s390: [wasm][liftoff] Detect NaNs for fuzzing

Port e6961df2

Original Commit Message:

    Instrument floating-point operations to set a flag if the result is NaN.

R=martyn.capewell@arm.com, joransiu@ca.ibm.com, junyan@redhat.com, midawson@redhat.com
BUG=
LOG=N

Change-Id: I6f3fe550bf30f85bbb3fa9437d676896e876fd30
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3137418Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/main@{#76645}

src/execution/s390/simulator-s390.cc

@@ -4374,20 +4374,35 @@ EVALUATE(VFMAX) {
 #undef CASE
 
 template <class S, class D, class Operation>
-void VectorFPCompare(Simulator* sim, int dst, int src1, int src2,
+void VectorFPCompare(Simulator* sim, int dst, int src1, int src2, int m6,
                      Operation op) {
   static_assert(sizeof(S) == sizeof(D),
                 "Expect input type size == output type size");
+  bool some_zero = false;
+  bool all_zero = true;
   FOR_EACH_LANE(i, D) {
     S src1_val = sim->get_simd_register_by_lane<S>(src1, i);
     S src2_val = sim->get_simd_register_by_lane<S>(src2, i);
     D value = op(src1_val, src2_val);
     sim->set_simd_register_by_lane<D>(dst, i, value);
+    if (value) {
+      all_zero = false;
+    } else {
+      some_zero = true;
+    }
+  }
+  // TODO(miladfarca) implement other conditions.
+  if (m6) {
+    if (all_zero) {
+      sim->condition_reg_ = CC_OF;
+    } else if (some_zero) {
+      sim->condition_reg_ = 0x04;
+    }
   }
 }
 
-#define VECTOR_FP_COMPARE_FOR_TYPE(S, D, op) \
-  VectorFPCompare<S, D>(this, r1, r2, r3,    \
+#define VECTOR_FP_COMPARE_FOR_TYPE(S, D, op)  \
+  VectorFPCompare<S, D>(this, r1, r2, r3, m6, \
                         [](S a, S b) { return (a op b) ? -1 : 0; });
 
 #define VECTOR_FP_COMPARE(op)                                               \
@@ -4421,7 +4436,6 @@ void VectorFPCompare(Simulator* sim, int dst, int src1, int src2,
 EVALUATE(VFCE) {
   DCHECK_OPCODE(VFCE);
   DECODE_VRR_C_INSTRUCTION(r1, r2, r3, m6, m5, m4);
-  USE(m6);
   VECTOR_FP_COMPARE(==)
   return length;
 }

src/wasm/baseline/s390/liftoff-assembler-s390.h

@@ -3041,14 +3041,40 @@ void LiftoffAssembler::MaybeOSR() {}
 
 void LiftoffAssembler::emit_set_if_nan(Register dst, DoubleRegister src,
                                        ValueKind kind) {
-  UNIMPLEMENTED();
+  Label return_nan, done;
+  if (kind == kF32) {
+    cebr(src, src);
+    bunordered(&return_nan);
+  } else {
+    DCHECK_EQ(kind, kF64);
+    cdbr(src, src);
+    bunordered(&return_nan);
+  }
+  b(&done);
+  bind(&return_nan);
+  StoreF32LE(src, MemOperand(dst), r0);
+  bind(&done);
 }
 
 void LiftoffAssembler::emit_s128_set_if_nan(Register dst, LiftoffRegister src,
                                             Register tmp_gp,
                                             LiftoffRegister tmp_s128,
                                             ValueKind lane_kind) {
-  UNIMPLEMENTED();
+  Label return_nan, done;
+  if (lane_kind == kF32) {
+    vfce(tmp_s128.fp(), src.fp(), src.fp(), Condition(1), Condition(0),
+         Condition(2));
+    b(Condition(0x5), &return_nan);  // If any or all are NaN.
+  } else {
+    DCHECK_EQ(lane_kind, kF64);
+    vfce(tmp_s128.fp(), src.fp(), src.fp(), Condition(1), Condition(0),
+         Condition(3));
+    b(Condition(0x5), &return_nan);
+  }
+  b(&done);
+  bind(&return_nan);
+  StoreF32LE(src.fp(), MemOperand(dst), r0);
+  bind(&done);
 }
 
 void LiftoffStackSlots::Construct(int param_slots) {