jim-wilson
commented
5 years ago The function printnum has while (1) { digs[pos++] = num % base; if (num < base) break; num /= base; } This is the typical way to convert a number into a string, by using divide and modulus operations.
If you comment out the gotos, then gcc can optimize away some dead code, which is the code that calls printnum.
umoddi3 and udivdi3 come from libgcc, which is a library that contains helper functions for gcc. You should always link with libgcc.
pentin-as
aswaterman
I'm using the toolchain with RV32I. I compile benchmarks (which support the corresponding extension).
I have an error: Debug/common/syscalls.c.o: In function '.L46': syscalls.c:(.text+0x224): undefined reference to 'umoddi3' Debug/common/syscalls.c.o: In function '.L57': syscalls.c:(.text+0x242): undefined reference to 'udivdi3' syscalls.c:(.text+0x252): undefined reference to '__umoddi3'
This is the assembly file to which the syscall.c file is being compiled: syscalls.c.s.txt
If I comment goto on signed_number (line 305) and unsigned_number (lines 310 and 316), everything works. https://github.com/riscv/riscv-tests/blob/294bfce8a1ca2fc501b8939292146e44f813a2b8/benchmarks/common/syscalls.c#L305 https://github.com/riscv/riscv-tests/blob/294bfce8a1ca2fc501b8939292146e44f813a2b8/benchmarks/common/syscalls.c#L310 https://github.com/riscv/riscv-tests/blob/294bfce8a1ca2fc501b8939292146e44f813a2b8/benchmarks/common/syscalls.c#L316
I understand that in order for __umoddi3 (and so on) to appear in the project, I must link newlib, which in the benchmarks does not link. But I do not understand why the goto may need division and the remainder of the division. I think this is a mistake.
I'm attaching my test case (without toolchain). test_rv32i.zip