diff options
Diffstat (limited to 'gcc/doc/rtl.texi')
| -rw-r--r-- | gcc/doc/rtl.texi | 29 |
1 files changed, 26 insertions, 3 deletions
diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi index 5b61409..6963950 100644 --- a/gcc/doc/rtl.texi +++ b/gcc/doc/rtl.texi @@ -1156,6 +1156,20 @@ bits but small enough to fit within twice that number of bits (GCC does not provide a mechanism to represent even larger constants). In the latter case, @var{m} will be @code{VOIDmode}. +@findex const_vector +@item (const_vector:@var{m} [@var{x0} @var{x1} @dots{}]) +Represents a vector constant. The square brackets stand for the vector +containing the constant elements. @var{x0}, @var{x1} and so on are +the @code{const_int} or @code{const_double} elements. + +The number of units in a @code{const_vector} is obtained with the macro +@code{CONST_VECTOR_NUNITS} as in @code{CONST_VECTOR_NUNITS (@var{v})}. + +Individual elements in a vector constant are accessed with the macro +@code{CONST_VECTOR_ELT} as in @code{CONST_VECTOR_ELT (@var{v}, @var{n}) +where @var{v} is the vector constant and @var{n} is the element +desired. + @findex CONST_DOUBLE_MEM @findex CONST_DOUBLE_CHAIN @var{addr} is used to contain the @code{mem} expression that corresponds @@ -1185,10 +1199,14 @@ the precise bit pattern used by the target machine, use the macro @findex CONST2_RTX The macro @code{CONST0_RTX (@var{mode})} refers to an expression with value 0 in mode @var{mode}. If mode @var{mode} is of mode class -@code{MODE_INT}, it returns @code{const0_rtx}. Otherwise, it returns a -@code{CONST_DOUBLE} expression in mode @var{mode}. Similarly, the macro +@code{MODE_INT}, it returns @code{const0_rtx}. If mode @var{mode} is of +mode class @code{MODE_FLOAT}, it returns a @code{CONST_DOUBLE} +expression in mode @var{mode}. Otherwise, it returns a +@code{CONST_VECTOR} expression in mode @var{mode}. Similarly, the macro @code{CONST1_RTX (@var{mode})} refers to an expression with value 1 in -mode @var{mode} and similarly for @code{CONST2_RTX}. +mode @var{mode} and similarly for @code{CONST2_RTX}. The +@code{CONST1_RTX} and @code{CONST2_RTX} macros are undefined +for vector modes. @findex const_string @item (const_string @var{str}) @@ -3331,6 +3349,11 @@ There is only one @code{cc0} expression. There is only one @code{const_double} expression with value 0 for each floating point mode. Likewise for values 1 and 2. +@cindex @code{const_vector}, RTL sharing +@item +There is only one @code{const_vector} expression with value 0 for +each vector mode, be it an integer or a double constant vector. + @cindex @code{label_ref}, RTL sharing @cindex @code{scratch}, RTL sharing @item |