User`s guide

Contents

Preface ............................................................ ix

Part I Concepts and Methodology

1 Preparing to Port Macro-32 Code

1.1 Features of the MACRO Compiler ............................... 1–1

1.2 Differences Between the Compiler and the Assembler ............... 1–2

1.2.1 Moving Code ............................................ 1–2

1.2.2 Replicating Code . ........................................ 1–3

1.2.3 Removing Code . . ........................................ 1–3

1.2.4 Interleaving Instructions . . . ................................ 1–4

1.2.5 Reserved Operand Faults . . . ................................ 1–4

1.3 Step-by-Step Porting Process for OpenVMS VAX to OpenVMS Alpha or

OpenVMS I64 .............................................. 1–4

1.4 Step-by-Step Porting Process for OpenVMS Alpha to OpenVMS I64 ..... 1–6

1.5 Identifying Nonportable VAX MACRO Coding Practices .............. 1–6

1.6 Establishing Useful Coding Conventions . . . ....................... 1–8

1.7 Maintaining Common Sources . . ................................ 1–8

1.7.1 Including Compiler Directive Deﬁnitions ....................... 1–9

1.7.2 Removing VAX Dependencies ................................ 1–9

1.7.3 Conditionalizing Architecture-Speciﬁc Code ..................... 1–9

2 How the MACRO Compiler Functions on Different Platforms

2.1 Using Alpha and Itanium Registers .............................. 2–1

2.2 Itanium Architecture, Calling Standard, and Register Mapping . ....... 2–2

2.3 Routine Calls and Declarations . ................................ 2–4

2.3.1 Linkage Section (OpenVMS Alpha only) ....................... 2–5

2.3.2 Prologue and Epilogue Code . ................................ 2–5

2.3.3 When to Declare Entry Points ............................... 2–6

2.3.4 Directives for Designating Routine Entry Points . . ............... 2–6

2.3.5 Code Generation for Routine Calls ............................ 2–7

2.4 Declaring CALL Entry Points . . ................................ 2–8

2.4.1 Homed Argument Lists .................................... 2–9

2.4.2 Saving Modiﬁed Registers . . ................................ 2–10

2.4.3 Modifying the Argument Pointer ............................. 2–10

2.4.4 Establishing Dynamic Condition Handlers in Called Routines ...... 2–10

2.5 Declaring JSB Routine Entry Points ............................. 2–11

2.5.1 Differences Between .JSB_ENTRY and .JSB32_ENTRY ........... 2–11

2.5.2 Two General Cases for Using .JSB32_ENTRY ................... 2–12

2.5.3 PUSHR and POPR Instructions Within JSB Routines ............. 2–12

2.5.4 Establishing Dynamic Condition Handlers in JSB Routines . ....... 2–12

2.6 Declaring a Routine’s Register Use .............................. 2–12

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