* gcc.c-torture/execute/20020720-1.x: Skip test on

	mmix-knuth-mmixware.  Correct comment.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@56708 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 16 insertions, 8 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3f3a17da070..8369762497c 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2002-08-31  Roger Sayle  <roger@eyesopen.com>
+	    Hans-Peter Nilsson  <hp@bitrange.com>
+
+	* gcc.c-torture/execute/20020720-1.x: Skip test on
+	mmix-knuth-mmixware.  Correct comment.
+
 2002-08-27  Mark Mitchell  <mark@codesourcery.com>
 
 	* testsuite/g++.dg/abi/bitfield5.C: New test.
diff --git a/gcc/testsuite/gcc.c-torture/execute/20020720-1.x b/gcc/testsuite/gcc.c-torture/execute/20020720-1.x
index 6534217d7c8..4cf53d0d595 100644
--- a/gcc/testsuite/gcc.c-torture/execute/20020720-1.x
+++ b/gcc/testsuite/gcc.c-torture/execute/20020720-1.x
@@ -1,15 +1,17 @@
 # The following targets fail 20020720-1.c for several reasons:
 # (1) They implement floating point instructions via software, or
-# (2) Their machine descriptions obfuscate the "abs(x) < 0.0" comparison.
-#     For example, 1 insn performs abs, 1 insn loads 0.0, 1 insn sets
-#     CCmode flags based upon the FP comparison, and a 4th insn makes
-#     a conditional branch based upon the appropriate bits in the flags.
-#     If the intermediate comparison can't be recognized, the combiner
-#     is unable to optimize all four RTL instructions simultaneously.
-
+# (2) The "abs(x) < 0.0" comparison is split up in too many intermediate
+#     insns for combine to handle -- it can handle max three insns
+#     simultaneously.  For example, for RISCy machines it is common that 1
+#     insn performs abs, 1 insn loads 0.0, 1 insn sets CCmode flags based
+#     upon the FP comparison, and a 4th insn makes a conditional branch
+#     based upon the appropriate bits in the flags.  On the other hand, if
+#     for example the comparison insn takes 0.0 as an operand, the
+#     combiner is able to see all intermediate instructions simultaneously
+#     and can make the optimization.
 if { [istarget "powerpc-*-*"] || [istarget "rs6000-*-*"] \
      || [istarget "mips*-*-*"] || [istarget "xtensa-*-*"] \
-     || [istarget "sh-*-*"] } {
+     || [istarget "sh-*-*"] || [istarget "mmix-*-*"] } {
     return 1
 }