[AArch64][SVE2] Asm: add ext (immediate offset, constructive) instruction

[c-rhodes]

Summary

The specification can be found here:
https://developer.arm.com/docs/ddi0602/latest

lib/Target/AArch64/AArch64SVEInstrInfo.td

let Predicates = [HasSVE2] in {
   def BSL_ZZZZ_D    : sve2_int_bitwise_ternary_op_d<0b001, "bsl">;
   def BSL1N_ZZZZ_D  : sve2_int_bitwise_ternary_op_d<0b011, "bsl1n">;
   def BSL2N_ZZZZ_D  : sve2_int_bitwise_ternary_op_d<0b101, "bsl2n">;
   def NBSL_ZZZZ_D   : sve2_int_bitwise_ternary_op_d<0b111, "nbsl">;
 
   // sve_int_rotate_imm
   defm XAR_ZZZI : sve2_int_rotate_right_imm<"xar">;
 
+  // SVE2 extract vector (immediate offset, constructive)
+  def EXT_ZZI_B : sve2_int_perm_extract_i_cons<"ext">;
+
   // Predicated shifts
   defm SQSHL_ZPmI  : sve_int_bin_pred_shift_imm_left< 0b0110, "sqshl">;
   defm UQSHL_ZPmI  : sve_int_bin_pred_shift_imm_left< 0b0111, "uqshl">;
   defm SRSHR_ZPmI  : sve_int_bin_pred_shift_imm_right<0b1100, "srshr">;
   defm URSHR_ZPmI  : sve_int_bin_pred_shift_imm_right<0b1101, "urshr">;
   defm SQSHLU_ZPmI : sve_int_bin_pred_shift_imm_left< 0b1111, "sqshlu">;
 }
 

lib/Target/AArch64/SVEInstrFormats.td

: I<(outs ZPR8:$Zdn), (ins ZPR8:$_Zdn, ZPR8:$Zm, imm0_255:$imm8),
   let Inst{9-5}   = Zm;
   let Inst{4-0}   = Zdn;
 
   let Constraints = "$Zdn = $_Zdn";
   let DestructiveInstType = Destructive;
   let ElementSize = ElementSizeNone;
 }
 
+class sve2_int_perm_extract_i_cons<string asm>
+: I<(outs ZPR8:$Zd), (ins ZZ_b:$Zn, imm0_255:$imm8),
+  asm, "\t$Zd, $Zn, $imm8",
+  "", []>, Sched<[]> {
+  bits<5> Zd;
+  bits<5> Zn;
+  bits<8> imm8;
+  let Inst{31-21} = 0b00000101011;
+  let Inst{20-16} = imm8{7-3};
+  let Inst{15-13} = 0b000;
+  let Inst{12-10} = imm8{2-0};
+  let Inst{9-5}   = Zn;
+  let Inst{4-0}   = Zd;
+}
+
 //===----------------------------------------------------------------------===//
 // SVE Vector Select Group
 //===----------------------------------------------------------------------===//
 
 class sve_int_sel_vvv<bits<2> sz8_64, string asm, ZPRRegOp zprty>
 : I<(outs zprty:$Zd), (ins PPRAny:$Pg, zprty:$Zn, zprty:$Zm),
   asm, "\t$Zd, $Pg, $Zn, $Zm",
   "",

