diff options
Diffstat (limited to 'gcc/doc/rtl.texi')
| -rw-r--r-- | gcc/doc/rtl.texi | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi index 422f6d6d5e7..210e1823dbf 100644 --- a/gcc/doc/rtl.texi +++ b/gcc/doc/rtl.texi @@ -1100,15 +1100,16 @@ this is a double-precision IEEE floating point number. @findex XFmode @item XFmode -``Extended Floating'' mode represents a twelve byte floating point -number. This mode is used for IEEE extended floating point. On some -systems not all bits within these bytes will actually be used. +``Extended Floating'' mode represents an IEEE extended floating point +number. This mode only has 80 meaningful bits (ten bytes). Some +processors require such numbers to be padded to twelve bytes, others +to sixteen; this mode is used for either. @findex TFmode @item TFmode -``Tetra Floating'' mode represents a sixteen byte floating point number. -This gets used for both the 96-bit extended IEEE floating-point types -padded to 128 bits, and true 128-bit extended IEEE floating-point types. +``Tetra Floating'' mode represents a sixteen byte floating point number +all 128 of whose bits are meaningful. One common use is the +IEEE quad-precision format. @findex CCmode @item CCmode |