set CXXFLAGS "$saved_CXXFLAGS"
 }
 
-# Simple LTO tests and generate input files for complex LTO tests.
-set lto_link_tests {
-  {"LTO 1"
-   "-O2 -flto -fuse-linker-plugin" "-flto -fuse-linker-plugin"
-   {lto-1a.c lto-1b.c} {} "lto-1.exe"}
-  {"Compile 2"
-   "" "-O2 -flto -fuse-linker-plugin"
-   {lto-2.c} {} ""}
-  {"LTO 2"
-   "-static -O2 -flto -fuse-linker-plugin tmpdir/lto-2.o -lm" ""
-   {dummy.c} {} "lto-2.exe"}
-  {"Compile 3a"
-   "" "-flto"
-   {lto-3a.c} {} ""}
-  {"Compile 3c"
-   "" "-O2"
-   {lto-3c.c} {} ""}
-  {"Build liblto-3.a"
-   "" "-flto -ffat-lto-objects"
-   {lto-3b.c} {} "liblto-3.a"}
-  {"Compile 5a"
-   "" "-flto"
-   {lto-5a.c} {} ""}
-  {"Compile 5b"
-   "" "-flto"
-   {lto-5b.c} {} ""}
-  {"LTO 6"
-   "-O2 -flto -fuse-linker-plugin" ""
-   {lto-6.c} {} "lto-6.exe" "c"}
-  {"Compile 9"
-   "" "-O2 -finline -flto"
-   {lto-9.cc} {} "" "c++"}
-  {"Compile 11a"
-   "" "-O -flto"
-   {lto-11a.c} {} ""}
-  {"Compile 11b"
-   "" "-O -flto"
-   {lto-11b.c} {} ""}
-  {"Compile 11c"
-   "" "-O"
-   {lto-11c.c} {} ""}
-  {"Build liblto-12.a"
-   "" "-O2 -flto"
-   {lto-12c.c} {} "liblto-12.a"}
-  {"Compile 12"
-   "" "-O2 -flto"
-   {lto-12a.c lto-12b.c} {} ""}
-  {"Compile 13"
-   "" "-O2 -flto"
-   {lto-13a.c lto-13b.c} {} ""}
-  {"Build liblto-13.a"
-   "" "-O2"
-   {lto-13c.c} {} "liblto-13.a"}
-  {"Compile 14a"
-   "" "-flto"
-   {lto-14a.c lto-14b.c} {} ""}
-  {"Build liblto-14.a"
-   "" "-flto"
-   {lto-14c.c} {} "liblto-14.a"}
-  {"Compile 15a"
-   "" "-flto"
-   {lto-15a.c} {} ""}
-  {"Build liblto-15.a"
-   "" "-flto"
-   {lto-15b.c} {} "liblto-15.a"}
-  {"PR ld/12696"
-   "-O2 -flto -fuse-linker-plugin -r -nostdlib" "-O2 -flto"
-   {pr12696-1.cc} {} "pr12696-1r.o" "c++"}
-  {"Compile PR ld/12758"
-   "" ""
-   {pr12758a.s} {} ""}
-  {"Build libpr12758.a"
-   "" "-flto -O2 -ffat-lto-objects"
-   {pr12758b.c} {} "libpr12758.a"}
-  {"PR ld/12758"
-   "-O2 -Wl,-e,foo -nostdlib -flto -fuse-linker-plugin tmpdir/pr12758a.o -Wl,--start-group tmpdir/libpr12758.a -Wl,--end-group" ""
-   {dummy.c} {} "pr12758.exe"}
-  {"Compile PR ld/12760"
-   "" "-g -O0"
-   {pr12760a.c} {} ""}
-  {"Build libpr12760.a"
-   "" "-flto -O2 -ffat-lto-objects"
-   {pr12760b.c} {} "libpr12760.a"}
-  {"PR ld/12760"
-   "-O2 -Wl,-e,foo -nostdlib -flto -fuse-linker-plugin tmpdir/pr12760a.o -Wl,--start-group tmpdir/libpr12760.a -Wl,--end-group" ""
-   {dummy.c} {} "pr12760.exe" "c" "pr12760a.c:6: warning: Bad bar"}
-  {"Build libpr13183.a"
-   "-T" "-flto -O2 -ffat-lto-objects"
-   {pr13183a.c} {} "libpr13183.a"}
-  {"Compile PR ld/13183"
-   "" "-flto -O2"
-   {pr13183b.c} {} ""}
-  {"Compile PR ld/13201"
