diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/doc/md.texi | 5 |
2 files changed, 9 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a9f5350..7637d26 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2014-07-04 Tom de Vries <tom@codesourcery.com> + * doc/md.texi (@subsection Constraint Modifier Characters): Clarify + combination of earlyclobber and read/write modifiers. + +2014-07-04 Tom de Vries <tom@codesourcery.com> + * config/aarch64/aarch64-simd.md (define_insn "vec_unpack_trunc_<mode>"): Fix constraint. diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi index 539865e..fde67d7 100644 --- a/gcc/doc/md.texi +++ b/gcc/doc/md.texi @@ -1582,7 +1582,10 @@ alternatives of this form often allows GCC to produce better code when only some of the inputs can be affected by the earlyclobber. See, for example, the @samp{mulsi3} insn of the ARM@. -@samp{&} does not obviate the need to write @samp{=}. +Furthermore, if the @dfn{earlyclobber} operand is also read/write operand, then +that operand is modified only after it's used. + +@samp{&} does not obviate the need to write @samp{=} or @samp{+}. @cindex @samp{%} in constraint @item % |