[ARM] Add an MVE execution domain

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.

Patch by: Simon Tatham

Differential Revision: https://reviews.llvm.org/D60703

llvm-svn: 362068

2 files changed, 8 insertions, 6 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrFormats.td b/llvm/lib/Target/ARM/ARMInstrFormats.td
index 00a72026c27..b09aa8a97df 100644
--- a/llvm/lib/Target/ARM/ARMInstrFormats.td
+++ b/llvm/lib/Target/ARM/ARMInstrFormats.td
@@ -120,14 +120,15 @@ def IndexModePost : IndexMode<2>;
 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.
@@ -324,8 +325,8 @@ class InstTemplate<AddrMode am, int sz, IndexMode im,
   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;
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMBaseInfo.h b/llvm/lib/Target/ARM/MCTargetDesc/ARMBaseInfo.h
index 21a7f2dfb33..a654e645ba0 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMBaseInfo.h
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMBaseInfo.h
@@ -385,16 +385,17 @@ namespace ARMII {
     // 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