Revision: 4091
Author: [email protected]
Date: Wed Mar 10 13:08:39 2010
Log: Adding missing file.
Review URL: http://codereview.chromium.org/825004
http://code.google.com/p/v8/source/detail?r=4091
Added:
/branches/bleeding_edge/test/cctest/test-dtoa.h
=======================================
--- /dev/null
+++ /branches/bleeding_edge/test/cctest/test-dtoa.h Wed Mar 10 13:08:39 2010
@@ -0,0 +1,91 @@
+static const int kBufferSize = 50;
+
+static double ComposeDouble(char* buffer, int sign, int length, int point)
{
+ int k = point - length;
+ // Integrate exponent into buffer.
+ buffer[length] = 'e';
+ snprintf(&buffer[length+1], kBufferSize - length - 1, "%d", k);
+ double result;
+ sscanf(buffer, "%lf", &result); // NOLINT
+ if (sign) {
+ result *= -1;
+ }
+ return result;
+}
+
+
+static bool IsCorrect(double v, char* buffer, int sign, int length, int
point) {
+ return v == ComposeDouble(buffer, sign, length, point);
+}
+
+
+// The precision of long doubles is not enough to ensure the correct
rounding.
+static bool IsRounded(double v, char* buffer, int sign, int length, int
point) {
+ // We don't test when v is 0.
+ if (v == 0) return true;
+
+ // Simplify things by working with positive numbers.
+ if (v < 0) v = -v;
+ char correct_buffer[100];
+ snprintf(correct_buffer, sizeof(correct_buffer), "%.90e", v);
+ // Get rid of the '.'
+ correct_buffer[1] = correct_buffer[0];
+ char* correct_str = &correct_buffer[1];
+
+ int i = 0;
+ while (true) {
+ if (correct_str[i] == '\0' || correct_str[i] == 'e') {
+ // We should never need all digits.
+ return false;
+ }
+
+ if (buffer[i] == '\0' || buffer[i] == 'e') {
+ // Verify that the remaining correct digits are small enough.
+ if (correct_str[i] < '5') return true;
+ return false; // For simplicity we assume that '5' is rounded up.
+ }
+
+ if (buffer[i] != correct_str[i]) {
+ if (buffer[i] < correct_str[i]) return false;
+ if (buffer[i] - correct_str[i] != 1) return false;
+ if (correct_str[i+1] < '5') return false;
+ return true;
+ }
+
+ // Both characters are equal
+ i++;
+ }
+}
+
+
+static bool IsShortest(double v,
+ char* buffer,
+ int sign,
+ int length,
+ int point) {
+ // Now test if a shorter version would still yield the same result.
+ // Not an exhaustive test, but better than nothing.
+
+ if (length == 1) return true;
+
+ char last_digit = buffer[length - 1];
+
+ if (buffer[length - 1] == '0') return false;
+
+ if (v == ComposeDouble(buffer, sign, length - 1, point)) {
+ return false;
+ }
+
+ bool result = true;
+ if (buffer[length-2] != '9') {
+ buffer[length - 2]++;
+ double changed_value = ComposeDouble(buffer, sign, length-1, point);
+ if (v == changed_value) {
+ printf("ROUNDED FAILED DEBUG: %s\n", buffer);
+ result = false;
+ }
+ buffer[length - 2]--;
+ }
+ buffer[length - 1] = last_digit;
+ return result;
+}
--
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