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dev:crosscompiler:backend_arm:code_generator [2019/07/16 14:11] – [Code Generator for ARM] ursgraf | dev:crosscompiler:backend_arm:code_generator [2019/07/16 14:14] – [Stackframe] ursgraf | ||
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Explanation: | Explanation: | ||
- | LR is saved onto the stack together with the necessary nonvolatile GPRs. Even if method is a leaf method LR must be saved onto the stack because LR serves as a scratch register within a method. Considering the GPR's and EXTRs, all nonvolatile register, which are used within this method, must be saved on the stack. | + | LR is saved onto the stack together with the necessary nonvolatile GPRs. Even if method is a leaf method LR must be saved onto the stack because LR serves as a scratch register within a method. Considering the GPR's and EXTRs, all nonvolatile register, which are used within this method, must be saved on the stack. |
Important: volatile EXTR's must be saved as well if '' | Important: volatile EXTR's must be saved as well if '' | ||
- | The field //local variables// is only used if the number of registers does not suffice and locals must be assigned a slot on the stack. When calling interface methods some temporary space on the stack might be necessary. | + | The field //local variables// is only used if the number of registers does not suffice and locals must be assigned a slot on the stack. When calling interface methods some temporary space on the stack might be necessary |
The field // | The field // | ||
The stack pointer always points to the top of the actual frame. At the top the stack pointer of the caller has to be stored. The back chain pointer is used for the debugger, for exceptions and for the garbage collection. | The stack pointer always points to the top of the actual frame. At the top the stack pointer of the caller has to be stored. The back chain pointer is used for the debugger, for exceptions and for the garbage collection. |