PPC [simd]: optimize I16x8Mul in codegen

Change-Id: I7174f13634112f9cc185fb422fb15cb6ea0b2dd5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3015517Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#75648}

src/compiler/backend/ppc/code-generator-ppc.cc

@@ -2441,14 +2441,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       Simd128Register src0 = i.InputSimd128Register(0);
       Simd128Register src1 = i.InputSimd128Register(1);
       Simd128Register dst = i.OutputSimd128Register();
-      Simd128Register tempFPReg1 = i.ToSimd128Register(instr->TempAt(0));
-      __ vmuleuh(kScratchSimd128Reg, src0, src1);
-      __ vmulouh(i.OutputSimd128Register(), src0, src1);
-      __ xxspltib(tempFPReg1, Operand(16));
-      __ vslw(kScratchSimd128Reg, kScratchSimd128Reg, tempFPReg1);
-      __ vslw(dst, dst, tempFPReg1);
-      __ vsrw(dst, dst, tempFPReg1);
-      __ vor(dst, kScratchSimd128Reg, dst);
+      __ vxor(kScratchSimd128Reg, kScratchSimd128Reg, kScratchSimd128Reg);
+      __ vmladduhm(dst, src0, src1, kScratchSimd128Reg);
       break;
     }
     case kPPC_I8x16Add: {

src/execution/ppc/simulator-ppc.cc

@@ -4917,6 +4917,20 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
       }
       break;
     }
+    case VMLADDUHM: {
+      int vrt = instr->RTValue();
+      int vra = instr->RAValue();
+      int vrb = instr->RBValue();
+      int vrc = instr->RCValue();
+      FOR_EACH_LANE(i, uint16_t) {
+        uint16_t vra_val = get_simd_register_by_lane<uint16_t>(vra, i);
+        uint16_t vrb_val = get_simd_register_by_lane<uint16_t>(vrb, i);
+        uint16_t vrc_val = get_simd_register_by_lane<uint16_t>(vrc, i);
+        set_simd_register_by_lane<uint16_t>(vrt, i,
+                                            (vra_val * vrb_val) + vrc_val);
+      }
+      break;
+    }
 #define VECTOR_UNARY_OP(type, op)                         \
   int t = instr->RTValue();                               \
   int b = instr->RBValue();                               \