feat(avm-mini): call and return opcodes #3704
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@@ -7,6 +7,18 @@ namespace avmMini(256); | |||||
| pol constant clk(i) { i }; | ||||||
| pol constant first = [1] + [0]*; // Used mostly to toggle off the first row consisting | ||||||
| // only in first element of shifted polynomials. | ||||||
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| //===== CONTROL FLOW ========================================================== | ||||||
| // Program counter | ||||||
| pol commit pc; | ||||||
| // Return Pointer | ||||||
| pol commit internal_return_ptr; | ||||||
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| pol commit sel_internal_call; | ||||||
| pol commit sel_internal_return; | ||||||
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| // Halt program execution | ||||||
| pol commit sel_halt; | ||||||
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| //===== TABLE SUBOP-TR ======================================================== | ||||||
| // Boolean selectors for (sub-)operations. Only one operation is activated at | ||||||
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@@ -61,6 +73,11 @@ namespace avmMini(256); | |||||
| sel_op_sub * (1 - sel_op_sub) = 0; | ||||||
| sel_op_mul * (1 - sel_op_mul) = 0; | ||||||
| sel_op_div * (1 - sel_op_div) = 0; | ||||||
| sel_op_div * (1 - sel_op_div) = 0; | ||||||
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| sel_internal_call * (1 - sel_internal_call) = 0; | ||||||
| sel_internal_return * (1 - sel_internal_return) = 0; | ||||||
| sel_halt * (1 - sel_halt) = 0; | ||||||
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| op_err * (1 - op_err) = 0; | ||||||
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@@ -108,4 +125,32 @@ namespace avmMini(256); | |||||
| // Same for the relations related to the error activation: | ||||||
| // (ib * inv - 1 + op_div_err) = 0 && op_err * (1 - inv) = 0 | ||||||
| // This works in combination with op_div_err * (sel_op_div - 1) = 0; | ||||||
| // Drawback is the need to paralllelize the latter. | ||||||
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| //===== CALL_RETURN ======================================================== | ||||||
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There was a problem hiding this comment. do i need to assert the internal call counter does not change between calls? resolved |
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| // The program counter in the next row should be equal to the value loaded from the ia register | ||||||
| // This implies that a load from memory must occur at the same time | ||||||
| // Imply that we must load the jump selector into mema | ||||||
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There was a problem hiding this comment. @Maddiaa0 mema is not a defined term. Did you mean mem_idx_a? |
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| #[return_pointer_increment] | ||||||
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There was a problem hiding this comment. @Maddiaa0 All identifiers for relations in my PR are capitalized. I think it helps with visibility. At least we should agree on using the same notation. |
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| sel_internal_call * ( internal_return_ptr' - ( internal_return_ptr + 1)) = 0; // we increment our jump selector | ||||||
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There was a problem hiding this comment. @Maddiaa0 We might use another term than "jump selector" as the operations are not named JUMP anymore. |
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| sel_internal_call * ( internal_return_ptr - mem_idx_a) = 0; | ||||||
| sel_internal_call * (rwa - 1) = 0; // it must be a write | ||||||
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There was a problem hiding this comment. @Maddiaa0 In the original design, it was meant that there would be a fixed tuple lookup mapping an operation to the corresponding sub-operations included load/store. In this case, relations would not be required. I did not introduce such ones for the arithmetic operations. |
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| sel_internal_call * (mem_op_a - 1) = 0; | ||||||
| sel_internal_call * ((pc + 1) - ia) = 0; | ||||||
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| // We must load the memory pointer to be the internal_return_ptr | ||||||
| #[return_pointer_decrement] | ||||||
| sel_internal_return * ( internal_return_ptr' - ( internal_return_ptr - 1)) = 0; // We decrement out jump selector | ||||||
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Suggested change
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| sel_internal_return * ( (internal_return_ptr - 1) - mem_idx_a) = 0; | ||||||
| sel_internal_return * (pc' - ia) = 0; | ||||||
| sel_internal_return * rwa = 0; | ||||||
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There was a problem hiding this comment. Same remark as above related to the OP-SUBOP table. |
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| sel_internal_return * (mem_op_a - 1) = 0; | ||||||
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| // Program counter must increment if not jumping or returning | ||||||
| #[pc_increment] | ||||||
| (1-first) * (1- sel_halt) * (sel_op_add + sel_op_sub + sel_op_div + sel_op_mul) * (pc' - (pc + 1)) = 0; | ||||||
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There was a problem hiding this comment. @Maddiaa0 Please be consistent with spacing between arithmetic operations:
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There was a problem hiding this comment. @Maddiaa0 Should not we have a constraint on internal_return_ptr value staying constant for all other operations? Otherwise, we could change maliciously the index between to internal_return/call, no? There was a problem hiding this comment. #3704 (comment) yes! I wondered this. I shall implement it |
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| // TODO: we want to set an initial number for the reserved memory of the jump pointer | ||||||
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@Maddiaa0 Did you duplicate this line by mistake?
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good catch!