Fast double-to-ascii conversion.

test/cctest/test-grisu3.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 "gay_shortest.h"
 #include "grisu3.h"
 
-#include "test-dtoa.h"
-
 using namespace v8::internal;
 
-TEST(DoubleExtremes) {
+static const int kBufferSize = 100;
+
+TEST(GrisuVariousDoubles) {
   char buffer[kBufferSize];
+  int sign;
   int length;
-  int sign;
   int point;
-  bool status;
+  int status;
+
   double min_double = 5e-324;
   status = grisu3(min_double, buffer, &sign, &length, &point);
   CHECK(status);
   CHECK_EQ(0, sign);
   CHECK_EQ("5", buffer);
   CHECK_EQ(-323, point);
 
   double max_double = 1.7976931348623157e308;
   status = grisu3(max_double, buffer, &sign, &length, &point);
   CHECK(status);
   CHECK_EQ(0, sign);
   CHECK_EQ("17976931348623157", buffer);
   CHECK_EQ(309, point);
-}
 
-
-TEST(DoubleTestFunctions) {
-  char buffer[kBufferSize];
-
-  strncpy(buffer, "12345", kBufferSize);
-  CHECK(IsCorrect(123.45, buffer, 0, 5, 3));
-  strncpy(buffer, "12345", kBufferSize);
-  CHECK(IsCorrect(1.2345, buffer, 0, 5, 1));
-  strncpy(buffer, "12345", kBufferSize);
-  CHECK(!IsCorrect(1.2344, buffer, 0, 5, 1));
-  strncpy(buffer, "12345", kBufferSize);
-  CHECK(!IsCorrect(1.2345, buffer, 0, 5, 2));
-  strncpy(buffer, "12345", kBufferSize);
-  CHECK(!IsCorrect(1.2345, buffer, 0, 4, 1));
-
-  strncpy(buffer, "1234", kBufferSize);
-  CHECK(IsRounded(123.44, buffer, 0, 4, 3));
-  strncpy(buffer, "1234", kBufferSize);
-  CHECK(!IsRounded(123.4500000000001, buffer, 0, 4, 3));
-  strncpy(buffer, "1234", kBufferSize);
-  CHECK(IsRounded(123.44999999, buffer, 0, 4, 3));
-  strncpy(buffer, "1234", kBufferSize);
-  CHECK(IsRounded(123.44999999, buffer, 0, 3, 3));
-
-  strncpy(buffer, "1234567000000000000000000001", kBufferSize);
-  CHECK(IsShortest(123.45, buffer, 0, 5, 3));
-  strncpy(buffer, "1234567000000000000000000001", kBufferSize);
-  CHECK(IsShortest(123.4567, buffer, 0, 7, 3));
-  strncpy(buffer, "1234567000000000000000000001", kBufferSize);
-  CHECK(!IsShortest(123.4567, buffer, 0, strlen(buffer), 3));
-
-  strncpy(buffer, "123456699999999999999999999999999999", kBufferSize);
-  CHECK(!IsShortest(123.4567, buffer, 0, strlen(buffer), 3));
-  strncpy(buffer, "123456699999999999999999999999999999", kBufferSize);
-  CHECK(IsShortest(123.456, buffer, 0, 6, 3));
-}
-
-
-TEST(VariousDoubles) {
-  char buffer[kBufferSize];
-  int sign;
-  int length;
-  int point;
-  int status;
   status = grisu3(4294967272.0, buffer, &sign, &length, &point);
   CHECK(status);
   CHECK_EQ(0, sign);
   CHECK_EQ("4294967272", buffer);
   CHECK_EQ(10, point);
 
   status = grisu3(4.1855804968213567e298, buffer, &sign, &length, &point);
   CHECK(status);
   CHECK_EQ(0, sign);
   CHECK_EQ("4185580496821357", buffer);
@@ skipping 16 matching lines @@
     CHECK_EQ("35844466002796428", buffer);
     CHECK_EQ(0, sign);
     CHECK_EQ(299, point);
   }
 
   uint64_t smallest_normal64 = V8_2PART_UINT64_C(0x00100000, 00000000);
   double v = Double(smallest_normal64).value();
   status = grisu3(v, buffer, &sign, &length, &point);
   if (status) {
     CHECK_EQ(0, sign);
-    CHECK(IsCorrect(v, buffer, 0, length, point));
-    CHECK(IsRounded(v, buffer, 0, length, point));
-    CHECK(IsShortest(v, buffer, 0, length, point));
+    CHECK_EQ("22250738585072014", buffer);
+    CHECK_EQ(-307, point);
   }
 
   uint64_t largest_denormal64 = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF);
   v = Double(largest_denormal64).value();
   status = grisu3(v, buffer, &sign, &length, &point);
   if (status) {
     CHECK_EQ(0, sign);
-    CHECK(IsCorrect(v, buffer, 0, length, point));
-    CHECK(IsRounded(v, buffer, 0, length, point));
-    CHECK(IsShortest(v, buffer, 0, length, point));
+    CHECK_EQ("2225073858507201", buffer);
+    CHECK_EQ(-307, point);
   }
 }
 
 
-static double random_double() {
-  uint64_t double64 = 0;
-  for (int i = 0; i < 8; i++) {
-    double64 <<= 8;
-    double64 += rand() % 256;  // NOLINT
-  }
-  return Double(double64).value();
-}
-
-
-TEST(RandomDoubles) {
-  // For a more thorough testing increase the iteration count.
-  // We also check kGrisu3MaximalLength in here.
-  const int kIterationCount = 100000;
+TEST(GrisuGayShortest) {
+  char buffer[kBufferSize];
+  bool status;
+  int sign;
+  int length;
+  int point;
   int succeeded = 0;
   int total = 0;
-  char buffer[kBufferSize];
-  int length;
-  int sign;
-  int point;
   bool needed_max_length = false;
 
-  for (int i = 0; i < kIterationCount; ++i) {
-    double v = random_double();
-    if (v != v) continue;  // NaN
-    if (v == 0.0) continue;
-    if (v < 0) v = -v;
+  Vector<const GayShortest> precomputed = PrecomputedShortestRepresentations();
+  for (int i = 0; i < precomputed.length(); ++i) {
+    const GayShortest current_test = precomputed[i];
     total++;
-    int status = grisu3(v, buffer, &sign, &length, &point);
+    double v = current_test.v;
+    status = grisu3(v, buffer, &sign, &length, &point);
     CHECK_GE(kGrisu3MaximalLength, length);
+    if (!status) continue;
     if (length == kGrisu3MaximalLength) needed_max_length = true;
-    if (!status) continue;
     succeeded++;
-    CHECK(IsCorrect(v, buffer, 0, length, point));
-    CHECK(IsRounded(v, buffer, 0, length, point));
-    CHECK(IsShortest(v, buffer, 0, length, point));
+    CHECK_EQ(0, sign);  // All precomputed numbers are positive.
+    CHECK_EQ(current_test.decimal_point, point);
+    CHECK_EQ(current_test.representation, buffer);
   }
   CHECK_GT(succeeded*1.0/total, 0.99);
   CHECK(needed_max_length);
 }