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+ Comment about behavior of DBRA instruction

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git-svn-id: trunk@29321 -
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sergei 2014-12-25 09:32:10 +00:00
parent 9a72100405
commit 38d5be4182
1 changed files with 3 additions and 1 deletions
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rtl/m68k/m68k.inc
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@ -99,7 +99,9 @@ asm
ble @LMEMSET5
{$ifdef CPUM68K_HAS_DBRA}
{ FIXME: Any reason why not always just use DBRA mode on
CPUs which support it? (KB) }
CPUs which support it? (KB)
- DBRA does only 16-bit decrements, so handling more than 65535 bytes
requires additional code anyway (Sergei) }
cmpi.l #65535, d1 { check, if this is a word move }
ble @LMEMSET3 { use fast dbra mode }
{$endif CPUM68K_HAS_DBRA}