From 02209d8a5f7b26d503ca5c3a73219fa8839243f6 Mon Sep 17 00:00:00 2001
From: Marc Tiehuis <marc@tiehu.is>
Date: Tue, 3 May 2022 19:04:16 +1200
Subject: [PATCH] fix aarch64 f16 nan parse test failure

---
 lib/std/fmt/parse_float/parse.zig | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/lib/std/fmt/parse_float/parse.zig b/lib/std/fmt/parse_float/parse.zig
index 104052c3b3..3b757c7c41 100644
--- a/lib/std/fmt/parse_float/parse.zig
+++ b/lib/std/fmt/parse_float/parse.zig
@@ -240,14 +240,15 @@ pub fn parseNumber(comptime T: type, s: []const u8, negative: bool) ?Number(T) {
     return null;
 }
 
-fn parsePartialInfOrNan(comptime T: type, s: []const u8, n: *usize) ?T {
+fn parsePartialInfOrNan(comptime T: type, s: []const u8, negative: bool, n: *usize) ?T {
     // inf/infinity; infxxx should only consume inf.
     if (std.ascii.startsWithIgnoreCase(s, "inf")) {
         n.* = 3;
         if (std.ascii.startsWithIgnoreCase(s[3..], "inity")) {
             n.* = 8;
         }
-        return std.math.inf(T);
+
+        return if (!negative) std.math.inf(T) else -std.math.inf(T);
     }
 
     if (std.ascii.startsWithIgnoreCase(s, "nan")) {
@@ -260,11 +261,8 @@ fn parsePartialInfOrNan(comptime T: type, s: []const u8, n: *usize) ?T {
 
 pub fn parseInfOrNan(comptime T: type, s: []const u8, negative: bool) ?T {
     var consumed: usize = 0;
-    if (parsePartialInfOrNan(T, s, &consumed)) |special| {
+    if (parsePartialInfOrNan(T, s, negative, &consumed)) |special| {
         if (s.len == consumed) {
-            if (negative) {
-                return -1 * special;
-            }
             return special;
         }
     }