From: Jan Engelhardt <jengelh@inai.de>
Date: 2022-04-14 16:00:12.633272404 +0200

Modeled upon a similar patch for opensuse's ICU package.

---
 configure.ac                   |    4 ++--
 src/include/fst/float-weight.h |    4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

Index: openfst-1.8.3/configure.ac
===================================================================
--- openfst-1.8.3.orig/configure.ac
+++ openfst-1.8.3/configure.ac
@@ -160,10 +160,10 @@ AC_RUN_IFELSE([AC_LANG_PROGRAM([
                  #include <cstdio>
 
                  template <typename T>
-                 bool FloatEqIsReflexive(T m) {
+                 bool FloatEqIsReflexive(volatile T m) {
                    volatile T x = 1.111;
                    x *= m;
-                   T y = 1.111;
+                   volatile T y = 1.111;
                    y *= m;
                    return x == y;
                  }
Index: openfst-1.8.3/src/include/fst/float-weight.h
===================================================================
--- openfst-1.8.3.orig/src/include/fst/float-weight.h
+++ openfst-1.8.3/src/include/fst/float-weight.h
@@ -121,7 +121,9 @@ constexpr bool operator==(const FloatWei
 // register may cause it to compare unequal to that same weight when
 // stored to memory. This breaks =='s reflexivity, in turn breaking
 // NaturalLess.
-#error "Please compile with -msse -mfpmath=sse, or equivalent."
+// So, store it in memory.
+  volatile T a = w1.Value(), b = w2.Value();
+  return a == b;
 #endif
   return w1.Value() == w2.Value();
 }