re PR target/85756 (wrong code at -Os on x86-64-linux-gnu in 32-bit mode)

	PR target/85756
	* config/i386/i386.md: Disallow non-commutative arithmetics in
	last twpeephole for mem {+,-,&,|,^}= x; mem != 0 after cmpelim
	optimization.  Use COMMUTATIVE_ARITH_P test rather than != MINUS
	in the peephole2 before it.

testsuite/ChangeLog:

	* gcc.c-torture/execute/pr85756.c: New test.

From-SVN: r260231

gcc/ChangeLog

+2018-05-14  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/85756
+	* config/i386/i386.md: Disallow non-commutative arithmetics in
+	last twpeephole for mem {+,-,&,|,^}= x; mem != 0 after cmpelim
+	optimization.  Use COMMUTATIVE_ARITH_P test rather than != MINUS
+	in the peephole2 before it.
+
 2018-05-14  Sebastian Peryt  <sebastian.peryt@intel.com>
 
 	* common/config/i386/i386-common.c (OPTION_MASK_ISA_CLDEMOTE_SET,

gcc/config/i386/i386.md

@@ -19370,7 +19370,7 @@
    (set (match_dup 1) (match_dup 0))
    (set (reg FLAGS_REG) (compare (match_dup 0) (const_int 0)))]
   "(TARGET_READ_MODIFY_WRITE || optimize_insn_for_size_p ())
-   && GET_CODE (operands[2]) != MINUS
+   && COMMUTATIVE_ARITH_P (operands[2])
    && peep2_reg_dead_p (3, operands[0])
    && !reg_overlap_mentioned_p (operands[0], operands[1])
    && ix86_match_ccmode (peep2_next_insn (2),
@@ -19400,11 +19400,11 @@
 	      (set (match_dup 0) (match_dup 2))])
    (set (match_dup 1) (match_dup 0))]
   "(TARGET_READ_MODIFY_WRITE || optimize_insn_for_size_p ())
+   && COMMUTATIVE_ARITH_P (operands[2])
    && peep2_reg_dead_p (2, operands[0])
    && !reg_overlap_mentioned_p (operands[0], operands[1])
    && ix86_match_ccmode (peep2_next_insn (0),
-			 (GET_CODE (operands[2]) == PLUS
-			  || GET_CODE (operands[2]) == MINUS)
+			 GET_CODE (operands[2]) == PLUS
 			 ? CCGOCmode : CCNOmode)"
   [(parallel [(set (match_dup 3) (match_dup 5))
 	      (set (match_dup 1) (match_dup 4))])]

gcc/testsuite/ChangeLog

+2018-05-14  Jakub Jelinek  <jakub@redhat.com>
+
+	* gcc.c-torture/execute/pr85756.c: New test.
+
 2018-05-14  Sebastian Peryt  <sebastian.peryt@intel.com>
 
 	* gcc.target/i386/cldemote-1.c: New test.

gcc/testsuite/gcc.c-torture/execute/pr85756.c

+/* PR target/85756 */
+
+#if __CHAR_BIT__ == 8 && __SIZEOF_SHORT__ == 2 && __SIZEOF_INT__ == 4
+int a, c, *e, f, h = 10;
+short b;
+unsigned int p;
+
+__attribute__((noipa)) void
+bar (int a)
+{
+  asm volatile ("" : : "r" (a) : "memory");
+}
+
+void
+foo ()
+{
+  unsigned j = 1, m = 430523;
+  int k, n = 1, *l = &h;
+lab:
+  p = m;
+  m = -((~65535U | j) - n);
+  f = b << ~(n - 8);
+  n = (m || b) ^ f;
+  j = p;
+  if (p < m)
+    *l = k < 3;
+  if (!n)
+    l = &k;
+  if (c)
+    {
+      bar (a);
+      goto lab;
+    }
+  if (!*l)
+    *e = 1;
+}
+
+int
+main ()
+{
+  foo ();
+  return 0;
+}
+#else
+int
+main ()
+{
+  return 0;
+}
+#endif