(x86 asm): Zero the high parts of the ?MM registers if available.

[catacomb] / base / dispatch.c

diff --git a/base/dispatch.c b/base/dispatch.c
index 908a4e3..9ba6a7c 100644 (file)
--- a/base/dispatch.c
+++ b/base/dispatch.c
@@ -47,6 +47,7 @@
 #  define CPUID1D_SSE2 (1u << 26)
 #  define CPUID1D_FXSR (1u << 24)
 #  define CPUID1C_AESNI (1u << 25)
+#  define CPUID1C_AVX (1u << 28)
 #  define CPUID1C_RDRAND (1u << 30)
 
 struct cpuid { unsigned a, b, c, d; };
@@ -545,6 +546,9 @@ int cpu_feature_p(int feat)
                 cpuid_features_p(CPUID1D_SSE2, CPUID1C_AESNI));
     CASE_CPUFEAT(X86_RDRAND, "x86:rdrand",
                 cpuid_features_p(0, CPUID1C_RDRAND));
+    CASE_CPUFEAT(X86_AVX, "x86:avx",
+                xmm_registers_available_p() &&
+                cpuid_features_p(0, CPUID1C_AVX));
 #endif
 #ifdef CAPMAP
 #  define FEATP__CASE(feat, tok)                                       \