Switch x86 and x86-64 to __builtin_bswap*.
Bug: 18597513
Change-Id: I0781208efb3b560d7c6fa48f41be7bc6fc83521e
diff --git a/libc/arch-x86/include/machine/endian.h b/libc/arch-x86/include/machine/endian.h
index e1506b1..5feebd8 100644
--- a/libc/arch-x86/include/machine/endian.h
+++ b/libc/arch-x86/include/machine/endian.h
@@ -27,33 +27,14 @@
#ifndef _MACHINE_ENDIAN_H_
#define _MACHINE_ENDIAN_H_
-#ifdef __GNUC__
-
-#define __swap32md(x) __statement({ \
- uint32_t __swap32md_x = (x); \
- \
- __asm ("bswap %0" : "+r" (__swap32md_x)); \
- __swap32md_x; \
-})
-
-#define __swap64md(x) __statement({ \
- uint64_t __swap64md_x = (x); \
- \
- (uint64_t)__swap32md(__swap64md_x >> 32) | \
- (uint64_t)__swap32md(__swap64md_x & 0xffffffff) << 32; \
-})
-#define __swap16md(x) __statement({ \
- uint16_t __swap16md_x = (x); \
- \
- __asm ("rorw $8, %w0" : "+r" (__swap16md_x)); \
- __swap16md_x; \
-})
+/* Use GCC builtins */
+#define __swap16md(x) __builtin_bswap16(x)
+#define __swap32md(x) __builtin_bswap32(x)
+#define __swap64md(x) __builtin_bswap64(x)
/* Tell sys/endian.h we have MD variants of the swap macros. */
#define MD_SWAP
-#endif /* __GNUC__ */
-
#define _BYTE_ORDER _LITTLE_ENDIAN
#include <sys/types.h>
#include <sys/endian.h>
diff --git a/libc/arch-x86_64/include/machine/endian.h b/libc/arch-x86_64/include/machine/endian.h
index 8a3b0c5..2c493b2 100644
--- a/libc/arch-x86_64/include/machine/endian.h
+++ b/libc/arch-x86_64/include/machine/endian.h
@@ -27,34 +27,14 @@
#ifndef _MACHINE_ENDIAN_H_
#define _MACHINE_ENDIAN_H_
-#ifdef __GNUC__
-
-#define __swap32md(x) __statement({ \
- u_int32_t __swap32md_x = (x); \
- \
- __asm ("bswap %0" : "+r" (__swap32md_x)); \
- __swap32md_x; \
-})
-
-#define __swap64md(x) __statement({ \
- u_int64_t __swap64md_x = (x); \
- \
- __asm ("bswapq %0" : "+r" (__swap64md_x)); \
- __swap64md_x; \
-})
-
-#define __swap16md(x) __statement({ \
- u_int16_t __swap16md_x = (x); \
- \
- __asm ("rorw $8, %w0" : "+r" (__swap16md_x)); \
- __swap16md_x; \
-})
+/* Use GCC builtins */
+#define __swap16md(x) __builtin_bswap16(x)
+#define __swap32md(x) __builtin_bswap32(x)
+#define __swap64md(x) __builtin_bswap64(x)
/* Tell sys/endian.h we have MD variants of the swap macros. */
#define MD_SWAP
-#endif /* __GNUC__ */
-
#define _BYTE_ORDER _LITTLE_ENDIAN
#include <sys/types.h>
#include <sys/endian.h>
