From 2b8d6fa0acacba4dee31ed618a5596414b2279d5 Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Mon, 25 May 2020 20:13:03 +0200
Subject: [PATCH] Revert "[PGO] Fix computation of function Hash"

This reverts commit 7c298c104bfe725d4315926a656263e8a5ac3054.
Fails make check-clang.

Failing Tests (8):
	Clang :: Profile/c-counter-overflows.c
	Clang :: Profile/c-general.c
	Clang :: Profile/c-unprofiled-blocks.c
	Clang :: Profile/cxx-rangefor.cpp
	Clang :: Profile/cxx-throws.cpp
	Clang :: Profile/misexpect-switch-default.c
	Clang :: Profile/misexpect-switch-nonconst.c
	Clang :: Profile/misexpect-switch.c
---
 clang/lib/CodeGen/CodeGenPGO.cpp |  8 +++-----
 clang/test/Profile/c-collision.c | 22 ----------------------
 2 files changed, 3 insertions(+), 27 deletions(-)
 delete mode 100644 clang/test/Profile/c-collision.c

diff --git a/clang/lib/CodeGen/CodeGenPGO.cpp b/clang/lib/CodeGen/CodeGenPGO.cpp
index 98827bc3eec5e..3c91a04d54642 100644
--- a/clang/lib/CodeGen/CodeGenPGO.cpp
+++ b/clang/lib/CodeGen/CodeGenPGO.cpp
@@ -747,15 +747,13 @@ uint64_t PGOHash::finalize() {
     return Working;
 
   // Check for remaining work in Working.
-  if (Working) {
-    using namespace llvm::support;
-    uint64_t Swapped = endian::byte_swap<uint64_t, little>(Working);
-    MD5.update(llvm::makeArrayRef((uint8_t *)&Swapped, sizeof(Swapped)));
-  }
+  if (Working)
+    MD5.update(Working);
 
   // Finalize the MD5 and return the hash.
   llvm::MD5::MD5Result Result;
   MD5.final(Result);
+  using namespace llvm::support;
   return Result.low();
 }
 
diff --git a/clang/test/Profile/c-collision.c b/clang/test/Profile/c-collision.c
deleted file mode 100644
index fabecd752b4ef..0000000000000
--- a/clang/test/Profile/c-collision.c
+++ /dev/null
@@ -1,22 +0,0 @@
-// Test that a slight change in the code leads to a different hash.
-// RUN: %clang_cc1 -UEXTRA -triple x86_64-unknown-linux-gnu -main-file-name c-collision.c %s -o - -emit-llvm -fprofile-instrument=clang | FileCheck %s --check-prefix=CHECK-NOEXTRA
-// RUN: %clang_cc1 -DEXTRA -triple x86_64-unknown-linux-gnu -main-file-name c-collision.c %s -o - -emit-llvm -fprofile-instrument=clang | FileCheck %s --check-prefix=CHECK-EXTRA
-
-// CHECK-NOEXTRA: @__profd_foo = private global { {{.*}} } { i64 6699318081062747564, i64 7156072912471487002,
-// CHECK-EXTRA:   @__profd_foo = private global { {{.*}} } { i64 6699318081062747564, i64 -4383447408116050035,
-
-extern int bar;
-void foo() {
-  if (bar) {
-  }
-  if (bar) {
-  }
-  if (bar) {
-    if (bar) {
-#ifdef EXTRA
-      if (bar) {
-      }
-#endif
-    }
-  }
-}