-   "" "-flto -O2"
-   {pr13201.c} {} ""}
-  {"PR ld/13287"
-   "-flto -fuse-linker-plugin -Wl,--as-needed" "-flto"
-   {pr13287.cc} {} "pr13287.exe" "c++"}
-  {"PR ld/15323"
-   "" "-O2"
-   {pr15323a.c} {} "" "c"}
-  {"Compile(1) PR ld/pr16846"
-   "" "-flto"
-   {pr16846a.c pr16846b.c} {} ""}
-  {"Compile(2) PR ld/pr16846"
-   "" ""
-   {pr16846c.c} {} ""}
-  {"PR ld/pr16846(1)"
-   "-flto -fuse-linker-plugin tmpdir/pr16846a.o tmpdir/pr16846b.o tmpdir/pr16846c.o" ""
-   {dummy.c} {} "pr16846a.exe"}
-  {"PR ld/pr16846(2)"
-   "-flto -fuse-linker-plugin tmpdir/pr16846a.o tmpdir/pr16846c.o tmpdir/pr16846b.o" ""
-   {dummy.c} {} "pr16846b.exe"}
+set plugin_names {
+    liblto_plugin.so
+    liblto_plugin-0.dll
+    cyglto_plugin-0.dll
 }
+set plug_opt ""
+foreach plug $plugin_names {
+    set plug_so [run_host_cmd $CC "--print-prog-name $plug"]
+    if { $plug_so ne $plug } then {
+       set plug_opt "--plugin $plug_so"
+       break
+    }
+}
+set lto_fat ""
+if { [check_lto_fat_available] } {
+  set lto_fat "-ffat-lto-objects"
+}
+
+# Simple LTO tests and generate input files for complex LTO tests.
+set lto_link_tests [list \
+  [list "LTO 1" \
+   "-O2 -flto -fuse-linker-plugin" "-flto -fuse-linker-plugin" \
+   {lto-1a.c lto-1b.c} {} "lto-1.exe"] \
+  [list "Compile 2" \
+   "" "-O2 -flto -fuse-linker-plugin" \
+   {lto-2.c} {} ""] \
+  [list "LTO 2" \
+   "-static -O2 -flto -fuse-linker-plugin tmpdir/lto-2.o -lm" "" \
+   {dummy.c} {} "lto-2.exe"] \
+  [list "Compile 3a" \
+   "" "-flto" \
+   {lto-3a.c} {} ""] \
+  [list "Compile 3c" \
+   "" "-O2" \
+   {lto-3c.c} {} ""] \
+  [list "Build liblto-3.a" \
+   "" "-flto $lto_fat" \
+   {lto-3b.c} {} "liblto-3.a"] \
+  [list "Compile 5a" \
+   "" "-flto $lto_fat" \
+   {lto-5a.c} {} ""] \
+  [list "Compile 5b" \
+   "" "-flto $lto_fat" \
+   {lto-5b.c} {} ""] \
+  [list "LTO 6" \
+   "-O2 -flto -fuse-linker-plugin" "" \
+   {lto-6.c} {} "lto-6.exe" "c"] \
+  [list "Compile 9" \
+   "" "-O2 -finline -flto" \
+   {lto-9.cc} {} "" "c++"] \
+  [list "Compile 11a" \
+   "" "-O -flto" \
+   {lto-11a.c} {} ""] \
+  [list "Compile 11b" \
+   "" "-O -flto" \
+   {lto-11b.c} {} ""] \
+  [list "Compile 11c" \
+   "" "-O" \
+   {lto-11c.c} {} ""] \
+  [list "Build liblto-12.a" \
+   "$plug_opt" "-O2 -flto" \
+   {lto-12c.c} {} "liblto-12.a"] \
+  [list "Compile 12" \
+   "" "-O2 -flto" \
+   {lto-12a.c lto-12b.c} {} ""] \
+  [list "Compile 13" \
+   "" "-O2 -flto" \
+   {lto-13a.c lto-13b.c} {} ""] \
+  [list "Build liblto-13.a" \
+   "" "-O2" \
+   {lto-13c.c} {} "liblto-13.a"] \
+  [list "Compile 14a" \
+   "" "-flto" \
+   {lto-14a.c lto-14b.c} {} ""] \
