util: add auxv based PowerPC AltiVec/VSX detection

[mesa.git] / src / util / u_cpu_detect.c

diff --git a/src/util/u_cpu_detect.c b/src/util/u_cpu_detect.c
index 4df10c62ef531dd7288606bba909930efd1492c3..abfea65b24d8b145590fcda1e99e7e93902b62c6 100644 (file)
--- a/src/util/u_cpu_detect.c
+++ b/src/util/u_cpu_detect.c
@@ -92,7 +92,7 @@ static int has_cpuid(void);
 #endif
 
 
-#if defined(PIPE_ARCH_PPC) && !defined(PIPE_OS_APPLE)
+#if defined(PIPE_ARCH_PPC) && !defined(PIPE_OS_APPLE) && !defined(PIPE_OS_LINUX)
 static jmp_buf  __lv_powerpc_jmpbuf;
 static volatile sig_atomic_t __lv_powerpc_canjump = 0;
 
@@ -126,8 +126,29 @@ check_os_altivec_support(void)
          util_cpu_caps.has_altivec = 1;
       }
    }
-#else /* !PIPE_OS_APPLE */
-   /* not on Apple/Darwin, do it the brute-force way */
+#elif defined(PIPE_OS_LINUX) /* !PIPE_OS_APPLE */
+#if defined(PIPE_ARCH_PPC_64)
+    Elf64_auxv_t aux;
+#else
+    Elf32_auxv_t aux;
+#endif
+    int fd = open("/proc/self/auxv", O_RDONLY | O_CLOEXEC);
+    if (fd >= 0) {
+       while (read(fd, &aux, sizeof(aux)) == sizeof(aux)) {
+          if (aux.a_type == AT_HWCAP) {
+             char *env_vsx = getenv("GALLIVM_VSX");
+             uint64_t hwcap = aux.a_un.a_val;
+             util_cpu_caps.has_altivec = (hwcap >> 28) & 1;
+             if (!env_vsx || env_vsx[0] != '0') {
+                util_cpu_caps.has_vsx  = (hwcap >>  7) & 1;
+             }
+             break;
+          }
+       }
+       close(fd);
+    }
+#else /* !PIPE_OS_APPLE && !PIPE_OS_LINUX */
+   /* not on Apple/Darwin or Linux, do it the brute-force way */
    /* this is borrowed from the libmpeg2 library */
    signal(SIGILL, sigill_handler);
    if (setjmp(__lv_powerpc_jmpbuf)) {
@@ -171,7 +192,7 @@ check_os_altivec_support(void)
          util_cpu_caps.has_altivec = 0;
       }
    }
-#endif /* !PIPE_OS_APPLE */
+#endif /* !PIPE_OS_APPLE && !PIPE_OS_LINUX */
 }
 #endif /* PIPE_ARCH_PPC */