[asmjs] Do constant folding for I32Asmjs(Div|Rem)S to avoid checks of constant divisors

test/cctest/wasm/test-run-wasm.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 <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "src/base/platform/elapsed-timer.h"
 #include "src/utils.h"
@@ skipping 430 matching lines @@
     for (int32_t val = -7; val < 8; ++val) {
       if (denom == 0) {
         CHECK_TRAP(r.Call(val));
       } else {
         CHECK_EQ(val / denom, r.Call(val));
       }
     }
   }
 }
 
+WASM_EXEC_TEST(Int32AsmjsDivS_byzero_const) {
+  for (int8_t denom = -2; denom < 8; ++denom) {
+    TestingModule module(execution_mode);
+    module.ChangeOriginToAsmjs();
+    WasmRunner<int32_t> r(&module, MachineType::Int32());
+    BUILD(r, WASM_I32_ASMJS_DIVS(WASM_GET_LOCAL(0), WASM_I8(denom)));
+    FOR_INT32_INPUTS(i) {
+      if (denom == 0) {
+        CHECK_EQ(0, r.Call(*i));
+      } else if (denom == -1 && *i == std::numeric_limits<int32_t>::min()) {
+        CHECK_EQ(std::numeric_limits<int32_t>::min(), r.Call(*i));
+      } else {
+        CHECK_EQ(*i / denom, r.Call(*i));
+      }
+    }
+  }
+}
+
+WASM_EXEC_TEST(Int32AsmjsRemS_byzero_const) {
+  for (int8_t denom = -2; denom < 8; ++denom) {
+    TestingModule module(execution_mode);
+    module.ChangeOriginToAsmjs();
+    WasmRunner<int32_t> r(&module, MachineType::Int32());
+    BUILD(r, WASM_I32_ASMJS_REMS(WASM_GET_LOCAL(0), WASM_I8(denom)));
+    FOR_INT32_INPUTS(i) {
+      if (denom == 0) {
+        CHECK_EQ(0, r.Call(*i));
+      } else if (denom == -1 && *i == std::numeric_limits<int32_t>::min()) {
+        CHECK_EQ(0, r.Call(*i));
+      } else {
+        CHECK_EQ(*i % denom, r.Call(*i));
+      }
+    }
+  }
+}
+
 WASM_EXEC_TEST(Int32DivU_byzero_const) {
   for (uint32_t denom = 0xfffffffe; denom < 8; ++denom) {
     WasmRunner<uint32_t> r(execution_mode, MachineType::Uint32());
     BUILD(r, WASM_I32_DIVU(WASM_GET_LOCAL(0), WASM_I32V_1(denom)));
 
     for (uint32_t val = 0xfffffff0; val < 8; ++val) {
       if (denom == 0) {
         CHECK_TRAP(r.Call(val));
       } else {
         CHECK_EQ(val / denom, r.Call(val));
@@ skipping 2478 matching lines @@
   BUILD(r, WASM_I32_REMS(WASM_GET_LOCAL(0), WASM_GET_LOCAL(1)), WASM_DROP,
         WASM_ZERO);
   const int32_t kMin = std::numeric_limits<int32_t>::min();
   CHECK_EQ(0, r.Call(133, 100));
   CHECK_EQ(0, r.Call(kMin, -1));
   CHECK_EQ(0, r.Call(0, 1));
   CHECK_TRAP(r.Call(100, 0));
   CHECK_TRAP(r.Call(-1001, 0));
   CHECK_TRAP(r.Call(kMin, 0));
 }