diff options
Diffstat (limited to 'src/display/display_sink/imp_x86.rs')
| -rw-r--r-- | src/display/display_sink/imp_x86.rs | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/src/display/display_sink/imp_x86.rs b/src/display/display_sink/imp_x86.rs new file mode 100644 index 0000000..9290c3c --- /dev/null +++ b/src/display/display_sink/imp_x86.rs @@ -0,0 +1,175 @@ +/// append `data` to `buf`, assuming `data` is less than 8 bytes and that `buf` has enough space +/// remaining to hold all bytes in `data`. +/// +/// Safety: callers must ensure that `buf.capacity() - buf.len() >= data.len()`. +#[inline(always)] +pub unsafe fn append_string_lt_8_unchecked(buf: &mut alloc::string::String, data: &str) { + // Safety: we are appending only valid utf8 strings to `self.buf`, as `s` is known to + // be valid utf8 + let buf = unsafe { buf.as_mut_vec() }; + let new_bytes = data.as_bytes(); + + unsafe { + let dest = buf.as_mut_ptr().offset(buf.len() as isize); + let src = new_bytes.as_ptr(); + + let rem = new_bytes.len() as isize; + + // set_len early because there is no way to avoid the following asm!() writing that + // same number of bytes into buf + buf.set_len(buf.len() + new_bytes.len()); + + core::arch::asm!( + "8:", + "cmp {rem:e}, 4", + "jb 9f", + "mov {buf:e}, dword ptr [{src} + {rem} - 4]", + "mov dword ptr [{dest} + {rem} - 4], {buf:e}", + "sub {rem:e}, 4", + "jz 11f", + "9:", + "cmp {rem:e}, 2", + "jb 10f", + "mov {buf:x}, word ptr [{src} + {rem} - 2]", + "mov word ptr [{dest} + {rem} - 2], {buf:x}", + "sub {rem:e}, 2", + "jz 11f", + "10:", + "cmp {rem:e}, 1", + "jb 11f", + "mov {buf:l}, byte ptr [{src} + {rem} - 1]", + "mov byte ptr [{dest} + {rem} - 1], {buf:l}", + "11:", + src = in(reg) src, + dest = in(reg) dest, + rem = inout(reg) rem => _, + buf = out(reg) _, + options(nostack), + ); + } +} + +/// append `data` to `buf`, assuming `data` is less than 16 bytes and that `buf` has enough space +/// remaining to hold all bytes in `data`. +/// +/// Safety: callers must ensure that `buf.capacity() - buf.len() >= data.len()`. +#[inline(always)] +pub unsafe fn append_string_lt_16_unchecked(buf: &mut alloc::string::String, data: &str) { + // Safety: we are appending only valid utf8 strings to `self.buf`, as `s` is known to + // be valid utf8 + let buf = unsafe { buf.as_mut_vec() }; + let new_bytes = data.as_bytes(); + + unsafe { + let dest = buf.as_mut_ptr().offset(buf.len() as isize); + let src = new_bytes.as_ptr(); + + let rem = new_bytes.len() as isize; + + // set_len early because there is no way to avoid the following asm!() writing that + // same number of bytes into buf + buf.set_len(buf.len() + new_bytes.len()); + + core::arch::asm!( + "7:", + "cmp {rem:e}, 8", + "jb 8f", + "mov {buf:r}, qword ptr [{src} + {rem} - 8]", + "mov qword ptr [{dest} + {rem} - 8], {buf:r}", + "sub {rem:e}, 8", + "jz 11f", + "8:", + "cmp {rem:e}, 4", + "jb 9f", + "mov {buf:e}, dword ptr [{src} + {rem} - 4]", + "mov dword ptr [{dest} + {rem} - 4], {buf:e}", + "sub {rem:e}, 4", + "jz 11f", + "9:", + "cmp {rem:e}, 2", + "jb 10f", + "mov {buf:x}, word ptr [{src} + {rem} - 2]", + "mov word ptr [{dest} + {rem} - 2], {buf:x}", + "sub {rem:e}, 2", + "jz 11f", + "10:", + "cmp {rem:e}, 1", + "jb 11f", + "mov {buf:l}, byte ptr [{src} + {rem} - 1]", + "mov byte ptr [{dest} + {rem} - 1], {buf:l}", + "11:", + src = in(reg) src, + dest = in(reg) dest, + rem = inout(reg) rem => _, + buf = out(reg) _, + options(nostack), + ); + } +} + +/// append `data` to `buf`, assuming `data` is less than 32 bytes and that `buf` has enough space +/// remaining to hold all bytes in `data`. +/// +/// Safety: callers must ensure that `buf.capacity() - buf.len() >= data.len()`. +#[inline(always)] +pub unsafe fn append_string_lt_32_unchecked(buf: &mut alloc::string::String, data: &str) { + // Safety: we are appending only valid utf8 strings to `self.buf`, as `s` is known to + // be valid utf8 + let buf = unsafe { buf.as_mut_vec() }; + let new_bytes = data.as_bytes(); + + unsafe { + let dest = buf.as_mut_ptr().offset(buf.len() as isize); + let src = new_bytes.as_ptr(); + + let rem = new_bytes.len() as isize; + + // set_len early because there is no way to avoid the following asm!() writing that + // same number of bytes into buf + buf.set_len(buf.len() + new_bytes.len()); + + core::arch::asm!( + "6:", + "cmp {rem:e}, 16", + "jb 7f", + "mov {buf:r}, qword ptr [{src} + {rem} - 16]", + "mov qword ptr [{dest} + {rem} - 16], {buf:r}", + "mov {buf:r}, qword ptr [{src} + {rem} - 8]", + "mov qword ptr [{dest} + {rem} - 8], {buf:r}", + "sub {rem:e}, 16", + "jz 11f", + "7:", + "cmp {rem:e}, 8", + "jb 8f", + "mov {buf:r}, qword ptr [{src} + {rem} - 8]", + "mov qword ptr [{dest} + {rem} - 8], {buf:r}", + "sub {rem:e}, 8", + "jz 11f", + "8:", + "cmp {rem:e}, 4", + "jb 9f", + "mov {buf:e}, dword ptr [{src} + {rem} - 4]", + "mov dword ptr [{dest} + {rem} - 4], {buf:e}", + "sub {rem:e}, 4", + "jz 11f", + "9:", + "cmp {rem:e}, 2", + "jb 10f", + "mov {buf:x}, word ptr [{src} + {rem} - 2]", + "mov word ptr [{dest} + {rem} - 2], {buf:x}", + "sub {rem:e}, 2", + "jz 11f", + "10:", + "cmp {rem:e}, 1", + "jb 11f", + "mov {buf:l}, byte ptr [{src} + {rem} - 1]", + "mov byte ptr [{dest} + {rem} - 1], {buf:l}", + "11:", + src = in(reg) src, + dest = in(reg) dest, + rem = inout(reg) rem => _, + buf = out(reg) _, + options(nostack), + ); + } +} |