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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: Pa0TL+Gwecbi6n4l/inszoPebhxj8tD9p1z+GT/p7K4TS0o+BVE3poEDss/XdKWrjUeRcvmTmpye6bmJopajNVxqVvTYFhsYkUQUky4U+BH9wtduh1mB1uMMgmoFP+ATxTLSfobRBsHHFZeXx91ydgHytJpiwt4/hdStnXPpOQOO0VsqyqVYM2HQzuXSFkFl7/NRTNRwxCNovTCyrGESwkKAUmDtMF59teLr9hZUOq9uwYNdlk04I473RcXr/gyDiBnWUNCmW+e5j4vobNW2SbCRVENjOwl/F5Xef5nGB4y5k3XraBeBM1acjhWPv2f1QPX3/8S4ewoYAwZ+1vo1NSzSad909fg6SqG0LviuCwrLR1jdY1tNFQnzU9xMhFE7G+XANwOtWVYzkYKXW5nUItlk3AChHKW0wEvweAV8KPxtH2ZktBLOjrCf2Id8iMkb X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Mar 2026 17:11:27.6423 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 992b7fe5-1303-49c7-4165-08de837f0f79 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb08.amd.com] X-MS-Exchange-CrossTenant-AuthSource: BN3PEPF0000B371.namprd21.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS5PPF6BCF148B6 Hello David, On 3/16/2026 5:20 PM, David Laight wrote: >> Introduce runtime_const_mask_32 to further optimize the mask operation >> in the futex hash computation hot path. GCC generates a: >> >> movz w1, #lo16, lsl #0 // w1 = bits [15:0] >> movk w1, #hi16, lsl #16 // w1 = full 32-bit value >> and w0, w0, w1 // w0 = w0 & w1 > > I don't thing the '&' needs to be part of the asm block. > Just generate the 32bit constant and do the mask in C. > That will let the compiler schedule the instructions. > It also make the code patching more generally useful. Ack! That makes sense. I'll update it in the next version. Thank you for taking a look at the series. -- Thanks and Regards, Prateek