[machinst x64]: add punpack[hl]bw instructions

cranelift/codegen/src/isa/x64/inst/args.rs

@@ -482,6 +482,8 @@ pub enum SseOpcode {
     Psubusb,
     Psubusw,
     Ptest,
+    Punpckhbw,
+    Punpcklbw,
     Pxor,
     Rcpss,
     Roundss,
@@ -616,6 +618,8 @@ impl SseOpcode {
             | SseOpcode::Psubsw
             | SseOpcode::Psubusb
             | SseOpcode::Psubusw
+            | SseOpcode::Punpckhbw
+            | SseOpcode::Punpcklbw
             | SseOpcode::Pxor
             | SseOpcode::Sqrtpd
             | SseOpcode::Sqrtsd
@@ -783,6 +787,8 @@ impl fmt::Debug for SseOpcode {
             SseOpcode::Psubusb => "psubusb",
             SseOpcode::Psubusw => "psubusw",
             SseOpcode::Ptest => "ptest",
+            SseOpcode::Punpckhbw => "punpckhbw",
+            SseOpcode::Punpcklbw => "punpcklbw",
             SseOpcode::Pxor => "pxor",
             SseOpcode::Rcpss => "rcpss",
             SseOpcode::Roundss => "roundss",

cranelift/codegen/src/isa/x64/inst/emit.rs

@@ -1826,6 +1826,8 @@ pub(crate) fn emit(
                 SseOpcode::Psubsw => (LegacyPrefixes::_66, 0x0FE9, 2),
                 SseOpcode::Psubusb => (LegacyPrefixes::_66, 0x0FD8, 2),
                 SseOpcode::Psubusw => (LegacyPrefixes::_66, 0x0FD9, 2),
+                SseOpcode::Punpckhbw => (LegacyPrefixes::_66, 0x0F68, 2),
+                SseOpcode::Punpcklbw => (LegacyPrefixes::_66, 0x0F60, 2),
                 SseOpcode::Pxor => (LegacyPrefixes::_66, 0x0FEF, 2),
                 SseOpcode::Subps => (LegacyPrefixes::None, 0x0F5C, 2),
                 SseOpcode::Subpd => (LegacyPrefixes::_66, 0x0F5C, 2),

cranelift/codegen/src/isa/x64/inst/emit_tests.rs

@@ -3157,6 +3157,18 @@ fn test_x64_emit() {
         "packsswb %xmm11, %xmm2",
     ));
 
+    insns.push((
+        Inst::xmm_rm_r(SseOpcode::Punpckhbw, RegMem::reg(xmm3), w_xmm2),
+        "660F68D3",
+        "punpckhbw %xmm3, %xmm2",
+    ));
+
+    insns.push((
+        Inst::xmm_rm_r(SseOpcode::Punpcklbw, RegMem::reg(xmm1), w_xmm8),
+        "66440F60C1",
+        "punpcklbw %xmm1, %xmm8",
+    ));
+
     // ========================================================
     // XMM_RM_R: Integer Conversion
     insns.push((