From f74b38aa2b13ba253e0835764df1caed5b0ad9ad Mon Sep 17 00:00:00 2001 From: Guillaume Gomez Date: Wed, 20 Nov 2024 14:31:27 +0100 Subject: [PATCH] Reduce integer `Display` implementation size --- core/src/fmt/num.rs | 82 ++++++++++++++++++++++----------------------- 1 file changed, 41 insertions(+), 41 deletions(-) diff --git a/core/src/fmt/num.rs b/core/src/fmt/num.rs index f2d7e0f481e76..01b5d46a8f696 100644 --- a/core/src/fmt/num.rs +++ b/core/src/fmt/num.rs @@ -199,35 +199,45 @@ static DEC_DIGITS_LUT: &[u8; 200] = b"0001020304050607080910111213141516171819\ 8081828384858687888990919293949596979899"; macro_rules! impl_Display { - ($($t:ident $(as $positive:ident)? named $name:ident,)* ; as $u:ident via $conv_fn:ident named $gen_name:ident) => { + ($($signed:ident, $unsigned:ident,)* ; as $u:ident via $conv_fn:ident named $gen_name:ident) => { $( #[stable(feature = "rust1", since = "1.0.0")] - impl fmt::Display for $t { + impl fmt::Display for $unsigned { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - // If it's a signed integer. - $( - let is_nonnegative = *self >= 0; + #[cfg(not(feature = "optimize_for_size"))] + { + self._fmt(true, f) + } + #[cfg(feature = "optimize_for_size")] + { + $gen_name(self.$conv_fn(), true, f) + } + } + } + #[stable(feature = "rust1", since = "1.0.0")] + impl fmt::Display for $signed { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let is_nonnegative = *self >= 0; + + if !is_nonnegative { #[cfg(not(feature = "optimize_for_size"))] { - if !is_nonnegative { - // convert the negative num to positive by summing 1 to its 2s complement - return (!self as $positive).wrapping_add(1)._fmt(false, f); - } + // convert the negative num to positive by summing 1 to its 2s complement + return (!self as $unsigned).wrapping_add(1)._fmt(false, f); } #[cfg(feature = "optimize_for_size")] { - if !is_nonnegative { - // convert the negative num to positive by summing 1 to its 2s complement - return $gen_name((!self.$conv_fn()).wrapping_add(1), false, f); - } + // convert the negative num to positive by summing 1 to its 2s complement + return $gen_name((!self.$conv_fn()).wrapping_add(1), false, f); } - )? + } + // If it's a positive integer. #[cfg(not(feature = "optimize_for_size"))] { - self._fmt(true, f) + (*self as $unsigned)._fmt(true, f) } #[cfg(feature = "optimize_for_size")] { @@ -237,9 +247,9 @@ macro_rules! impl_Display { } #[cfg(not(feature = "optimize_for_size"))] - impl $t { - fn _fmt(mut self: $t, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::Result { - const SIZE: usize = $t::MAX.ilog(10) as usize + 1; + impl $unsigned { + fn _fmt(mut self, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::Result { + const SIZE: usize = $unsigned::MAX.ilog(10) as usize + 1; let mut buf = [MaybeUninit::::uninit(); SIZE]; let mut curr = SIZE; let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf); @@ -258,7 +268,7 @@ macro_rules! impl_Display { #[allow(unused_comparisons)] // This block will be removed for smaller types at compile time and in the worst // case, it will prevent to have the `10000` literal to overflow for `i8` and `u8`. - if core::mem::size_of::<$t>() >= 2 { + if core::mem::size_of::<$unsigned>() >= 2 { // eagerly decode 4 characters at a time while self >= 10000 { let rem = (self % 10000) as usize; @@ -312,8 +322,8 @@ macro_rules! impl_Display { #[cfg(feature = "optimize_for_size")] fn $gen_name(mut n: $u, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::Result { - // 2^128 is about 3*10^38, so 39 gives an extra byte of space - let mut buf = [MaybeUninit::::uninit(); 39]; + const SIZE: usize = $u::MAX.ilog(10) as usize + 1; + let mut buf = [MaybeUninit::::uninit(); SIZE]; let mut curr = buf.len(); let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf); @@ -523,16 +533,11 @@ impl_Debug! { mod imp { use super::*; impl_Display!( - i8 as u8 named fmt_i8, - u8 named fmt_u8, - i16 as u16 named fmt_i16, - u16 named fmt_u16, - i32 as u32 named fmt_i32, - u32 named fmt_u32, - i64 as u64 named fmt_i64, - u64 named fmt_u64, - isize as usize named fmt_isize, - usize named fmt_usize, + i8, u8, + i16, u16, + i32, u32, + i64, u64, + isize, usize, ; as u64 via to_u64 named fmt_u64 ); impl_Exp!( @@ -545,18 +550,13 @@ mod imp { mod imp { use super::*; impl_Display!( - i8 as u8 named fmt_i8, - u8 named fmt_u8, - i16 as u16 named fmt_i16, - u16 named fmt_u16, - i32 as u32 named fmt_i32, - u32 named fmt_u32, - isize as usize named fmt_isize, - usize named fmt_usize, + i8, u8, + i16, u16, + i32, u32, + isize, usize, ; as u32 via to_u32 named fmt_u32); impl_Display!( - i64 as u64 named fmt_i64, - u64 named fmt_u64, + i64, u64, ; as u64 via to_u64 named fmt_u64); impl_Exp!(i8, u8, i16, u16, i32, u32, isize, usize as u32 via to_u32 named exp_u32);