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From: Marcus Comstedt <marcus@mc.pp.se> To: nobody@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, Subject: Re: optimization/8867: [sh] wrong code: double use of register Date: Sat, 10 May 2003 16:36:00 -0000 [thread overview] Message-ID: <20030510163600.16540.qmail@sources.redhat.com> (raw) The following reply was made to PR optimization/8867; it has been noted by GNATS. From: Marcus Comstedt <marcus@mc.pp.se> To: Dara Hazeghi <dhazeghi@yahoo.com> Cc: gcc-gnats@gcc.gnu.org Subject: Re: optimization/8867: [sh] wrong code: double use of register Date: 10 May 2003 18:29:43 +0200 Dara Hazeghi <dhazeghi@yahoo.com> writes: > code generated by 3.3: [...] > .L5: > mov #64,r1 > add r14,r1 > mov.l @(0,r1),r2 > mov.l @(12,r1),r1 ! > add r1,r2 > mov #64,r1 * > add r14,r1 * > mov.l r2,@(0,r1) [...] This looks ok. The offset in r1 is recomputed by the instructions I marked with * to compensate for the fact that the instruction marked ! overwrites r1. > Code generated by 3.4: [...] > .L4: > add r10,r11 [...] Here, gcc has made a completely different (probably much better) register allocation, so both x and l7 are allocated to registers. Since the stack accesses are gone, there is no way to tell whether the actual bug is still there or not, but the generated code looks ok at any rate. // Marcus
next reply other threads:[~2003-05-10 16:36 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2003-05-10 16:36 Marcus Comstedt [this message] -- strict thread matches above, loose matches on Subject: below -- 2003-05-12 11:28 giovannibajo 2003-05-10 19:46 Dara Hazeghi 2003-05-10 9:16 Dara Hazeghi
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