[Liftoff][arm] Fix stack moves

Use the right register type for the temporary register.

R=titzer@chromium.org

Bug: v8:6600, chromium:917588
Change-Id: Ia2617f6b406924ca7f496608fd495faf04dff25b
Reviewed-on: https://chromium-review.googlesource.com/c/1403127Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58711}

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

@@ -499,7 +499,7 @@ void LiftoffAssembler::LoadCallerFrameSlot(LiftoffRegister dst,
 void LiftoffAssembler::MoveStackValue(uint32_t dst_index, uint32_t src_index,
                                       ValueType type) {
   DCHECK_NE(dst_index, src_index);
-  LiftoffRegister reg = GetUnusedRegister(kGpReg);
+  LiftoffRegister reg = GetUnusedRegister(reg_class_for(type));
   Fill(reg, src_index, type);
   Spill(dst_index, reg, type);
 }

test/mjsunit/regress/wasm/regress-917588b.js

+// Copyright 2019 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.
+
+load('test/mjsunit/wasm/wasm-constants.js');
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+const builder = new WasmModuleBuilder();
+const sig0 = builder.addType(makeSig([kWasmF32], [kWasmI32]));
+const sig1 = builder.addType(makeSig([kWasmI64, kWasmI32, kWasmI64, kWasmF32, kWasmI64], [kWasmF32]));
+const sig2 = builder.addType(makeSig([kWasmF32], [kWasmF32]));
+// Generate function 1 (out of 3).
+builder.addFunction(undefined, sig0).addBody([kExprI32Const, 0x00]);
+// Generate function 2 (out of 3).
+builder.addFunction(undefined, sig1)
+  .addBody([
+    // signature: f_lilfl
+    kExprBlock, kWasmF32,   // @1 f32
+    kExprI32Const, 0x00,
+    kExprIf, kWasmStmt,   // @5
+      kExprLoop, kWasmStmt,   // @7
+        kExprBlock, kWasmI32,   // @9 i32
+          kExprF32Const, 0x00, 0x00, 0x80, 0xc1,
+          kExprF32Const, 0x00, 0x00, 0x80, 0x45,
+          kExprCallFunction, 0x00, // function #0: i_f
+          kExprBrIf, 0x03,   // depth=3
+          kExprDrop,
+          kExprI32Const, 0xd8, 0x00,
+          kExprEnd,   // @29
+        kExprBrIf, 0x00,   // depth=0
+        kExprEnd,   // @32
+      kExprF32Const, 0x00, 0x00, 0x80, 0x3f,
+      kExprF32Const, 0x00, 0x00, 0x80, 0xc6,
+      kExprBlock, kWasmI32,   // @43 i32
+        kExprF32Const, 0x00, 0x00, 0x80, 0x3f,
+        kExprCallFunction, 0x02, // function #2: f_f
+        kExprDrop,
+        kExprI32Const, 0x68,
+        kExprEnd,   // @55
+      kExprBrIf, 0x01,   // depth=1
+      kExprI32Const, 0x00,
+      kExprSelect,
+      kExprDrop,
+      kExprUnreachable,
+    kExprElse,   // @63
+      kExprNop,
+      kExprEnd,   // @65
+    kExprF32Const, 0x00, 0x00, 0x69, 0x43,
+    kExprEnd   // @71
+]);
+// Generate function 3 (out of 3).
+builder.addFunction(undefined, sig2).addBody([
+  kExprF32Const, 0x00, 0x00, 0x80, 0x3f
+]);
+builder.instantiate();