3 files changed, 55 insertions, 76 deletions

diff --git a/src/opcode.cc b/src/opcode.cc
index 6bb01d46..98cfe99e 100644
--- a/src/opcode.cc
+++ b/src/opcode.cc
@@ -337,4 +337,33 @@ bool Opcode::IsEnabled(const Features& features) const {
   }
 }
 
+uint32_t Opcode::GetSimdLaneCount() const {
+  switch (enum_) {
+    case Opcode::I8X16ExtractLaneS:
+    case Opcode::I8X16ExtractLaneU:
+    case Opcode::I8X16ReplaceLane:
+      return 16;
+      break;
+    case Opcode::I16X8ExtractLaneS:
+    case Opcode::I16X8ExtractLaneU:
+    case Opcode::I16X8ReplaceLane:
+      return 8;
+      break;
+    case Opcode::F32X4ExtractLane:
+    case Opcode::F32X4ReplaceLane:
+    case Opcode::I32X4ExtractLane:
+    case Opcode::I32X4ReplaceLane:
+      return 4;
+      break;
+    case Opcode::F64X2ExtractLane:
+    case Opcode::F64X2ReplaceLane:
+    case Opcode::I64X2ExtractLane:
+    case Opcode::I64X2ReplaceLane:
+      return 2;
+      break;
+    default:
+      WABT_UNREACHABLE;
+  }
+}
+
 }  // end anonymous namespace
diff --git a/src/opcode.h b/src/opcode.h
index 86838db7..61d7a3ad 100644
--- a/src/opcode.h
+++ b/src/opcode.h
@@ -61,6 +61,9 @@ struct Opcode {
   Type GetParamType3() const { return GetInfo().param3_type; }
   Address GetMemorySize() const { return GetInfo().memory_size; }
 
+  // Get the lane count of an extract/replace simd op.
+  uint32_t GetSimdLaneCount() const;
+
   // Return 1 if |alignment| matches the alignment of |opcode|, or if
   // |alignment| is WABT_USE_NATURAL_ALIGNMENT.
   bool IsNaturallyAligned(Address alignment) const;
diff --git a/src/type-checker.cc b/src/type-checker.cc
index 7e68f6b0..52001139 100644
--- a/src/type-checker.cc
+++ b/src/type-checker.cc
@@ -16,6 +16,8 @@
 
 #include "src/type-checker.h"
 
+#include <cinttypes>
+
 namespace wabt {
 
 TypeChecker::Label::Label(LabelType label_type,
@@ -597,102 +599,47 @@ Result TypeChecker::OnTernary(Opcode opcode) {
 
 Result TypeChecker::OnSimdLaneOp(Opcode opcode, uint64_t lane_idx) {
   Result result = Result::Error;
+  uint32_t lane_count = opcode.GetSimdLaneCount();
+  if (lane_idx >= lane_count) {
+    PrintError("lane index must be less than %d (got %" PRIu64 ")", lane_count,
+               lane_idx);
+  }
+
   switch (opcode) {
     case Opcode::I8X16ExtractLaneS:
-    case Opcode::I8X16ExtractLaneU: {
-      if(lane_idx >= 16) {
-        PrintError("TypeChecker: I8X16 lane Operations: lane index must\
-                                                      be less than 16.");
-        break;
-      }
-      result = CheckOpcode1(opcode);
-      break;
-    }
+    case Opcode::I8X16ExtractLaneU:
     case Opcode::I16X8ExtractLaneS:
-    case Opcode::I16X8ExtractLaneU: {
-      if(lane_idx >= 8) {
-        PrintError("TypeChecker: I16X8 lane Operations: lane index must\
-                                                       be less than 8.");
-        break;
-      }
-      result = CheckOpcode1(opcode);
-      break;
-    }
+    case Opcode::I16X8ExtractLaneU:
     case Opcode::I32X4ExtractLane:
-    case Opcode::F32X4ExtractLane: {
-      if(lane_idx >= 4) {
-        PrintError("TypeChecker: (I/f)32X4 lane Operations: lane index must\
-                                                           be less than 4.");
-        break;
-      }
-      result = CheckOpcode1(opcode);
-      break;
-    }
+    case Opcode::F32X4ExtractLane:
     case Opcode::I64X2ExtractLane:
-    case Opcode::F64X2ExtractLane: {
-      if(lane_idx >= 2) {
-        PrintError("TypeChecker: (I/f)64X2 lane Operations: lane index must\
-                                                           be less than 2.");
-        break;
-      }
+    case Opcode::F64X2ExtractLane:
       result = CheckOpcode1(opcode);
       break;
-    }
-    case Opcode::I8X16ReplaceLane: {
-      if(lane_idx >= 16) {
-        PrintError("TypeChecker: I8X16 lane Operations: lane index must\
-                                                      be less than 16.");
-        break;
-      }
-      result = CheckOpcode2(opcode);
-      break;
-    }
-    case Opcode::I16X8ReplaceLane: {
-      if(lane_idx >= 8) {
-        PrintError("TypeChecker: I16X8 lane Operations: lane index must\
-                                                       be less than 8.");
-        break;
-      }
-      result = CheckOpcode2(opcode);
-      break;
-    }
+    case Opcode::I8X16ReplaceLane:
+    case Opcode::I16X8ReplaceLane:
     case Opcode::I32X4ReplaceLane:
-    case Opcode::F32X4ReplaceLane: {
-      if(lane_idx >= 4) {
-        PrintError("TypeChecker: (I/f)32X4 lane Operations: lane index must\
-                                                           be less than 4.");
-        break;
-      }
-      result = CheckOpcode2(opcode);
-      break;
-    }
+    case Opcode::F32X4ReplaceLane:
     case Opcode::I64X2ReplaceLane:
-    case Opcode::F64X2ReplaceLane: {
-      if(lane_idx >= 2) {
-        PrintError("TypeChecker: (I/f)64X2 lane Operations: lane index must\
-                                                           be less than 2.");
-        break;
-      }
+    case Opcode::F64X2ReplaceLane:
       result = CheckOpcode2(opcode);
       break;
-    }
     default:
-      PrintError("TypeChecker::OnSimdLane: called by invalid opcode.");
-  }  
+      WABT_UNREACHABLE;
+  }
   return result;
 }
 
 Result TypeChecker::OnSimdShuffleOp(Opcode opcode, v128 lane_idx) {
   Result result = Result::Error;
   uint8_t simd_data[16];
-  memcpy(simd_data, &(lane_idx), 16);
-  for(int i = 0; i < 16; i++) {
-    if(simd_data[i] >= 32) {
-      PrintError("TypeChecker: v8x16 shuffle: each lane index must be >=0 and < 32.");
-      return result;  
+  memcpy(simd_data, &lane_idx, 16);
+  for (int i = 0; i < 16; i++) {
+    if (simd_data[i] >= 32) {
+      PrintError("lane index must be less than 32 (got %d)", simd_data[i]);
     }
   }
-  
+
   result = CheckOpcode2(opcode);
   return result;
 }