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xiv
MPC7400 RISC Microprocessor Users Manual
CONTENTS
Paragraph
Number
Title
Page
Number
6.4.5
6.4.5.1
6.4.5.2
6.4.6
6.4.7
6.4.7.1
6.4.7.2
6.4.8
6.4.8.1
6.4.8.2
6.4.8.2.1
6.4.8.2.2
6.4.8.2.3
6.5
6.5.1
6.5.2
6.6
6.6.1
6.6.1.1
6.6.1.2
6.6.1.3
6.7
Load/Store Unit Execution Timing............................................................... 6-30
Effect of Operand Placement on Performance ......................................... 6-30
Integer Store Gathering............................................................................. 6-31
System Register Unit Execution Timing...................................................... 6-32
AltiVec Instructions Executed by the LSU................................................... 6-32
LRU Instructions ...................................................................................... 6-32
Transient Instructions ............................................................................... 6-32
AltiVec Instructions...................................................................................... 6-33
AltiVec Permute Unit (VPU) Execution Timing...................................... 6-33
AltiVec Arithmetic Logical Unit (VALU) Execution Timing................. 6-33
Vector Simple Integer Unit (VSIU) Execution Timing........................ 6-33
Vector Complex Integer Unit (VCIU) Execution Timing.................... 6-33
Vector Floating-Point Unit (VFPU) Execution Timing....................... 6-33
Memory Performance Considerations.............................................................. 6-35
Caching and Memory Coherency................................................................. 6-35
Effect of TLB Miss on Performance............................................................. 6-36
Instruction Scheduling Guidelines.................................................................... 6-37
Branch, Dispatch, and Completion Unit Resource Requirements................ 6-38
Branch Resolution Resource Requirements ............................................. 6-38
Dispatch Unit Resource Requirements..................................................... 6-38
Completion Unit Resource Requirements................................................ 6-39
Instruction Latency Summary........................................................................... 6-39
Chapter 7
The AltiVec Technology Implementation
7.1
7.1.1
7.1.1.1
7.1.1.2
7.1.1.3
7.1.1.4
7.1.1.5
7.1.2
7.1.2.1
7.1.2.2
7.1.2.3
7.1.2.4
7.1.2.4.1
AltiVec Technology and the Programming Model............................................. 7-1
Register Set..................................................................................................... 7-2
Changes to the Condition Register............................................................. 7-2
Addition to the Machine State Register...................................................... 7-2
Vector Registers (VRs)............................................................................... 7-2
Vector Status and Control Register (VSCR).............................................. 7-2
Vector Save/Restore Register (VRSAVE) ................................................. 7-4
AltiVec Instruction Set ................................................................................... 7-4
LRU Instructions ........................................................................................ 7-5
Transient Instructions ................................................................................. 7-5
Data Stream Touch Instructions ................................................................. 7-6
Stream Engine Tags.................................................................................... 7-7
Speculative Execution and Pipeline Stalls for
Data Stream Instructions ........................................................................ 7-7
Static/Transient Data Stream Touch Instructions....................................... 7-8
Relationship with the sync/tblsync Instructions..................................... 7-8
7.1.2.5
7.1.2.5.1