+  [list "Build liblto-14.a" \
+   "$plug_opt" "-flto" \
+   {lto-14c.c} {} "liblto-14.a"] \
+  [list "Compile 15a" \
+   "" "-flto" \
+   {lto-15a.c} {} ""] \
+  [list "Build liblto-15.a" \
+   "$plug_opt" "-flto" \
+   {lto-15b.c} {} "liblto-15.a"] \
+  [list "PR ld/12696" \
+   "-O2 -flto -fuse-linker-plugin -r -nostdlib" "-O2 -flto" \
+   {pr12696-1.cc} {} "pr12696-1r.o" "c++"] \
+  [list "Compile PR ld/12758" \
+   "" "" \
+   {pr12758a.s} {} ""] \
+  [list "Build libpr12758.a" \
+   "" "-flto -O2 $lto_fat" \
+   {pr12758b.c} {} "libpr12758.a"] \
+  [list "PR ld/12758" \
+   "-O2 -Wl,-e,foo -nostdlib -flto -fuse-linker-plugin tmpdir/pr12758a.o -Wl,--start-group tmpdir/libpr12758.a -Wl,--end-group" "" \
+   {dummy.c} {} "pr12758.exe"] \
+  [list "Compile PR ld/12760" \
+   "" "-g -O0" \
+   {pr12760a.c} {} ""] \
+  [list "Build libpr12760.a" \
+   "" "-flto -O2 $lto_fat" \
+   {pr12760b.c} {} "libpr12760.a"] \
+  [list "PR ld/12760" \
+   "-O2 -Wl,-e,foo -nostdlib -flto -fuse-linker-plugin tmpdir/pr12760a.o -Wl,--start-group tmpdir/libpr12760.a -Wl,--end-group" "" \
+   {dummy.c} {} "pr12760.exe" "c" "pr12760a.c:6: warning: Bad bar"] \
+  [list "Build libpr13183.a" \
+   "-T" "-flto -O2 $lto_fat" \
+   {pr13183a.c} {} "libpr13183.a"] \
+  [list "Compile PR ld/13183" \
+   "" "-flto -O2" \
+   {pr13183b.c} {} ""] \
+  [list "Compile PR ld/13201" \
+   "" "-flto -O2" \
+   {pr13201.c} {} ""] \
+  [list "PR ld/13287" \
+   "-flto -fuse-linker-plugin -Wl,--as-needed" "-flto" \
+   {pr13287.cc} {} "pr13287.exe" "c++"] \
+  [list "PR ld/15323" \
+   "" "-O2" \
+   {pr15323a.c} {} "" "c"] \
+  [list "Compile(1) PR ld/pr16846" \
+   "" "-flto" \
+   {pr16846a.c pr16846b.c} {} ""] \
+  [list "Compile(2) PR ld/pr16846" \
+   "" "" \
+   {pr16846c.c} {} ""] \
+  [list "PR ld/pr16846(1)" \
+   "-flto -fuse-linker-plugin tmpdir/pr16846a.o tmpdir/pr16846b.o tmpdir/pr16846c.o" "" \
+   {dummy.c} {} "pr16846a.exe"] \
+  [list "PR ld/pr16846(2)" \
+   "-flto -fuse-linker-plugin tmpdir/pr16846a.o tmpdir/pr16846c.o tmpdir/pr16846b.o" "" \
+   {dummy.c} {} "pr16846b.exe"] \
+]
 
 if { [at_least_gcc_version 4 7] } {
-    set lto_link_tests [concat $lto_link_tests {
-      {"Compile PR ld/12942 (1)"
-       "" "-flto -O2"
-       {pr12942a.cc pr12942c.cc} {} "" "c++"}
-      {"Compile PR ld/12942 (2)"
-       "" "-O0"
-       {pr12942b.cc} {} "" "c++"}
-    }]
+    set lto_link_tests [concat $lto_link_tests [list \
+      [list "Compile PR ld/12942 (1)" \
+       "" "-flto -O2" \
+       {pr12942a.cc pr12942c.cc} {} "" "c++"] \
+      [list "Compile PR ld/12942 (2)" \
+       "" "-O0" \
+       {pr12942b.cc} {} "" "c++"] \
+    ]]
 }
 
