More canonical installation on Cygwin:

* The DLL is named cygopenblas.dll, not libopenblas.dll
* The import lib (still called libopenblas.dll.a) is installed

Makefile.install

@@ -90,10 +90,11 @@ ifeq ($(OSNAME), Darwin)
 endif
 ifeq ($(OSNAME), WINNT)
 	@-cp $(LIBDLLNAME) "$(DESTDIR)$(OPENBLAS_BINARY_DIR)"
-	@-cp $(LIBDLLNAME).a "$(DESTDIR)$(OPENBLAS_LIBRARY_DIR)"
+	@-cp $(IMPLIBNAME) "$(DESTDIR)$(OPENBLAS_LIBRARY_DIR)"
 endif
 ifeq ($(OSNAME), CYGWIN_NT)
 	@-cp $(LIBDLLNAME) "$(DESTDIR)$(OPENBLAS_BINARY_DIR)"
+	@-cp $(IMPLIBNAME) "$(DESTDIR)$(OPENBLAS_LIBRARY_DIR)"
 endif
 endif
 

Makefile.system

@@ -944,9 +944,15 @@ SYMBOLSUFFIX =
 endif
 
 ifndef LIBNAMESUFFIX
-LIBPREFIX = lib$(SYMBOLPREFIX)openblas$(SYMBOLSUFFIX)
+LIBNAMEBASE = $(SYMBOLPREFIX)openblas$(SYMBOLSUFFIX)
 else
-LIBPREFIX = lib$(SYMBOLPREFIX)openblas$(SYMBOLSUFFIX)_$(LIBNAMESUFFIX)
+LIBNAMEBASE = $(SYMBOLPREFIX)openblas$(SYMBOLSUFFIX)_$(LIBNAMESUFFIX)
+endif
+
+ifeq ($(OSNAME), CYGWIN_NT)
+LIBPREFIX = cyg$(LIBNAMEBASE)
+else
+LIBPREFIX = lib$(LIBNAMEBASE)
 endif
 
 KERNELDIR	= $(TOPDIR)/kernel/$(ARCH)
@@ -1105,6 +1111,7 @@ endif
 
 
 LIBDLLNAME   = $(LIBPREFIX).dll
+IMPLIBNAME   = lib$(LIBNAMEBASE).dll.a
 LIBSONAME    = $(LIBNAME:.$(LIBSUFFIX)=.so)
 LIBDYNNAME   = $(LIBNAME:.$(LIBSUFFIX)=.dylib)
 LIBDEFNAME   = $(LIBNAME:.$(LIBSUFFIX)=.def)

exports/Makefile

@@ -89,13 +89,13 @@ dll  : ../$(LIBDLLNAME)
 # in their import table.  By instead using a stable name it is possible to
 # upgrade between library versions, without needing to re-link an application.
 # For more details see: https://github.com/xianyi/OpenBLAS/issues/127.
-../$(LIBDLLNAME) : ../$(LIBNAME) libopenblas.def dllinit.$(SUFFIX)
+../$(LIBDLLNAME) : ../$(LIBNAME) $(LIBPREFIX).def dllinit.$(SUFFIX)
 	$(RANLIB) ../$(LIBNAME)
-	$(CC) $(CFLAGS) $(LDFLAGS) libopenblas.def dllinit.$(SUFFIX) \
-	-shared -o ../$(LIBDLLNAME) -Wl,--out-implib,../$(LIBDLLNAME).a \
+	$(CC) $(CFLAGS) $(LDFLAGS) $(LIBPREFIX).def dllinit.$(SUFFIX) \
+	-shared -o ../$(LIBDLLNAME) -Wl,--out-implib,../$(IMPLIBNAME) \
 	-Wl,--whole-archive ../$(LIBNAME) -Wl,--no-whole-archive $(FEXTRALIB) $(EXTRALIB)
 
-libopenblas.def : gensymbol
+$(LIBPREFIX).def : gensymbol
 	perl ./gensymbol win2k    $(ARCH) dummy $(EXPRECISION) $(NO_CBLAS) $(NO_LAPACK) $(NO_LAPACKE) $(NEED2UNDERSCORES) $(ONLY_CBLAS) "$(SYMBOLPREFIX)" "$(SYMBOLSUFFIX)" $(BUILD_LAPACK_DEPRECATED) > $(@F)
 
 libgoto_hpl.def : gensymbol