SHA1H

SHA1 fixed rotate

SHA1 fixed rotate.

Advanced SIMD
(FEAT_SHA1)

313029282726252423222120191817161514131211109876543210
0101111000101000000010RnRd
sizeopcode

Encoding

SHA1H <Sd>, <Sn>

Decode for this encoding

if !IsFeatureImplemented(FEAT_SHA1) then EndOfDecode(Decode_UNDEF); end; let d : integer{} = UInt(Rd); let n : integer{} = UInt(Rn);

Assembler Symbols

<Sd>

Is the 32-bit name of the SIMD&FP destination register, encoded in the "Rd" field.

<Sn>

Is the 32-bit name of the SIMD&FP source register, encoded in the "Rn" field.

Operation

AArch64_CheckFPAdvSIMDEnabled(); let operand : bits(32) = V{}(n); // read element [0] only, [1-3] zeroed V{32}(d) = ROL(operand, 30);

Operational information

This instruction is a data-independent-time instruction as described in About PSTATE.DIT.


2026-03_rel 2026-03-26 20:48:11

Copyright © 2010-2026 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.