 # Generate input files for complex LTO tests for ELF.
-set lto_link_elf_tests {
-  {"Compile 7"
-   "" "-flto -O2"
-   {lto-7a.c lto-7b.c lto-7c.c} {} ""}
-  {"Build liblto-7.so"
-   "-shared" "-O2 -fpic"
-   {lto-7d.c} {} "liblto-7.so" "c"}
-  {"Compile 8a"
-   "" "-O2"
-   {lto-8a.c} {} ""}
-  {"Compile 8b"
-   "" "-flto -O2"
-   {lto-8b.c} {} ""}
-  {"Build liblto-17a.so"
-   "-shared -O2 -fpic -flto -fuse-linker-plugin" "-O2 -fpic -flto"
-   {lto-17a.c} {{"nm" {} "lto-17a.d"}} "liblto-17a.so" "c"}
-  {"Build liblto-17b.so 1"
-   "-shared -O2 -fpic -flto -fuse-linker-plugin tmpdir/lto-17a.o" "-O2 -fpic -flto"
-   {lto-17b.c} {{"nm" {} "lto-17b-1.d"}} "liblto-17b.so"}
-  {"Build liblto-17b.so 2"
-   "-shared -O2 -fpic -flto -fuse-linker-plugin tmpdir/lto-17a.o" "-O2 -fpic -flto"
-   {lto-17b.c} {{"nm" {} "lto-17b-2.d"}} "liblto-17b.so"}
-  {"PR ld/12982"
-   "-O2 -flto -fuse-linker-plugin" "-O2 -flto"
-   {pr12982.c} {{"readelf" {-l --wide} "pr12982.d"}} "pr12982.exe"}
-  {"PR ld/12975"
-   "-shared -O2 -fPIC -flto -fuse-linker-plugin -nostdlib -Wl,-version-script,pr12975.t" "-O2 -flto"
-   {pr12975.c} {{"readelf" {-s --wide} "pr12975.d"}} "pr12975.so" "c"}
-  {"PR ld/13229"
-   "-shared -O2 -fPIC -flto -fuse-linker-plugin -nostdlib" "-O2 -finline -fno-early-inlining -flto"
-   {pr13229.cc} {{"readelf" {-s --wide} "pr13229.d"}} "pr13229.so" "c++"}
-  {"PR ld/13244"
-   "-shared -O2 -fPIC -flto -fuse-linker-plugin -nostdlib" "-O2 -fno-early-inlining -flto"
-   {pr13244.c} {{"readelf" {-s --wide} "pr13244.d"}} "pr13244.so" "c"}
-  {"Build libpr15146a.a"
-   "" "-flto -O2"
-   {pr15146a.c} {} "lib15146a.a"}
-  {"Build pr15146b.so"
-   "-shared" "-O2 -fpic"
-   {pr15146b.c} {} "pr15146b.so" "c"}
-  {"Build pr15146c.so"
-   "-shared -Wl,--no-as-needed tmpdir/pr15146b.so" "-O2 -fpic"
-   {pr15146c.c} {} "pr15146c.so" "c"}
-  {"PR ld/15146 (1)"
-   "-O2 -flto -fuse-linker-plugin -Wl,-rpath-link,. -Wl,--no-copy-dt-needed-entries -Wl,--no-as-needed tmpdir/pr15146a.o tmpdir/pr15146c.so" ""
-   {dummy.c} {{"readelf" {-d} "pr15146.d"}} "pr15146a.exe"}
-  {"Build libpr15146d.a"
-   "" "-flto -O2"
-   {pr15146d.c} {} "lib15146d.a"}
-  {"Build libpr15146d.a"
-   "" "-flto -O2"
-   {pr15146d.c} {} "lib15146d.a"}
-}
+set lto_link_elf_tests [list \
