From bb5034594dba704b2a8d2aebfad2d9b5101c450d Mon Sep 17 00:00:00 2001
From: Gareth Rees <gdr@ravenbrook.com>
Date: Fri, 22 Jun 2018 14:09:56 +0100
Subject: [PATCH] Event alignment doesn't need to be mps_pf_align (that's
 wasteful on windows).

Copied from Perforce
 Change: 194091
---
 mps/code/event.c    | 4 ++--
 mps/code/event.h    | 6 +++---
 mps/code/eventcom.h | 3 +++
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/mps/code/event.c b/mps/code/event.c
index 5b4a11eac93..4a7575f3390 100644
--- a/mps/code/event.c
+++ b/mps/code/event.c
@@ -53,7 +53,7 @@ static Res eventClockSync(void)
   Res res;
   size_t size;
 
-  size= size_tAlignUp(sizeof(eventClockSyncStruct), MPS_PF_ALIGN);
+  size= size_tAlignUp(sizeof(eventClockSyncStruct), EVENT_ALIGN);
   eventClockSyncStruct.code = EventEventClockSyncCode;
   eventClockSyncStruct.size = (EventSize)size;
   EVENT_CLOCK(eventClockSyncStruct.clock);
@@ -182,7 +182,7 @@ void EventInit(void)
   EVENT_PARAM_CHECK_##sort(name, index, ident)
 
 #define EVENT_CHECK(X, name, code, always, kind) \
-  AVER(size_tAlignUp(sizeof(Event##name##Struct), MPS_PF_ALIGN) \
+  AVER(size_tAlignUp(sizeof(Event##name##Struct), EVENT_ALIGN) \
        <= EventSizeMAX); \
   AVER(Event##name##Code == code); \
   AVER(0 <= code); \
diff --git a/mps/code/event.h b/mps/code/event.h
index 987068feb13..57865bd00f9 100644
--- a/mps/code/event.h
+++ b/mps/code/event.h
@@ -48,13 +48,13 @@ extern char *EventLogged[EventKindLIMIT];
 extern Word EventKindControl;
 
 
-/* Write event into buffer and maybe flush the buffer. */
+/* EVENT_BEGIN -- flush buffer if necessary and write event header */
 
 #define EVENT_BEGIN(name, structSize)                                   \
   BEGIN {                                                               \
     if(EVENT_ALL || Event##name##Always) { /* see config.h */           \
       Event##name##Struct *_event;                                      \
-      size_t _size = size_tAlignUp(structSize, MPS_PF_ALIGN);           \
+      size_t _size = size_tAlignUp(structSize, EVENT_ALIGN);            \
       if (_size > (size_t)(EventBuffer[Event##name##Kind]               \
                            + EventBufferSIZE                            \
                            - EventLogged[Event##name##Kind]))           \
@@ -62,7 +62,7 @@ extern Word EventKindControl;
       AVER(_size <= (size_t)(EventBuffer[Event##name##Kind]             \
                              + EventBufferSIZE                          \
                              - EventLogged[Event##name##Kind]));        \
-      _event = (void *)(EventLogged[Event##name##Kind]);                \
+      _event = (void *)EventLogged[Event##name##Kind];                  \
       _event->code = Event##name##Code;                                 \
       _event->size = (EventSize)_size;                                  \
       EVENT_CLOCK(_event->clock);
diff --git a/mps/code/eventcom.h b/mps/code/eventcom.h
index 29054edc777..528b8769980 100644
--- a/mps/code/eventcom.h
+++ b/mps/code/eventcom.h
@@ -115,6 +115,9 @@ typedef unsigned char EventFB;          /* Boolean */
 
 EVENT_LIST(EVENT_STRUCT, X)
 
+/* Maximum alignment requirement of any event type. */
+#define EVENT_ALIGN (sizeof(EventFP))
+
 
 /* Event -- event union type
  *