diff options
| -rw-r--r-- | src/long_mode/display.rs | 116 |
1 files changed, 78 insertions, 38 deletions
diff --git a/src/long_mode/display.rs b/src/long_mode/display.rs index 2404847..d9f7f9e 100644 --- a/src/long_mode/display.rs +++ b/src/long_mode/display.rs @@ -428,6 +428,14 @@ pub trait DisplaySink: fmt::Write { fn write_u32(&mut self, v: u32) -> Result<(), core::fmt::Error> { write!(self, "{:x}", v) } + /// write a u64 to the output as a base-16 integer. + /// + /// this is provided for optimization opportunities when the formatted integer can be written + /// directly to the sink (rather than formatted to an intermediate buffer and output as a + /// followup step) + fn write_u64(&mut self, v: u64) -> Result<(), core::fmt::Error> { + write!(self, "{:x}", v) + } // fn write_char(&mut self, c: char) -> Result<(), core::fmt::Error>; fn span_enter(&mut self, ty: TokenType); fn span_end(&mut self, ty: TokenType); @@ -830,6 +838,38 @@ impl DisplaySink for alloc::string::String { Ok(()) } + /// write a u64 to the output as a base-16 integer. + /// + /// this is provided for optimization opportunities when the formatted integer can be written + /// directly to the sink (rather than formatted to an intermediate buffer and output as a + /// followup step) + #[inline(always)] + fn write_u64(&mut self, mut v: u64) -> Result<(), core::fmt::Error> { + // we can fairly easily predict the size of a formatted string here with lzcnt, which also + // means we can write directly into the correct offsets of the output string. + let printed_size = (((64 - v.leading_zeros()) >> 2) + 1) as usize; + self.reserve(printed_size); + + unsafe { + let buf = unsafe { self.as_mut_vec() }; + let p = buf.as_mut_ptr(); + let mut curr = printed_size; + loop { + let digit = v % 16; + let c = c_to_hex(digit as u8); + curr -= 1; + p.offset(curr as isize).write(c); + v = v / 16; + if v == 0 { + break; + } + } + + buf.set_len(buf.len() + printed_size); + } + + Ok(()) + } fn span_enter(&mut self, ty: TokenType) {} fn span_end(&mut self, ty: TokenType) {} } @@ -1161,6 +1201,37 @@ impl DisplaySink for BigEnoughString { Ok(()) } + /// write a u64 to the output as a base-16 integer. + /// + /// this is provided for optimization opportunities when the formatted integer can be written + /// directly to the sink (rather than formatted to an intermediate buffer and output as a + /// followup step) + #[inline(always)] + fn write_u64(&mut self, mut v: u64) -> Result<(), core::fmt::Error> { + // we can fairly easily predict the size of a formatted string here with lzcnt, which also + // means we can write directly into the correct offsets of the output string. + let printed_size = (((64 - v.leading_zeros()) >> 2) + 1) as usize; + + unsafe { + let buf = unsafe { self.content.as_mut_vec() }; + let p = buf.as_mut_ptr(); + let mut curr = printed_size; + loop { + let digit = v % 16; + let c = c_to_hex(digit as u8); + curr -= 1; + p.offset(curr as isize).write(c); + v = v / 16; + if v == 0 { + break; + } + } + + buf.set_len(buf.len() + printed_size); + } + + Ok(()) + } fn span_enter(&mut self, ty: TokenType) {} fn span_end(&mut self, ty: TokenType) {} } @@ -1264,24 +1335,7 @@ impl <T: DisplaySink> crate::long_mode::OperandVisitor for ColorizingOperandVisi fn visit_u64(&mut self, imm: u64) -> Result<Self::Ok, Self::Error> { self.f.span_enter(TokenType::Immediate); self.f.write_fixed_size("0x")?; - let mut buf = [MaybeUninit::<u8>::uninit(); 16]; - let mut curr = buf.len(); - let mut v = imm; - loop { - let digit = v % 16; - let c = c_to_hex(digit as u8); - curr -= 1; - buf[curr].write(c); - v = v / 16; - if v == 0 { - break; - } - } - let buf = &buf[curr..]; - let s: &str = unsafe { - core::mem::transmute::<&[MaybeUninit<u8>], &str>(buf) - }; - self.f.write_fixed_size(s)?; + self.f.write_u64(imm)?; self.f.span_end(TokenType::Immediate); Ok(()) } @@ -1293,25 +1347,7 @@ impl <T: DisplaySink> crate::long_mode::OperandVisitor for ColorizingOperandVisi v = -imm as u64; } self.f.write_fixed_size("0x")?; - let mut buf = [core::mem::MaybeUninit::<u8>::uninit(); 64]; - let mut curr = buf.len(); - loop { - let digit = v % 16; - let c = c_to_hex(digit as u8); - curr -= 1; - buf[curr].write(c); - v = v / 16; - if v == 0 { - break; - } - } - let buf = &buf[curr..]; - let s = unsafe { - core::mem::transmute::<&[core::mem::MaybeUninit<u8>], &str>(buf) - }; - - // not actually fixed size, but this should optimize right i hope.. - self.f.write_fixed_size(s)?; + self.f.write_u64(v)?; self.f.span_end(TokenType::Immediate); Ok(()) } @@ -1393,7 +1429,11 @@ impl <T: DisplaySink> crate::long_mode::OperandVisitor for ColorizingOperandVisi self.f.write_char(name[1] as char)?; self.f.write_char(':')?; } - write!(self.f, "[{}]", u64_hex(imm)) + self.f.write_fixed_size("[")?; + self.f.write_fixed_size("0x")?; + self.f.write_u64(imm)?; + self.f.write_fixed_size("]")?; + Ok(()) } fn visit_disp(&mut self, reg: RegSpec, disp: i32) -> Result<Self::Ok, Self::Error> { unsafe { self.f.write_lt_8(MEM_SIZE_STRINGS.get_kinda_unchecked(self.instr.mem_size as usize))? }; |