+  [list "Compile 7" \
+   "" "-flto -O2" \
+   {lto-7a.c lto-7b.c lto-7c.c} {} ""] \
+  [list "Build liblto-7.so" \
+   "-shared" "-O2 -fpic" \
+   {lto-7d.c} {} "liblto-7.so" "c"] \
+  [list "Compile 8a" \
+   "" "-O2" \
+   {lto-8a.c} {} ""] \
+  [list "Compile 8b" \
+   "" "-flto -O2" \
+   {lto-8b.c} {} ""] \
+  [list "Build liblto-17a.so" \
+   "-shared -O2 -fpic -flto -fuse-linker-plugin" "-O2 -fpic -flto" \
+   {lto-17a.c} {{"nm" {} "lto-17a.d"}} "liblto-17a.so" "c"] \
+  [list "Build liblto-17b.so 1" \
+   "-shared -O2 -fpic -flto -fuse-linker-plugin tmpdir/lto-17a.o" "-O2 -fpic -flto" \
+   {lto-17b.c} {{"nm" {} "lto-17b-1.d"}} "liblto-17b.so"] \
+  [list "Build liblto-17b.so 2" \
+   "-shared -O2 -fpic -flto -fuse-linker-plugin tmpdir/lto-17a.o" "-O2 -fpic -flto" \
+   {lto-17b.c} {{"nm" {} "lto-17b-2.d"}} "liblto-17b.so"] \
+  [list "PR ld/12982" \
+   "-O2 -flto -fuse-linker-plugin" "-O2 -flto" \
+   {pr12982.c} {{"readelf" {-l --wide} "pr12982.d"}} "pr12982.exe"] \
+  [list "PR ld/12975" \
+   "-shared -O2 -fPIC -flto -fuse-linker-plugin -nostdlib -Wl,-version-script,pr12975.t" "-O2 -flto" \
+   {pr12975.c} {{"readelf" {-s --wide} "pr12975.d"}} "pr12975.so" "c"] \
+  [list "PR ld/13229" \
+   "-shared -O2 -fPIC -flto -fuse-linker-plugin -nostdlib" "-O2 -finline -fno-early-inlining -flto" \
+   {pr13229.cc} {{"readelf" {-s --wide} "pr13229.d"}} "pr13229.so" "c++"] \
+  [list "PR ld/13244" \
+   "-shared -O2 -fPIC -flto -fuse-linker-plugin -nostdlib" "-O2 -fno-early-inlining -flto" \
+   {pr13244.c} {{"readelf" {-s --wide} "pr13244.d"}} "pr13244.so" "c"] \
+  [list "Build libpr15146a.a" \
+   "$plug_opt" "-flto -O2" \
+   {pr15146a.c} {} "lib15146a.a"] \
+  [list "Build pr15146b.so" \
+   "-shared" "-O2 -fpic" \
+   {pr15146b.c} {} "pr15146b.so" "c"] \
+  [list "Build pr15146c.so" \
+   "-shared -Wl,--no-as-needed tmpdir/pr15146b.so" "-O2 -fpic" \
+   {pr15146c.c} {} "pr15146c.so" "c"] \
+  [list "PR ld/15146 (1)" \
+   "-O2 -flto -fuse-linker-plugin -Wl,-rpath-link,. -Wl,--no-copy-dt-needed-entries -Wl,--no-as-needed tmpdir/pr15146a.o tmpdir/pr15146c.so" "" \
+   {dummy.c} {{"readelf" {-d} "pr15146.d"}} "pr15146a.exe"] \
+  [list "Build libpr15146d.a" \
+   "$plug_opt" "-flto -O2" \
+   {pr15146d.c} {} "lib15146d.a"] \
+]
 
