From 1bcd53f0e7d734ecb346ddf33d64cf64cc241c0a Mon Sep 17 00:00:00 2001
From: Serge Rogatch <srogatch@accesssoftek.com>
Date: Tue, 17 Jan 2017 11:53:38 +0000
Subject: [PATCH] [XRay][Arm] Enable back XRay testing on Arm32 and fix the
 failing tests

Summary:
Testing of XRay was occasionally disabled on 32-bit Arm targets (someone assumed that XRay was supported on 64-bit targets only). This patch should fix that problem. Also here the instruction&data cache incoherency problem is fixed, because it may be causing a test to fail.
This patch is one of a series: see also
- https://reviews.llvm.org/D28624

Reviewers: dberris, rengolin

Reviewed By: rengolin

Subscribers: llvm-commits, aemerson, rengolin, dberris, iid_iunknown

Differential Revision: https://reviews.llvm.org/D28623

llvm-svn: 292211
---
 compiler-rt/lib/xray/xray_arm.cc | 7 ++++++-
 compiler-rt/test/xray/lit.cfg    | 4 +++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/compiler-rt/lib/xray/xray_arm.cc b/compiler-rt/lib/xray/xray_arm.cc
index d89322e833e5..f5e2cd2a93c2 100644
--- a/compiler-rt/lib/xray/xray_arm.cc
+++ b/compiler-rt/lib/xray/xray_arm.cc
@@ -19,6 +19,8 @@
 #include <atomic>
 #include <cassert>
 
+extern "C" void __clear_cache(void* start, void* end);
+
 namespace __xray {
 
 uint64_t cycleFrequency() XRAY_NEVER_INSTRUMENT {
@@ -116,8 +118,8 @@ inline static bool patchSled(const bool Enable, const uint32_t FuncId,
   //   B #20
 
   uint32_t *FirstAddress = reinterpret_cast<uint32_t *>(Sled.Address);
+  uint32_t *CurAddress = FirstAddress + 1;
   if (Enable) {
-    uint32_t *CurAddress = FirstAddress + 1;
     CurAddress =
         Write32bitLoadR0(CurAddress, reinterpret_cast<uint32_t>(FuncId));
     CurAddress =
@@ -125,6 +127,7 @@ inline static bool patchSled(const bool Enable, const uint32_t FuncId,
     *CurAddress = uint32_t(PatchOpcodes::PO_BlxIp);
     CurAddress++;
     *CurAddress = uint32_t(PatchOpcodes::PO_PopR0Lr);
+    CurAddress++;
     std::atomic_store_explicit(
         reinterpret_cast<std::atomic<uint32_t> *>(FirstAddress),
         uint32_t(PatchOpcodes::PO_PushR0Lr), std::memory_order_release);
@@ -133,6 +136,8 @@ inline static bool patchSled(const bool Enable, const uint32_t FuncId,
         reinterpret_cast<std::atomic<uint32_t> *>(FirstAddress),
         uint32_t(PatchOpcodes::PO_B20), std::memory_order_release);
   }
+  __clear_cache(reinterpret_cast<char*>(FirstAddress),
+      reinterpret_cast<char*>(CurAddress));
   return true;
 }
 
diff --git a/compiler-rt/test/xray/lit.cfg b/compiler-rt/test/xray/lit.cfg
index 5d030e101452..571fe91c9926 100644
--- a/compiler-rt/test/xray/lit.cfg
+++ b/compiler-rt/test/xray/lit.cfg
@@ -30,7 +30,9 @@ config.substitutions.append(
 # Default test suffixes.
 config.suffixes = ['.c', '.cc', '.cpp']
 
-if config.host_os not in ['Linux'] or config.host_arch.find('64') == -1:
+if config.host_os not in ['Linux']:
+  config.unsupported = True
+elif config.host_arch.find('64') == -1 and config.host_arch.find('arm') == -1:
   config.unsupported = True
 
 # Allow tests to use REQUIRES=stable-runtime.  For use when you cannot use XFAIL