From 805a5e4736bdd0f3156fc4120e4866e30f09d964 Mon Sep 17 00:00:00 2001
From: Adeel Mujahid <3840695+am11@users.noreply.github.com>
Date: Mon, 7 Feb 2022 19:28:54 +0200
Subject: [PATCH] Turn off -ffp-contract on Unix (#64847)

---
 eng/native/configurecompiler.cmake | 4 ++++
 src/mono/CMakeLists.txt            | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/eng/native/configurecompiler.cmake b/eng/native/configurecompiler.cmake
index b67594cb60fb2..4324e23ed1fa2 100644
--- a/eng/native/configurecompiler.cmake
+++ b/eng/native/configurecompiler.cmake
@@ -390,6 +390,10 @@ if (CLR_CMAKE_HOST_UNIX)
 
   add_compile_options(-Wno-unused-but-set-variable)
 
+  # Turn off floating point expression contraction because it is considered a value changing
+  # optimization in the IEEE 754 specification and is therefore considered unsafe.
+  add_compile_options(-ffp-contract=off)
+
   if (CMAKE_C_COMPILER_ID MATCHES "Clang")
     add_compile_options(-Wno-unknown-warning-option)
 
diff --git a/src/mono/CMakeLists.txt b/src/mono/CMakeLists.txt
index 348b5e9960bab..d9d118066d975 100644
--- a/src/mono/CMakeLists.txt
+++ b/src/mono/CMakeLists.txt
@@ -485,6 +485,11 @@ if(GCC)
     # We require C99 with some GNU extensions, e.g. `linux` macro
     set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
   endif()
+
+  # Turn off floating point expression contraction because it is considered a value changing
+  # optimization in the IEEE 754 specification and is therefore considered unsafe.
+  add_compile_options(-ffp-contract=off)
+
   # The runtime code does not respect ANSI C strict aliasing rules
   append("-fno-strict-aliasing" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
   # We rely on signed overflow to behave