test/MC/AArch64/SVE2/ext-diagnostics.s

+// RUN: not llvm-mc -triple=aarch64 -show-encoding -mattr=+sve2  2>&1 < %s| FileCheck %s
+
+
+// ------------------------------------------------------------------------- //
+// Invalid element widths.
+
+ext z0.h, { z1.h, z2.h }, #0
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid element width
+// CHECK-NEXT: ext z0.h, { z1.h, z2.h }, #0
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+ext z0.s, { z1.s, z2.s }, #0
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid element width
+// CHECK-NEXT: ext z0.s, { z1.s, z2.s }, #0
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+ext z0.d, { z1.d, z2.d }, #0
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid element width
+// CHECK-NEXT: ext z0.d, { z1.d, z2.d }, #0
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// ------------------------------------------------------------------------- //
+// Invalid immediate range.
+
+ext z0.b, { z1.b, z2.b }, #-1
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: immediate must be an integer in range [0, 255].
+// CHECK-NEXT: ext z0.b, { z1.b, z2.b }, #-1
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+ext z0.b, { z1.b, z2.b }, #256
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: immediate must be an integer in range [0, 255].
+// CHECK-NEXT: ext z0.b, { z1.b, z2.b }, #256
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
+// Invalid vector list.
+
+ext z0.b, { }, #0
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: vector register expected
+// CHECK-NEXT: ext z0.b, { }, #0
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+ext z0.b, { z1.b }, #0
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid operand for instruction
+// CHECK-NEXT: ext z0.b, { z1.b }, #0
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+ext z0.b, { z1.b, z2.b, z3.b }, #0
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid operand for instruction
+// CHECK-NEXT: ext z0.b, { z1.b, z2.b, z3.b }, #0
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+ext z0.b, { z1.b, z2.h }, #0
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: mismatched register size suffix
+// CHECK-NEXT: ext z0.b, { z1.b, z2.h }, #0
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+ext z0.b, { z1.b, z31.b }, #0
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: registers must be sequential
+// CHECK-NEXT: ext z0.b, { z1.b, z31.b }, #0
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+ext z0.b, { v0.4b, v1.4b }, #0
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid operand for instruction
+// CHECK-NEXT: ext z0.b, { v0.4b, v1.4b }, #0
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+
+// --------------------------------------------------------------------------//
+// Negative tests for instructions that are incompatible with movprfx
+
+movprfx z31, z6
+ext z31.b, { z30.b, z31.b }, #255
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: instruction is unpredictable when following a movprfx, suggest replacing movprfx with mov
+// CHECK-NEXT: ext z31.b, { z30.b, z31.b }, #255
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
+movprfx z31.b, p0/z, z6.b
+ext z31.b, { z30.b, z31.b }, #255
+// CHECK: [[@LINE-1]]:{{[0-9]+}}: error: instruction is unpredictable when following a movprfx, suggest replacing movprfx with mov
+// CHECK-NEXT: ext z31.b, { z30.b, z31.b }, #255
+// CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:

test/MC/AArch64/SVE2/ext.s

+// RUN: llvm-mc -triple=aarch64 -show-encoding -mattr=+sve2 < %s \
+// RUN:        | FileCheck %s --check-prefixes=CHECK-ENCODING,CHECK-INST
+// RUN: not llvm-mc -triple=aarch64 -show-encoding < %s 2>&1 \
+// RUN:        | FileCheck %s --check-prefix=CHECK-ERROR
+// RUN: llvm-mc -triple=aarch64 -filetype=obj -mattr=+sve2 < %s \
+// RUN:        | llvm-objdump -d -mattr=+sve2 - | FileCheck %s --check-prefix=CHECK-INST
+// RUN: llvm-mc -triple=aarch64 -filetype=obj -mattr=+sve2 < %s \
+// RUN:        | llvm-objdump -d - | FileCheck %s --check-prefix=CHECK-UNKNOWN
+
+ext z0.b, { z1.b, z2.b }, #0
+// CHECK-INST: ext z0.b, { z1.b, z2.b }, #0
+// CHECK-ENCODING: [0x20,0x00,0x60,0x05]
+// CHECK-ERROR: instruction requires: sve2
+// CHECK-UNKNOWN: 20 00 60 05 <unknown>
+
+ext z31.b, { z30.b, z31.b }, #255
+// CHECK-INST: ext z31.b, { z30.b, z31.b }, #255
+// CHECK-ENCODING: [0xdf,0x1f,0x7f,0x05]
+// CHECK-ERROR: instruction requires: sve2
+// CHECK-UNKNOWN: df 1f 7f 05 <unknown>