PPC: [wasm-simd] Add debug info the simd instructions:

- vspltb
- vspltw
- vsplth


Change-Id: I76d42f301c10ff357a6b34825a3f6790b83758f9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2173243Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#67482}

src/codegen/ppc/constants-ppc.h

@@ -2593,7 +2593,8 @@ enum Opcode : uint32_t {
   opcode_name = opcode_value,
   PPC_OPCODE_LIST(DECLARE_INSTRUCTION)
 #undef DECLARE_INSTRUCTION
-      EXT1 = 0x4C000000,  // Extended code set 1
+      EXT0 = 0x10000000,  // Extended code set 0
+  EXT1 = 0x4C000000,      // Extended code set 1
   EXT2 = 0x7C000000,      // Extended code set 2
   EXT3 = 0xEC000000,      // Extended code set 3
   EXT4 = 0xFC000000,      // Extended code set 4

src/diagnostics/ppc/disasm-ppc.cc

@@ -74,6 +74,7 @@ class Decoder {
   void Unknown(Instruction* instr);
   void UnknownFormat(Instruction* instr, const char* opcname);
 
+  void DecodeExt0(Instruction* instr);
   void DecodeExt1(Instruction* instr);
   void DecodeExt2(Instruction* instr);
   void DecodeExt3(Instruction* instr);
@@ -219,6 +220,11 @@ int Decoder::FormatOption(Instruction* instr, const char* format) {
       out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", value);
       return 6;
     }
+    case 'U': {  // UIM
+      int32_t value = instr->Bits(20, 16);
+      out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", value);
+      return 3;
+    }
     case 'l': {
       // Link (LK) Bit 0
       if (instr->Bit(0) == 1) {
@@ -351,6 +357,23 @@ void Decoder::UnknownFormat(Instruction* instr, const char* name) {
   Format(instr, buffer);
 }
 
+void Decoder::DecodeExt0(Instruction* instr) {
+  switch (EXT0 | (instr->BitField(10, 0))) {
+    case VSPLTB: {
+      Format(instr, "vspltb   'Dt, 'Db, 'UIM");
+      break;
+    }
+    case VSPLTW: {
+      Format(instr, "vspltw   'Dt, 'Db, 'UIM");
+      break;
+    }
+    case VSPLTH: {
+      Format(instr, "vsplth   'Dt, 'Db, 'UIM");
+      break;
+    }
+  }
+}
+
 void Decoder::DecodeExt1(Instruction* instr) {
   switch (EXT1 | (instr->BitField(10, 1))) {
     case MCRF: {
@@ -1276,6 +1299,10 @@ int Decoder::InstructionDecode(byte* instr_ptr) {
       Format(instr, "b'l'a 'target26");
       break;
     }
+    case EXT0: {
+      DecodeExt0(instr);
+      break;
+    }
     case EXT1: {
       DecodeExt1(instr);
       break;