Floating-Point Multiply-Add/Subtract | Fujitsu Fujitsu SPARC64 V

A.24.1 Floating-Point Multiply-Add/Subtract

SPARC64 V uses IMPDEP2B opcode space to encode the Floating-Point Multiply Add/Subtract instructions.

Opcode	Variation	Size†	Operation

FMADDs	00	01	Multiply-Add Single
FMADDd	00	10	Multiply-Add Double
FMSUBs	01	01	Multiply-Subtract Single
FMSUBd	01	10	Multiply-Subtract Double
FNMADDs	11	01	Negative Multiply-Add Single
FNMADDd	11	10	Negative Multiply-Add Double
FNMSUBs	10	01	Negative Multiply-Subtract Single
FNMSUBd	10	10	Negative Multiply-Subtract Double

†11 is reserved for quad.

Format (5)

10		rd			110111		rs1		rs3			var	size			rs2

31 30	29	25 24			19 18		14 13		9 8			7	6	5 4		0

			Operation				Implementation

Multiply-Add

Multiply-Subtract

Negative Multiply-Subtract

Negative Multiple-Add


rd ←	rs1 ⋅		rs2 +		rs3
rd ←	rs1 ⋅		rs2 −		rs3
rd ←	−	(rs1 ⋅		rs2 −		rs3)
rd ←	−	(rs1 ⋅		rs2 +		rs3)

