Store Pair of SIMD&FP registers. This instruction stores a pair of SIMD&FP registers to memory. The address used for the store is calculated from a base register value and an immediate offset.
Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.
It has encodings from 3 classes: Post-index , Pre-index and Signed offset
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| opc | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 | imm7 | Rt2 | Rn | Rt | |||||||||||||||||||
| L | |||||||||||||||||||||||||||||||
boolean wback = TRUE; boolean postindex = TRUE;
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| opc | 1 | 0 | 1 | 1 | 0 | 1 | 1 | 0 | imm7 | Rt2 | Rn | Rt | |||||||||||||||||||
| L | |||||||||||||||||||||||||||||||
boolean wback = TRUE; boolean postindex = FALSE;
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| opc | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | imm7 | Rt2 | Rn | Rt | |||||||||||||||||||
| L | |||||||||||||||||||||||||||||||
boolean wback = FALSE; boolean postindex = FALSE;
| <Dt1> |
Is the 64-bit name of the first SIMD&FP register to be transferred, encoded in the "Rt" field. |
| <Dt2> |
Is the 64-bit name of the second SIMD&FP register to be transferred, encoded in the "Rt2" field. |
| <Qt1> |
Is the 128-bit name of the first SIMD&FP register to be transferred, encoded in the "Rt" field. |
| <Qt2> |
Is the 128-bit name of the second SIMD&FP register to be transferred, encoded in the "Rt2" field. |
| <St1> |
Is the 32-bit name of the first SIMD&FP register to be transferred, encoded in the "Rt" field. |
| <St2> |
Is the 32-bit name of the second SIMD&FP register to be transferred, encoded in the "Rt2" field. |
| <Xn|SP> |
Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field. |
integer n = UInt(Rn); integer t = UInt(Rt); integer t2 = UInt(Rt2); AccType acctype = AccType_VEC; MemOp memop = if L == '1' then MemOp_LOAD else MemOp_STORE; if opc == '11' then UNDEFINED; integer scale = 2 + UInt(opc); integer datasize = 8 << scale; bits(64) offset = LSL(SignExtend(imm7, 64), scale); boolean tag_checked = wback || n != 31; boolean rt_unknown = FALSE; if memop == MemOp_LOAD && t == t2 then Constraint c = ConstrainUnpredictable(Unpredictable_LDPOVERLAP); assert c IN {Constraint_UNKNOWN, Constraint_UNDEF, Constraint_NOP}; case c of when Constraint_UNKNOWN rt_unknown = TRUE; // result is UNKNOWN when Constraint_UNDEF UNDEFINED; when Constraint_NOP EndOfInstruction();
CheckFPEnabled64(); bits(64) address; bits(datasize) data1; bits(datasize) data2; constant integer dbytes = datasize DIV 8; if HaveMTE2Ext() then SetTagCheckedInstruction(tag_checked); if n == 31 then CheckSPAlignment(); address = SP[]; else address = X[n]; if ! postindex then address = address + offset; case memop of when MemOp_STORE data1 = V[t]; data2 = V[t2]; Mem[address + 0 , dbytes, acctype] = data1; Mem[address + dbytes, dbytes, acctype] = data2; when MemOp_LOAD data1 = Mem[address + 0 , dbytes, acctype]; data2 = Mem[address + dbytes, dbytes, acctype]; if rt_unknown then data1 = bits(datasize) UNKNOWN; data2 = bits(datasize) UNKNOWN; V[t] = data1; V[t2] = data2; if wback then if postindex then address = address + offset; if n == 31 then SP[] = address; else X[n] = address;
If PSTATE.DIT is 1, the timing of this instruction is insensitive to the value of the data being loaded or stored.
Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41
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