diff --git a/configure.ac b/configure.ac index 875c434983c6..9544ab7bcfd1 100644 --- a/configure.ac +++ b/configure.ac @@ -2495,6 +2495,12 @@ COMPATH=`echo $COMPATH | $SED "s@/[[Bb]][[Ii]][[Nn]]\\\$@@"` # Set the ENABLE_LTO variable # =================================================================== AC_MSG_CHECKING([whether to use link-time optimization]) +if test $_os = WINNT -a "$WITH_MINGW" != yes -a -z "$enable_lto" -a \ + \( -z "$enable_dbgutil" -o "$enable_dbgutil" = no \) -a \ + \( -z "$enable_debug" -o "$enable_debug" = no \); then + # Turn on LTO for MSVC when optimising unless told not to + enable_lto=yes +fi if test -n "$enable_lto" -a "$enable_lto" != "no"; then ENABLE_LTO="TRUE" AC_MSG_RESULT([yes])