[v1.05][ARM] Properly implement SVE detection

Makefile

@@ -46,8 +46,6 @@ ifneq ($(OS),Windows_NT)
 			SOURCE += $(SRC_COMMON)sysctl.c
 			HEADERS += $(SRC_COMMON)sysctl.h
 		endif
-
-		SOURCE += $(SRC_DIR)sve_test.o
 	else ifeq ($(arch), $(filter $(arch), riscv64 riscv32))
 		SRC_DIR=src/riscv/
 		SOURCE += $(COMMON_SRC) $(SRC_DIR)riscv.c $(SRC_DIR)uarch.c $(SRC_COMMON)soc.c $(SRC_DIR)soc.c $(SRC_DIR)udev.c
@@ -93,9 +91,6 @@ freq_avx.o: Makefile $(SRC_DIR)freq/freq_avx.c $(SRC_DIR)freq/freq_avx.h $(SRC_D
 freq_avx512.o: Makefile $(SRC_DIR)freq/freq_avx512.c $(SRC_DIR)freq/freq_avx512.h $(SRC_DIR)freq/freq.h
 	$(CC) $(CFLAGS) $(SANITY_FLAGS) -c -mavx512f -pthread $(SRC_DIR)freq/freq_avx512.c -o $@
 
-$(SRC_DIR)sve_test.o: Makefile $(SRC_DIR)sve_test.c
-	$(CC) $(CFLAGS) $(SANITY_FLAGS) -c -march=armv8-a+sve $(SRC_DIR)sve_test.c -o $@	
-
 $(OUTPUT): Makefile $(SOURCE) $(HEADERS)
 ifeq ($(GIT_VERSION),"")
 	$(CC) $(CFLAGS) $(SANITY_FLAGS) $(SOURCE) -o $(OUTPUT)

src/arm/midr.c

@@ -142,6 +142,20 @@ void init_cpu_info(struct cpuInfo* cpu) {
   cpu->next_cpu = NULL;
 }
 
+// https://learn.arm.com/learning-paths/servers-and-cloud-computing/sve/sve_basics/#:~:text=Using%20a%20text%20editor%20of%20your%20choice%2C%20copy,svcntb%28%29%29%3B%20%7D%20This%20program%20prints%20the%20vector%20length
+static inline uint32_t sve_cntb(void) {
+    uint32_t x0 = 0;
+
+#ifdef __ARM_FEATURE_SVE
+    __asm volatile("cntb %0"
+         : "=r"(x0));
+    printf("cntb=%d\n", x0);
+#endif
+
+    return x0;
+}
+
+
 // We assume all cpus share the same hardware
 // capabilities but I'm not sure it is always
 // true...
@@ -168,6 +182,15 @@ struct features* get_features_info(void) {
     feat->SHA1 = hwcaps & HWCAP_SHA1;
     feat->SHA2 = hwcaps & HWCAP_SHA2;
     feat->NEON = hwcaps & HWCAP_ASIMD;
+    feat->SVE = hwcaps & HWCAP_SVE;
+
+    hwcaps = getauxval(AT_HWCAP2);
+    if (errno == ENOENT) {
+      printWarn("Unable to retrieve AT_HWCAP2 using getauxval");
+    }
+    else {
+      feat->SVE2 = hwcaps & HWCAP2_SVE2;
+    }
   }
 #else
   else {
@@ -183,6 +206,8 @@ struct features* get_features_info(void) {
     feat->CRC32 = hwcaps & HWCAP2_CRC32;
     feat->SHA1 = hwcaps & HWCAP2_SHA1;
     feat->SHA2 = hwcaps & HWCAP2_SHA2;
+    feat->SVE = false;
+    feat->SVE2 = false;
   }
 #endif // ifdef __aarch64__
 #elif defined __APPLE__ || __MACH__
@@ -192,8 +217,13 @@ struct features* get_features_info(void) {
   feat->SHA1 = true;
   feat->SHA2 = true;
   feat->NEON = true;
+  feat->SVE = false;
+  feat->SVE2 = false;
 #endif  // ifdef __linux__
 
+  if (feat->SVE || feat->SVE2)
+    feat->cntb = sve_cntb();
+
   return feat;
 }
 
@@ -430,7 +460,7 @@ char* get_str_topology(struct cpuInfo* cpu, struct topology* topo, bool dual_soc
 
 char* get_str_features(struct cpuInfo* cpu) {
   struct features* feat = cpu->feat;
-  uint32_t max_len = strlen("NEON,SHA1,SHA2,AES,CRC32,") + 1;
+  uint32_t max_len = strlen("NEON,SHA1,SHA2,AES,CRC32,SVE,SVE2") + 1;
   uint32_t len = 0;
   char* string = ecalloc(max_len, sizeof(char));
 
