[llvm] 04f8ffd - [llvm-exegesis] Fix compilation with old libpfm versions.

[Clement Courbet via llvm-commits]

Author: Clement Courbet
Date: 2021-07-12T07:48:29+02:00
New Revision: 04f8ffd98306a0b0b60987208547ee6745b0fc3e

URL: https://github.com/llvm/llvm-project/commit/04f8ffd98306a0b0b60987208547ee6745b0fc3e
DIFF: https://github.com/llvm/llvm-project/commit/04f8ffd98306a0b0b60987208547ee6745b0fc3e.diff

LOG: [llvm-exegesis] Fix compilation with old libpfm versions.

Do not try include `perfmon/perf_event.h` when we are not sure that it
exists.

Fixes PR51017.

Differential Revision: https://reviews.llvm.org/D105615

Added: 
    

Modified: 
    llvm/tools/llvm-exegesis/lib/X86/X86Counter.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/tools/llvm-exegesis/lib/X86/X86Counter.cpp b/llvm/tools/llvm-exegesis/lib/X86/X86Counter.cpp
index 4d2262750e9a..e5b490e02049 100644
--- a/llvm/tools/llvm-exegesis/lib/X86/X86Counter.cpp
+++ b/llvm/tools/llvm-exegesis/lib/X86/X86Counter.cpp
@@ -8,6 +8,8 @@
 
 #include "X86Counter.h"
 
+#if defined(HAVE_LIBPFM) && defined(LIBPFM_HAS_FIELD_CYCLES)
+
 // FIXME: Use appropriate wrappers for poll.h and mman.h
 // to support Windows and remove this linux-only guard.
 #ifdef __linux__
@@ -32,7 +34,6 @@
 #include <sys/mman.h>
 #include <unistd.h>
 
-#if defined(HAVE_LIBPFM) && defined(LIBPFM_HAS_FIELD_CYCLES)
 namespace llvm {
 namespace exegesis {
 
@@ -178,6 +179,7 @@ llvm::Error X86LbrCounter::checkLbrSupport() {
   }
 
   counter.stop();
+  (void)Sum;
 
   auto ResultOrError = counter.doReadCounter(nullptr, nullptr);
   if (ResultOrError)