Renesas M32R-FPU, Software Manual

Page: 185 / 194

APPENDICES
APPENDICES-27 M32R-FPU Software Manual (Rev.1.01)
(4) When Inexact Operation Exception occurs in Step 1
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If an Inexact Operation occurs due to rounding:
<When EX = 0: IXCT occurs>
Type of R0 Condition FMUL + FADD Operation FMADD Operation
Normalized – R0 = rounded value of Same as left
number, 0, R1*R2 + R0
Infinity
Denormalized DN=0 UIPL occurs, EIT occurs Same as left
number R0 = maintained
DN=1 R0 = rounded value of Same as left
R1*R2
QNaN – R0 = maintained (QNaN) Same as left
SNaN EV=0 IVLD occurs Same as left
R0 = R0 converted to QNaN
EV=1 IVLD occurs, EIT occurs Same as left
R0 = maintained (SNaN)
<When EX = 1: IXCT occurs>
Type of R0 Condition FMUL + FADD Operation FMADD Operation
Normalized – EIT occurs when FMUL is EIT occurs,
number, 0, completed R0 = maintained
Infinity R0 = maintained
Denormalized DN=0 Same as above UIPL occurs,
number EIT occurs
R0 = maintained
DN=0 Same as above EIT occurs
R0 = maintained
QNaN – Same as above Same as above
SNaN EV=0 Same as above IVLD occurs,
EIT occurs
R0 = maintained
EV=1 Same as above Same as above
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When an Inexact Operation occurs due to an OVF at EO = 0:
<When EV = 0: IXCT occurs>
Refer to “(1) Overflow occurs in Step 1 <When EO = 0, EX = 0: OVF and IXCT occur>”.
<When EV = 1: IXCT occurs>
Same results as “
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If an Inexact Operation occurs due to rounding <when EX = 1: IXCT
occurs>”.
APPENDIX 6
Appendix 6 M32R-FPU Specification Supplemental Explanation