On Tue, Oct 2, 2012 at 12:35 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
> Hi,
>
> This patch checks SSE and YMM state support for -march=native. Tested
> on Linux/x86-64. OK to install?
>
> Thanks.
>
>
> H.J.
> ---
> 2012-10-02 H.J. Lu <hongjiu...@intel.com>
>
> PR target/54741
> * config/i386/driver-i386.c (XCR_XFEATURE_ENABLED_MASK): New.
> (XSTATE_FP): Likewise.
> (XSTATE_SSE): Likewise.
> (XSTATE_YMM): Likewise.
> (host_detect_local_cpu): Disable AVX, AVX2, FMA, FMA4 and XOP if
> SSE and YMM states aren't supported.
>
> diff --git a/gcc/config/i386/driver-i386.c b/gcc/config/i386/driver-i386.c
> index bda4e02..4dffc51 100644
> --- a/gcc/config/i386/driver-i386.c
> +++ b/gcc/config/i386/driver-i386.c
> @@ -390,6 +390,7 @@ const char *host_detect_local_cpu (int argc, const char
> **argv)
> unsigned int has_hle = 0, has_rtm = 0;
> unsigned int has_rdrnd = 0, has_f16c = 0, has_fsgsbase = 0;
> unsigned int has_rdseed = 0, has_prfchw = 0, has_adx = 0;
> + unsigned int has_osxsave = 0;
>
> bool arch;
>
> @@ -431,6 +432,7 @@ const char *host_detect_local_cpu (int argc, const char
> **argv)
> has_sse4_1 = ecx & bit_SSE4_1;
> has_sse4_2 = ecx & bit_SSE4_2;
> has_avx = ecx & bit_AVX;
> + has_osxsave = ecx & bit_OSXSAVE;
> has_cmpxchg16b = ecx & bit_CMPXCHG16B;
> has_movbe = ecx & bit_MOVBE;
> has_popcnt = ecx & bit_POPCNT;
> @@ -460,6 +462,26 @@ const char *host_detect_local_cpu (int argc, const char
> **argv)
> has_adx = ebx & bit_ADX;
> }
>
> + /* Get XCR_XFEATURE_ENABLED_MASK register with xgetbv. */
> +#define XCR_XFEATURE_ENABLED_MASK 0x0
> +#define XSTATE_FP 0x1
> +#define XSTATE_SSE 0x2
> +#define XSTATE_YMM 0x4
> + if (has_osxsave)
> + asm (".byte 0x0f; .byte 0x01; .byte 0xd0"
> + : "=a" (eax), "=d" (edx)
> + : "c" (XCR_XFEATURE_ENABLED_MASK));
> +
> + /* Check if SSE and YMM states are supported. */
> + if ((eax & (XSTATE_SSE | XSTATE_YMM)) == (XSTATE_SSE | XSTATE_YMM))
> + {
> + has_avx = 0;
> + has_avx2 = 0;
> + has_fma = 0;
> + has_fma4 = 0;
> + has_xop = 0;
> + }
> +
> /* Check cpuid level of extended features. */
> __cpuid (0x80000000, ext_level, ebx, ecx, edx);
>
This is very embarrassing. Thanks to Andrew, I checked his fix
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54741#c18
into trunk, 4.6 and 4.7 branches.
--
H.J.
