X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fcmm%2Fcmm-notes;h=4a87911ec544ea5d076f73ea86a61751f50e74c0;hp=c0ccadfbecaa9673906f4e639d1adc4713733a15;hb=de2d10e18ce23e5df7fa4f3433b85c95d6092b58;hpb=ce8ae48278e629b8143edebe05347d92723fdf67

diff --git a/compiler/cmm/cmm-notes b/compiler/cmm/cmm-notes
index c0ccadf..4a87911 100644
--- a/compiler/cmm/cmm-notes
+++ b/compiler/cmm/cmm-notes
@@ -1,3 +1,34 @@
+More notes (June 11)
+~~~~~~~~~~~~~~~~~~~~
+* Possible refactoring: Nuke AGraph in favour of 
+      mkIfThenElse :: Expr -> Graph -> Graph -> FCode Graph
+  or even
+      mkIfThenElse :: HasUniques m => Expr -> Graph -> Graph -> m Graph
+  (Remmber that the .cmm file parser must use this function)
+
+  or parameterise FCode over its envt; the CgState part seem useful for both
+
+* "Remove redundant reloads" in CmmSpillReload should be redundant; since
+  insertLateReloads is now gone, every reload is reloading a live variable.
+  Test and nuke.
+
+* Sink and inline S(RegSlot(x)) = e in precisely the same way that we
+  sink and inline x = e
+
+* Stack layout is very like register assignment: find non-conflicting assigments.
+  In particular we can use colouring or linear scan (etc).
+
+  We'd fine-grain interference (on a word by word basis) to get maximum overlap.
+  But that may make very big interference graphs.  So linear scan might be
+  more attactive.
+
+  NB: linear scan does on-the-fly live range splitting.
+
+* When stubbing dead slots be careful not to write into an area that
+  overlaps with an area that's in use.  So stubbing needs to *follow* 
+  stack layout.
+
+
 More notes (May 11)
 ~~~~~~~~~~~~~~~~~~~
 In CmmNode, consider spliting CmmCall into two: call and jump
@@ -217,7 +248,7 @@ CmmCvt.hs      Conversion between old and new Cmm reps
 CmmOpt.hs      Hopefully-redundant optimiser
 
 -------- Stuff to keep ------------
-CmmCPS.hs                 Driver for new pipeline
+CmmPipeline.hs            Driver for new pipeline
 
 CmmLive.hs                Liveness analysis, dead code elim
 CmmProcPoint.hs           Identifying and splitting out proc-points
@@ -264,24 +295,24 @@ BlockId.hs          BlockId, BlockEnv, BlockSet
       type RawCmm = GenCmm CmmStatic [CmmStatic] (ListGraph CmmStmt)
 
 * HscMain.tryNewCodeGen
-    - STG->Cmm:    StgCmm.codeGen (new codegen)
-    - Optimise:    CmmContFlowOpt (simple optimisations, very self contained)
-    - Cps convert: CmmCPS.protoCmmCPS 
-    - Optimise:    CmmContFlowOpt again
-    - Convert:     CmmCvt.cmmOfZgraph (convert to old rep) very self contained
+    - STG->Cmm:         StgCmm.codeGen (new codegen)
+    - Optimize and CPS: CmmPipeline.cmmPipeline
+    - Convert:          CmmCvt.cmmOfZgraph (convert to old rep) very self contained
 
 * StgCmm.hs  The new STG -> Cmm conversion code generator
   Lots of modules StgCmmXXX
 
 
 ----------------------------------------------------
-      CmmCPS.protoCmmCPS   The new pipeline
+      CmmPipeline.cmmPipeline   The new pipeline
 ----------------------------------------------------
 
-CmmCPS.protoCmmCPS:
-   1. Do cpsTop for each procedures separately
-   2. Build SRT representation; this spans multiple procedures
-	(unless split-objs)
+CmmPipeline.cmmPipeline:
+   1. Do control flow optimization
+   2. Do cpsTop for each procedures separately
+   3. Build SRT representation; this spans multiple procedures
+        (unless split-objs)
+   4. Do control flow optimization on all resulting procedures
 
 cpsTop:
   * CmmCommonBlockElim.elimCommonBlocks:
@@ -419,7 +450,7 @@ a dominator analysis, using the Dataflow Engine.
   f's keep-alive refs to include h1.
 
 * The SRT info is the C_SRT field of Cmm.ClosureTypeInfo in a
-  CmmInfoTable attached to each CmmProc.  CmmCPS.toTops actually does
+  CmmInfoTable attached to each CmmProc.  CmmPipeline.toTops actually does
   the attaching, right at the end of the pipeline.  The C_SRT part
   gives offsets within a single, shared table of closure pointers.