From ddd4dcdcde7b655fbebd17b1e684b171e72025be Mon Sep 17 00:00:00 2001
From: Julian Seward <jseward@acm.org>
Date: Tue, 17 Aug 2004 13:31:55 +0000
Subject: [PATCH] Make a start on the intermediate-representation optimiser.

git-svn-id: svn://svn.valgrind.org/vex/trunk@171
---
 VEX/Makefile        |   5 ++
 VEX/priv/ir/iropt.c | 118 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 123 insertions(+)
 create mode 100644 VEX/priv/ir/iropt.c

diff --git a/VEX/Makefile b/VEX/Makefile
index 179740d53..9b6beb054 100644
--- a/VEX/Makefile
+++ b/VEX/Makefile
@@ -10,6 +10,7 @@ PRIV_HEADERS = 	priv/host-x86/hdefs.h			\
 		priv/guest-x86/gdefs.h
 
 LIB_OBJS = 	priv/ir/irdefs.o			\
+		priv/ir/iropt.o				\
 		priv/main/vex_main.o			\
 		priv/main/vex_globals.o			\
 		priv/main/vex_util.o			\
@@ -72,6 +73,10 @@ priv/ir/irdefs.o: $(ALL_HEADERS) priv/ir/irdefs.c
 	$(CC) $(CCFLAGS) $(ALL_INCLUDES) -o priv/ir/irdefs.o \
 					 -c priv/ir/irdefs.c
 
+priv/ir/iropt.o: $(ALL_HEADERS) priv/ir/iropt.c
+	$(CC) $(CCFLAGS) $(ALL_INCLUDES) -o priv/ir/iropt.o \
+					 -c priv/ir/iropt.c
+
 priv/main/vex_main.o: $(ALL_HEADERS) priv/main/vex_main.c
 	$(CC) $(CCFLAGS) $(ALL_INCLUDES) -o priv/main/vex_main.o \
 					 -c priv/main/vex_main.c
diff --git a/VEX/priv/ir/iropt.c b/VEX/priv/ir/iropt.c
new file mode 100644
index 000000000..e1825158e
--- /dev/null
+++ b/VEX/priv/ir/iropt.c
@@ -0,0 +1,118 @@
+
+/*---------------------------------------------------------------*/
+/*---                                                         ---*/
+/*--- This file (ir/iropt.c) is                               ---*/
+/*--- Copyright (c) 2004 OpenWorks LLP.  All rights reserved. ---*/
+/*---                                                         ---*/
+/*---------------------------------------------------------------*/
+
+#include "libvex_basictypes.h"
+#include "libvex.h"
+
+#include "main/vex_util.h"
+
+
+/*---------------------------------------------------------------*/
+/*--- Finite mappery, of a sort                               ---*/
+/*---------------------------------------------------------------*/
+
+/* General map from 64-bit thing 64-bit thing.  Could be done faster
+   by hashing. */
+
+typedef
+   struct {
+      Bool*  inuse;
+      ULong* key;
+      ULong* val;
+      Int    size;
+      Int    used;
+   }
+   Hash64;
+
+static Hash64* newH64 ( void )
+{
+   Hash64* h = LibVEX_Alloc(sizeof(Hash64));
+   h->size   = 4;
+   h->used   = 0;
+   h->inuse  = LibVEX_Alloc(h->size * sizeof(Bool));
+   h->key    = LibVEX_Alloc(h->size * sizeof(ULong));
+   h->val    = LibVEX_Alloc(h->size * sizeof(ULong));
+   return h;
+}
+
+
+/* Lookup key in the map. */
+
+static Bool lookupH64 ( /*OUT*/ULong* val, Hash64* h, ULong key )
+{
+   Int i;
+   for (i = 0; i < h->used; i++) {
+      if (h->inuse[i] && h->key[i] == key) {
+         *val = h->val[i];
+         return True;
+      }
+   }
+   return False;
+}
+
+
+/* Delete any binding for key in h. */
+
+static void delFromH64 ( Hash64* h, ULong key )
+{
+   Int i;
+   for (i = 0; i < h->used; i++) {
+      if (h->inuse[i] && h->key[i] == key) {
+         h->inuse[i] = False;
+         return;
+      }
+   }
+}
+
+
+
+/* Add key->val to the map.  Replaces any existing binding for key. */
+
+static void addToH64 ( Hash64* h, ULong key, ULong val )
+{
+   Int i, j;
+
+   /* Find and replace existing binding, if any. */
+   for (i = 0; i < h->used; i++) {
+      if (h->inuse[i] && h->key[i] == key) {
+         h->val[i] = val;
+         return;
+      }
+   }
+
+   /* Ensure a space is available. */
+   if (h->used == h->size) {
+      /* Copy into arrays twice the size. */
+      Bool*  inuse2 = LibVEX_Alloc(2 * h->size * sizeof(Bool));
+      ULong* key2   = LibVEX_Alloc(2 * h->size * sizeof(ULong));
+      ULong* val2   = LibVEX_Alloc(2 * h->size * sizeof(ULong));
+      for (i = j = 0; i < h->size; i++) {
+         if (!h->inuse[i]) continue;
+         inuse2[j] = True;
+         key2[j] = h->key[i];
+         val2[j] = h->val[i];
+         j++;
+      }
+      h->used = j;
+      h->size *= 2;
+      h->inuse = inuse2;
+      h->key = key2;
+      h->val = val2;
+   }
+
+   /* Finally, add it. */
+   vassert(h->used < h->size);
+   h->inuse[h->used] = True;
+   h->key[h->used] = key;
+   h->key[h->used] = val;
+   h->used++;
+}
+
+/*---------------------------------------------------------------*/
+/*--- end                                          ir/iropt.c ---*/
+/*---------------------------------------------------------------*/