fixed from MR review

Author: hmcty

lib/std/fmt/format_float.zig

@@ -1521,15 +1521,13 @@ fn check(comptime T: type, value: T, comptime expected: []const u8) !void {
     const s = try formatFloat(&buf, value, .{});
     try std.testing.expectEqualStrings(expected, s);
 
-    if (@bitSizeOf(T) != 80) {
-        const o = try std.fmt.parseFloat(T, s);
-        const o_bits: I = @bitCast(o);
+    const o = try std.fmt.parseFloat(T, s);
+    const o_bits: I = @bitCast(o);
 
-        if (std.math.isNan(value)) {
-            try std.testing.expect(std.math.isNan(o));
-        } else {
-            try std.testing.expectEqual(value_bits, o_bits);
-        }
+    if (std.math.isNan(value)) {
+        try std.testing.expect(std.math.isNan(o));
+    } else {
+        try std.testing.expectEqual(value_bits, o_bits);
     }
 }
 

lib/std/fmt/parse_float/FloatInfo.zig

@@ -60,7 +60,7 @@ pub fn from(comptime T: type) Self {
             .max_exponent_fast_path_disguised = 7,
             .max_mantissa_fast_path = 2 << std.math.floatMantissaBits(T),
             // Slow + Eisel-Lemire
-            .mantissa_explicit_bits = std.math.floatMantissaBits(T),
+            .mantissa_explicit_bits = std.math.floatFractionalBits(T),
             .infinite_power = 0x1f,
             // Eisel-Lemire
             .smallest_power_of_ten = -26, // TODO: refine, fails one test
@@ -81,7 +81,7 @@ pub fn from(comptime T: type) Self {
             .max_exponent_fast_path_disguised = 17,
             .max_mantissa_fast_path = 2 << std.math.floatMantissaBits(T),
             // Slow + Eisel-Lemire
-            .mantissa_explicit_bits = std.math.floatMantissaBits(T),
+            .mantissa_explicit_bits = std.math.floatFractionalBits(T),
             .infinite_power = 0xff,
             // Eisel-Lemire
             .smallest_power_of_ten = -65,
@@ -133,7 +133,7 @@ pub fn from(comptime T: type) Self {
             .max_exponent_fast_path_disguised = 82,
             .max_mantissa_fast_path = 2 << std.math.floatMantissaBits(T),
             // Slow + Eisel-Lemire
-            .mantissa_explicit_bits = std.math.floatMantissaBits(T),
+            .mantissa_explicit_bits = std.math.floatFractionalBits(T),
             .infinite_power = 0x7fff,
             // Eisel-Lemire.
             // NOTE: Not yet tested (no f128 eisel-lemire implementation)

lib/std/fmt/parse_float/common.zig

@@ -77,6 +77,8 @@ pub fn isEightDigits(v: u64) bool {
 }
 
 pub fn isDigit(c: u8, comptime base: u8) bool {
+    std.debug.assert(base == 10 or base == 16);
+
     return if (base == 10)
         '0' <= c and c <= '9'
     else