On Sun, Mar 9, 2025 at 11:34 PM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> While working on a local x86 patch, which passed the GCC testsuite, I got
> a compiler error:
>
> In function ‘paravirt_read_msr’,
> inlined from ‘perf_ibs_handle_irq’ at arch/x86/events/amd/ibs.c:1055:2:
> ./arch/x86/include/asm/paravirt_types.h:397:17: error: ‘asm’ operand has
> impossible constraints or there are not enough registers
> 397 | asm volatile(ALTERNATIVE(PARAVIRT_CALL,
> ALT_CALL_INSTR, \
> | ^~~
>
> when building x86-64 Linux kernel. RDI, RSI, RDX and RCX registers are
> used to pass arguments in 64-bit mode. EAX, EDX and ECX registers are
> used to pass arguments in 32-bit mode. But there is no coverage in the
> GCC testsuite. Add tests to verify that argument registers are spilled
> properly.
>
> PR target/119171
> * gcc.target/i386/pr119171-1.c: New test.
> * gcc.target/i386/pr119171-2.c: Likewise.
OK.
Thanks,
Uros.
>
> Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
> ---
> gcc/testsuite/gcc.target/i386/pr119171-1.c | 14 ++++++++++++++
> gcc/testsuite/gcc.target/i386/pr119171-2.c | 13 +++++++++++++
> 2 files changed, 27 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr119171-1.c
> create mode 100644 gcc/testsuite/gcc.target/i386/pr119171-2.c
>
> diff --git a/gcc/testsuite/gcc.target/i386/pr119171-1.c
> b/gcc/testsuite/gcc.target/i386/pr119171-1.c
> new file mode 100644
> index 00000000000..a017e6e215f
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr119171-1.c
> @@ -0,0 +1,14 @@
> +/* { dg-do compile { target { ! ia32 } } } */
> +/* { dg-options "-O2" } */
> +
> +extern long a1, a2, a3, a4;
> +extern void foo (void *, void *, void *, void *);
> +void
> +bar (void *rdi, void *rsi, void *rdx, void *rcx)
> +{
> + asm ("" : "=D"(a1) : "D"(0));
> + asm ("" : "=S"(a2) : "S"(0));
> + asm ("" : "=d"(a3) : "d"(0));
> + asm ("" : "=c"(a4) : "c"(0));
> + foo (rdi, rsi, rdx, rcx);
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr119171-2.c
> b/gcc/testsuite/gcc.target/i386/pr119171-2.c
> new file mode 100644
> index 00000000000..5c209f9aed0
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr119171-2.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-O2 -mregparm=3" } */
> +
> +extern long a1, a2, a3;
> +extern void foo (void *, void *, void *);
> +void
> +bar (void *eax, void *edx, void *ecx)
> +{
> + asm ("" : "=a"(a1) : "a"(0));
> + asm ("" : "=d"(a2) : "d"(0));
> + asm ("" : "=c"(a3) : "c"(0));
> + foo (eax, edx, ecx);
> +}
> --
> 2.48.1
>
