[wasm-simd][scalar-lowering] Fix v128.const lowering for f32x4

We need to construct Float32 nodes for f32x4, using Word32 operators
will cause the wrong register to be allocated, triggering a CHECK
failure.

Bug: v8:10507
Change-Id: I70842f1d61b90fed2407ee52af4bc5a6b1b82ba6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2399050Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69856}

src/compiler/simd-scalar-lowering.cc

@@ -1201,8 +1201,7 @@ void SimdScalarLowering::LowerNode(Node* node) {
           }
           break;
         }
-        case SimdType::kInt32x4:
-        case SimdType::kFloat32x4: {
+        case SimdType::kInt32x4: {
           uint32_t val[kNumLanes32];
           memcpy(val, params.data(), kSimd128Size);
           for (int i = 0; i < num_lanes; ++i) {
@@ -1210,6 +1209,14 @@ void SimdScalarLowering::LowerNode(Node* node) {
           }
           break;
         }
+        case SimdType::kFloat32x4: {
+          float val[kNumLanes32];
+          memcpy(val, params.data(), kSimd128Size);
+          for (int i = 0; i < num_lanes; ++i) {
+            rep_node[i] = mcgraph_->Float32Constant(val[i]);
+          }
+          break;
+        }
         default: {
           UNIMPLEMENTED();
         }

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

@@ -124,6 +124,27 @@ WASM_SIMD_TEST(I8x16Eq_ToTest_S128Const) {
   CHECK_EQ(0xffffffff, r.Call());
 }
 
+WASM_SIMD_TEST(F32x4_S128Const) {
+  // Test that S128Const lowering is done correctly when it is used as an input
+  // into a f32x4 operation. This was triggering a CHECK failure in the
+  // register-allocator-verifier.
+  TestSignatures sigs;
+  WasmRunner<float> r(execution_tier, lower_simd);
+
+  // f32x4(1.0, 2.0, 3.0, 4.0)
+  byte c1[16] = {0x00, 0x00, 0x80, 0x3f, 0x00, 0x00, 0x00, 0x40,
+                 0x00, 0x00, 0x40, 0x40, 0x00, 0x00, 0x80, 0x40};
+  // f32x4(5.0, 6.0, 7.0, 8.0)
+  byte c2[16] = {0x00, 0x00, 0xa0, 0x40, 0x00, 0x00, 0xc0, 0x40,
+                 0x00, 0x00, 0xe0, 0x40, 0x00, 0x00, 0x00, 0x41};
+
+  BUILD(r,
+        WASM_SIMD_BINOP(kExprF32x4Min, WASM_SIMD_CONSTANT(c1),
+                        WASM_SIMD_CONSTANT(c2)),
+        WASM_SIMD_OP(kExprF32x4ExtractLane), TO_BYTE(0));
+  CHECK_EQ(1.0, r.Call());
+}
+
 }  // namespace test_run_wasm_simd
 }  // namespace wasm
 }  // namespace internal