Assembly Language Syntax

fmadds fregrs1, fregrs2, fregrs3, fregrd

fmaddd fregrs1, fregrs2, fregrs3, fregrd

fmsubs fregrs1, fregrs2, fregrs3, fregrd

fmsubd fregrs1, fregrs2, fregrs3, fregrd

fnmadds fregrs1, fregrs2, fregrs3, fregrd

fnmaddd fregrs1, fregrs2, fregrs3, fregrd

fnmsubs fregrs1, fregrs2, fregrs3, fregrd

fnmsubd fregrs1, fregrs2, fregrs3, fregrd

50 SPARC JPS1 Implementation Supplement: Fujitsu SPARC64 V • Release 1.0, 1 July 2002

Image 61

Fujitsu Fujitsu SPARC64 V manual Floating-Point Multiply-Add/Subtract, Format

Contents

Sparc JPS1 Release 1.0, 1 July Chapter Page Contents Traps Instructions Memory Models Sparc JPS1 Implementation-Dependent TrapsImplementation Dependencies Level-1 Instruction Cache L1I Cache Cache Organization 125 Cache Types Error Handling 149 Error Classification Reset, REDstate, and errorstate 137 Reset TypesFatal Error Asistchgerrorinfo General References UPA Programmer’s ModelIndex Page Navigating the SPARC64 V Implementation Supplement OverviewFonts and Notational Conventions Microarchitecture for High Performance SPARC64 V processorHigh Integration High Reliability and High Integrity Advanced RAS features for the core Advanced RAS features for cachesExtended RAS interface to software Component Overview Asynchronous data error ADE trap for additional errors SX-Unit Execution Unit EU Instruction Control Unit IU1Instruction Control Unit Major Blocks 2Execution Unit Major Blocks Storage Unit Major Blocks Storage Unit SU 4Secondary Cache and External Access Unit Major Blocks Secondary Cache and External Access Unit SXU Instruction dispatch Synonym instruction initiation Definitions Issue-stalling Sync Synonym machine sync Page Architectural Overview Page Please refer to , Data Formats in Commonality Data FormatsPage Nonprivileged Registers Registers FSRnonstandardfp NS Floating-Point State Register FSRFSRversion ver FSRfloating-pointtraptype ftt Tick Tick Register Privileged RegistersTrap State Tstate Register FSR Conformance Ancillary State Registers ASRs Version VER RegisterPerformance Control Register PCR ASR 1shows the values for the VER register for SPARC64 Ovro OVF Registers Referenced Through ASIs Accessibility as described above impl. dep. #250Performance Instrumentation Counter PIC Register ASR Dispatch Control Register DCR ASR VM70 PM70 IU Deferred-Trap Queue Floating-Point Deferred-Trap Queue FQData Watchpoint Registers Instruction Trap Register Instruction Execution InstructionsData Prefetch Instruction Prefetch 1SPARC64 V Syncing Instructions Syncing Instructions 2Instruction Fields Specific to SPARC64 Instruction Formats and FieldsYes Control-Transfer Instructions CTIs Instruction CategoriesCall and Jmpl Instructions Control transfer CTI Implementation-Dependent Instructions Floating-Point Operate FPop Instructions Instruction Fetch Stages Processor Pipeline Brhis Execution Stages Issue Stages Completion Stages Execution Stages for Cache Access Processor States, Normal and Special Traps TrapsPlease refer to .1 of Commonality REDstate ErrorstateREDstate Trap Table REDstate Execution Environment Trap Categories Reset TrapsDeferred Traps Uses of the Trap Categories Trap-Table Entry Addresses Trap ControlPIL Control Trap Type TT Exception and Interrupt Descriptions Trap ProcessingDetails of Supported Traps Sparc JPS1 Implementation-Dependent TrapsPage Sparc V9 Memory Model on Memory Models Overview Mode ControlSparc V9 Memory Model Synchronizing Instruction and Data Memory Release 1.0, 1 July Memory Models Page Table A-1Implementation-Specific Instructions Instruction Definitions SPARC64 V ExtensionsPage Block Load and Store Instructions VIS Invalid Valid Implementation-Dependent Instructions Call and Link Format Floating-Point Multiply-Add/SubtractPage Non-Trapping aexc When FSR.NS = Non-Trapping cexc When FSR.NS =Operation, and inexact, respectively Jump and Link Exceptions fpdisabled Format 3 Ldda Load Quadword, Atomic Physical Memory Barrier Bits in the cmask Field Order Constraints Imposed by mmask Bits Prefetch Data Partial Store VIS01816 Table A-7describes prefetch variants implemented in SPARC64 Read State RegisterTable A-7Prefetch Variants Deprecated Instructions Write State RegisterStore Barrier Page Ieee Std 754-1985 Requirements for Floating-Point Nonstandard ModeTraps Inhibiting Results Fpexceptionother Exception ftt=unfinishedFPop Generates an unfinishedFPop exception Denormalized number, eres is less than zeroUnfinishedFPop Boundary Conditions Table B-2unfinishedFPop Boundary Conditions Pessimistic Zero Pessimistic Overflow Operation Under FSR.NS =Table B-3Conditions for a Pessimistic Zero Table B-4Pessimistic Overflow Conditions UnfinishedFPop4 Floating-Point Exceptional Conditions and Results Yes and op2 Nv, dNaN Nonarithmetic Operations Under FSR.NS =Page Definition of an Implementation Dependency Implementation DependenciesPlease refer to Section C.1 of Commonality Implementation Dependency Categories Hardware CharacteristicsList of Implementation Dependencies Please refer to Section C.2 of Commonality Table C-1SPARC64 V Implementation Dependencies Entering errorstate on implementation-dependent errors Reset trapErrorstate processor state Deferred traps Clean windows trap Data access FPU trapFlush instruction Floating-point underflow detection MMU disabled prefetch behavior SIRenable control flagIMPDEPn instructions