Re: Bug#972202: python3.9: Please build with -O1 on sh4 to temporarily work around GCC bug

Hello!

On 10/14/20 12:15 PM, John Paul Adrian Glaubitz wrote:
> I will try to track down which particular optimization flag causes the miscompilation
> and report the issue to GCC upstream.

Turns out the offending optimization flag is "-finline-small-functions", so this
workaround makes the package build.

diff -Nru old/python3.9-3.9.0/debian/rules new/python3.9-3.9.0/debian/rules
--- old/python3.9-3.9.0/debian/rules    2020-09-03 21:33:00.000000000 +0200
+++ new/python3.9-3.9.0/debian/rules    2020-10-14 22:45:31.423587080 +0200
@@ -170,6 +170,9 @@
 ifeq ($(DEB_HOST_ARCH),ia64)
     EXTRA_OPT_CFLAGS += -O2
 endif
+ifeq ($(DEB_HOST_ARCH),sh4)
+    EXTRA_OPT_CFLAGS += -fno-inline-small-functions
+endif
 ifneq (,$(filter $(DEB_HOST_ARCH), ppc64 ppc64el))
     OPT_CFLAGS += -fexceptions
     DEBUG_CFLAGS += -fexceptions

I will report the issue to gcc upstream.

Adrian