re PR c/39902 (x * 1.0DF gets wrong value)

	PR c/39902
	* simplify-rtx.c (simplify_binary_operation_1): Disable
	simplifications for decimal float operations.

	PR c/39902
	* gcc.target/powerpc/pr39902-2.c: New test.

From-SVN: r150383

gcc/ChangeLog

+2009-08-03  Janis Johnson  <janis187@us.ibm.com>
+
+	PR c/39902
+	* simplify-rtx.c (simplify_binary_operation_1): Disable
+	simplifications for decimal float operations.
+
 2009-08-03  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/40943

gcc/simplify-rtx.c

@@ -1997,6 +1997,7 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
       /* x*2 is x+x and x*(-1) is -x */
       if (GET_CODE (trueop1) == CONST_DOUBLE
 	  && SCALAR_FLOAT_MODE_P (GET_MODE (trueop1))
+	  && !DECIMAL_FLOAT_MODE_P (GET_MODE (trueop1))
 	  && GET_MODE (op0) == mode)
 	{
 	  REAL_VALUE_TYPE d;

gcc/testsuite/ChangeLog

+2009-08-03  Janis Johnson  <janis187@us.ibm.com>
+
+	PR c/39902
+	* gcc.target/powerpc/pr39902-2.c: New test.
+
 2009-08-03  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/40943

gcc/testsuite/gcc.target/powerpc/pr39902-2.c

+/* Check that simplification "x*(-1)" -> "-x" is not performed for decimal
+   float types.  */
+
+/* { dg-do compile { target { powerpc*-*-linux* && powerpc_fprs } } } */
+/* { dg-options "-std=gnu99 -O -mcpu=power6" } */
+/* { dg-final { scan-assembler-not "fneg" } } */
+
+extern _Decimal32 a32, b32;
+extern _Decimal64 a64, b64;
+extern _Decimal128 a128, b128;
+
+void
+foo32 (void)
+{
+  b32 = a32 * -1.0DF;
+}
+
+void
+foo64 (void)
+{
+  b64 = a64 * -1.0DD;
+}
+
+void
+foo128 (void)
+{
+  b128 = a128 * -1.0DL;
+}