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From: cinap_lenrek@felloff.net
To: 9front@9front.org
Subject: Re: [9front] Re: [9front] reform hjfs file creation broken in current release and after
Date: Wed, 05 Jul 2023 02:02:52 +0200	[thread overview]
Message-ID: <F3A5ED8754709FED1D5A28F39DAD5AA7@felloff.net> (raw)
In-Reply-To: <19324C57-6024-44E1-9F78-F5564055B6BB@stanleylieber.com>

ok, found it and pushed a fix to 7c.

The problem was the line

uvlong i;
int j;

i = j = -1;

generating:

MOVW $-1, R1			<- !!!!
/* SXTW R1, R1			<- missing */
MOVW R1, j+xxx(SP)
MOV R1, i+xxx(SP)

the SXTW was missing because of an optimisation,
eliding these SXTW's as MOVW generally sign
extends already so the SXTW instruction is
not needed...

but there is an exception!

MOVW with a *CONSTANT* is actually equivalent to
MOVWU and always zero extends! (because you
could'v just used MOV instead if you wanted 64-bit?)

fixed the optimiser handling this special case.

--
cinap

  parent reply	other threads:[~2023-07-05  0:04 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-04  4:51 Stanley Lieber
2023-07-04 13:26 ` Sigrid Solveig Haflínudóttir
2023-07-04 19:07   ` sl
2023-07-04 19:46     ` Sigrid Solveig Haflínudóttir
2023-07-04 20:18       ` [9front] " Stanley Lieber
2023-07-04 20:24       ` Stanley Lieber
2023-07-04 21:13         ` cinap_lenrek
2023-07-04 21:30           ` sl
2023-07-05  0:02         ` cinap_lenrek [this message]
2023-07-05  2:26           ` sl
2023-07-05 10:57             ` cinap_lenrek
2023-07-05 11:21               ` cinap_lenrek
2023-07-05 14:05               ` [9front] " Stanley Lieber
2023-07-06  7:05                 ` cinap_lenrek

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