 # Check final symbols in executables.
-set lto_link_symbol_tests {
-  {"LTO 3 symbol"
-   "-O2 -flto -fuse-linker-plugin tmpdir/lto-3a.o tmpdir/lto-3c.o tmpdir/liblto-3.a" ""
-   {dummy.c} {{"nm" {} "lto-3.d"}} "lto-3.exe" "c"}
-  {"LTO 5 symbol"
-   "-O2 -flto -fuse-linker-plugin tmpdir/lto-5.o" ""
-   {dummy.c} {{"nm" {} "lto-5.d"}} "lto-5.exe" "c"}
-  {"LTO 9 symbol"
-   "-O2 -flto -fuse-linker-plugin tmpdir/lto-9.o" ""
-   {dummy.c} {{"nm" {-C} "lto-9.d"}} "lto-9.exe" "c++"}
-  {"LTO 16a symbol"
-   "-O2 -Wl,-e,foo -nostdlib -flto -fuse-linker-plugin" "-flto"
-   {lto-16a.c} {{"nm" {} "lto-16a.d"}} "lto-16.exe" "c"}
-  {"LTO 16b symbol"
-   "-O2 -Wl,-e,foo -u bar -nostdlib -flto -fuse-linker-plugin" "-flto"
-   {lto-16a.c lto-16b.c} {{"nm" {} "lto-16b.d"}} "lto-16b.exe" "c"}
-  {"PR ld/13183"
-   "-O2 -flto -fuse-linker-plugin tmpdir/pr13183b.o tmpdir/libpr13183.a" ""
-   {dummy.c} {{"nm" {} "pr13183.d"}} "pr13183.exe" "c"}
-}
+set lto_link_symbol_tests [list \
+  [list "LTO 3 symbol" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/lto-3a.o tmpdir/lto-3c.o tmpdir/liblto-3.a" "" \
+   {dummy.c} {{"nm" {} "lto-3.d"}} "lto-3.exe" "c"] \
+  [list "LTO 5 symbol" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/lto-5.o" "" \
+   {dummy.c} {{"nm" {} "lto-5.d"}} "lto-5.exe" "c"] \
+  [list "LTO 9 symbol" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/lto-9.o" "" \
+   {dummy.c} {{"nm" {-C} "lto-9.d"}} "lto-9.exe" "c++"] \
+  [list "LTO 16a symbol" \
+   "-O2 -Wl,-e,foo -nostdlib -flto -fuse-linker-plugin" "-flto" \
+   {lto-16a.c} {{"nm" {} "lto-16a.d"}} "lto-16.exe" "c"] \
+  [list "LTO 16b symbol" \
+   "-O2 -Wl,-e,foo -u bar -nostdlib -flto -fuse-linker-plugin" "-flto" \
+   {lto-16a.c lto-16b.c} {{"nm" {} "lto-16b.d"}} "lto-16b.exe" "c"] \
+  [list "PR ld/13183" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/pr13183b.o tmpdir/libpr13183.a" "" \
+   {dummy.c} {{"nm" {} "pr13183.d"}} "pr13183.exe" "c"] \
+]
 
 # LTO run-time tests.
-set lto_run_tests {
-  {"LTO 3a"
-   "-O2 -flto -fuse-linker-plugin tmpdir/lto-3a.o tmpdir/lto-3c.o tmpdir/liblto-3.a" ""
-   {dummy.c} "lto-3b.exe" "lto-3.out" "" "c"}
-  {"LTO 3b"
-   "-O2 -flto -fuse-linker-plugin tmpdir/lto-3a.o tmpdir/lto-3c.o tmpdir/lto-3.o" ""
-   {dummy.c} "lto-3c.exe" "lto-3.out" "" "c"}
-  {"LTO 3c"
-   "-O2 -flto -fuse-linker-plugin tmpdir/lto-3a.o tmpdir/lto-3c.o -Wl,--whole-archive tmpdir/liblto-3.a -Wl,--no-whole-archive tmpdir/liblto-3.a" ""
-   {dummy.c} "lto-3d.exe" "lto-3.out" "" "c"}
-  {"LTO 5"
-   "-O2 -flto -fuse-linker-plugin tmpdir/lto-5.o" ""
-   {dummy.c} "lto-5.exe" "lto-5.out" "" "c"}
-  {"LTO 11"
-   "-O -flto -fuse-linker-plugin tmpdir/liblto-11.a" ""
-   {dummy.c} "lto-11.exe" "lto-11.out" "" "c"}
-  {"LTO 12a"
-   "-O -flto -fuse-linker-plugin tmpdir/lto-12a.o tmpdir/liblto-12.a tmpdir/lto-12b.o" ""
