armmtflag

LBT intrinsic · group: LBT State Transfer

Synopsis

Instruction: armmtflag rd, mask
CPU Flags: LBT

Description

Move to ARMFLAGS: write selected ARM flags (N, Z, C, V) in ARMFLAGS from the corresponding bit positions in rd, as determined by mask.

Operation

uint64_t v = a;
if (mask & (1 << 4))
  ARMFLAGS.N = (v >> 31) & 1;
if (mask & (1 << 3))
  ARMFLAGS.Z = (v >> 30) & 1;
if (mask & (1 << 0))
  ARMFLAGS.C = (v >> 29) & 1;
if (mask & (1 << 5))
  ARMFLAGS.V = (v >> 28) & 1;

Tested on real machine.

Latency and Throughput

CPU	µarch	Latency	Throughput (IPC)
3C5000	LA464	N/A	0.5(1/2)
3C6000	LA664	N/A	0.5(1/2)

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