Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!overload!dillon From: dillon@overload.Berkeley.CA.US (Matthew Dillon) Newsgroups: comp.sys.amiga.programmer Subject: Re: Macro-68 Questions Message-ID: Date: 12 May 91 17:50:11 GMT References: <1991May8.205935.26761@unislc.uucp> <1991May10.193126.29483@starnet.uucp> Organization: Not an Organization Lines: 42 In article <1991May10.193126.29483@starnet.uucp> sschaem@starnet.uucp (Stephan Schaem) writes: > > > No , you wont use HI and EQ, but CC and VS. > Usally only CC is nesesary... You could say that CC can replace HS. > VS is to check that if you didn't branch it wasn't cause by a carry > set... > > Stephan. you only need one branch, the confusion is due to motorola never equiviacting BCC and BCS. BCC == BHS >= 0 unsigned comparison BCS == BLO < 0 unsigned BHI > 0 unsigned BLS <= 0 unsigned BGE >= 0 signed comparison BLT < 0 signed BGT > 0 signed BLE <= 0 signed BMI < 0 after test (note that BLT is < 0 after a signed compare, same as BMI except that overflow is checked for. However, after a TST or MOVE instruction, BMI is the same as BLT because the V bit is set to zero). BEQ == 0 BNE != 0 BVC no overflow on signed operation BVS overflow on signed operation -Matt -- Matthew Dillon dillon@Overload.Berkeley.CA.US 891 Regal Rd. uunet.uu.net!overload!dillon Berkeley, Ca. 94708 USA