From d35e2f38eb28ad09010a0616a34fd87dfbfd6609 Mon Sep 17 00:00:00 2001
From: Kris Kwiatkowski <contact@amongbytes.com>
Date: Fri, 21 May 2021 09:47:32 +0100
Subject: [PATCH] Detect Intel's Multi-Precision Add-Carry Instruction
 Extensions (#157)

---
 include/cpuinfo_x86.h    | 2 ++
 src/cpuinfo_x86.c        | 4 +++-
 test/cpuinfo_x86_test.cc | 1 +
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/include/cpuinfo_x86.h b/include/cpuinfo_x86.h
index fe31237..e3fa0be 100644
--- a/include/cpuinfo_x86.h
+++ b/include/cpuinfo_x86.h
@@ -89,6 +89,7 @@ typedef struct {
 
   int dca : 1;
   int ss : 1;
+  int adx : 1;
   // Make sure to update X86FeaturesEnum below if you add a field here.
 } X86Features;
 
@@ -214,6 +215,7 @@ typedef enum {
   X86_RDRND,
   X86_DCA,
   X86_SS,
+  X86_ADX,
   X86_LAST_,
 } X86FeaturesEnum;
 
diff --git a/src/cpuinfo_x86.c b/src/cpuinfo_x86.c
index 674583e..1d8d902 100644
--- a/src/cpuinfo_x86.c
+++ b/src/cpuinfo_x86.c
@@ -88,7 +88,8 @@
   FEATURE(X86_MOVBE, movbe, "movbe", 0, 0)                                     \
   FEATURE(X86_RDRND, rdrnd, "rdrnd", 0, 0)                                     \
   FEATURE(X86_DCA, dca, "dca", 0, 0)                                           \
-  FEATURE(X86_SS, ss, "ss", 0, 0)
+  FEATURE(X86_SS, ss, "ss", 0, 0)                                              \
+  FEATURE(X86_ADX, adx, "adx", 0, 0)
 #define DEFINE_TABLE_FEATURE_TYPE X86Features
 #define DEFINE_TABLE_DONT_GENERATE_HWCAPS
 #include "define_tables.h"
@@ -1314,6 +1315,7 @@ static void ParseCpuId(const uint32_t max_cpuid_leaf,
   features->sha = IsBitSet(leaf_7.ebx, 29);
   features->vaes = IsBitSet(leaf_7.ecx, 9);
   features->vpclmulqdq = IsBitSet(leaf_7.ecx, 10);
+  features->adx = IsBitSet(leaf_7.ebx, 19);
 
   if (os_support.have_sse_via_os) {
     DetectSseViaOs(features);
diff --git a/test/cpuinfo_x86_test.cc b/test/cpuinfo_x86_test.cc
index 636d0f9..42d5931 100644
--- a/test/cpuinfo_x86_test.cc
+++ b/test/cpuinfo_x86_test.cc
@@ -148,6 +148,7 @@ TEST_F(CpuidX86Test, SandyBridge) {
   EXPECT_TRUE(features.popcnt);
   EXPECT_FALSE(features.movbe);
   EXPECT_FALSE(features.rdrnd);
+  EXPECT_FALSE(features.adx);
 }
 
 const int KiB = 1024;