rando@skipper.dfrf.nasa.gov (Randy Brumbaugh) (11/07/90)
I feel I have had more than my fair share of problems with the 3L C compiler (IMHO). Now this . . . The 3L compiler/ assembler doesn't like the constant 0x20800000. Yes! That's right! It turns out that this is a very important constant for my application. Here is the input: func() { asm { ldc 0x20800000; } } This will produce an error message about an undefined forward reference. However, either of the following (very similar) functions will compile: func() { asm { ldc 0x30800000; } } func() { asm { ldc 0x10400000; } } Thinking it was the hex expression it didn't like, I tried good ol' base 10: func() { asm { ldc 545259520; } } Same problem; same error. Then I thought I had a way to fool the compiler: literal bytes of machine code. (It was VERY important that I load this constant - it is an address for a memory mapped i/o register ). func() { asm { byte 0x22, 0x20, 0x28, 0x20, 0x20, 0x20, 0x20, 0x40;}} But the compiler caught this and barfed again! It only seems to happen in asm statements -- the C compiler can use the constant. So? If anybody has an explanation for this that is even close to rational, I'd really like to hear it! Or - if the error doesn't happen on your system! I have V 2.0 of the compiler, which I admit is one rev out, but this behavior is way out! If you care, I did fool the compiler and load the constant like this: func() { asm { ldc 0x10400000; ldc 2; shl; } } I also figured I could use Norton Utils and patch the .bin file. These methods will work while I scrape money together for a Logical Systems C compiler. Randy Brumbaugh rando@skipper.dfrf.nasa.gov
rando@skipper.dfrf.nasa.gov (Randy Brumbaugh) (11/07/90)
I meant "ldc 1" NOT "ldc 2" in the code at the end of the original posting. I expect I'll get enough interesting replies without this little mistake. Sorry.
galuska@udel.edu (Scott Galuska) (11/08/90)
In article <671@skipper.dfrf.nasa.gov> rando@skipper.dfrf.nasa.gov (Randy Brumbaugh) writes: >I feel I have had more than my fair share of problems with the >3L C compiler (IMHO). Now this . . . >The 3L compiler/ assembler doesn't like the constant 0x20800000. >Yes! That's right! It turns out that this is a very important >constant for my application. Here is the input: >func() { asm { ldc 0x20800000; } } >This will produce an error message about an undefined forward >reference. However, either of the following (very similar) >functions will compile: Welcome to the club! I had a very similar problem- for me, it choked on ldc 32; /* decimal */ And I tried also to fool it- I used hex, octal, binary. didn't like any of 'em! What I eventually did was to assign the value to a variable outside of the asm section and then use the variable. That worked. >rational, I'd really like to hear it! Or - if the error doesn't >happen on your system! I have V 2.0 of the compiler, which I admit >is one rev out, but this behavior is way out! This alos happened to me in V2.0. When I upgraded to V2.1, the error went away. I also tried yours on V2.1- it compiled just fine. -- Scott Galuska Dept. of Computer & Info. Science Univ of Delaware galuska@dewey.udel.edu