i386: Make _m_prefetchw parameter const-qualified

Match Clang's declaration of _m_prefetchw to avoid requiring
const_cast<void *> at call sites.

gcc/ChangeLog:

	* config/i386/prfchwintrin.h (_m_prefetchw): Take
	volatile const void * instead of void *.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/prfchw-Wcast-qual-1.c: New test.

Signed-off-by: oltolm <oleg.tolmatcev@gmail.com>

diff --git a/gcc/config/i386/prfchwintrin.h b/gcc/config/i386/prfchwintrin.h
index af3bded18e06283c172b79dc9299eb63ae3598f6..2ac190964decbc51356c4fb3787c0434af73f55e 100644 (file)
--- a/gcc/config/i386/prfchwintrin.h
+++ b/gcc/config/i386/prfchwintrin.h
@@ -29,9 +29,9 @@
 #define _PRFCHWINTRIN_H_INCLUDED
 
 extern __inline void __attribute__((__gnu_inline__, __always_inline__, __artificial__))
-_m_prefetchw (void *__P)
+_m_prefetchw (volatile const void *__P)
 {
-  __builtin_prefetch (__P, 1, 3 /* _MM_HINT_T0 */);
+  __builtin_prefetch ((const void *) __P, 1, 3 /* _MM_HINT_T0 */);
 }
 
 #endif /* _PRFCHWINTRIN_H_INCLUDED */

diff --git a/gcc/testsuite/gcc.target/i386/prfchw-Wcast-qual-1.c b/gcc/testsuite/gcc.target/i386/prfchw-Wcast-qual-1.c
new file mode 100644 (file)
index 0000000..c6e86aa
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/prfchw-Wcast-qual-1.c
@@ -0,0 +1,16 @@
+/* Verify that _m_prefetchw does not produce -Wcast-qual warnings when\r
+   included as a system header.  The cast (const void *) drops volatile\r
+   from volatile const void *, which would trigger -Wcast-qual if not\r
+   in a system header.  */\r
+/* { dg-do compile } */\r
+/* { dg-options "-mprfchw -O2 -Wcast-qual" } */\r
+\r
+#include <x86intrin.h>\r
+\r
+void\r
+prefetchw_cast_qual_test (volatile void *p)\r
+{\r
+    _m_prefetchw (p);\r
+}\r
+\r
+/* { dg-bogus "cast discards .volatile. qualifier" "" { target *-*-* } 0 } */\r