Subject: factor: infinite loop on Linux/powerpc
From: Colin Watson <[email-masked]>
To: [email-masked]
Date: Thu, 29 Nov 2012 14:28:18 +0000
List-Id: <debbugs-submit.debbugs.gnu.org>

Both Debian and Ubuntu builds of coreutils 8.20 hang while running the
test suite on powerpc.  This turns out to be reproducible using 'factor
122'.

This turns out to be somewhat related to
http://debbugs.gnu.org/cgi/bugreport.cgi?bug=12754, but not quite the
same.  uintmax_t is 64 bits, but the cntlzw instruction takes 32-bit
operands, and the cntlzd option is only available on 64-bit hardware.  I
believe the correct answer is to add an _LP64 check around the PPC64
code, so that this falls back to the C implementations:

--- coreutils-8.20~/src/longlong.h	2012-11-29 14:25:07.000000000 +0000
+++ coreutils-8.20/src/longlong.h	2012-11-29 14:26:40.000000000 +0000
@@ -1398,7 +1398,7 @@
 
 /* We should test _IBMR2 here when we add assembly support for the system
    vendor compilers.  */
-#if HAVE_HOST_CPU_FAMILY_powerpc && W_TYPE_SIZE == 64
+#if HAVE_HOST_CPU_FAMILY_powerpc && W_TYPE_SIZE == 64 && defined (_LP64)
 #if !defined (_LONG_LONG_LIMB)
 /* _LONG_LONG_LIMB is ABI=mode32 where adde operates on 32-bit values.  So
    use adde etc only when not _LONG_LONG_LIMB.  */

Thanks,

-- 
Colin Watson                                       [[email-masked]]