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Diffstat (limited to 'gcc/doc/md.texi')
| -rw-r--r-- | gcc/doc/md.texi | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi index 8e3f8f5..dcb3ee0 100644 --- a/gcc/doc/md.texi +++ b/gcc/doc/md.texi @@ -5331,6 +5331,18 @@ corresponds to the C data type @code{double} and the @code{sqrtf} built-in function uses the mode which corresponds to the C data type @code{float}. +@cindex @code{rsqrt@var{m}2} instruction pattern +@item @samp{rsqrt@var{m}2} +Store the reciprocal of the square root of operand 1 into operand 0. +On most architectures this pattern is only approximate, so either +its C condition or the @code{TARGET_OPTAB_SUPPORTED_P} hook should +check for the appropriate math flags. (Using the C condition is +more direct, but using @code{TARGET_OPTAB_SUPPORTED_P} can be useful +if a target-specific built-in also uses the @samp{rsqrt@var{m}2} +pattern.) + +This pattern is not allowed to @code{FAIL}. + @cindex @code{fmod@var{m}3} instruction pattern @item @samp{fmod@var{m}3} Store the remainder of dividing operand 1 by operand 2 into |