[wasm-simd][liftoff][ia32][x64] Implement load splat

Bug: v8:9909
Change-Id: Ic3a13131e07487512161eec1bec0cdc33a0a3f63
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2207664Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67986}

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

@@ -2137,8 +2137,8 @@ void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
                  static_cast<int32_t>(offset_imm)};
   *protected_load_pc = pc_offset();
 
+  MachineType memtype = type.mem_type();
   if (transform == LoadTransformationKind::kExtend) {
-    MachineType memtype = type.mem_type();
     if (memtype == MachineType::Int8()) {
       Pmovsxbw(dst.fp(), src_op);
     } else if (memtype == MachineType::Uint8()) {
@@ -2154,7 +2154,19 @@ void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
     }
   } else {
     DCHECK_EQ(LoadTransformationKind::kSplat, transform);
-    bailout(kSimd, "load splats unimplemented");
+    if (memtype == MachineType::Int8()) {
+      Pinsrb(dst.fp(), src_op, 0);
+      Pxor(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg);
+      Pshufb(dst.fp(), liftoff::kScratchDoubleReg);
+    } else if (memtype == MachineType::Int16()) {
+      Pinsrw(dst.fp(), src_op, 0);
+      Pshuflw(dst.fp(), dst.fp(), uint8_t{0});
+      Punpcklqdq(dst.fp(), dst.fp());
+    } else if (memtype == MachineType::Int32()) {
+      Vbroadcastss(dst.fp(), src_op);
+    } else if (memtype == MachineType::Int64()) {
+      Movddup(dst.fp(), src_op);
+    }
   }
 }
 

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

@@ -2183,8 +2183,8 @@ void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
   }
   Operand src_op = liftoff::GetMemOp(this, src_addr, offset_reg, offset_imm);
   *protected_load_pc = pc_offset();
+  MachineType memtype = type.mem_type();
   if (transform == LoadTransformationKind::kExtend) {
-    MachineType memtype = type.mem_type();
     if (memtype == MachineType::Int8()) {
       Pmovsxbw(dst.fp(), src_op);
     } else if (memtype == MachineType::Uint8()) {
@@ -2200,7 +2200,25 @@ void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
     }
   } else {
     DCHECK_EQ(LoadTransformationKind::kSplat, transform);
-    bailout(kSimd, "load splats unimplemented");
+    if (memtype == MachineType::Int8()) {
+      Pinsrb(dst.fp(), src_op, 0);
+      Pxor(kScratchDoubleReg, kScratchDoubleReg);
+      Pshufb(dst.fp(), kScratchDoubleReg);
+    } else if (memtype == MachineType::Int16()) {
+      Pinsrw(dst.fp(), src_op, 0);
+      Pshuflw(dst.fp(), dst.fp(), uint8_t{0});
+      Punpcklqdq(dst.fp(), dst.fp());
+    } else if (memtype == MachineType::Int32()) {
+      if (CpuFeatures::IsSupported(AVX)) {
+        CpuFeatureScope avx_scope(this, AVX);
+        vbroadcastss(dst.fp(), src_op);
+      } else {
+        Movss(dst.fp(), src_op);
+        Shufps(dst.fp(), dst.fp(), byte{0});
+      }
+    } else if (memtype == MachineType::Int64()) {
+      Movddup(dst.fp(), src_op);
+    }
   }
 }