Hi!
The builtin_decl_explicit_p changes broke the __builtin_va_start
-> __builtin_next_arg folding, previously it was testing that
built_in_decls[BUILT_IN_NEXT_ARG] == NULL (and giving up in that case),
so the conversion missed !.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
ok for trunk/4.7?
2012-03-28 Jakub Jelinek <ja...@redhat.com>
PR middle-end/52691
* tree-ssa-ccp.c (optimize_stdarg_builtin): Optimize
__builtin_va_start to __builtin_next_arg if the latter is
builtin_decl_explicit_p rather than when it is not.
* gcc.dg/pr52691.c: New test.
--- gcc/tree-ssa-ccp.c.jj 2012-01-13 21:47:35.000000000 +0100
+++ gcc/tree-ssa-ccp.c 2012-03-28 12:48:44.358615418 +0200
@@ -2288,7 +2288,7 @@ optimize_stdarg_builtin (gimple call)
case BUILT_IN_VA_START:
if (!va_list_simple_ptr
|| targetm.expand_builtin_va_start != NULL
- || builtin_decl_explicit_p (BUILT_IN_NEXT_ARG))
+ || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG))
return NULL_TREE;
if (gimple_call_num_args (call) != 2)
--- gcc/testsuite/gcc.dg/pr52691.c.jj 2012-03-28 12:57:34.555364325 +0200
+++ gcc/testsuite/gcc.dg/pr52691.c 2012-03-28 13:11:16.020328633 +0200
@@ -0,0 +1,24 @@
+/* PR middle-end/52691 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+#include <stdarg.h>
+
+int
+foo (int a, ...)
+{
+ int b = 0, c = 0;
+ va_list ap;
+ va_start (ap, a);
+ if (a > 1)
+ b = va_arg (ap, double);
+ if (a > 2)
+ c = va_arg (ap, long long);
+ va_end (ap);
+ return a + b + c;
+}
+
+/* { dg-final { scan-tree-dump "__builtin_next_arg" "optimized" { target { {
i?86-*-* x86_64-*-* } && ia32 } } } } */
+/* { dg-final { scan-tree-dump "__builtin_next_arg" "optimized" { target {
powerpc*-*-darwin* powerpc*-*-aix* } } } } */
+/* { dg-final { scan-tree-dump "__builtin_next_arg" "optimized" { target {
powerpc*-*-linux* && lp64 } } } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
Jakub
