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Diffstat (limited to 'gcc/doc/rtl.texi')
| -rw-r--r-- | gcc/doc/rtl.texi | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi index 4f9b990..7c12991 100644 --- a/gcc/doc/rtl.texi +++ b/gcc/doc/rtl.texi @@ -1711,6 +1711,24 @@ machine's or host machine's floating point format. To convert them to the precise bit pattern used by the target machine, use the macro @code{REAL_VALUE_TO_TARGET_DOUBLE} and friends (@pxref{Data Output}). +@findex const_double_zero +The host dependency for the number of integers used to store a double +value makes it problematic for machine descriptions to use expressions +of code @code{const_double} and therefore a syntactic alias has been +provided: + +@smallexample +(const_double_zero) +@end smallexample + +standing for: + +@smallexample +(const_double 0 0 @dots{}) +@end smallexample + +for matching the floating-point value zero, possibly the only useful one. + @findex CONST_WIDE_INT @item (const_wide_int:@var{m} @var{nunits} @var{elt0} @dots{}) This contains an array of @code{HOST_WIDE_INT}s that is large enough |