C11 Annex G corrects a bug in the sample complex divide implementation
from C99 that was identified in
<http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1496.htm>.
GCC's implementation of complex divide is different enough from the Annex
G implementation not to have this bug. I've applied this patch to add a
testcase that verifies the bug is absent. Tested
x86_64-unknown-linux-gnu.
Index: gcc/testsuite/ChangeLog
===================================================================
--- gcc/testsuite/ChangeLog (revision 204731)
+++ gcc/testsuite/ChangeLog (working copy)
@@ -1,5 +1,9 @@
2013-11-13 Joseph Myers <jos...@codesourcery.com>
+ * gcc.dg/c11-complex-1.c: New test.
+
+2013-11-13 Joseph Myers <jos...@codesourcery.com>
+
* gcc.dg/atomic/stdatomic-vm.c, gcc.dg/auto-type-1.c,
gcc.dg/auto-type-2.c: New tests.
Index: gcc/testsuite/gcc.dg/c11-complex-1.c
===================================================================
--- gcc/testsuite/gcc.dg/c11-complex-1.c (revision 0)
+++ gcc/testsuite/gcc.dg/c11-complex-1.c (revision 0)
@@ -0,0 +1,42 @@
+/* Test complex divide does not have the bug identified in N1496. */
+/* { dg-do run } */
+/* { dg-options "-std=c11 -pedantic-errors" } */
+
+extern void abort (void);
+extern void exit (int);
+
+#define CMPLX(x, y) __builtin_complex ((double) (x), (double) (y))
+#define CMPLXF(x, y) __builtin_complex ((float) (x), (float) (y))
+#define CMPLXL(x, y) __builtin_complex ((long double) (x), (long double) (y))
+#define NAN __builtin_nanf ("")
+#define isnan(x) __builtin_isnan (x)
+
+volatile _Complex float num_f = CMPLXF (1, 1);
+volatile _Complex float den_f = CMPLXF (0, NAN);
+volatile _Complex float res_f, cres_f = CMPLXF (1, 1) / CMPLXF (0, NAN);
+
+volatile _Complex double num_d = CMPLX (1, 1);
+volatile _Complex double den_d = CMPLX (0, NAN);
+volatile _Complex double res_d, cres_d = CMPLX (1, 1) / CMPLX (0, NAN);
+
+volatile _Complex long double num_ld = CMPLXL (1, 1);
+volatile _Complex long double den_ld = CMPLXL (0, NAN);
+volatile _Complex long double res_ld, cres_ld = CMPLXL (1, 1) / CMPLXL (0,
NAN);
+
+int
+main (void)
+{
+ res_f = num_f / den_f;
+ if (!isnan (__real__ res_f) || !isnan (__imag__ res_f)
+ || !isnan (__real__ cres_f) || !isnan (__imag__ cres_f))
+ abort ();
+ res_d = num_d / den_d;
+ if (!isnan (__real__ res_d) || !isnan (__imag__ res_d)
+ || !isnan (__real__ cres_d) || !isnan (__imag__ cres_d))
+ abort ();
+ res_ld = num_ld / den_ld;
+ if (!isnan (__real__ res_ld) || !isnan (__imag__ res_ld)
+ || !isnan (__real__ cres_ld) || !isnan (__imag__ cres_ld))
+ abort ();
+ exit (0);
+}
--
Joseph S. Myers
jos...@codesourcery.com
