[WASM] Skip SIMD test values that may result in denormalized numbers.

test/cctest/wasm/test-run-wasm-simd.cc

 // Copyright 2016 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/wasm/wasm-macro-gen.h"
 
 #include "test/cctest/cctest.h"
 #include "test/cctest/compiler/value-helper.h"
 #include "test/cctest/wasm/wasm-run-utils.h"
 
@@ skipping 218 matching lines @@
                WASM_SET_LOCAL(simd1, WASM_SIMD_BINOP(simd_op & 0xffu,
                                                      WASM_GET_LOCAL(simd0),
                                                      WASM_GET_LOCAL(simd1))),
                WASM_SIMD_CHECK_SPLAT4_F32(F32x4, simd1, expected),
                WASM_RETURN1(WASM_ONE)));
 
   FOR_FLOAT32_INPUTS(i) {
     if (std::isnan(*i)) continue;
     FOR_FLOAT32_INPUTS(j) {
       if (std::isnan(*j)) continue;
-      CHECK_EQ(1, r.Call(*i, *j, expected_op(*i, *j)));
+      float expected = expected_op(*i, *j);

[titzer, 2016/12/21 10:19:08]

IIUC, arm does flush-to-zero for sub-normal numbers, so we could make this check
more strict and check against zero.

Can you add a TODO here to that effect?

[bbudge, 2016/12/21 15:03:39]

Done.

+      // SIMD on some platforms may handle denormalized numbers differently.
+      if (std::fpclassify(expected) == FP_SUBNORMAL) continue;
+      CHECK_EQ(1, r.Call(*i, *j, expected));
     }
   }
 }
 
 WASM_EXEC_TEST(F32x4Add) { RunF32x4BinOpTest(kExprF32x4Add, Add); }
 WASM_EXEC_TEST(F32x4Sub) { RunF32x4BinOpTest(kExprF32x4Sub, Sub); }
 
 void RunF32x4CompareOpTest(WasmOpcode simd_op, FloatCompareOp expected_op) {
   FLAG_wasm_simd_prototype = true;
   WasmRunner<int32_t, float, float, int32_t> r(kExecuteCompiled);
   byte a = 0;
   byte b = 1;
   byte expected = 2;
   byte simd0 = r.AllocateLocal(kAstS128);
   byte simd1 = r.AllocateLocal(kAstS128);
   BUILD(r, WASM_BLOCK(
                WASM_SET_LOCAL(simd0, WASM_SIMD_F32x4_SPLAT(WASM_GET_LOCAL(a))),
                WASM_SET_LOCAL(simd1, WASM_SIMD_F32x4_SPLAT(WASM_GET_LOCAL(b))),
                WASM_SET_LOCAL(simd1, WASM_SIMD_BINOP(simd_op & 0xffu,
                                                      WASM_GET_LOCAL(simd0),
                                                      WASM_GET_LOCAL(simd1))),
                WASM_SIMD_CHECK_SPLAT4(I32x4, simd1, I32, expected),
                WASM_RETURN1(WASM_ONE)));
 
   FOR_FLOAT32_INPUTS(i) {
     if (std::isnan(*i)) continue;
     FOR_FLOAT32_INPUTS(j) {
       if (std::isnan(*j)) continue;
+      // SIMD on some platforms may handle denormalized numbers differently.
+      // Check for number pairs that are very close together.
+      if (std::fpclassify(*i - *j) == FP_SUBNORMAL) continue;
       CHECK_EQ(1, r.Call(*i, *j, expected_op(*i, *j)));
     }
   }
 }
 
 WASM_EXEC_TEST(F32x4Equal) { RunF32x4CompareOpTest(kExprF32x4Eq, Equal); }
 WASM_EXEC_TEST(F32x4NotEqual) { RunF32x4CompareOpTest(kExprF32x4Ne, NotEqual); }
 #endif  // V8_TARGET_ARCH_ARM
 
 WASM_EXEC_TEST(I32x4Splat) {
@@ skipping 147 matching lines @@
 
 WASM_EXEC_TEST(I32x4Add) { RunI32x4BinOpTest(kExprI32x4Add, Add); }
 
 WASM_EXEC_TEST(I32x4Sub) { RunI32x4BinOpTest(kExprI32x4Sub, Sub); }
 
 #if V8_TARGET_ARCH_ARM
 WASM_EXEC_TEST(I32x4Equal) { RunI32x4BinOpTest(kExprI32x4Eq, Equal); }
 
 WASM_EXEC_TEST(I32x4NotEqual) { RunI32x4BinOpTest(kExprI32x4Ne, NotEqual); }
 #endif  // V8_TARGET_ARCH_ARM