From d4afd4977ce8b7ba6293946c74914afe79536059 Mon Sep 17 00:00:00 2001

From: rogerman <rogerman@users.noreply.github.com>

Date: Mon, 20 Jun 2022 11:22:26 -0700

Subject: [PATCH] libretro-common: Compiling tune-up for ARM architectures. -

 Fixes a mismatched register warning in arm_enable_runfast_mode() when

 compiling for AArch64. - Fix compiling check_arm_cpu_feature() on non-ARM

 architectures by being super explicit and pedantic about checking for

 __ARM_ARCH; none of this compiler-assumes-a-macro-equals-zero-if-undefined

 stuff.

---

 desmume/src/libretro-common/features/features_cpu.c | 13 ++++++++++---

 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/desmume/src/libretro-common/features/features_cpu.c b/desmume/src/libretro-common/features/features_cpu.c

index 0980821f9..2c41d5732 100644

--- a/desmume/src/libretro-common/features/features_cpu.c

+++ b/desmume/src/libretro-common/features/features_cpu.c

@@ -300,10 +300,17 @@ static void arm_enable_runfast_mode(void)

    static const unsigned y = 0x03000000;

    int r;

    __asm__ volatile(

+#if defined(__aarch64__) || defined(_M_ARM64)

+         "fmrx	%w0, fpscr   \n\t" /* w0 = FPSCR */

+         "and	%w0, %w0, %w1  \n\t" /* w0 = w0 & 0x04086060 */

+         "orr	%w0, %w0, %w2  \n\t" /* w0 = w0 | 0x03000000 */

+         "fmxr	fpscr, %w0   \n\t" /* FPSCR = w0 */

+#else

          "fmrx	%0, fpscr   \n\t" /* r0 = FPSCR */

          "and	%0, %0, %1  \n\t" /* r0 = r0 & 0x04086060 */

          "orr	%0, %0, %2  \n\t" /* r0 = r0 | 0x03000000 */

          "fmxr	fpscr, %0   \n\t" /* FPSCR = r0 */

+#endif

          : "=r"(r)

          : "r"(x), "r"(y)

         );

@@ -311,13 +318,13 @@ static void arm_enable_runfast_mode(void)

 #endif

 #if defined(__linux__) && !defined(CPU_X86)

-#if __ARM_ARCH

+#if defined(__ARM_ARCH) && (__ARM_ARCH > 0)

 #include <sys/auxv.h>

 #endif

 static unsigned char check_arm_cpu_feature(const char* feature)

 {

-#if __ARM_ARCH < 8

+#if defined(__ARM_ARCH) && (__ARM_ARCH < 8)

    uint64_t hwcap = getauxval(AT_HWCAP);

    if (!strcmp(feature, "neon"))

       return (hwcap & HWCAP_ARM_NEON) != 0;

@@ -326,7 +333,7 @@ static unsigned char check_arm_cpu_feature(const char* feature)

    if (!strcmp(feature, "vfpv4"))

       return (hwcap & HWCAP_ARM_VFPv4) != 0;

    return 0;

-#elif __ARM_ARCH == 8

+#elif defined(__ARM_ARCH) && (__ARM_ARCH == 8)

    uint64_t hwcap = getauxval(AT_HWCAP);

    if (!strcmp(feature, "asimd"))

       return (hwcap & HWCAP_ASIMD) != 0;