@@ -438,6 +468,14 @@ char* get_str_features(struct cpuInfo* cpu) {
     strcat(string, "NEON,");
     len += 5;
   }
+  if(feat->SVE) {
+    strcat(string, "SVE,");
+    len += 4;
+  }
+  if(feat->SVE2) {
+    strcat(string, "SVE2,");
+    len += 5;
+  }
   if(feat->SHA1) {
     strcat(string, "SHA1,");
     len += 5;

src/arm/midr.h

@@ -11,7 +11,6 @@ char* get_str_features(struct cpuInfo* cpu);
 
 void print_debug(struct cpuInfo* cpu);
 void free_topo_struct(struct topology* topo);
-void SVE_exp(struct cpuInfo* cpu);
 
 // Code taken from cpuinfo (https://github.com/pytorch/cpuinfo/blob/master/src/arm/midr.h)
 #define CPUINFO_ARM_MIDR_IMPLEMENTER_MASK  UINT32_C(0xFF000000)

src/arm/sve_test.c

@@ -1,71 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <assert.h>
-#include <stdbool.h>
-#include <errno.h>
-
-#ifdef __linux__
-  #include <sys/auxv.h>
-  #include <asm/hwcap.h>
-  #include "../common/freq.h"
-#elif defined __APPLE__ || __MACH__
-  #include "../common/sysctl.h"
-#endif
-
-#include "../common/global.h"
-#include "../common/soc.h"
-#include "../common/args.h"
-#include "udev.h"
-#include "midr.h"
-#include "uarch.h"
-
-// https://docs.kernel.org/arch/arm64/elf_hwcaps.html
-void check_for_SVE(void) {
-  errno = 0;
-  long hwcaps = getauxval(AT_HWCAP);
-
-  if(errno == ENOENT) {
-    printWarn("Unable to retrieve AT_HWCAP using getauxval");
-  }
-
-  if (hwcaps & HWCAP_SVE) printf("SVE: Yes\n");
-  else printf("SVE: No\n");
-
-  hwcaps = getauxval(AT_HWCAP2);
-
-  if (hwcaps & HWCAP2_SVE2) printf("SVE2: Yes\n");
-  else printf("SVE2: No\n");
-}
-
-#include <arm_sve.h>
-
-#ifndef __ARM_FEATURE_SVE
-#warning "Make sure to compile for SVE!"
-#endif
-
-// https://learn.arm.com/learning-paths/servers-and-cloud-computing/sve/sve_basics/#:~:text=Using%20a%20text%20editor%20of%20your%20choice%2C%20copy,svcntb%28%29%29%3B%20%7D%20This%20program%20prints%20the%20vector%20length
-void SVE_exp(struct cpuInfo* cpu) {
-  check_for_SVE();
-
-  uint32_t core = 4;
-  if (!bind_to_cpu(core)) {
-    printErr("Failed binding the process to CPU %d", core);
-    return;
-  }
-  printf("[%d] SVE vector length is: %ld bytes\n", core, svcntb());
-
-  core = 7;
-  if (!bind_to_cpu(core)) {
-    printErr("Failed binding the process to CPU %d", core);
-    return;
-  }
-  printf("[%d] SVE vector length is: %ld bytes\n", core, svcntb());
-
-  core = 0;
-  if (!bind_to_cpu(core)) {
-    printErr("Failed binding the process to CPU %d", core);
-    return;
-  }
-  printf("[%d] SVE vector length is: %ld bytes\n", core, svcntb());
-}

src/arm/uarch.c

@@ -294,7 +294,10 @@ int get_vpus_width(struct cpuInfo* cpu) {
     case UARCH_NEOVERSE_V1:
       return 256;
     default:
-      if(cpu->feat->NEON) {
+      if (cpu->feat->SVE) {
+        return cpu->feat->cntb * 8;
+      }
+      else if (cpu->feat->NEON) {
         if(is_ARMv8_or_newer(cpu)) {
           return 128;
         }

src/common/cpu.h

@@ -124,6 +124,9 @@ struct features {
   bool SHA1;
   bool SHA2;
   bool CRC32;
+  bool SVE;
+  bool SVE2;
+  uint32_t cntb;
 #endif  
 };
 

src/common/main.c

@@ -132,7 +132,6 @@ int main(int argc, char* argv[]) {
   }
 
   if(print_cpufetch(cpu, get_style(), get_colors(), show_full_cpu_name())) {
-    SVE_exp(cpu);
     return EXIT_SUCCESS;
   }
   else {