[VE] Add vector control instructions

[kaz7]

Summary

Add LVL/SVL/SMVL/LVIX isntructions. Add regression tests too.

llvm/lib/Target/VE/VEInstrVec.td

 // Section 8.17.10 - PCVM (Population Count of VM)
 defm PCVM : RVMSm<"pcvm", 0xa4, VM>;
 
 // Section 8.17.11 - LZVM (Leading Zero of VM)
 defm LZVM : RVMSm<"lzvm", 0xa5, VM>;
 
 // Section 8.17.12 - TOVM (Trailing One of VM)
 defm TOVM : RVMSm<"tovm", 0xa6, VM>;
+
+//-----------------------------------------------------------------------------
+// Section 8.18 - Vector Control Instructions
+//-----------------------------------------------------------------------------
+
+// Section 8.18.1 - LVL (Load VL)
+let sx = 0, cz = 0, sz = 0, hasSideEffects = 0, Defs = [VL] in {
+  def LVLr : RR<0xbf, (outs), (ins I64:$sy), "lvl $sy">;
+  let cy = 0 in def LVLi : RR<0xbf, (outs), (ins simm7:$sy), "lvl $sy">;
+}
+
+// Section 8.18.2 - SVL (Save VL)
+let cy = 0, sy = 0, cz = 0, sz = 0, hasSideEffects = 0, Uses = [VL] in
+def SVL : RR<0x2f, (outs I64:$sx), (ins), "svl $sx">;
+
+// Section 8.18.3 - SMVL (Save Maximum Vector Length)
+let cy = 0, sy = 0, cz = 0, sz = 0, hasSideEffects = 0 in
+def SMVL : RR<0x2e, (outs I64:$sx), (ins), "smvl $sx">;
+
+// Section 8.18.4 - LVIX (Load Vector Data Index)
+let sx = 0, cz = 0, sz = 0, hasSideEffects = 0, Defs = [VIX] in {
+  def LVIXr : RR<0xaf, (outs), (ins I64:$sy), "lvix $sy">;
+  let cy = 0 in def LVIXi : RR<0xaf, (outs), (ins uimm6:$sy), "lvix $sy">;
+}

llvm/test/MC/VE/LVIX.s

+# RUN: llvm-mc -triple=ve --show-encoding < %s \
+# RUN:     | FileCheck %s --check-prefixes=CHECK-ENCODING,CHECK-INST
+# RUN: llvm-mc -triple=ve -filetype=obj < %s | llvm-objdump -d - \
+# RUN:     | FileCheck %s --check-prefixes=CHECK-INST
+
+# CHECK-INST: lvix %s11
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x8b,0x00,0xaf]
+lvix %s11
+
+# CHECK-INST: lvix 63
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x3f,0x00,0xaf]
+lvix 63
+
+# CHECK-INST: lvix %s63
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0xbf,0x00,0xaf]
+lvix %s63

llvm/test/MC/VE/LVL.s

+# RUN: llvm-mc -triple=ve --show-encoding < %s \
+# RUN:     | FileCheck %s --check-prefixes=CHECK-ENCODING,CHECK-INST
+# RUN: llvm-mc -triple=ve -filetype=obj < %s | llvm-objdump -d - \
+# RUN:     | FileCheck %s --check-prefixes=CHECK-INST
+
+# CHECK-INST: lvl %s11
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x8b,0x00,0xbf]
+lvl %s11
+
+# CHECK-INST: lvl 63
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x3f,0x00,0xbf]
+lvl 63
+
+# CHECK-INST: lvl -64
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x40,0x00,0xbf]
+lvl -64

llvm/test/MC/VE/SMVL.s

+# RUN: llvm-mc -triple=ve --show-encoding < %s \
+# RUN:     | FileCheck %s --check-prefixes=CHECK-ENCODING,CHECK-INST
+# RUN: llvm-mc -triple=ve -filetype=obj < %s | llvm-objdump -d - \
+# RUN:     | FileCheck %s --check-prefixes=CHECK-INST
+
+# CHECK-INST: smvl %s11
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x00,0x0b,0x2e]
+smvl %s11
+
+# CHECK-INST: smvl %s0
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x2e]
+smvl %s0
+
+# CHECK-INST: smvl %s63
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x00,0x3f,0x2e]
+smvl %s63

llvm/test/MC/VE/SVL.s

+# RUN: llvm-mc -triple=ve --show-encoding < %s \
+# RUN:     | FileCheck %s --check-prefixes=CHECK-ENCODING,CHECK-INST
+# RUN: llvm-mc -triple=ve -filetype=obj < %s | llvm-objdump -d - \
+# RUN:     | FileCheck %s --check-prefixes=CHECK-INST
+
+# CHECK-INST: svl %s11
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x00,0x0b,0x2f]
+svl %s11
+
+# CHECK-INST: svl %s0
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x2f]
+svl %s0
+
+# CHECK-INST: svl %s63
+# CHECK-ENCODING: encoding: [0x00,0x00,0x00,0x00,0x00,0x00,0x3f,0x2f]
+svl %s63