------- Additional Comments From uros at kss-loka dot si 2005-01-18 15:58
-------
This patch unfortunatelly didn't help:
http://gcc.gnu.org/ml/gcc-cvs/2005-01/msg00651.html
With the patch, tracing abyss.pov generates these warnings:
Parsing.............File: ../scenes/advanced/abyss.pov Line: 434
Warning: Degenerate CSG bounding box (not used!).
......File: ../scenes/advanced/abyss.pov Line: 642
Warning: Degenerate CSG bounding box (not used!).
...............................................File:
../scenes/advanced/abyss.pov Line: 728
Warning: Degenerate CSG bounding box (not used!).
Trying to get a smaller testcase, I have found that this problem can be somehow
fixed by following change in ix86_fp_comparison_codes():
Index: i386.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/i386/i386.c,v
retrieving revision 1.780
diff -u -p -r1.780 i386.c
--- i386.c 18 Jan 2005 11:08:33 -0000 1.780
+++ i386.c 18 Jan 2005 15:51:18 -0000
@@ -8446,6 +8446,8 @@ ix86_fp_comparison_codes (enum rtx_code
case LT: /* LTU - CF=1 - fails on unordered */
*first_code = UNLT;
*bypass_code = UNORDERED;
+ return;
+
break;
case LE: /* LEU - CF=1 | ZF=1 - fails on unordered */
*first_code = UNLE;
This change protects *bypass_code from being cleared back to UNKNOWN by
following code at the end of function:
...
if (!TARGET_IEEE_FP)
{
*second_code = UNKNOWN;
*bypass_code = UNKNOWN;
}
}
It looks that something is wrong with LT compares.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19506
