re PR rtl-optimization/59647 (ICE in simplify_const_unary_operation, at simplify-rtx.c:1597)

	PR rtl-optimization/59647
	* cse.c (cse_process_notes_1): Don't substitute negative VOIDmode
	new_rtx into UNSIGNED_FLOAT rtxes.

	* g++.dg/opt/pr59647.C: New test.

From-SVN: r206267

gcc/cse.c

@@ -6090,6 +6090,18 @@ cse_process_notes_1 (rtx x, rtx object, bool *changed)
 	return x;
       }
 
+    case UNSIGNED_FLOAT:
+      {
+	rtx new_rtx = cse_process_notes (XEXP (x, 0), object, changed);
+	/* We don't substitute negative VOIDmode constants into these rtx,
+	   since they would impede folding.  */
+	if (GET_MODE (new_rtx) != VOIDmode
+	    || (CONST_INT_P (new_rtx) && INTVAL (new_rtx) >= 0)
+	    || (CONST_DOUBLE_P (new_rtx) && CONST_DOUBLE_HIGH (new_rtx) >= 0))
+	  validate_change (object, &XEXP (x, 0), new_rtx, 0);
+	return x;
+      }
+
     case REG:
       i = REG_QTY (REGNO (x));
 

gcc/testsuite/g++.dg/opt/pr59647.C

+// PR rtl-optimization/59647
+// { dg-do compile }
+// { dg-options "-O2 -fno-tree-vrp" }
+// { dg-additional-options "-msse2 -mfpmath=sse" { target { { i?86-*-* x86_64-*-* } && ia32 } } }
+
+void f1 (int);
+void f2 ();
+double f3 (int);
+
+struct A
+{
+  int f4 () const
+  {
+    if (a == 0)
+      return 1;
+    return 0;
+  }
+  unsigned f5 ()
+  {
+    if (!f4 ())
+      f2 ();
+    return a;
+  }
+  int a;
+};
+
+void
+f6 (A *x)
+{
+  unsigned b = x->f5 ();
+  f1 (b - 1 - f3 (x->f5 () - 1U));
+}