Fix a grammaro and clarify a comment.

llvm-svn: 72668
This commit is contained in:
Dan Gohman 2009-05-31 17:52:18 +00:00
parent 2299d2ba2f
commit c1c2c68945
1 changed files with 5 additions and 5 deletions

View File

@ -1588,11 +1588,11 @@ def : Pat<(i8 (trunc GR16:$src)),
Requires<[In64BitMode]>;
// h-register tricks.
// For now, be conservative and only the extract if the value is immediately
// zero-extended or stored, which are somewhat common cases. This uses a bunch
// of code to prevent a register requiring a REX prefix from being allocated in
// the same instruction as the h register, as there's currently no way to
// describe this requirement to the register allocator.
// For now, be conservative on x86-64 and use an h-register extract only if the
// value is immediately zero-extended or stored, which are somewhat common
// cases. This uses a bunch of code to prevent a register requiring a REX prefix
// from being allocated in the same instruction as the h register, as there's
// currently no way to describe this requirement to the register allocator.
// h-register extract and zero-extend.
def : Pat<(and (srl_su GR64:$src, (i8 8)), (i64 255)),