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3.2 Other Register Conventions

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The following are guaranteed to be preserved across calls:

  • The procedure entry value of SP.

  • The value of DP.

  • Space registers sr3, sr4, sr5, sr6, and sr7.

The following are not necessarily preserved across calls:

  • Floating-point registers fr1, fr2, and fr3.

  • Space registers srO, sr1, and sr2.

  • The Processor Status Word (PSW).

  • The shift amount register (cr 11) or any control registers that are modified by privileged software (e.g. Protection IDs).

  • The state, including internal registers, of any special function units accessed by the architected SPOP operations.



3.1 Register Partitioning

3.3 The Floating-Point Coprocessor Status Register