[Pixman] [PATCH 09/10] Simplifications to ARM CPU detection
Søren Sandmann Pedersen
sandmann at cs.au.dk
Fri Jun 29 13:44:54 PDT 2012
From: Søren Sandmann Pedersen <ssp at redhat.com>
Organize pixman-arm.c such that each operating system/compiler exports
a detect_cpu_features() function that returns a bitmask with the
various features that we are interested in. A new function
have_feature() then calls this function, caches the result, and return
whether the given feature is available.
The result is that all the pixman_have_arm_<feature> functions become
redundant and can be deleted.
---
pixman/pixman-arm.c | 244 ++++++++++++++++++---------------------------------
1 file changed, 87 insertions(+), 157 deletions(-)
diff --git a/pixman/pixman-arm.c b/pixman/pixman-arm.c
index 6625d7f..23374e4 100644
--- a/pixman/pixman-arm.c
+++ b/pixman/pixman-arm.c
@@ -25,132 +25,83 @@
#include "pixman-private.h"
+typedef enum
+{
+ ARM_V7 = (1 << 0),
+ ARM_V6 = (1 << 1),
+ ARM_VFP = (1 << 2),
+ ARM_NEON = (1 << 3),
+ ARM_IWMMXT = (1 << 4)
+} arm_cpu_features_t;
+
#if defined(USE_ARM_SIMD) || defined(USE_ARM_NEON) || defined(USE_ARM_IWMMXT)
-#include <string.h>
-#include <stdlib.h>
+#if defined(_MSC_VER)
-#if defined(USE_ARM_SIMD) && defined(_MSC_VER)
/* Needed for EXCEPTION_ILLEGAL_INSTRUCTION */
#include <windows.h>
-#endif
-#if defined(__APPLE__)
-#include "TargetConditionals.h"
-#endif
-
-#if defined(_MSC_VER)
-
-#if defined(USE_ARM_SIMD)
+extern int pixman_msvc_try_arm_neon_op ();
extern int pixman_msvc_try_arm_simd_op ();
-pixman_bool_t
-pixman_have_arm_simd (void)
+static arm_cpu_features_t
+detect_cpu_features (void)
{
- static pixman_bool_t initialized = FALSE;
- static pixman_bool_t have_arm_simd = FALSE;
+ arm_cpu_features_t features = 0;
- if (!initialized)
+ __try
+ {
+ pixman_msvc_try_arm_simd_op ();
+ features |= ARM_V6;
+ }
+ __except (GetExceptionCode () == EXCEPTION_ILLEGAL_INSTRUCTION)
{
- __try {
- pixman_msvc_try_arm_simd_op ();
- have_arm_simd = TRUE;
- } __except (GetExceptionCode () == EXCEPTION_ILLEGAL_INSTRUCTION) {
- have_arm_simd = FALSE;
- }
- initialized = TRUE;
}
- return have_arm_simd;
-}
-
-#endif /* USE_ARM_SIMD */
-
-#if defined(USE_ARM_NEON)
-extern int pixman_msvc_try_arm_neon_op ();
-
-pixman_bool_t
-pixman_have_arm_neon (void)
-{
- static pixman_bool_t initialized = FALSE;
- static pixman_bool_t have_arm_neon = FALSE;
-
- if (!initialized)
+ __try
+ {
+ pixman_msvc_try_arm_neon_op ();
+ features |= ARM_NEON;
+ }
+ __except (GetExceptionCode () == EXCEPTION_ILLEGAL_INSTRUCTION)
{
- __try
- {
- pixman_msvc_try_arm_neon_op ();
- have_arm_neon = TRUE;
- }
- __except (GetExceptionCode () == EXCEPTION_ILLEGAL_INSTRUCTION)
- {
- have_arm_neon = FALSE;
- }
- initialized = TRUE;
}
- return have_arm_neon;
+ return features;
}
-#endif /* USE_ARM_NEON */
-
-#elif (defined (__APPLE__) && defined(TARGET_OS_IPHONE)) /* iOS (iPhone/iPad/iPod touch) */
-
-/* Detection of ARM NEON on iOS is fairly simple because iOS binaries
- * contain separate executable images for each processor architecture.
