re PR tree-optimization/66739 (FAIL: gcc.target/aarch64/subs.c scan-assembler subs\tw[0-9])

2015-07-07 Richard Biener <rguenther@suse.de> PR middle-end/66739 * match.pd: Condition A - B ==/!= 0 -> A ==/!= B on single-use A - B. From-SVN: r225502

re PR tree-optimization/66739 (FAIL: gcc.target/aarch64/subs.c scan-assembler subs\tw[0-9])
2015-07-07 Richard Biener <rguenther@suse.de> PR middle-end/66739 * match.pd: Condition A - B ==/!= 0 -> A ==/!= B on single-use A - B. From-SVN: r225502
d9ba1961 · Richard Biener · Richard Biener · fc1cbdf3 · d9ba1961 · d9ba1961
Commit d9ba1961 authored 9 years ago by Richard Biener Committed by Richard Biener 9 years ago
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gcc/ChangeLog
+6 -0

gcc/match.pd
+3 -2

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--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
+2015-07-07  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/66739
+	* match.pd: Condition A - B ==/!= 0 -> A ==/!= B on single-use
+	A - B.
+
 2015-07-06  Uros Bizjak  <ubizjak@gmail.com>

 	* config/i386/i386.md (insv<mode>): Rename from insv.  Use SWI48

--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1334,8 +1334,9 @@ along with GCC; see the file COPYING3.  If not see
   attempts to synthetize ABS_EXPR.  */
 (for cmp (eq ne)
 (simplify
-  (cmp (minus @0 @1) integer_zerop)
-  (cmp @0 @1)))
+  (cmp (minus@2 @0 @1) integer_zerop)
+  (if (single_use (@2))
+   (cmp @0 @1))))

 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
   signed arithmetic case.  That form is created by the compiler