-   {dummy.c} "lto-12a.exe" "lto-12.out" "" "c"}
-  {"LTO 12b"
-   "-O -flto -fuse-linker-plugin tmpdir/lto-12a.o tmpdir/lto-12b.o tmpdir/liblto-12.a" ""
-   {dummy.c} "lto-12b.exe" "lto-12.out" "" "c"}
-  {"LTO 13"
-   "-O -flto -fuse-linker-plugin tmpdir/lto-13a.o tmpdir/liblto-13.a tmpdir/lto-13b.o" ""
-   {dummy.c} "lto-13.exe" "lto-13.out" "" "c"}
-  {"LTO 14"
-   "-O2 -flto -fuse-linker-plugin tmpdir/lto-14a.o -Wl,--whole-archive tmpdir/liblto-14.a -Wl,--no-whole-archive tmpdir/lto-14b.o" ""
-   {dummy.c} "lto-14.exe" "lto-14.out" "" "c"}
-  {"LTO 15"
-   "-O2 -flto -fuse-linker-plugin -Wl,--start-group tmpdir/liblto-15.a tmpdir/lto-15a.o -Wl,--end-group" ""
-   {dummy.c} "lto-15.exe" "lto-15.out" "" "c"}
-  {"PR ld/13066"
-   "-O2 -flto -fuse-linker-plugin" ""
-   {pr13066.cc} "pr13066.exe" "pr13066.out" "" "c++"}
-  {"PR ld/13201"
-   "-O2 -flto -fuse-linker-plugin -Wl,--as-needed tmpdir/pr13201.o -lm" ""
-   {dummy.c} "pr13201.exe" "pr13201.out" "" "c"}
-  {"PR ld/15323"
-   "-O2 -flto -fuse-linker-plugin tmpdir/pr15323a.o" ""
-   {pr15323b.c} "pr15323.exe" "pr15323.out" "-flto -O2" "c"}
-}
+set lto_run_tests [list \
+  [list "LTO 3a" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/lto-3a.o tmpdir/lto-3c.o tmpdir/liblto-3.a" "" \
+   {dummy.c} "lto-3b.exe" "lto-3.out" "" "c"] \
+  [list "LTO 3b" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/lto-3a.o tmpdir/lto-3c.o tmpdir/lto-3.o" "" \
+   {dummy.c} "lto-3c.exe" "lto-3.out" "" "c"] \
+  [list "LTO 3c" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/lto-3a.o tmpdir/lto-3c.o -Wl,--whole-archive tmpdir/liblto-3.a -Wl,--no-whole-archive tmpdir/liblto-3.a" "" \
+   {dummy.c} "lto-3d.exe" "lto-3.out" "" "c"] \
+  [list "LTO 5" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/lto-5.o" "" \
+   {dummy.c} "lto-5.exe" "lto-5.out" "" "c"] \
+  [list "LTO 11" \
+   "-O -flto -fuse-linker-plugin tmpdir/liblto-11.a" "" \
+   {dummy.c} "lto-11.exe" "lto-11.out" "" "c"] \
+  [list "LTO 12a" \
+   "-O -flto -fuse-linker-plugin tmpdir/lto-12a.o tmpdir/liblto-12.a tmpdir/lto-12b.o" "" \
+   {dummy.c} "lto-12a.exe" "lto-12.out" "" "c"] \
+  [list "LTO 12b" \
+   "-O -flto -fuse-linker-plugin tmpdir/lto-12a.o tmpdir/lto-12b.o tmpdir/liblto-12.a" "" \
+   {dummy.c} "lto-12b.exe" "lto-12.out" "" "c"] \
+  [list "LTO 13" \
+   "-O -flto -fuse-linker-plugin tmpdir/lto-13a.o tmpdir/liblto-13.a tmpdir/lto-13b.o" "" \
+   {dummy.c} "lto-13.exe" "lto-13.out" "" "c"] \
+  [list "LTO 14" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/lto-14a.o -Wl,--whole-archive tmpdir/liblto-14.a -Wl,--no-whole-archive tmpdir/lto-14b.o" "" \
+   {dummy.c} "lto-14.exe" "lto-14.out" "" "c"] \
+  [list "LTO 15" \
+   "-O2 -flto -fuse-linker-plugin -Wl,--start-group tmpdir/liblto-15.a tmpdir/lto-15a.o -Wl,--end-group" "" \
+   {dummy.c} "lto-15.exe" "lto-15.out" "" "c"] \
