Fix AVX instructions used on CPUs that don't support them (#1935)

* Fix AVX instructions used on CPUs that don't support them It's supposed to check all bits are enabled, not just one of them. This causes a crash using OpenColorIO on older CPUs. Thanks to Ray Molenkamp for help tracking this down. Signed-off-by: Brecht Van Lommel <[email protected]> * Fix another case pointed out in review Signed-off-by: Brecht Van Lommel <[email protected]> --------- Signed-off-by: Brecht Van Lommel <[email protected]>
AcademySoftwareFoundation · Jan 26, 2024 · 0c90ded · 0c90ded
1 parent aadf595
commit 0c90ded
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/src/OpenColorIO/CPUInfo.cpp b/src/OpenColorIO/CPUInfo.cpp
@@ -107,10 +107,10 @@ CPUInfo::CPUInfo()
             flags |= X86_CPU_FLAG_SSE42;
 
         /* Check OSXSAVE and AVX bits */
-        if (info.reg.ecx & 0x18000000)
+        if ((info.reg.ecx & 0x18000000) == 0x18000000)
         {
             xcr = xgetbv();
-            if(xcr & 0x6) {
+            if((xcr & 0x6) == 0x6) {
                 flags |= X86_CPU_FLAG_AVX;
 
                 if(info.reg.ecx & 0x20000000) {
@@ -129,7 +129,7 @@ CPUInfo::CPUInfo()
 
         /* OPMASK/ZMM state */
         if ((xcr & 0xe0) == 0xe0) {
-            if ((flags & X86_CPU_FLAG_AVX2) && (info.reg.ebx & 0xd0030000))
+            if ((flags & X86_CPU_FLAG_AVX2) && ((info.reg.ebx & 0xd0030000) == 0xd0030000))
                 flags |= X86_CPU_FLAG_AVX512;
         }
     }