Renesas M32R-FPU - Manual (Page 186)

APPENDICES
APPENDICES-28 M32R-FPU Software Manual (Rev.1.01)
APPENDIX 6
Appendix 6 M32R-FPU Specification Supplemental Explanation
Appendix 6.2 Rules concerning Generation of QNaN in M32R-FPU
T h e f o l l o w i n g a r e r u l e s c o n c e r n i n g g e n e r a t i n g a Q N a N a s a n o p e r a t i o n r e s u l t .
Instructions that generate NaNs as operation results are FADD, FSUB, FMUL, FDIV,
FMADD, and FMSUB.
[Important Note]
This rule does not apply when the data that is sent to Rdest, the results of the FCMP or
FCMPE comparison, comprise a NaN bit pattern.
<FADD, FSUB, FMUL, FDIV>
Source Operand (Rsrc1, Rsrc2) Rdest
SNaN and QNaN SNaN converted to QNaN (Note 1)
Both SNaN Rsrc2 converted to QNaN (Note 1)
Both QNaN Rscr2
SNaN and actual number SNaN converted to QNaN (Note 1)
QNaN and actual number QNaN
Neither operand is NaN; IVLD occurs H'7FFF FFFF
Note 1: SNaN b9 is set to “1” and the operand is converted to QNaN.
<FMADD, FMSUB>
Source Operand Rdest
Rdest Rsrc1, Rsrc2
Actual number SNaN and QNaN SNaN converted to QNaN (Note 1)
Both SNaN Rsrc2 converted to QNaN (Note 1)
Both QNaN Rscr2
SNaN and actual number SNaN converted to QNaN (Note 1)
QNaN and actual number QNaN
Neither operand is NaN; IVLD occurs H'7FFF FFFF
QNaN Don't care Rdest (maintained)
SNaN Don't care Rdest converted to QNaN (Note 1)
Note 1: SNaN b9 is set to “1” and the operand is converted to QNaN.