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+AVX128: VPERM{Q,PD} can be more optimized
+We only hand optimize four selectors out of the total 256. Anything that falls out of those four turns in to a zero-register plus four inserts which is pretty bad. We don't have these sitting in instcountci at all right now.
+
+An example of the bad output.
+```json
+    "vpermpd ymm0, ymm1, 01101011b": {
+      "ExpectedInstructionCount": 9,
+      "Comment": [
+        "Map 3 0b01 0x01 256-bit"
+      ],
+      "ExpectedArm64ASM": [
+        "ldr q2, [x28, #32]",
+        "movi v3.2d, #0x0",
+        "mov v4.16b, v3.16b",
+        "mov v4.d[0], v2.d[1]",
+        "mov v16.16b, v4.16b",
+        "mov v16.d[1], v2.d[0]",
+        "mov v3.d[0], v2.d[0]",
+        "mov v3.d[1], v17.d[1]",
+        "str q3, [x28, #16]"
+      ]
+    },
+``` 
+
+Theoretically worst case should devolve in to a TBL2 instruction which would be better than that mess of inserts, and of course we should support solving more selectors with handwritten optimizations.
+
+VPERMQ and VPERMPD are aliases of each other so they behave the same.
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