re PR rtl-optimization/57568 (wrong code for assignment in conditional at -Os)

	PR target/57568
	* config/i386/i386.md (TARGET_READ_MODIFY_WRITE peepholes): Ensure
	that operands[2] doesn't overlap with operands[0].

	* gcc.c-torture/execute/pr57568.c: New test.

From-SVN: r199870

gcc/ChangeLog

+2013-06-09  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/57568
+	* config/i386/i386.md (TARGET_READ_MODIFY_WRITE peepholes): Ensure
+	that operands[2] doesn't overlap with operands[0].
+
 2013-06-09  David Edelsohn  <dje.gcc@gmail.com>
 	    Jan Hubicka  <jh@suse.cz>
 

gcc/config/i386/i386.md

@@ -16591,6 +16591,7 @@
   "(TARGET_READ_MODIFY_WRITE || optimize_insn_for_size_p ())
    && peep2_reg_dead_p (4, operands[0])
    && !reg_overlap_mentioned_p (operands[0], operands[1])
+   && !reg_overlap_mentioned_p (operands[0], operands[2])
    && (<MODE>mode != QImode
        || immediate_operand (operands[2], QImode)
        || q_regs_operand (operands[2], QImode))
@@ -16655,6 +16656,7 @@
        || immediate_operand (operands[2], SImode)
        || q_regs_operand (operands[2], SImode))
    && !reg_overlap_mentioned_p (operands[0], operands[1])
+   && !reg_overlap_mentioned_p (operands[0], operands[2])
    && ix86_match_ccmode (peep2_next_insn (3),
 			 (GET_CODE (operands[3]) == PLUS
 			  || GET_CODE (operands[3]) == MINUS)

gcc/testsuite/ChangeLog

+2013-06-09  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/57568
+	* gcc.c-torture/execute/pr57568.c: New test.
+
 2013-06-09  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/37404

gcc/testsuite/gcc.c-torture/execute/pr57568.c

+/* PR target/57568 */
+
+extern void abort (void);
+int a[6][9] = { }, b = 1, *c = &a[3][5];
+
+int
+main ()
+{
+  if (b && (*c = *c + *c))
+    abort ();
+  return 0;
+}