From 707cd64b8a942de7fcc66575619c9b5d25d94104 Mon Sep 17 00:00:00 2001
From: Dr-Noob <peibolms@gmail.com>
Date: Thu, 8 Aug 2024 09:54:51 +0200
Subject: [PATCH] [v1.05][ARM] Another try at properly implement SVE detection:
 move it to a separate file

---
 Makefile       | 10 +++++++---
 src/arm/midr.c | 16 +---------------
 src/arm/sve.c  | 16 ++++++++++++++++
 src/arm/sve.h  |  6 ++++++
 4 files changed, 30 insertions(+), 18 deletions(-)
 create mode 100644 src/arm/sve.c
 create mode 100644 src/arm/sve.h

diff --git a/Makefile b/Makefile
index 8c3b9e6..a4e5d13 100644
--- a/Makefile
+++ b/Makefile
@@ -38,13 +38,14 @@ ifneq ($(OS),Windows_NT)
 		CFLAGS += -DARCH_PPC -std=gnu99 -fstack-protector-all -Wno-language-extension-token
 	else ifeq ($(arch), $(filter $(arch), arm aarch64_be aarch64 arm64 armv8b armv8l armv7l armv6l))
 		SRC_DIR=src/arm/
-		SOURCE += $(COMMON_SRC) $(SRC_DIR)midr.c $(SRC_DIR)uarch.c $(SRC_COMMON)soc.c $(SRC_DIR)soc.c $(SRC_COMMON)pci.c $(SRC_DIR)udev.c
+		SOURCE += $(COMMON_SRC) $(SRC_DIR)midr.c $(SRC_DIR)uarch.c $(SRC_COMMON)soc.c $(SRC_DIR)soc.c $(SRC_COMMON)pci.c $(SRC_DIR)udev.c sve.o
 		HEADERS += $(COMMON_HDR) $(SRC_DIR)midr.h $(SRC_DIR)uarch.h  $(SRC_COMMON)soc.h $(SRC_DIR)soc.h $(SRC_COMMON)pci.h $(SRC_DIR)udev.c $(SRC_DIR)socs.h
 		CFLAGS += -DARCH_ARM -Wno-unused-parameter -std=c99 -fstack-protector-all
 
-		is_sve_flag_supported := $(shell touch foo.c && $(CC) -march=armv8-a+sve -c foo.c -o foo.o &> /dev/null && echo 'yes'; rm -f foo.c foo.o)
+		# Check if the compiler supports -march=armv8-a+sve. We will use it (if supported) to compile SVE detection code later
+		is_sve_flag_supported := $(shell $(CC) -march=armv8-a+sve -c $(SRC_DIR)sve.c -o sve_test.o 2> /dev/null && echo 'yes'; rm -f sve_test.o)
 		ifeq ($(is_sve_flag_supported), yes)
-			CFLAGS += -march=armv8-a+sve
+			SVE_FLAGS += -march=armv8-a+sve
 		endif
 
 		ifeq ($(os), Darwin)
@@ -96,6 +97,9 @@ 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 $@
 
+sve.o: Makefile $(SRC_DIR)sve.c $(SRC_DIR)sve.h
+	$(CC) $(CFLAGS) $(SANITY_FLAGS) $(SVE_FLAGS) -c $(SRC_DIR)sve.c -o $@
+
 $(OUTPUT): Makefile $(SOURCE) $(HEADERS)
 ifeq ($(GIT_VERSION),"")
 	$(CC) $(CFLAGS) $(SANITY_FLAGS) $(SOURCE) -o $(OUTPUT)
diff --git a/src/arm/midr.c b/src/arm/midr.c
index 44f25d1..5874e46 100644
--- a/src/arm/midr.c
+++ b/src/arm/midr.c
@@ -19,6 +19,7 @@
 #include "udev.h"
 #include "midr.h"
 #include "uarch.h"
+#include "sve.h"
 
 bool cores_are_equal(int c1pos, int c2pos, uint32_t* midr_array, int32_t* freq_array) {
   return midr_array[c1pos] == midr_array[c2pos] && freq_array[c1pos] == freq_array[c2pos];
@@ -142,21 +143,6 @@ 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) {
-  #ifdef __ARM_FEATURE_SVE
-    uint32_t x0 = 0;
-    __asm volatile("cntb %0"
-         : "=r"(x0));
-    printf("cntb=%d\n", x0);
-    return x0;
-  #else
-    printBug("sve_cntb: SVE not enabled by the compiler");
-    return 0;
-  #endif
-}
-
-
 // We assume all cpus share the same hardware
 // capabilities but I'm not sure it is always
 // true...
diff --git a/src/arm/sve.c b/src/arm/sve.c
new file mode 100644
index 0000000..cb8217f
--- /dev/null
+++ b/src/arm/sve.c
@@ -0,0 +1,16 @@
+#include <stdint.h>
+#include "../common/global.h"
+
+// 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
+uint64_t sve_cntb(void) {
+  #ifdef __ARM_FEATURE_SVE
+    uint64_t x0 = 0;
+    __asm volatile("cntb %0"
+         : "=r"(x0));
+    printf("cntb=%ld\n", x0);
+    return x0;
+  #else
+    printBug("sve_cntb: SVE not enabled by the compiler");
+    return 0;
+  #endif
+}
diff --git a/src/arm/sve.h b/src/arm/sve.h
new file mode 100644
index 0000000..ddb3f70
--- /dev/null
+++ b/src/arm/sve.h
@@ -0,0 +1,6 @@
+#ifndef __SVE_DETECTION__
+#define __SVE_DETECTION__
+
+uint64_t sve_cntb(void);
+
+#endif