Porting VAX MACRO Code to OpenVMS Alpha

Updated: 11 December 1998

Porting VAX MACRO Code to OpenVMS Alpha

Contents

Index

Chapter 4

4 Improving the Performance of Ported Code

     4.1     Aligning Data

         4.1.1         Alignment Assumptions

         4.1.2         Directives and Qualifier for Changing Alignment Assumptions

         4.1.3         Precedence of Alignment Controls

         4.1.4         Recommendations for Aligning Data

     4.2     Code Flow and Branch Prediction

         4.2.1         Default Code Flow and Branch Prediction

         4.2.2         Changing the Compiler's Branch Prediction

         4.2.3         How to Use .BRANCH_LIKELY

         4.2.4         How to Use .BRANCH_UNLIKELY

         4.2.5         Forward Jumps into Loops

     4.3     Code Optimization

         4.3.1         Using the VAXREGS Optimization

     4.4     Common-Based Referencing

         4.4.1         Creating a Prefix File for Common-Based Referencing

Part 2

Part 2 Reference

Appendix A

Appendix A Compiler Qualifiers

    Command 1     MACRO/MIGRATION

Appendix B

Appendix B Compiler Directives

     B.1     Support of VAX MACRO Assembler Directives

     B.2     Compiler Directives

    Command 2     .BRANCH_LIKELY

    Command 3     .BRANCH_UNLIKELY

    Command 4     .CALL_ENTRY

    Command 5     .DEFINE_PAL

    Command 6     .DISABLE

    Command 7     .ENABLE

    Command 8     .EXCEPTION_ENTRY

    Command 9     .GLOBAL_LABEL

    Command 10     .JSB_ENTRY

    Command 11     .JSB32_ENTRY

    Command 12     .LINKAGE_PSECT

    Command 13     .PRESERVE

    Command 14     .SET_REGISTERS

    Command 15     .SYMBOL_ALIGNMENT

Appendix C

Appendix C Compiler Built-Ins

     C.1     Alpha Instruction Built-Ins

     C.2     Alpha PALcode Built-Ins

Appendix D

Appendix D Macros for Porting to OpenVMS Alpha

     D.1     Page-Related Calculations

    Command 16     $BYTES_TO_PAGES

    Command 17     $NEXT_PAGE

    Command 18     $PAGES_TO_BYTES

    Command 19     $PREVIOUS_PAGE

    Command 20     $ROUND_RETADR

    Command 21     $START_OF_PAGE

     D.2     Saving and Restoring Alpha Registers

    Command 22     $POP64

    Command 23     $PUSH64

     D.3     Locking Pages into a Working Set

         D.3.1         Image Initialization-Time Lockdown

    Command 24     $LOCK_PAGE_INIT

    Command 25     $LOCKED_PAGE_END

    Command 26     $LOCKED_PAGE_START

         D.3.2         On-the-Fly Lockdown

    Command 27     $LOCK_PAGE

    Command 28     $UNLOCK_PAGE

Index

Index

Tables

3-1 Image Initialization-Time Lockdown

3-2 On-the-Fly Lockdown

3-3 Image Initialization-Time Lockdown with the Same Code

A-1 Compiler Qualifiers

B-1 Operand Descriptors

C-1 Alpha Instruction Built-Ins

C-2 Alpha PALcode Built-Ins

D-1 Shift Values

Chapter 4
4	Improving the Performance of Ported Code
4.1	Aligning Data
4.1.1	Alignment Assumptions
4.1.2	Directives and Qualifier for Changing Alignment Assumptions
4.1.3	Precedence of Alignment Controls
4.1.4	Recommendations for Aligning Data
4.2	Code Flow and Branch Prediction
4.2.1	Default Code Flow and Branch Prediction
4.2.2	Changing the Compiler's Branch Prediction
4.2.3	How to Use .BRANCH_LIKELY
4.2.4	How to Use .BRANCH_UNLIKELY
4.2.5	Forward Jumps into Loops
4.3	Code Optimization
4.3.1	Using the VAXREGS Optimization
4.4	Common-Based Referencing
4.4.1	Creating a Prefix File for Common-Based Referencing
Part 2
Part 2	Reference
Appendix A
Appendix A	Compiler Qualifiers
Command 1	MACRO/MIGRATION
Appendix B
Appendix B	Compiler Directives
B.1	Support of VAX MACRO Assembler Directives
B.2	Compiler Directives
Command 2	.BRANCH_LIKELY
Command 3	.BRANCH_UNLIKELY
Command 4	.CALL_ENTRY
Command 5	.DEFINE_PAL
Command 6	.DISABLE
Command 7	.ENABLE
Command 8	.EXCEPTION_ENTRY
Command 9	.GLOBAL_LABEL
Command 10	.JSB_ENTRY
Command 11	.JSB32_ENTRY
Command 12	.LINKAGE_PSECT
Command 13	.PRESERVE
Command 14	.SET_REGISTERS
Command 15	.SYMBOL_ALIGNMENT
Appendix C
Appendix C	Compiler Built-Ins
C.1	Alpha Instruction Built-Ins
C.2	Alpha PALcode Built-Ins
Appendix D
Appendix D	Macros for Porting to OpenVMS Alpha
D.1	Page-Related Calculations
Command 16	$BYTES_TO_PAGES
Command 17	$NEXT_PAGE
Command 18	$PAGES_TO_BYTES
Command 19	$PREVIOUS_PAGE
Command 20	$ROUND_RETADR
Command 21	$START_OF_PAGE
D.2	Saving and Restoring Alpha Registers
Command 22	$POP64
Command 23	$PUSH64
D.3	Locking Pages into a Working Set
D.3.1	Image Initialization-Time Lockdown
Command 24	$LOCK_PAGE_INIT
Command 25	$LOCKED_PAGE_END
Command 26	$LOCKED_PAGE_START
D.3.2	On-the-Fly Lockdown
Command 27	$LOCK_PAGE
Command 28	$UNLOCK_PAGE
Index
Index
Tables
3-1	Image Initialization-Time Lockdown
3-2	On-the-Fly Lockdown
3-3	Image Initialization-Time Lockdown with the Same Code
A-1	Compiler Qualifiers
B-1	Operand Descriptors
C-1	Alpha Instruction Built-Ins
C-2	Alpha PALcode Built-Ins
D-1	Shift Values

Contents

Index

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