From d5021e7ed5aa3f30e25125e2569a6a94bbe502c4 Mon Sep 17 00:00:00 2001
From: Keith Rothman <537074+litghost@users.noreply.github.com>
Date: Thu, 18 Mar 2021 14:01:40 -0700
Subject: [PATCH] Add IPO support for nextpnr, and have it enabled by default.

Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
---
 CMakeLists.txt | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index daddb258..704815e3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,6 +4,11 @@ project(nextpnr CXX C)
 # Allow family.cmake add additional dependencies to gui_${family}.
 cmake_policy(SET CMP0079 NEW)
 
+# Enable IPO support.
+cmake_policy(SET CMP0069 NEW)
+include(CheckIPOSupported)
+check_ipo_supported()
+
 option(BUILD_GUI "Build GUI" OFF)
 option(BUILD_PYTHON "Build Python Integration" ON)
 option(BUILD_TESTS "Build tests" OFF)
@@ -14,6 +19,8 @@ option(STATIC_BUILD "Create static build" OFF)
 option(EXTERNAL_CHIPDB "Create build with pre-built chipdb binaries" OFF)
 option(WERROR "pass -Werror to compiler (used for CI)" OFF)
 
+set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
+
 if(WIN32 OR EXTERNAL_CHIPDB)
     set(BBASM_MODE "binary")
 else()