[wasm] Put the condition last in kExprSelect.

src/wasm/ast-decoder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/base/platform/elapsed-timer.h"
 #include "src/signature.h"
 
 #include "src/bit-vector.h"
 #include "src/flags.h"
 #include "src/handles.h"
@@ skipping 946 matching lines @@
           // False expr done.
           IfEnv* env = &ifs_.back();
           MergeIntoProduction(p, env->merge_env, p->last());
           SetEnv("if_else:merge", env->merge_env);
           ifs_.pop_back();
         }
         break;
       }
       case kExprSelect: {
         if (p->index == 1) {
-          // Condition done.
-          TypeCheckLast(p, kAstI32);
-        } else if (p->index == 2) {
           // True expression done.
           p->tree->type = p->last()->type;
           if (p->tree->type == kAstStmt) {
             error(p->pc(), p->tree->children[1]->pc,
                   "select operand should be expression");
           }
+        } else if (p->index == 2) {
+          // False expression done.
+          TypeCheckLast(p, p->tree->type);
         } else {
-          // False expression done.
+          // Condition done.
           DCHECK(p->done());
-          TypeCheckLast(p, p->tree->type);
+          TypeCheckLast(p, kAstI32);
           if (build()) {
             TFNode* controls[2];
-            builder_->Branch(p->tree->children[0]->node, &controls[0],
+            builder_->Branch(p->tree->children[2]->node, &controls[0],
                              &controls[1]);
             TFNode* merge = builder_->Merge(2, controls);
-            TFNode* vals[2] = {p->tree->children[1]->node,
-                               p->tree->children[2]->node};
+            TFNode* vals[2] = {p->tree->children[0]->node,
+                               p->tree->children[1]->node};
             TFNode* phi = builder_->Phi(p->tree->type, 2, vals, merge);
             p->tree->node = phi;
             ssa_env_->control = merge;
           }
         }
         break;
       }
       case kExprBr: {
         BreakDepthOperand operand(this, p->pc());
         CHECK(Validate(p->pc(), operand, blocks_));
@@ skipping 657 matching lines @@
 
 BitVector* AnalyzeLoopAssignmentForTesting(Zone* zone, FunctionEnv* env,
                                            const byte* start, const byte* end) {
   LoopAssignmentAnalyzer analyzer(zone, env);
   return analyzer.Analyze(start, end);
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8