On 6/29/24 01:56, Akihiko Odaki wrote:
> clang version 18.1.6 does not allow specifying an integer as the value
> of a single-precision register. Manually bit-cast into float with vmov
> first.
>
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> ---
> tests/tcg/arm/fcvt.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/tests/tcg/arm/fcvt.c b/tests/tcg/arm/fcvt.c
> index f631197287a1..5263f607b59c 100644
> --- a/tests/tcg/arm/fcvt.c
> +++ b/tests/tcg/arm/fcvt.c
> @@ -355,7 +355,9 @@ static void convert_half_to_single(void)
>
> print_half_number(i, input);
> #if defined(__arm__)
> - asm("vcvtb.f32.f16 %0, %1" : "=w" (output) : "x" ((uint32_t)input));
> + float tmp;
> + asm("vmov %0, %1" : "=w" (tmp) : "r" (input));
> + asm("vcvtb.f32.f16 %0, %1" : "=w" (output) : "x" (tmp));
> #else
> asm("fcvt %s0, %h1" : "=w" (output) : "w" (input));
> #endif
Better as
#if defined(__arm__)
- asm("vcvtb.f32.f16 %0, %1" : "=w" (output) : "x" ((uint32_t)input));
+ /*
+ * Clang refuses to allocate an integer to a fp register.
+ * Perform the move from a general register by hand.
+ */
+ asm("vmov %0, %1\n\t"
+ "vcvtb.f32.f16 %0, %0" : "=w" (output) : "r" (input));
#else
without the C temporary. With that,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~