[AArch64] Re-add patterns for (s/u)mull2.

[efriedma]

Summary

These patterns were added in D46009, but removed in D54276 due to missing test coverage.

[samparker]

The tests still looking rather lacking... Where are the ones for unsigned and the other data types..?

[efriedma]

Added tests. Thanks for insisting that I do this right. :)

[samparker]

Thanks!

llvm/lib/Target/AArch64/AArch64InstrInfo.td

def : Pat<(v2i64 (opnode (v2i32 V64:$Rn), (v2i32 V64:$Rm))),
             (INST2S V64:$Rn, V64:$Rm)>;
 }
 
 defm : Neon_mul_widen_patterns<AArch64smull, SMULLv8i8_v8i16,
   SMULLv4i16_v4i32, SMULLv2i32_v2i64>;
 defm : Neon_mul_widen_patterns<AArch64umull, UMULLv8i8_v8i16,
   UMULLv4i16_v4i32, UMULLv2i32_v2i64>;
 
+// Patterns for smull2/umull2.
+multiclass Neon_mul_high_patterns<SDPatternOperator opnode,
+  Instruction INST8B, Instruction INST4H, Instruction INST2S> {
+  def : Pat<(v8i16 (opnode (extract_high_v16i8 V128:$Rn),
+                           (extract_high_v16i8 V128:$Rm))),
+             (INST8B V128:$Rn, V128:$Rm)>;
+  def : Pat<(v4i32 (opnode (extract_high_v8i16 V128:$Rn),
+                           (extract_high_v8i16 V128:$Rm))),
+             (INST4H V128:$Rn, V128:$Rm)>;
+  def : Pat<(v2i64 (opnode (extract_high_v4i32 V128:$Rn),
+                           (extract_high_v4i32 V128:$Rm))),
+             (INST2S V128:$Rn, V128:$Rm)>;
+}
+
+defm : Neon_mul_high_patterns<AArch64smull, SMULLv16i8_v8i16,
+  SMULLv8i16_v4i32, SMULLv4i32_v2i64>;
+defm : Neon_mul_high_patterns<AArch64umull, UMULLv16i8_v8i16,
+  UMULLv8i16_v4i32, UMULLv4i32_v2i64>;
+
 // Additional patterns for SMLAL/SMLSL and UMLAL/UMLSL
 multiclass Neon_mulacc_widen_patterns<SDPatternOperator opnode,
   Instruction INST8B, Instruction INST4H, Instruction INST2S> {
   def : Pat<(v8i16 (opnode (v8i16 V128:$Rd), (v8i8 V64:$Rn), (v8i8 V64:$Rm))),
             (INST8B V128:$Rd, V64:$Rn, V64:$Rm)>;
   def : Pat<(v4i32 (opnode (v4i32 V128:$Rd), (v4i16 V64:$Rn), (v4i16 V64:$Rm))),
             (INST4H V128:$Rd, V64:$Rn, V64:$Rm)>;
   def : Pat<(v2i64 (opnode (v2i64 V128:$Rd), (v2i32 V64:$Rn), (v2i32 V64:$Rm))),

llvm/test/CodeGen/AArch64/aarch64-smull.ll

; CHECK: umlal [[REG1]], {{v[0-9]+}}.8b, [[REG2]]
   %11 = zext <8 x i8> %10 to <8 x i16>
   %12 = add <8 x i16> %7, %11
   %13 = mul <8 x i16> %12, %8
   %14 = bitcast i16* %dst to i8*
   tail call void @llvm.aarch64.neon.vst1.v8i16(i8* %14, <8 x i16> %13, i32 2)
   ret void
 }
 
+define <8 x i32> @smull2(<8 x i16> %arg1, <8 x i16> %arg2) {
+; CHECK-LABEL: smull2:
+; CHECK-DAG: smull2 {{v[0-9]+}}.4s, {{v[0-9]+}}.8h, {{v[0-9]+}}.8h
+; CHECK-DAG: smull {{v[0-9]+}}.4s, {{v[0-9]+}}.4h, {{v[0-9]+}}.4h
+  %arg1_ext = sext <8 x i16> %arg1 to <8 x i32>
+  %arg2_ext = sext <8 x i16> %arg2 to <8 x i32>
+  %mul = mul <8 x i32> %arg1_ext, %arg2_ext
+  ret <8 x i32> %mul
+}
+
 declare <16 x i8> @llvm.aarch64.neon.vld1.v16i8(i8*, i32) nounwind readonly
 
 declare void @llvm.aarch64.neon.vst1.v8i16(i8*, <8 x i16>, i32) nounwind