From: Mark Wooding <mdw@distorted.org.uk>
Date: Thu, 26 Sep 2019 11:09:10 +0000 (+0100)
Subject: base/dispatch.c: Check for XMM registers after CPUID probe.
X-Git-Tag: 2.4.4~4
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/catacomb/commitdiff_plain/4fab22c212bfd0737ad0f42370911589ae62fb52

base/dispatch.c: Check for XMM registers after CPUID probe.

`fxsave' isn't universally available, but if CPUID is reporting that XMM
instructions are available, we can definitely use it.
---

diff --git a/base/dispatch.c b/base/dispatch.c
index 908a4e31..b281ec3d 100644
--- a/base/dispatch.c
+++ b/base/dispatch.c
@@ -538,11 +538,11 @@ int cpu_feature_p(int feat)
   switch (feat) {
 #if CPUFAM_X86 || CPUFAM_AMD64
     CASE_CPUFEAT(X86_SSE2, "x86:sse2",
-		 xmm_registers_available_p() &&
-		 cpuid_features_p(CPUID1D_SSE2, 0));
+		 cpuid_features_p(CPUID1D_SSE2, 0) &&
+		 xmm_registers_available_p());
     CASE_CPUFEAT(X86_AESNI, "x86:aesni",
-		 xmm_registers_available_p() &&
-		 cpuid_features_p(CPUID1D_SSE2, CPUID1C_AESNI));
+		 cpuid_features_p(CPUID1D_SSE2, CPUID1C_AESNI) &&
+		 xmm_registers_available_p());
     CASE_CPUFEAT(X86_RDRAND, "x86:rdrand",
 		 cpuid_features_p(0, CPUID1C_RDRAND));
 #endif