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

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

Index: test/cctest/wasm/test-run-wasm-simd.cc
diff --git a/test/cctest/wasm/test-run-wasm-simd.cc b/test/cctest/wasm/test-run-wasm-simd.cc
index eb05a02ac1e014cb50346639d00fd1d3e15b8690..cee924d87c10f050e34e00b8cfdcc73e22d45272 100644
--- a/test/cctest/wasm/test-run-wasm-simd.cc
+++ b/test/cctest/wasm/test-run-wasm-simd.cc
@@ -236,7 +236,10 @@ void RunF32x4BinOpTest(WasmOpcode simd_op, FloatBinOp expected_op) {
     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));
     }
   }
 }
@@ -265,6 +268,9 @@ void RunF32x4CompareOpTest(WasmOpcode simd_op, FloatCompareOp expected_op) {
     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)));
     }
   }