From d20b113a00bfd5269ec2d05a8abe33fdd59bfc95 Mon Sep 17 00:00:00 2001
From: Adam Sampson <ats@offog.org>
Date: Wed, 25 Apr 2007 21:24:20 +0000
Subject: [PATCH] Generate AFTER using > and MINUS

---
 fco2/GenerateC.hs     |  1 -
 fco2/SimplifyExprs.hs | 18 ++++++++++++++++++
 fco2/fco_support.h    | 13 -------------
 3 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/fco2/GenerateC.hs b/fco2/GenerateC.hs
index e9b7476..965b9fc 100644
--- a/fco2/GenerateC.hs
+++ b/fco2/GenerateC.hs
@@ -440,7 +440,6 @@ genDyadic _ A.Less e f = genSimpleDyadic "<" e f
 genDyadic _ A.More e f = genSimpleDyadic ">" e f
 genDyadic _ A.LessEq e f = genSimpleDyadic "<=" e f
 genDyadic _ A.MoreEq e f = genSimpleDyadic ">=" e f
-genDyadic m A.After e f = genFuncDyadic m "after" e f
 --}}}
 
 --{{{  input/output items
diff --git a/fco2/SimplifyExprs.hs b/fco2/SimplifyExprs.hs
index 4f1f346..2078275 100644
--- a/fco2/SimplifyExprs.hs
+++ b/fco2/SimplifyExprs.hs
@@ -16,6 +16,7 @@ simplifyExprs = runPasses passes
   where
     passes =
       [ ("Convert FUNCTIONs to PROCs", functionsToProcs)
+      , ("Convert AFTER to MINUS", removeAfter)
       , ("Pull up definitions", pullUp)
       ]
 
@@ -54,6 +55,23 @@ functionsToProcs = doGeneric `extM` doSpecification
     vpToProc (A.ValOfSpec m s vp) vs = A.ProcSpec m s (vpToProc vp vs)
     vpToProc (A.ValOf m p el) vs = A.Seq m [p, A.Assign m vs el]
 
+-- | Convert AFTER expressions to the equivalent using MINUS (which is how the
+-- occam 3 manual defines AFTER).
+removeAfter :: Data t => t -> PassM t
+removeAfter = doGeneric `extM` doExpression
+  where
+    doGeneric :: Data t => t -> PassM t
+    doGeneric = gmapM removeAfter
+
+    doExpression :: A.Expression -> PassM A.Expression
+    doExpression (A.Dyadic m A.After a b)
+        =  do a' <- removeAfter a
+              b' <- removeAfter b
+              t <- typeOfExpression a'
+              let zero = A.ExprLiteral m $ A.Literal m t $ A.IntLiteral m "0"
+              return $ A.Dyadic m A.More (A.Dyadic m A.Minus a' b') zero
+    doExpression e = doGeneric e
+
 -- | Find things that need to be moved up to their enclosing process, and do
 -- so.
 pullUp :: Data t => t -> PassM t
diff --git a/fco2/fco_support.h b/fco2/fco_support.h
index bc77dcd..e994e08 100644
--- a/fco2/fco_support.h
+++ b/fco2/fco_support.h
@@ -100,11 +100,6 @@ static int occam_check_index (int i, int limit, const char *pos) {
 		} \
 		return a % b; \
 	}
-#define MAKE_AFTER(type) \
-	static bool occam_after_##type (type, type) occam_unused; \
-	static bool occam_after_##type (type a, type b) { \
-		return (a - b) > 0; \
-	}
 
 //{{{ char
 MAKE_RANGE_CHECK(char, "%d")
@@ -113,7 +108,6 @@ MAKE_SUBTR(char)
 MAKE_MUL(char)
 MAKE_DIV(char)
 MAKE_REM(char)
-MAKE_AFTER(char)
 //}}}
 //{{{ int16_t
 MAKE_RANGE_CHECK(int16_t, "%d")
@@ -122,7 +116,6 @@ MAKE_SUBTR(int16_t)
 MAKE_MUL(int16_t)
 MAKE_DIV(int16_t)
 MAKE_REM(int16_t)
-MAKE_AFTER(int16_t)
 //}}}
 //{{{ int
 MAKE_RANGE_CHECK(int, "%d")
@@ -131,7 +124,6 @@ MAKE_SUBTR(int)
 MAKE_MUL(int)
 MAKE_DIV(int)
 MAKE_REM(int)
-MAKE_AFTER(int)
 //}}}
 //{{{ int32_t
 MAKE_RANGE_CHECK(int32_t, "%d")
@@ -140,7 +132,6 @@ MAKE_SUBTR(int32_t)
 MAKE_MUL(int32_t)
 MAKE_DIV(int32_t)
 MAKE_REM(int32_t)
-MAKE_AFTER(int32_t)
 //}}}
 //{{{ int64_t
 MAKE_RANGE_CHECK(int64_t, "%lld")
@@ -149,7 +140,6 @@ MAKE_SUBTR(int64_t)
 MAKE_MUL(int64_t)
 MAKE_DIV(int64_t)
 MAKE_REM(int64_t)
-MAKE_AFTER(int64_t)
 //}}}
 // FIXME range checks for float and double shouldn't work this way
 //{{{ float
@@ -158,7 +148,6 @@ MAKE_ADD(float)
 MAKE_SUBTR(float)
 MAKE_MUL(float)
 MAKE_DIV(float)
-MAKE_AFTER(float)
 //}}}
 //{{{ double
 MAKE_RANGE_CHECK(double, "%d")
@@ -166,7 +155,6 @@ MAKE_ADD(double)
 MAKE_SUBTR(double)
 MAKE_MUL(double)
 MAKE_DIV(double)
-MAKE_AFTER(double)
 //}}}
 
 #undef MAKE_RANGE_CHECK
@@ -175,6 +163,5 @@ MAKE_AFTER(double)
 #undef MAKE_MUL
 #undef MAKE_DIV
 #undef MAKE_REM
-#undef MAKE_AFTER
 
 #endif