+  [list "PR ld/13066" \
+   "-O2 -flto -fuse-linker-plugin" "" \
+   {pr13066.cc} "pr13066.exe" "pr13066.out" "" "c++"] \
+  [list "PR ld/13201" \
+   "-O2 -flto -fuse-linker-plugin -Wl,--as-needed tmpdir/pr13201.o -lm" "" \
+   {dummy.c} "pr13201.exe" "pr13201.out" "" "c"] \
+  [list "PR ld/15323" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/pr15323a.o" "" \
+   {pr15323b.c} "pr15323.exe" "pr15323.out" "-flto -O2" "c"] \
+]
 
 if { [at_least_gcc_version 4 7] } {
-    set lto_run_tests [concat $lto_run_tests {
-      {"PR ld/12942 (1)"
-       "-O2 -flto -fuse-linker-plugin tmpdir/pr12942a.o tmpdir/pr12942b.o" ""
-       {dummy.c} "pr12942a.exe" "pr12942.out" "" "c++"}
-      {"PR ld/12942 (2)"
-       "-O2 -flto -fuse-linker-plugin tmpdir/pr12942a.o tmpdir/pr12942c.o" ""
-       {dummy.c} "pr12942c.exe" "pr12942.out" "" "c++"}
-    }]
+    set lto_run_tests [concat $lto_run_tests [list \
+      [list "PR ld/12942 (1)" \
+       "-O2 -flto -fuse-linker-plugin tmpdir/pr12942a.o tmpdir/pr12942b.o" "" \
+       {dummy.c} "pr12942a.exe" "pr12942.out" "" "c++"] \
+      [list "PR ld/12942 (2)" \
+       "-O2 -flto -fuse-linker-plugin tmpdir/pr12942a.o tmpdir/pr12942c.o" "" \
+       {dummy.c} "pr12942c.exe" "pr12942.out" "" "c++"] \
+    ]]
 }
 
 # LTO run-time tests for ELF
-set lto_run_elf_tests {
-  {"LTO 7"
-   "-O2 -flto -fuse-linker-plugin tmpdir/lto-7b.o tmpdir/lto-7c.o tmpdir/lto-7a.o -Wl,--no-as-needed tmpdir/liblto-7.so" ""
-   {dummy.c} "lto-7.exe" "lto-7.out" "" "c"}
-  {"LTO 8"
-   "-O2 -flto -fuse-linker-plugin tmpdir/lto-8b.o tmpdir/lto-8a.o" ""
-   {dummy.c} "lto-8.exe" "lto-8.out" "" "c"}
-  {"LTO TLS IE"
-   "-O2 -flto -fuse-linker-plugin" ""
-   {run-ie.c} "run-ie.exe" "run-ie.out" "" "c"}
-}
+set lto_run_elf_tests [list \
+  [list "LTO 7" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/lto-7b.o tmpdir/lto-7c.o tmpdir/lto-7a.o -Wl,--no-as-needed tmpdir/liblto-7.so" "" \
+   {dummy.c} "lto-7.exe" "lto-7.out" "" "c"] \
+  [list "LTO 8" \
+   "-O2 -flto -fuse-linker-plugin tmpdir/lto-8b.o tmpdir/lto-8a.o" "" \
+   {dummy.c} "lto-8.exe" "lto-8.out" "" "c"] \
+  [list "LTO TLS IE" \
+   "-O2 -flto -fuse-linker-plugin" "" \
+   {run-ie.c} "run-ie.exe" "run-ie.out" "" "c"] \
+]
 
 run_cc_link_tests $lto_link_tests
 
 
 set testname "Build liblto-11.a"
 remote_file host delete "tmpdir/liblto-11.a"
-set plugin_names {
-    liblto_plugin.so
-    liblto_plugin-0.dll
-    cyglto_plugin-0.dll
-}
-set plug_opt ""
-foreach plug $plugin_names {
-    set plug_so [run_host_cmd $CC "--print-prog-name $plug"]
-    if { $plug_so ne $plug } then {
-       set plug_opt "--plugin $plug_so"
-       break
-    }
-}
 set catch_output [run_host_cmd "$ar" "rc $plug_opt tmpdir/liblto-11.a tmpdir/lto-11a.o tmpdir/lto-11b.o tmpdir/lto-11c.o"]
 if {![string match "" $catch_output]} {
     unresolved $testname