Skip to content

Commit

Permalink
src: get rid of fp arithmetic in ParseIPv4Host
Browse files Browse the repository at this point in the history
Even though most compiler should not actually emit FPU instructions, it
is unnecessary to use floating-point arithmetic for powers of 2.

Also change some signed counters to unsigned integers.

PR-URL: #46326
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
  • Loading branch information
tniessen authored and juanarbol committed Mar 3, 2023
1 parent 13d8c39 commit 95b3e55
Showing 1 changed file with 7 additions and 12 deletions.
19 changes: 7 additions & 12 deletions src/node_url.cc
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,6 @@
#include "util-inl.h"

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <numeric>
#include <string>
Expand Down Expand Up @@ -477,19 +476,18 @@ void URLHost::ParseIPv4Host(const char* input, size_t length) {
const char* pointer = input;
const char* mark = input;
const char* end = pointer + length;
int parts = 0;
unsigned int parts = 0;
uint32_t val = 0;
uint64_t numbers[4];
int tooBigNumbers = 0;
unsigned int tooBigNumbers = 0;
if (length == 0)
return;

while (pointer <= end) {
const char ch = pointer < end ? pointer[0] : kEOL;
int64_t remaining = end - pointer - 1;
if (ch == '.' || ch == kEOL) {
if (++parts > static_cast<int>(arraysize(numbers)))
return;
if (++parts > arraysize(numbers)) return;
if (pointer == mark)
return;
int64_t n = ParseIPv4Number(mark, pointer);
Expand All @@ -511,18 +509,15 @@ void URLHost::ParseIPv4Host(const char* input, size_t length) {
// If any but the last item in numbers is greater than 255, return failure.
// If the last item in numbers is greater than or equal to
// 256^(5 - the number of items in numbers), return failure.
if (tooBigNumbers > 1 ||
(tooBigNumbers == 1 && numbers[parts - 1] <= 255) ||
numbers[parts - 1] >= pow(256, static_cast<double>(5 - parts))) {
if (tooBigNumbers > 1 || (tooBigNumbers == 1 && numbers[parts - 1] <= 255) ||
numbers[parts - 1] >= UINT64_C(1) << (8 * (5 - parts))) {
return;
}

type_ = HostType::H_IPV4;
val = static_cast<uint32_t>(numbers[parts - 1]);
for (int n = 0; n < parts - 1; n++) {
double b = 3 - n;
val +=
static_cast<uint32_t>(numbers[n]) * static_cast<uint32_t>(pow(256, b));
for (unsigned int n = 0; n < parts - 1; n++) {
val += static_cast<uint32_t>(numbers[n]) << (8 * (3 - n));
}

value_.ipv4 = val;
Expand Down

0 comments on commit 95b3e55

Please sign in to comment.