- * So all we have to do is detect the armv7 architecture build. The
- * operating system automatically runs the armv7 binary for armv7 devices
- * and the armv6 binary for armv6 devices.
- */
+#elif defined(__APPLE__) && defined(TARGET_OS_IPHONE) /* iOS */
-pixman_bool_t
-pixman_have_arm_simd (void)
-{
-#if defined(USE_ARM_SIMD)
- return TRUE;
-#else
- return FALSE;
-#endif
-}
+#include "TargetConditionals.h"
-pixman_bool_t
-pixman_have_arm_neon (void)
+static arm_cpu_features_t
+detect_cpu_features (void)
{
-#if defined(USE_ARM_NEON) && defined(__ARM_NEON__)
- /* This is an armv7 cpu build */
- return TRUE;
-#else
- /* This is an armv6 cpu build */
- return FALSE;
+ arm_cpu_features_t features = 0;
+
+ features |= ARM_V6;
+
+ /* Detection of ARM NEON on iOS is fairly simple because iOS binaries
+ * contain separate executable images for each processor architecture.
+ * So all we have to do is detect the armv7 architecture build. The
+ * operating system automatically runs the armv7 binary for armv7 devices
+ * and the armv6 binary for armv6 devices.
+ */
+#if defined(__ARM_NEON__)
+ features |= ARM_NEON;
#endif
-}
-pixman_bool_t
-pixman_have_arm_iwmmxt (void)
-{
-#if defined(USE_ARM_IWMMXT)
- return FALSE;
-#else
- return FALSE;
-#endif
+ return features;
}
-#elif defined (__linux__) || defined(__ANDROID__) || defined(ANDROID) /* linux ELF or ANDROID */
-
-static pixman_bool_t arm_has_v7 = FALSE;
-static pixman_bool_t arm_has_v6 = FALSE;
-static pixman_bool_t arm_has_vfp = FALSE;
-static pixman_bool_t arm_has_neon = FALSE;
-static pixman_bool_t arm_has_iwmmxt = FALSE;
-static pixman_bool_t arm_tests_initialized = FALSE;
-
-#if defined(__ANDROID__) || defined(ANDROID) /* Android device support */
+#elif defined(__ANDROID__) || defined(ANDROID) /* Android */
#include <cpu-features.h>
-static void
-pixman_arm_read_auxv_or_cpu_features ()
+static arm_cpu_features_t
+detect_cpu_features (void)
{
+ arm_cpu_features_t features = 0;
AndroidCpuFamily cpu_family;
uint64_t cpu_features;
@@ -160,16 +111,16 @@ pixman_arm_read_auxv_or_cpu_features ()
if (cpu_family == ANDROID_CPU_FAMILY_ARM)
{
if (cpu_features & ANDROID_CPU_ARM_FEATURE_ARMv7)
- arm_has_v7 = TRUE;
-
+ features |= ARM_V7;
+
if (cpu_features & ANDROID_CPU_ARM_FEATURE_VFPv3)
- arm_has_vfp = TRUE;
-
+ features |= ARM_VFP;
+
if (cpu_features & ANDROID_CPU_ARM_FEATURE_NEON)
- arm_has_neon = TRUE;
+ features |= ARM_NEON;
}
- arm_tests_initialized = TRUE;
+ return features;
}
#elif defined (__linux__) /* linux ELF */
@@ -182,11 +133,12 @@ pixman_arm_read_auxv_or_cpu_features ()
#include <string.h>
#include <elf.h>
-static void
-pixman_arm_read_auxv_or_cpu_features ()
+static arm_cpu_features_t
+detect_cpu_features (void)
{
- int fd;
+ arm_cpu_features_t features = 0;
Elf32_auxv_t aux;
+ int fd;
fd = open ("/proc/self/auxv", O_RDONLY);
if (fd >= 0)
@@ -196,100 +148,78 @@ pixman_arm_read_auxv_or_cpu_features ()
