kmp_affinity: Fix check if specific bit is set

Clang 4.0 trunk warns:
warning: logical not is only applied to the left hand side of this bitwise operator [-Wlogical-not-parentheses]

This points to a potential bug if the code really wants to check if the single
bit is not set: If for example (buf.edx >> 9) = 2 (has any bit set except the
least significant one), 'logical not' will return 0 which stays 0 after the
'bitwise and'.
To do this correctly we first need to evaluate the 'bitwise and'. In that case
it returns 2 & 1 = 0 which after the 'logical not' evaluates to 1.

Differential Revision: https://reviews.llvm.org/D28599

llvm-svn: 291764

1 files changed, 1 insertions, 1 deletions

diff --git a/openmp/runtime/src/kmp_affinity.cpp b/openmp/runtime/src/kmp_affinity.cpp
index f09c3cdac93..79b9b91df75 100644
--- a/openmp/runtime/src/kmp_affinity.cpp
+++ b/openmp/runtime/src/kmp_affinity.cpp
@@ -1022,7 +1022,7 @@ __kmp_affinity_create_apicid_map(AddrUnsPair **address2os,
         // The apic id and max threads per pkg come from cpuid(1).
         //
         __kmp_x86_cpuid(1, 0, &buf);
-        if (! (buf.edx >> 9) & 1) {
+        if (((buf.edx >> 9) & 1) == 0) {
             __kmp_set_system_affinity(oldMask, TRUE);
             __kmp_free(threadInfo);
             KMP_CPU_FREE(oldMask);