Re: [Qemu-devel] [PATCH] test-i386: Make x86 test program compile on clang

[Theodore Dubois]

ping http://patchwork.ozlabs.org/patch/786393/

~Theodore

> On Jul 10, 2017, at 1:57 PM, Theodore Dubois <address@hidden> wrote:
> 
> Clang's assembler is slightly incompatible with GCC's assembler, which
> caused the program to not compile on Clang for these reasons:
> 
>  - The "q" constraint was specified for an argument to the set
>    instruction, which didn't work because Clang chose the esi register,
>    which has no 8-bit form on i386.
>  - Clang doesn't support size suffixes on the loop instructions.
>  - Clang requires a size suffix on the fist instruction.
>  - Clang doesn't support specifying segment prefixes before the
>    instruction, and requires specifying them on the address.
>  - The arguments to the bound instruction are in the wrong order on
>    Clang. https://bugs.llvm.org/show_bug.cgi?id=27653
> 
> Signed-off-by: Theodore Dubois <address@hidden>
> ---
> tests/tcg/test-i386.c | 20 ++++++++++++++++----
> 1 file changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/tests/tcg/test-i386.c b/tests/tcg/test-i386.c
> index 0f7b943b0c..dcb8e4876e 100644
> --- a/tests/tcg/test-i386.c
> +++ b/tests/tcg/test-i386.c
> @@ -369,7 +369,7 @@ void test_lea(void)
>     asm("movl $0, %0\n\t"\
>         "cmpl %2, %1\n\t"\
>         "set" JCC " %b0\n\t"\
> -        : "=r" (res)\
> +        : "=q" (res)\
>         : "r" (v1), "r" (v2));\
>     printf("%-10s %d\n", "set" JCC, res);\
>  if (TEST_CMOV) {\
> @@ -491,15 +491,23 @@ void test_loop(void)
> 
> #if !defined(__x86_64__)
>     TEST_LOOP("jcxz");
> +#if !defined(__clang__)
>     TEST_LOOP("loopw");
>     TEST_LOOP("loopzw");
>     TEST_LOOP("loopnzw");
> #endif
> +#endif
> 
>     TEST_LOOP("jecxz");
> +#if !defined(__clang__)
>     TEST_LOOP("loopl");
>     TEST_LOOP("loopzl");
>     TEST_LOOP("loopnzl");
> +#else
> +    TEST_LOOP("loop");
> +    TEST_LOOP("loopz");
> +    TEST_LOOP("loopnz");
> +#endif
> }
> 
> #undef CC_MASK
> @@ -867,7 +875,7 @@ void test_fcvt(double a)
>         uint16_t val16;
>         val16 = (fpuc & ~0x0c00) | (i << 10);
>         asm volatile ("fldcw %0" : : "m" (val16));
> -        asm volatile ("fist %0" : "=m" (wa) : "t" (a));
> +        asm volatile ("fists %0" : "=m" (wa) : "t" (a));
>         asm volatile ("fistl %0" : "=m" (ia) : "t" (a));
>         asm volatile ("fistpll %0" : "=m" (lla) : "t" (a) : "st");
>         asm volatile ("frndint ; fstl %0" : "=m" (ra) : "t" (a));
> @@ -1318,12 +1326,12 @@ void test_segs(void)
>     seg_data1[1] = 0xaa;
>     seg_data2[1] = 0x55;
> 
> -    asm volatile ("fs movzbl 0x1, %0" : "=r" (res));
> +    asm volatile ("movzbl %%fs:0x1, %0" : "=r" (res));
>     printf("FS[1] = %02x\n", res);
> 
>     asm volatile ("pushl %%gs\n"
>                   "movl %1, %%gs\n"
> -                  "gs movzbl 0x1, %0\n"
> +                  "movzbl %%gs:0x1, %0\n"
>                   "popl %%gs\n"
>                   : "=r" (res)
>                   : "r" (MK_SEL(2)));
> @@ -1764,7 +1772,11 @@ void test_exceptions(void)
>         /* bound exception */
>         tab[0] = 1;
>         tab[1] = 10;
> +#if defined(__clang__)
> +        asm volatile ("bound %1, %0" : : "r" (11), "m" (tab[0]));
> +#else
>         asm volatile ("bound %0, %1" : : "r" (11), "m" (tab[0]));
> +#endif
>     }
> #endif
> 
> -- 
> 2.13.2
> 
> 
> 
> ~Theodore
> 
>