From 49626c85923fafb6088616cbda005efd329d3c34 Mon Sep 17 00:00:00 2001
From: Remy Noel <mocramis@gmail.com>
Date: Sat, 14 Apr 2018 10:45:15 +0200
Subject: pmu_intel: fix call to gcc's __builtin_popcount.

We do not use libgcc anymore due to its usage of redzone.
---
 arch/x86/machine/pmu_intel.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/arch/x86/machine/pmu_intel.c b/arch/x86/machine/pmu_intel.c
index 20d7aa2..c47be6c 100644
--- a/arch/x86/machine/pmu_intel.c
+++ b/arch/x86/machine/pmu_intel.c
@@ -113,6 +113,23 @@ pmu_intel_get(void)
     return &pmu_intel;
 }
 
+static unsigned int
+pmu_popcount(unsigned int bits)
+{
+    unsigned int count = 0;
+
+    /* XXX: Dummy version of popcount. We should implement a faster one if it
+     * gets needed somewhere else.
+     */
+    while (bits) {
+        if (bits & 1) {
+            count++;
+        }
+        bits >>= 1;
+    }
+    return count;
+}
+
 static void
 pmu_intel_info(void)
 {
@@ -120,7 +137,7 @@ pmu_intel_info(void)
     unsigned int nr_events;
 
     pmu = pmu_intel_get();
-    nr_events = __builtin_popcount(pmu->events);
+    nr_events = pmu_popcount(pmu->events);
     log_info("pmu: driver: intel, architectural v1\n"
             "pmu: nr_pmcs: %u, pmc_width: %u, events: %#x, nr_events: %u\n",
             pmu->nr_pmcs, pmu->pmc_width, pmu->events, nr_events);
-- 
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