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From: "luoxhu at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/102239] powerpc suboptimal boolean test of contiguous bits Date: Mon, 29 Nov 2021 06:36:02 +0000 [thread overview] Message-ID: <bug-102239-4-dOYCpwKxVq@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-102239-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102239 --- Comment #7 from luoxhu at gcc dot gnu.org --- 1| Dump of assembler code for function foo: 2| 0x00000000100005e0 <+0>: rldicr. r3,r3,29,1 3+> 0x00000000100005e4 <+4>: beq 0x100005f0 <foo+16> 4| 0x00000000100005e8 <+8>: blr 5| 0x00000000100005ec <+12>: ori r2,r2,0 6| 0x00000000100005f0 <+16>: blr 7| 0x00000000100005f4 <+20>: .long 0x0 8| 0x00000000100005f8 <+24>: .long 0x0 (gdb) si 0x00000000100005e4 in foo () 1: /x $r3 = 0xc000000000000000 2: /x $cr = 0x82000282 cr0 is negative if only rotldi3_mask_dot, but it was 0x42000282 on master code. BTW, clang also generated instructions with two rorates: foo(long): # @foo(long) rldicl 3, 3, 31, 33 rldicl. 3, 3, 33, 29 beq 0, .LBB0_2 blr .LBB0_2: blr .long 0 .quad 0
next prev parent reply other threads:[~2021-11-29 6:36 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-08 11:55 [Bug c/102239] New: " npiggin at gmail dot com 2021-09-09 19:40 ` [Bug target/102239] " segher at gcc dot gnu.org 2021-11-24 7:17 ` luoxhu at gcc dot gnu.org 2021-11-24 23:22 ` segher at gcc dot gnu.org 2021-11-26 8:50 ` luoxhu at gcc dot gnu.org 2021-11-26 15:53 ` segher at gcc dot gnu.org 2021-11-29 3:31 ` luoxhu at gcc dot gnu.org 2021-11-29 6:36 ` luoxhu at gcc dot gnu.org [this message] 2021-11-29 10:05 ` segher at gcc dot gnu.org 2021-11-30 5:28 ` luoxhu at gcc dot gnu.org 2021-11-30 22:59 ` segher at gcc dot gnu.org 2021-12-01 7:46 ` luoxhu at gcc dot gnu.org 2022-01-11 9:23 ` cvs-commit at gcc dot gnu.org 2022-01-12 0:27 ` luoxhu at gcc dot gnu.org
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