5.12.1 ScalableVectorExtension parameters

This section describes the parameters for the ScalableVectorExtension plug-in.

Each parameter is prefixed with SVE.ScalableVectorExtension, for example:

SVE.ScalableVectorExtension.veclen

Table 5-13 SVE parameters

Parameter Type Allowed values Default value Description
clear_constrained_lanes int 0x0-0x2 0x0 When a constrained vector length increases, previously inaccessible bits are set to zero according to the value of this parameter as follows:
0x0
Never
0x1
Always
0x2
If the register was written to while the vector length was constrained.
combine_movprfx_and_destructive bool true, false false Attempt to combine the execution of MOVPRFX and the destructively encoded instruction that follows it.
disable_speculative_accesses bool true, false false All speculative memory accesses behave as though faulting without accessing memory.
disass_internal bool true, false false Use the generated disassembler, which is lower quality disassembly but always matches the instruction decoder.
enable_at_reset bool true, false false Start with system registers set up for Scalable Vector Extension use.
fp_exception_report_lowest bool true, false false If true, for multiple trapped FP exceptions, report the lowest lane in VECITR. Otherwise, report the highest.
fp_exception_set_tfv bool true, false true Set ESR_ELx.TFV during FP exception. Trapped exception flags are valid.
fp_exception_set_vecitr bool true, false false If true, set ESR_ELx.VECITR during FP exception. Otherwise, set RES0.
support_npot_vl bool true, false true Support vector lengths that are not a power of two.
undef_invalid_combined_movprfx bool true, false true If a combined MOVPRFX is invalid, raise an UNDEF exception. Otherwise NOP the second half of the register.
unknown_value int 0x0- 0xffffffffffffffff 0xdeaddeaddeaddead Simulated value for a state that has an UNKNOWN value after reset.
veclen int 0x2-0x20 0x8 Size of the vector in units of 64-bit blocks.
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