[llvm] 4fbe60f - [PowerPC][NFC] Add file info and license that was missing from this file.

[Stefan Pintilie via llvm-commits]

Author: Stefan Pintilie
Date: 2022-02-25T10:28:02-06:00
New Revision: 4fbe60fd13a67e235ccd66517fa96a4434ddea87

URL: https://github.com/llvm/llvm-project/commit/4fbe60fd13a67e235ccd66517fa96a4434ddea87
DIFF: https://github.com/llvm/llvm-project/commit/4fbe60fd13a67e235ccd66517fa96a4434ddea87.diff

LOG: [PowerPC][NFC] Add file info and license that was missing from this file.

Added the license info as well as description about how classes should be named
based on existing documentation.

Reviewed By: lei, #powerpc

Differential Revision: https://reviews.llvm.org/D120530

Added: 
    

Modified: 
    llvm/lib/Target/PowerPC/PPCInstrP10.td

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/PowerPC/PPCInstrP10.td b/llvm/lib/Target/PowerPC/PPCInstrP10.td
index 4a7483c4fdd8a..81b2d835cbf24 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrP10.td
+++ b/llvm/lib/Target/PowerPC/PPCInstrP10.td
@@ -1,3 +1,56 @@
+//===-- PPCInstrP10.td - Power10 Instruction Set -----------*- tablegen -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file describes the instructions introduced for the Power10 CPU.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Naming convention for future instruction formats
+//
+// <INSTR_FORM>{_<OP_TYPE><OP_LENGTH>}+
+//
+// Where:
+// <INSTR_FORM> - name of instruction format as per the ISA
+//                (X-Form, VX-Form, etc.)
+// <OP_TYPE> - operand type
+//             * FRT/RT/VT/XT/BT - target register
+//                                 (FPR, GPR, VR, VSR, CR-bit respectively)
+//                                 In some situations, the 'T' is replaced by
+//                                 'D' when describing the target register.
+//             * [FR|R|V|X|B][A-Z] - register source (i.e. FRA, RA, XB, etc.)
+//             * IMM - immediate (where signedness matters,
+//                     this is SI/UI for signed/unsigned)
+//             * [R|X|FR]Tp - register pair target (i.e. FRTp, RTp)
+//             * R - PC-Relative bit
+//                   (denotes that the address is computed pc-relative)
+//             * VRM - Masked Registers
+//             * AT - target accumulator
+//             * N - the Nth bit in a VSR
+//             * Additional 1-bit operands may be required for certain
+//               instruction formats such as: MC, P, MP
+//             * X / Y / P - mask values. In the instruction encoding, this is
+//                           represented as XMSK, YMSK and PMSK.
+//             * MEM - indicates if the instruction format requires any memory
+//                     accesses. This does not have <OP_LENGTH> attached to it.
+// <OP_LENGTH> - the length of each operand in bits.
+//               For operands that are 1 bit, the '1' is omitted from the name.
+//
+// Example: 8RR_XX4Form_IMM8_XTAB6
+//          8RR_XX4Form is the instruction format.
+//          The operand is an 8-bit immediate (IMM), the destination (XT)
+//          and sources (XA, XB) that are all 6-bits. The destination and
+//          source registers are combined if they are of the same length.
+//          Moreover, the order of operands reflects the order of operands
+//          in the encoding.
+
 //-------------------------- Predicate definitions ---------------------------//
 def IsPPC32 : Predicate<"!Subtarget->isPPC64()">;