Re: [PATCH v3] RISC-V: Add autovec FP binary operations.

[Lehua Ding <lehua.ding@rivai.ai>]

Hi Robin,

> +# Return 1 if the we can build a vector example with proper -march flags
> +# and the current target can execute it, 0 otherwise.  Cache the result.
> +
> +proc check_effective_target_riscv_vector_hw { } {
> +
> +    return [check_runtime riscv_vector_hw32 {
> +        int main (void)
> +        {
> +            asm ("vsetivli zero,8,e16,m1,ta,ma");
> +            asm ("vadd.vv v8,v8,v16" : : : "v8");
> +            return 0;
> +        }
> +    } "-march=rv32gcv -mabi=ilp32d"] || [check_runtime riscv_vector_hw64 {
> +        int main (void)
> +        {
> +            asm ("vsetivli zero,8,e16,m1,ta,ma");
> +            asm ("vadd.vv v8,v8,v16" : : : "v8");
> +            return 0;
> +        }
> +    } "-march=rv64gcv -mabi=lp64d"]
> +}
> +
> +# Return 1 if the we can build a Zvfh vector example with proper -march flags
> +# and the current target can execute it, 0 otherwise.  Cache the result.
> +
> +proc check_effective_target_riscv_zvfh_hw { } {
> +    if ![check_effective_target_riscv_vector_hw] then {
> +        return 0
> +    }
> +
> +    return [check_runtime riscv_zvfh_hw32 {
> +        int main (void)
> +        {
> +            asm ("vsetivli zero,8,e16,m1,ta,ma");
> +            asm ("vfadd.vv v8,v8,v16" : : : "v8");
> +            return 0;
> +        }
> +    } "-march=rv32gcv_zvfh -mabi=ilp32d"]
> +    || [check_runtime riscv_zvfh_hw64 {
> +        int main (void)
> +        {
> +            asm ("vsetivli zero,8,e16,m1,ta,ma");
> +            asm ("vfadd.vv v8,v8,v16" : : : "v8");
> +            return 0;
> +        }
> +    } "-march=rv64gcv_zvfh -mabi=lp64d"]

May I ask if the compiler options "-march=rv64gcv_zvfh -mabi=lp64d" 
should be removed? Because we don't specify -march and -mabi when we run 
testcase (so but why we need to specify the -march and -mabi in this 
target check?), we run it with the default values. Assuming that the 
default is rv64gcv_zvfh_zfh, `riscv_vector` check will fail because 
compile and link with -march=rv64gcv will throw the following error if I 
doesn't compile a multilibs compilers. But in fact rv64gcv_zvfh_zfh 
contains rv64gcv, we should not let this case report link error.:

riscv64-unknown-elf-gcc: fatal error: Cannot find suitable multilib set 
for 
'-march=rv64imafdcv_zicsr_zifencei_zve32f_zve32x_zve64d_zve64f_zve64x_zvl128b_zvl32b_zvl64b'/'-mabi=lp64d'

I think we should use the default march and mabi to check whether we can 
compile and execute specified instructions.

-- 
Best,
Lehua