Unimplemented LDD trap Unimplemented values for PSTATE.MM Implicit ASI when TLCoherence and atomicity of memory operations Implementation-dependent memory model Table C-1SPARC64 V Implementation Dependencies 7 Table C-1SPARC64 V Implementation Dependencies 8 Table C-1SPARC64 V Implementation Dependencies 9 Table C-1SPARC64 V Implementation Dependencies 10 256 255257 258 Please refer to Appendix D of Commonality Formal Specification of the Memory ModelsPage Instruction65 Opcode MapsPage Virtual Address Translation Memory Management Unit Table F-1Organization of SPARC64 V TLBs Translation Table Entry TTE Release 1.0, 1 July Chapter F Memory Management Unit TSB Pointer Formation TSB OrganizationTSB Pointer Formation TLB miss 64 16-67 Faults and Traps Instructionaccessexception Reset, Disable, and REDstate Behavior Access Modes Supervisor read/write Accessing MMU RegistersInternal Registers and ASI operations Asimcntl Memory Control Register Table F-3MCNTL Field Description 10.4 I/D TLB Data In, Data Access, and Tag Read RegistersRMD JPS1TSBPPage TLB# Table F-4MMU TLB Data Access Address Assignment Kbyte page entry MMU TLB Tag Access Register MMU I/D Synchronous Fault Status Registers I-SFSR, D-SFSR 10.9 I/D Synchronous Fault Status Registers I-SFSR, D-SFSR10.7 I/D TSB Extension Registers TSB Base Registers EID Table F-5I-SFSRBit Description Table F-6describes the field encoding for ISFSR.FT FT60 Error DescriptionSFSRBit Description Table F-8D-SFSRBit Description 1 Isfsr Update Policy Table F-8D-SFSRBit Description 2 SFSRBit Description 3 Table F-9defines the encoding of the FT60 field Dsfsr Update Policy MMU Synchronous Fault Status Register FT Fault Type FieldFresh fault or miss3 MMU Bypass Table F-10DSFSR Update PolicyKbytes Table F-11Bypass Attribute Bits on SPARC64 Automatic TLB Replacement Rule TLB Replacement PolicyRestriction of sTLB Entry Direct Replacement Page Please refer to Appendix G of Commonality Assembly Language SyntaxPage Please refer to Appendix H of Commonality Software ConsiderationsPage Please refer to Appendix I of Commonality Extending the Sparc V9 ArchitecturePage Please refer to Appendix K of Commonality Changes from Sparc V8 to SparcPage Please refer to Appendix J of Commonality Programming with the Memory ModelsPage SPARC64 V ASI Assignments Address Space IdentifiersSPARC64 V ASI Assignments 1 TBD SPARC64 V ASI Assignments 2 SPARC64 V ASI Assignments 3 Special Memory Access ASIs Partial Store ASIs Block Load and Store ASIs Interface Definition Barrier Assist for Parallel ProcessingHigh-Speed Lbsy Read Mechanism High-Speed BST Write Mechanism ASI RegistersLbsy Control Register ASICLBSYR0, ASICLBSYR1 Bstw Busy Status Register Asicbstwbusy Bstw Control Register ASICBSTW0, ASICBSTW1 Barrier State Write ASIBSTW0, ASIBSTW1 Last Barrier Synchronization Status Read ASILBSYR0EF16 Read Write is ignored Cache Types Cache Organization Level-1 Instruction Cache L1I Cache Table M-1L1I Cache Characteristics Table M-3L2 Cache Characteristics Table M-2L1D Cache CharacteristicsLevel-1 Data Cache L1D Cache Level-2 Unified Cache L2 Cache Cache Control/Status Instructions Cache Coherency ProtocolsTable M-4Relationships Between Cache Coherency Protocols Table M-5L2 Cache Moesi States ASIFLUSHL1I Flush Level-1 Instruction Cache Level-2 Cache Control Register ASIL2CTRL 3 L2 Diagnostics Tag ReadTable M-6ASIL2CTRL Register Bits ASIL2DIAGTAGREADREG 4 L2 Diagnostics Tag Read RegistersPage Interrupt Dispatch Interrupt Handling Membar Figure N-2is an example of the interrupt receive flow Interrupt Receive Interrupt-Related ASR Registers Interrupt Global RegistersInterrupt Vector Dispatch Register Interrupt Vector Dispatch Status Register Reset Types Reset, REDstate, and errorstatePower-on Reset POR Appendix contains these sections Externally Initiated Reset XIR Watchdog Reset WDRSoftware-Initiated Reset SIR Figure O-1illustrates the processor state transition diagram REDstate and errorstate PA = 000007FFF000000016 CPU Fatal Error state Processor State after Reset and in REDstateInteger registers Floating Point registers Mask dependent TBA6315 ASI Register State After Reset and in REDstate 1 Table O-2ASR State after Reset and in REDstateCounter Others ASI Register State After Reset and in REDstate 2 ASI Register State After Reset and in REDstate 3 11011 Unchanged Operating Status Register Opsr Firmware Initialization Sequence Hardware Power-On Reset SequenceTo be defined later Page Error Classification Error HandlingFatal Error Urgent Error Errorstate Transition ErrorInstruction-Obstructing Error Urgent Error Independent of Instruction Execution Traps for Urgent Errors Restrainable ErrorCorrectable Error CE, corrected by hardware Registers Related to Error Handling Action and Error ControlFollowing registers are related to the error handling Table P-1Registers Related to Error Handling Table P-2summarizes what happens when an error is detected Summary of Actions Upon Error DetectionTable P-2Action Upon Detection of an Error 1 Ideal specification Table P-2Action Upon Detection of an Error 2Deviation in SPARC64 Table P-2Action Upon Detection of an Error Error Marking for Cacheable Data Error Marking for Cacheable Data Error Table P-3Syndrome for Data Marked for Error Format of Error-Marking DataTable P-4Format of Error-Marked Data Table P-5ERRORMARKID Bit Description Table P-6shows the Errormarkid