Changeset 78422 in vbox

Timestamp:

May 7, 2019 9:55:50 AM (6 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

130421

Message:

iprt/asm-amd64-x86.h: Don't use readeflags & writeeflags as they (or at least the latter) seems to confuse compiler optimizations and also is said to have other reordering issues. bugref:9180

File:

• trunk/include/iprt/asm-amd64-x86.h (modified) (6 diffs)

trunk/include/iprt/asm-amd64-x86.h

@@ -81 +81 @@
 # endif
 # if RT_INLINE_ASM_USES_INTRIN >= 15
-#  pragma intrinsic(__readeflags)
-#  pragma intrinsic(__writeeflags)
+/*#  pragma intrinsic(__readeflags)  - buggy intrinsics in VC++ 2010, reordering/optimizers issues
+#  pragma intrinsic(__writeeflags) */
 #  pragma intrinsic(__rdtscp)
 # endif
@@ -552 +552 @@
  * @returns [RE]FLAGS.
  */
-#if RT_INLINE_ASM_EXTERNAL && RT_INLINE_ASM_USES_INTRIN < 15
+#if RT_INLINE_ASM_EXTERNAL /*&& RT_INLINE_ASM_USES_INTRIN < 15 - buggy intrinsics in VC++ 2010, reordering/optimizers issues. */
 RT_ASM_DECL_PRAGMA_WATCOM(RTCCUINTREG) ASMGetFlags(void);
 #else
@@ -591 +591 @@
  * @param   uFlags      The new [RE]FLAGS value.
  */
-#if RT_INLINE_ASM_EXTERNAL && RT_INLINE_ASM_USES_INTRIN < 15
+#if RT_INLINE_ASM_EXTERNAL /*&& RT_INLINE_ASM_USES_INTRIN < 15 - see __readeflags() above. */
 RT_ASM_DECL_PRAGMA_WATCOM(void) ASMSetFlags(RTCCUINTREG uFlags);
 #else
@@ -630 +630 @@
  * @param   fOrEfl      Flags to be set.
  */
-#if RT_INLINE_ASM_EXTERNAL && RT_INLINE_ASM_USES_INTRIN < 15
+#if RT_INLINE_ASM_EXTERNAL /*&& RT_INLINE_ASM_USES_INTRIN < 15 - buggy intrinsics in VC++ 2010, reordering/optimizers issues. */
 RT_ASM_DECL_PRAGMA_WATCOM(RTCCUINTREG) ASMChangeFlags(RTCCUINTREG fAndEfl, RTCCUINTREG fOrEfl);
 #else
@@ -697 +697 @@
  * @param   fOrEfl      The flags to be set (ORed in).
  */
-#if RT_INLINE_ASM_EXTERNAL && RT_INLINE_ASM_USES_INTRIN < 15
+#if RT_INLINE_ASM_EXTERNAL /*&& RT_INLINE_ASM_USES_INTRIN < 15 - buggy intrinsics in VC++ 2010, reordering/optimizers issues. */
 RT_ASM_DECL_PRAGMA_WATCOM(RTCCUINTREG) ASMAddFlags(RTCCUINTREG fOrEfl);
 #else
@@ -752 +752 @@
  * @param   fAndEfl      The flags to keep.
  */
-#if RT_INLINE_ASM_EXTERNAL && RT_INLINE_ASM_USES_INTRIN < 15
+#if RT_INLINE_ASM_EXTERNAL /*&& RT_INLINE_ASM_USES_INTRIN < 15 - buggy intrinsics in VC++ 2010, reordering/optimizers issues. */
 RT_ASM_DECL_PRAGMA_WATCOM(RTCCUINTREG) ASMClearFlags(RTCCUINTREG fAndEfl);
 #else