20020720-1.x: Skip test on mmix-knuth-mmixware.

	* gcc.c-torture/execute/20020720-1.x: Skip test on
	mmix-knuth-mmixware.  Correct comment.

Co-Authored-By: Hans-Peter Nilsson <hp@bitrange.com>
From-SVN: r56708

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3f3a17da0701995fea3baa2dc5fafa66535d715e..8369762497c9d5b323eb986c81887df2aa08eb06 100644 (file)
--- 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 6534217d7c8c931d7b0d01c914edc898f116254d..4cf53d0d5957059a61c9f70d97c05c6cb441247b 100644 (file)
--- 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
 }