Re: gcc-vax in NetBSD-9.0: help needed to test patches

[Kalvis Duckmanton <kalvisd%gmail.com@localhost>]

Hi John,

On 27/7/20 5:35 am, John Klos wrote:
> FYI - I haven't had time to do much with this lately because I've been 
> traveling for work, but many things which weren't working are now 
> working :)
>
> The one place that is still not happy with -O2 is in pkgsrc/net/rsync:
>
> gcc -I. -I. -I./zlib -I./popt -O2 -D_FORTIFY_SOURCE=2 -I/usr/include 
> -DHAVE_CONFIG_H -Wall -W -I/usr/include -c checksum.c -o checksum.o
> checksum.c: In function 'get_checksum2':
> checksum.c:191:1: internal compiler error: in change_address_1, at 
> emit-rtl.c:2150
>  }
>  ^
> no stack trace because unwind library not available
> Please submit a full bug report,
> with preprocessed source if appropriate.
> See <http://www.NetBSD.org/support/send-pr.html> for instructions.
> *** Error code 1
>
> Any thoughts about what could be going on here? 

It could be the same problem I tripped over, where GCC is trying to 
optimise a bit field extraction by adjusting the source address.  I 
don't believe that this optimisation can be done when compiling 
position-independent code if the source address is given by an external 
symbol (but happy to take advice from GCC experts!).  The attached patch 
should help.

cheers

kalvis


diff --git a/external/gpl3/gcc/dist/gcc/config/vax/vax.md b/external/gpl3/gcc/dist/gcc/config/vax/vax.md
index 5b0bcf9843a1..932616d313d5 100644
--- a/external/gpl3/gcc/dist/gcc/config/vax/vax.md
+++ b/external/gpl3/gcc/dist/gcc/config/vax/vax.md
@@ -804,7 +804,7 @@
 				       MEM_ADDR_SPACE (operands[0]))))"
   "*
 {
-  if (REG_P (operands[0]))
+  if (REG_P (operands[0]) || flag_pic)
     {
       if (INTVAL (operands[2]) != 0)
 	return \"insv %3,%2,%1,%0\";
@@ -834,7 +834,7 @@
 				      MEM_ADDR_SPACE (operands[1]))))"
   "*
 {
-  if (REG_P (operands[1]))
+  if (REG_P (operands[1]) || flag_pic)
     {
       if (INTVAL (operands[3]) != 0)
 	return \"extzv %3,%2,%1,%0\";
@@ -863,7 +863,7 @@
 				      MEM_ADDR_SPACE (operands[1]))))"
   "*
 {
-  if (REG_P (operands[1]))
+  if (REG_P (operands[1]) || flag_pic)
     {
       if (INTVAL (operands[3]) != 0)
 	return \"extv %3,%2,%1,%0\";