Update testsuite (#1381)

* Add i{8x16,16x8,32x4}.abs instructions
* Implement IntAbs in interp-math.h

3 files changed, 19 insertions, 0 deletions

diff --git a/src/interp/interp-math.h b/src/interp/interp-math.h
index c3876810..f0ff96ef 100644
--- a/src/interp/interp-math.h
+++ b/src/interp/interp-math.h
@@ -91,6 +91,18 @@ template <typename T> T WABT_VECTORCALL IntAndNot(T lhs, T rhs) { return lhs & ~
 template <typename T> T WABT_VECTORCALL IntAvgr(T lhs, T rhs) { return (lhs + rhs + 1) / 2; }
 template <typename T> T WABT_VECTORCALL Xchg(T lhs, T rhs) { return rhs; }
 
+// This is a wrapping absolute value function, so a negative number that is not
+// representable as a positive number will be unchanged (e.g. abs(-128) = 128).
+//
+// Note that std::abs() does not have this behavior (e.g. abs(-128) is UB).
+// Similarly, using unary minus is also UB.
+template <typename T>
+T WABT_VECTORCALL IntAbs(T val) {
+  static_assert(std::is_unsigned<T>::value, "T must be unsigned.");
+  const auto signbit = T(-1) << (sizeof(T) * 8 - 1);
+  return (val & signbit) ? ~val + 1 : val;
+}
+
 // Because of the integer promotion rules [1], any value of a type T which is
 // smaller than `int` will be converted to an `int`, as long as `int` can hold
 // any value of type T.
diff --git a/src/interp/interp.cc b/src/interp/interp.cc
index 672f5a4f..57b0750f 100644
--- a/src/interp/interp.cc
+++ b/src/interp/interp.cc
@@ -1603,6 +1603,10 @@ RunResult Thread::StepInternal(Trap::Ptr* out_trap) {
     case O::I8X16AvgrU: return DoSimdBinop(IntAvgr<u8>);
     case O::I16X8AvgrU: return DoSimdBinop(IntAvgr<u16>);
 
+    case O::I8X16Abs: return DoSimdUnop(IntAbs<u8>);
+    case O::I16X8Abs: return DoSimdUnop(IntAbs<u16>);
+    case O::I32X4Abs: return DoSimdUnop(IntAbs<u32>);
+
     case O::AtomicNotify:
     case O::I32AtomicWait:
     case O::I64AtomicWait:
diff --git a/src/interp/istream.cc b/src/interp/istream.cc
index a45eb57a..ad92ce97 100644
--- a/src/interp/istream.cc
+++ b/src/interp/istream.cc
@@ -212,6 +212,9 @@ Instr Istream::Read(Offset* offset) const {
     case Opcode::I8X16Splat:
     case Opcode::RefIsNull:
     case Opcode::V128Not:
+    case Opcode::I8X16Abs:
+    case Opcode::I16X8Abs:
+    case Opcode::I32X4Abs:
       // 0 immediates, 1 operand.
       instr.kind = InstrKind::Imm_0_Op_1;
       break;