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author | Andrew Waterman <andrew@sifive.com> | 2019-03-05 15:10:43 -0800 |
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committer | Andrew Waterman <andrew@sifive.com> | 2019-03-05 15:10:59 -0800 |
commit | 013ba6dc8a504ee4ad7bee42554fecaef7ba797f (patch) | |
tree | b27185c044332808ecab31e5134ab803c188f493 /src | |
parent | e8e0b4c440753f38997d9e9bafe1268f897ecd37 (diff) | |
download | riscv-isa-manual-013ba6dc8a504ee4ad7bee42554fecaef7ba797f.zip riscv-isa-manual-013ba6dc8a504ee4ad7bee42554fecaef7ba797f.tar.gz riscv-isa-manual-013ba6dc8a504ee4ad7bee42554fecaef7ba797f.tar.bz2 |
Embellish descriptions in Q chapter
Diffstat (limited to 'src')
-rw-r--r-- | src/q.tex | 14 |
1 files changed, 10 insertions, 4 deletions
@@ -4,8 +4,9 @@ This chapter describes the Q standard extension for 128-bit quad-precision binary floating-point instructions compliant with the IEEE 754-2008 arithmetic standard. The quad-precision binary -floating-point instruction-set extension is named ``Q'', and requires -RV64IFD. The floating-point registers are now extended to hold either +floating-point instruction-set extension is named ``Q''; it depends +on the double-precision floating-point extension D. +The floating-point registers are now extended to hold either a single, double, or quad-precision floating-point value (FLEN=128). The NaN-boxing scheme described in Section~\ref{nanboxing} is now extended recursively to allow a single-precision value to be NaN-boxed @@ -186,8 +187,13 @@ FCVT.Q.{\em int} & Q & W[U]/L[U] & src & RM & dest & OP-FP \\ \end{tabular} \end{center} -New floating-point to floating-point conversion instructions FCVT.S.Q, -FCVT.Q.S, FCVT.D.Q, FCVT.Q.D are added. +New floating-point-to-floating-point conversion instructions are added. These +instructions are defined analogously to the double-precision floating-point-to-floating-point +conversion instructions. FCVT.S.Q or FCVT.Q.S converts a quad-precision +floating-point number to a single-precision floating-point number, or +vice-versa, respectively. FCVT.D.Q or FCVT.Q.D converts a quad-precision +floating-point number to a double-precision floating-point number, or +vice-versa, respectively. \vspace{-0.2in} \begin{center} |