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From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/98694] GCC produces incorrect code for loops with -O3 for skylake-avx512 and icelake-server Date: Fri, 15 Jan 2021 08:11:18 +0000 [thread overview] Message-ID: <bug-98694-4-jt3REm5NZl@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-98694-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98694 --- Comment #1 from Hongtao.liu <crazylht at gmail dot com> --- cprop hardreg change (insn 457 499 460 33 (set (reg:SI 39 r11 [orig:86 _11 ] [86]) (reg:SI 37 r9 [orig:86 _11 ] [86])) "test.c":29:36 75 {*movsi_internal} (expr_list:REG_DEAD (reg:SI 37 r9 [orig:86 _11 ] [86]) (nil))) to (insn 457 499 460 33 (set (reg:SI 39 r11 [orig:86 _11 ] [86]) (reg:SI 22 xmm2 [orig:86 _11 ] [86])) "test.c":29:36 75 {*movsi_internal} (expr_list:REG_DEAD (reg:SI 22 xmm2 [orig:86 _11 ] [86]) (nil))) since it thought the lower 32bit of r9 and xmm2 is the same? but with xmm2 defined as kmovw %k0, %edi # 69 [c=4 l=4] *movhi_internal/6 kmovd %k0, %edx # 487 [c=4 l=3] *movsi_internal/16 vmovd %edi, %xmm2 # 489 the bit16-32 is clear with kmovw(note k0 is equal to r9 with SImode, it's var_6 in source code) (insn 69 68 70 12 (set (reg:HI 5 di [orig:96 _52 ] [96]) (reg:HI 68 k0 [orig:82 var_6.0_1 ] [82])) "test.c":21:23 76 {*movhi_internal} (nil)) (insn 489 75 78 12 (set (reg:SI 22 xmm2 [297]) (reg:SI 5 di [orig:96 _52 ] [96])) 75 {*movsi_internal} (nil))
next prev parent reply other threads:[~2021-01-15 8:11 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-01-15 1:42 [Bug tree-optimization/98694] New: " vsevolod.livinskij at frtk dot ru 2021-01-15 8:11 ` crazylht at gmail dot com [this message] 2021-01-15 9:43 ` [Bug target/98694] " marxin at gcc dot gnu.org 2021-01-15 10:03 ` [Bug target/98694] [11 Regression] " rguenth at gcc dot gnu.org 2021-01-15 16:52 ` crazylht at gmail dot com 2021-01-15 16:56 ` crazylht at gmail dot com 2021-01-15 17:22 ` crazylht at gmail dot com 2021-01-15 17:33 ` crazylht at gmail dot com 2021-01-18 9:41 ` crazylht at gmail dot com 2021-01-21 5:30 ` cvs-commit at gcc dot gnu.org 2021-01-21 5:33 ` crazylht at gmail dot com 2021-01-21 9:41 ` [Bug target/98694] " rguenth at gcc dot gnu.org 2021-01-21 11:12 ` crazylht at gmail dot com 2021-05-05 17:48 ` jakub at gcc dot gnu.org 2022-05-10 8:17 ` cvs-commit at gcc dot gnu.org 2022-10-28 23:30 ` pinskia at gcc dot gnu.org
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