[wasm-simd][liftoff][ia32][x64] Implement v128.load_zero

Implement v128.load32_zero and v128.load64_zero on Liftoff, only for
ia32 and x64. ARM will follow.

Bug: v8:11038
Change-Id: I0fad054f462e27eb60825258dad385244b5e5a95
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2486236
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70782}

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

@@ -2257,6 +2257,8 @@ void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
            NeonMemOperand(actual_src_addr));
       vmovl(NeonU32, liftoff::GetSimd128Register(dst), dst.low_fp());
     }
+  } else if (transform == LoadTransformationKind::kZeroExtend) {
+    bailout(kSimd, "v128.load_zero unimplemented");
   } else {
     DCHECK_EQ(LoadTransformationKind::kSplat, transform);
     if (memtype == MachineType::Int8()) {

src/wasm/baseline/arm64/liftoff-assembler-arm64.h

@@ -1505,6 +1505,8 @@ void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
       Ldr(dst.fp().D(), src_op);
       Uxtl(dst.fp().V2D(), dst.fp().V2S());
     }
+  } else if (transform == LoadTransformationKind::kZeroExtend) {
+    bailout(kSimd, "v128.load_zero unimplemented");
   } else {
     // ld1r only allows no offset or post-index, so emit an add.
     DCHECK_EQ(LoadTransformationKind::kSplat, transform);

src/wasm/baseline/ia32/liftoff-assembler-ia32.h

@@ -2663,6 +2663,13 @@ void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
     } else if (memtype == MachineType::Uint32()) {
       Pmovzxdq(dst.fp(), src_op);
     }
+  } else if (transform == LoadTransformationKind::kZeroExtend) {
+    if (memtype == MachineType::Int32()) {
+      movss(dst.fp(), src_op);
+    } else {
+      DCHECK_EQ(MachineType::Int64(), memtype);
+      movsd(dst.fp(), src_op);
+    }
   } else {
     DCHECK_EQ(LoadTransformationKind::kSplat, transform);
     if (memtype == MachineType::Int8()) {

src/wasm/baseline/liftoff-compiler.cc

@@ -2291,15 +2291,11 @@ class LiftoffCompiler {
       return;
     }
 
-    if (transform == LoadTransformationKind::kZeroExtend) {
-      unsupported(decoder, kSimd, "prototyping s128 load zero extend");
-      return;
-    }
-
     LiftoffRegList pinned;
     Register index = pinned.set(__ PopToRegister()).gp();
-    // For load splats, LoadType is the size of the load, and for load
-    // extends, LoadType is the size of the lane, and it always loads 8 bytes.
+    // For load splats and load zero, LoadType is the size of the load, and for
+    // load extends, LoadType is the size of the lane, and it always loads 8
+    // bytes.
     uint32_t access_size =
         transform == LoadTransformationKind::kExtend ? 8 : type.size();
     if (BoundsCheckMem(decoder, access_size, imm.offset, index, pinned,

src/wasm/baseline/x64/liftoff-assembler-x64.h

@@ -2287,6 +2287,13 @@ void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
     } else if (memtype == MachineType::Uint32()) {
       Pmovzxdq(dst.fp(), src_op);
     }
+  } else if (transform == LoadTransformationKind::kZeroExtend) {
+    if (memtype == MachineType::Int32()) {
+      Movss(dst.fp(), src_op);
+    } else {
+      DCHECK_EQ(MachineType::Int64(), memtype);
+      Movsd(dst.fp(), src_op);
+    }
   } else {
     DCHECK_EQ(LoadTransformationKind::kSplat, transform);
     if (memtype == MachineType::Int8()) {