrecomputedPrecisionRepresentations(); for (int i = 0; i < precomputed.length(); ++i) { const PrecomputedPrecision current_test = precomputed[i]; double v = current_test.v; int number_digits = current_test.number_digits; total++; if (number_digits <= 15) total_15++; status = FastDtoa(v, FAST_DTOA_PRECISION, number_digits, buffer, &length, &point); CHECK_GE(number_digits, length); if (!status) continue; succeeded++; if (number_digits <= 15) succeeded_15++; TrimRepresentation(buffer); CHECK_EQ(current_test.decimal_point, point); CHECK_EQ(current_test.representation, buffer.start()); } // The precomputed numbers contain many entries with many requested // digits. These have a high failure rate and we therefore expect a lower // success rate than for the shortest representation. CHECK_GT(succeeded*1.0/total, 0.85); // However with less than 15 digits almost the algorithm should almost always // succeed. CHECK_GT(succeeded_15*1.0/total_15, 0.9999); }