[PATCH] D60703: [ARM] Add an MVE execution domain.

[Simon Tatham via Phabricator via llvm-commits]

simon_tatham created this revision.
simon_tatham added reviewers: dmgreen, samparker, SjoerdMeijer.
Herald added subscribers: llvm-commits, hiraditya, kristof.beyls, javed.absar.
Herald added a project: LLVM.

MVE architecturally specifies a 'beat' system in which a vector
instruction executed now will complete its actual operation over the
next four cycles, so it can overlap with the execution of the previous
and next MVE instruction.

This makes it generally an advantage to avoid moving values back and
forth between MVE registers and anywhere else, if there's any sensible
way to do the same processing in whatever register type the values
already occupied.

That's just what the 'execution domain' system is supposed to achieve.
So here we add a new execution domain which will contain all the MVE
vector instructions when they are added.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D60703

Files:
  llvm/lib/Target/ARM/ARMInstrFormats.td
  llvm/lib/Target/ARM/MCTargetDesc/ARMBaseInfo.h


Index: llvm/lib/Target/ARM/MCTargetDesc/ARMBaseInfo.h
===================================================================
--- llvm/lib/Target/ARM/MCTargetDesc/ARMBaseInfo.h
+++ llvm/lib/Target/ARM/MCTargetDesc/ARMBaseInfo.h
@@ -393,16 +393,17 @@
     // instruction. Used by the parser to determine whether to require the 'S'
     // suffix on the mnemonic (when not in an IT block) or preclude it (when
     // in an IT block).
-    ThumbArithFlagSetting = 1 << 18,
+    ThumbArithFlagSetting = 1 << 19,
 
     //===------------------------------------------------------------------===//
     // Code domain.
     DomainShift   = 15,
-    DomainMask    = 7 << DomainShift,
+    DomainMask    = 15 << DomainShift,
     DomainGeneral = 0 << DomainShift,
     DomainVFP     = 1 << DomainShift,
     DomainNEON    = 2 << DomainShift,
     DomainNEONA8  = 4 << DomainShift,
+    DomainMVE     = 8 << DomainShift,
 
     //===------------------------------------------------------------------===//
     // Field shifts - such shifts are used to set field while generating
Index: llvm/lib/Target/ARM/ARMInstrFormats.td
===================================================================
--- llvm/lib/Target/ARM/ARMInstrFormats.td
+++ llvm/lib/Target/ARM/ARMInstrFormats.td
@@ -124,14 +124,15 @@
 def IndexModeUpd  : IndexMode<3>;
 
 // Instruction execution domain.
-class Domain<bits<3> val> {
-  bits<3> Value = val;
+class Domain<bits<4> val> {
+  bits<4> Value = val;
 }
 def GenericDomain : Domain<0>;
 def VFPDomain     : Domain<1>; // Instructions in VFP domain only
 def NeonDomain    : Domain<2>; // Instructions in Neon domain only
 def VFPNeonDomain : Domain<3>; // Instructions in both VFP & Neon domains
 def VFPNeonA8Domain : Domain<5>; // Instructions in VFP & Neon under A8
+def MVEDomain : Domain<8>; // Instructions in MVE and ARMv8.1m
 
 //===----------------------------------------------------------------------===//
 // ARM special operands.
@@ -328,8 +329,8 @@
   let TSFlags{12-7} = Form;
   let TSFlags{13}    = isUnaryDataProc;
   let TSFlags{14}    = canXformTo16Bit;
-  let TSFlags{17-15} = D.Value;
-  let TSFlags{18}    = thumbArithFlagSetting;
+  let TSFlags{18-15} = D.Value;
+  let TSFlags{19}    = thumbArithFlagSetting;
 
   let Constraints = cstr;
   let Itinerary = itin;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D60703.195162.patch
Type: text/x-patch
Size: 2303 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190415/3e850478/attachment.bin>