https://community.hpe.com/t5/operating-system-linux/pa-risc2-0-assembly/m-p/3541777#M101593 I have a problem with a cast. A program is<BR />doing something roughly like this:<BR /><BR />#define NUM 45<BR />short n;<BR />n = 45;<BR /><BR />if (n == NUM)<BR /><BR />Ok, things are a bit more complex but...<BR />In the asm gerenated, we load the 45 in N<BR />from the stack frame where it was saved:<BR /><BR /> LDH -60(%r30),%r22 ;offset 0x40<BR /> EXTRW,S %r22,31,16,%r1 ;offset 0x44<BR /><BR />Then we extract the short value. My question<BR />is: Is the EXTRW,S ... a MUST be instruction?<BR />Isn't the LDH instruction expected to <BR />clear out the remaining bytes of the register?<BR /><BR />Reason I ask is that I have one program<BR />that fails the 'if' test though the value<BR />in memory is correct. However, the generated<BR />asm does not include the EXTRW instruction.<BR /><BR />Thank you<BR /><BR />dalla<BR /> Tue, 10 May 2005 21:31:43 GMT dalla-santa_1 2005-05-10T21:31:43Z https://community.hpe.com/t5/operating-system-linux/pa-risc2-0-assembly/m-p/3541777#M101593 I have a problem with a cast. A program is<BR />doing something roughly like this:<BR /><BR />#define NUM 45<BR />short n;<BR />n = 45;<BR /><BR />if (n == NUM)<BR /><BR />Ok, things are a bit more complex but...<BR />In the asm gerenated, we load the 45 in N<BR />from the stack frame where it was saved:<BR /><BR /> LDH -60(%r30),%r22 ;offset 0x40<BR /> EXTRW,S %r22,31,16,%r1 ;offset 0x44<BR /><BR />Then we extract the short value. My question<BR />is: Is the EXTRW,S ... a MUST be instruction?<BR />Isn't the LDH instruction expected to <BR />clear out the remaining bytes of the register?<BR /><BR />Reason I ask is that I have one program<BR />that fails the 'if' test though the value<BR />in memory is correct. However, the generated<BR />asm does not include the EXTRW instruction.<BR /><BR />Thank you<BR /><BR />dalla<BR /> Tue, 10 May 2005 21:31:43 GMT https://community.hpe.com/t5/operating-system-linux/pa-risc2-0-assembly/m-p/3541777#M101593 dalla-santa_1 2005-05-10T21:31:43Z https://community.hpe.com/t5/operating-system-linux/pa-risc2-0-assembly/m-p/3541778#M101594 The EXTRW,S is needed if "n" contains a negative value. If "n" was unsigned short, it wouldn't be needed. Thu, 09 Mar 2006 22:42:44 GMT https://community.hpe.com/t5/operating-system-linux/pa-risc2-0-assembly/m-p/3541778#M101594 Dennis Handly 2006-03-09T22:42:44Z