set by the CPU Table P-7Error Marking on SPARC64 IV and SPARC64 Difference Between Error Marking on SPARC64 IV Value in ASIERRORCONTROL, as defined in Table P-9 Control of Error Action AsierrorcontrolTable P-8 Asieidr Bit Description Rteue Ugehandler Weaked Table P-10Format of Asistchgerrorinfo Bit Description Fatal Error and errorstate Transition Error4C16 Always 0 Eeother Types of errorstate Transition Errors Fatal Error TypesCurrent SPARC64 V implementation Ideal specification not implemented Urgent ErrorTable P-11ASIUGESR Bit Description 1 Table P-11ASIUGESR Bit Description 2 Table P-11ASIUGESR Bit Description 3 Conditions that cause ADE trap Action of asyncdataerror ADE TrapTable P-11ASIUGESR Bit Description 4 Instend Priv Mugedae Mugeiae Mugeiuge Following three sets of registers are updated Set the specific register settingFollowing actions are executed in this order State transition Instruction End-Method at ADE Trap Update of ASIUGESR, as shown in Table P-13Upon completion of a Retry or Done instruction Instend Expected Software Handling of ADE Trap Void ExpectedsoftwarehandlingofADEtrap Data Access Errors Instruction Access ErrorsSee Appendix F, Memory Management Unit, for details Asiasyncfaultstatus Asiafsr Restrainable Errors Ceincomed DGL1$U2$STLB UERAWL2$FILL UedstbetoUERAWL2$INSD Implementation Deviation SPARC64 V sets WAY Contents Syndrome ASIASYNCFAULTADDRU2 register is described in Table P-17 Contents of PABIT423 Expected Software Handling of Restrainable ErrorsPage Register Error Handling Excluding ASRs and ASI Registers Handling of Internal Register ErrorsTable P-18shows error handling for most registers Terminology used in Table P-18is defined as follows Table P-19shows the handling of ASR errors ASR Error HandlingTable P-19ASR Error Handling ADE trap, W Error Protect ASI Register Error HandlingTerminology used in Table P-20is defined as follows Parity Always Error Detect Condition Correction Error Type Table P-20Handling of ASI Register Errors Table P-20shows the handling of ASI register errors Table P-20Handling of ASI Register Errors Handling of a Cache Tag Error Cache Error HandlingSPARC64 V Implementation and the Ideal Specification Error in D1 Cache Tag and I1 Cache Tag Error in U2 Unified Level 2 Cache Tag Handling of a D1 Cache Data Error Handling of an I1 Cache Data ErrorCorrectable Error in D1 Cache Data Marked Uncorrectable Error in D1 Cache Data Correctable Error in U2 Cache Data Handling of a U2 Cache Data ErrorMarked Uncorrectable Error in U2 Cache Data Raw Uncorrectable Error in U2 Cache Data Way Reduction Condition Automatic Way Reduction of I1 Cache, D1 Cache, and U2 CacheI1 Cache Way Reduction U2 Cache Way Reduction D1 Cache Way Reduction Handling of TLB Entry Errors TLB Error HandlingError in TLB Entry Detected on Ldxa Instruction Access Table P-22Error Protection and Detection of TLB Entries Automatic Way Reduction of sTLB Handling of Extended UPA Address Bus Error Handling of Extended UPA Bus Interface ErrorHandling of Extended UPA Data Bus Error STLB Way Reduction Correctable Error on Extended UPA Data Bus UE in Outgoing Data to Extended UPA Data Bus Page Performance Monitor Overview Performance InstrumentationSample Pseudocodes Counter Clear/Set Counter Stop and Read Counter Event Selection and Start Table Q-1Events and Encoding of Performance Monitor Performance Monitor Description Events and Encoding of Performance Monitor Instruction Statistics Counts the committed Floating Multiply-and-Add instructions Instruction Count instructioncounts Trap-Related Statistics Counts the occurrences of Tcc instructions MMU Event CountersCounts the occurrences of instruction uTLB misses Counts the occurrences of data uTLB misses Counts the occurrences of I1 cache misses Cache Event CountersCounts the occurrences of D1 cache misses Counts the total latency of I1 cache misses Counts L2 cache references by demand read access Counts the occurrences of L2 cache miss by demand access Counts the number of Sinvreq packets received UPA Event CountersCounts the number of Scpireq packets received Counts the number of Scpbreq packets received Barrier-Assist ASI Read Count asirdbar Miscellaneous CountersPage Mapping of the CPU’s UPA Port Slave Area UPA Programmer’s ModelTable R-1shows the mapping of the CPU’s UPA port slave area Table R-1CPU’s UPA Port Slave Area Mapping Table R-2UPA PortID Register Fields UPA PortID Register Table R-3UPA Config Register Description UPA Config RegisterUPA PortID Register Fields Upacap UPA Config Register Description UPCCAP2 PconMID UpccapPage SPARC64 V and UltraSPARC-III Differences 1 Summary of Differences between SPARC64 V and UltraSPARC-III UPA Table T-1SPARC64 V and UltraSPARC-III Differences 2 Sfsr Table T-1SPARC64 V and UltraSPARC-III Differences 3Page General References BibliographyPlease refer to Bibliography in Commonality Page Auge IndexPage ASIINTRW133 Page DAE Error detection action155 DGL1$L2$STLB error194 DGL1$U2$STLB error195 Dmmu On Jmpl instruction error53 update during MMU trap90 Persistence38 ECCerror exception46, 153, 155 Statistics monitoring206-207 FSR FQ17 Immu Isfsr Update during MMU trap90 PSO41 RMO41 Lddfa instruction80 OBP Release 1.0, 1 July Chapter Index PTE Release 1.0, 1 July Chapter Index Page TLB Way reduction194 uDTLB10, 85 UITLB10, 85, 90 uncorrectable error152UnimplementedFPop floating-point trap type70