[Bug target/106453] Redundant zero extension after crc32q

[amonakov at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106453

--- Comment #1 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
Any idea if the following is reasonable? It compiles and achieves the desired
result.

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index bdde577dd..d82656678 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -23598,10 +23598,10 @@

 (define_insn "sse4_2_crc32di"
   [(set (match_operand:DI 0 "register_operand" "=r")
-       (unspec:DI
-         [(match_operand:DI 1 "register_operand" "0")
+       (zero_extend:DI (unspec:SI
+         [(match_operand:SI 1 "register_operand" "0")
           (match_operand:DI 2 "nonimmediate_operand" "rm")]
-         UNSPEC_CRC32))]
+         UNSPEC_CRC32)))]
   "TARGET_64BIT && TARGET_CRC32"
   "crc32{q}\t{%2, %0|%0, %2}"
   [(set_attr "type" "sselog1")