if (aux.a_type == AT_HWCAP)
{
uint32_t hwcap = aux.a_un.a_val;
+
/* hardcode these values to avoid depending on specific
* versions of the hwcap header, e.g. HWCAP_NEON
*/
- arm_has_vfp = (hwcap & 64) != 0;
- arm_has_iwmmxt = (hwcap & 512) != 0;
+ if ((hwcap & 64) != 0)
+ features |= ARM_VFP;
+ if ((hwcap & 512) != 0)
+ features |= ARM_IWMMXT;
/* this flag is only present on kernel 2.6.29 */
- arm_has_neon = (hwcap & 4096) != 0;
+ if ((hwcap & 4096) != 0)
+ features |= ARM_NEON;
}
else if (aux.a_type == AT_PLATFORM)
{
const char *plat = (const char*) aux.a_un.a_val;
+
if (strncmp (plat, "v7l", 3) == 0)
- {
- arm_has_v7 = TRUE;
- arm_has_v6 = TRUE;
- }
+ features |= (ARM_V7 | ARM_V6);
else if (strncmp (plat, "v6l", 3) == 0)
- {
- arm_has_v6 = TRUE;
- }
+ features |= ARM_V6;
}
}
close (fd);
}
- arm_tests_initialized = TRUE;
+ return features;
}
-#endif /* Linux elf */
+#else /* Unknown */
-#if defined(USE_ARM_SIMD)
-pixman_bool_t
-pixman_have_arm_simd (void)
+static arm_cpu_features_t
+detect_cpu_features (void)
{
- if (!arm_tests_initialized)
- pixman_arm_read_auxv_or_cpu_features ();
-
- return arm_has_v6;
+ return 0;
}
-#endif /* USE_ARM_SIMD */
+#endif /* Linux elf */
-#if defined(USE_ARM_NEON)
-pixman_bool_t
-pixman_have_arm_neon (void)
+static pixman_bool_t
+have_feature (arm_cpu_features_t feature)
{
- if (!arm_tests_initialized)
- pixman_arm_read_auxv_or_cpu_features ();
-
- return arm_has_neon;
-}
+ static pixman_bool_t initialized;
+ static arm_cpu_features_t features;
-#endif /* USE_ARM_NEON */
-
-#if defined(USE_ARM_IWMMXT)
-pixman_bool_t
-pixman_have_arm_iwmmxt (void)
-{
- if (!arm_tests_initialized)
- pixman_arm_read_auxv_or_cpu_features ();
+ if (!initialized)
+ {
+ features = detect_cpu_features();
+ initialized = TRUE;
+ }
- return arm_has_iwmmxt;
+ return (features & feature) == feature;
}
-#endif /* USE_ARM_IWMMXT */
-
-#else /* !_MSC_VER && !Linux elf && !Android */
-
-#define pixman_have_arm_simd() FALSE
-#define pixman_have_arm_neon() FALSE
-#define pixman_have_arm_iwmmxt() FALSE
-
-#endif
-
#endif /* USE_ARM_SIMD || USE_ARM_NEON || USE_ARM_IWMMXT */
pixman_implementation_t *
_pixman_arm_get_implementations (pixman_implementation_t *imp)
{
#ifdef USE_ARM_SIMD
- if (!_pixman_disabled ("arm-simd") && pixman_have_arm_simd ())
+ if (!_pixman_disabled ("arm-simd") && have_feature (ARM_V6))
imp = _pixman_implementation_create_arm_simd (imp);
#endif
#ifdef USE_ARM_IWMMXT
- if (!_pixman_disabled ("arm-iwmmxt") && pixman_have_arm_iwmmxt ())
+ if (!_pixman_disabled ("arm-iwmmxt") && have_feature (ARM_IWMMXT))
imp = _pixman_implementation_create_mmx (imp);
#endif
#ifdef USE_ARM_NEON
- if (!_pixman_disabled ("arm-neon") && pixman_have_arm_neon ())
+ if (!_pixman_disabled ("arm-neon") && have_feature (ARM_NEON))
imp = _pixman_implementation_create_arm_neon (imp);
#endif
return imp;
}
-
--
1.7.10.4
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