PATCH: PR target/64200: CE: in decide_alg, at config/i386/i386.c:24510 with -mmemcpy-strategy=libcall:-1:align -minline-stringops-dynamically fails with -mcmodel=large -fpic

[H.J. Lu]

GCC manual says:

'-minline-stringops-dynamically'
     For string operations of unknown size, use run-time checks with
     inline code for small blocks and a library call for large blocks.

we get

Breakpoint 5, decide_alg (count=0, expected_size=-1, min_size=0, 
    max_size=2147483647, memset=false, zero_memset=false, 
    dynamic_check=0x7fffffffc924, noalign=0x7fffffffc923)
    at /export/gnu/import/git/gcc/gcc/config/i386/i386.c:24510
24510         if (TARGET_INLINE_STRINGOPS_DYNAMICALLY)
(gdb) p alg
$1 = libcall
(gdb) 

libcall is a valid choice here for -minline-stringops-dynamically.  This
patch avoids assert "alg != libcall" for
TARGET_INLINE_STRINGOPS_DYNAMICALLY.  OK for trunk and 4.9 branch?

Thanks.


H.J.
---
gcc/

2014-12-05  H.J. Lu  <hongjiu...@intel.com>

        PR target/64200
        * config/i386/i386.c (decide_alg): Don't assert "alg != libcall"
        for TARGET_INLINE_STRINGOPS_DYNAMICALLY.

gcc/testsuite/

2014-12-05  H.J. Lu  <hongjiu...@intel.com>

        PR target/64200
        * gcc.target/i386/memcpy-strategy-4.c: New test.

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 4f1a18b..aaf0b38 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -24507,9 +24507,10 @@ decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT 
expected_size,
       alg = decide_alg (count, max / 2, min_size, max_size, memset,
                        zero_memset, dynamic_check, noalign);
       gcc_assert (*dynamic_check == -1);
-      gcc_assert (alg != libcall);
       if (TARGET_INLINE_STRINGOPS_DYNAMICALLY)
        *dynamic_check = max;
+      else
+       gcc_assert (alg != libcall);
       return alg;
     }
   return (alg_usable_p (algs->unknown_size, memset)
diff --git a/gcc/testsuite/gcc.target/i386/memcpy-strategy-4.c 
b/gcc/testsuite/gcc.target/i386/memcpy-strategy-4.c
new file mode 100644
index 0000000..5c51248
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/memcpy-strategy-4.c
@@ -0,0 +1,21 @@
+/* PR target/64200 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=atom -mmemcpy-strategy=libcall:-1:align 
-minline-stringops-dynamically" } */
+
+#include <stdarg.h>
+
+extern void bar(char *x);
+
+void foo (int size, ...)
+{
+  struct
+  {
+    char x[size];
+  } d;
+
+  va_list ap;
+  va_start(ap, size);
+  d = va_arg(ap, typeof (d));
+  va_end(ap);
+  bar(d.x);
+}