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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/106277] missed-optimization: redundant movzx Date: Wed, 13 Jul 2022 15:49:52 +0000 [thread overview] Message-ID: <bug-106277-4-WtBwToR7O3@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-106277-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106277 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2022-07-13 Ever confirmed|0 |1 --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Because the RTL does not describe the load is zero-extended to SI: (insn 9 8 10 2 (set (reg:QI 91 [ *b_6(D) ]) (mem:QI (reg:DI 93) [0 *b_6(D)+0 S1 A8])) "/app/example.cpp":4:31 85 {*movqi_internal} (expr_list:REG_DEAD (reg:DI 93) (nil))) (insn 10 9 11 2 (parallel [ (set (reg:QI 89) (plus:QI (mem:QI (reg:DI 92) [0 *a_5(D)+0 S1 A8]) (reg:QI 91 [ *b_6(D) ]))) (clobber (reg:CC 17 flags)) ]) "/app/example.cpp":4:31 235 {*addqi_1} (expr_list:REG_DEAD (reg:DI 92) (expr_list:REG_UNUSED (reg:CC 17 flags) (expr_list:REG_DEAD (reg:QI 91 [ *b_6(D) ]) (nil))))) (insn 11 10 16 2 (set (reg:SI 88) (zero_extend:SI (reg:QI 89))) "/app/example.cpp":4:35 152 {*zero_extendqisi2} (expr_list:REG_DEAD (reg:QI 89) (nil))) That is why.
next prev parent reply other threads:[~2022-07-13 15:49 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-07-13 2:16 [Bug middle-end/106277] New: " jl1184 at duke dot edu 2022-07-13 15:49 ` pinskia at gcc dot gnu.org [this message] 2022-07-13 16:06 ` [Bug target/106277] " amonakov at gcc dot gnu.org
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