[project @ 1999-11-25 10:41:44 by simonpj]

Simon's driver changes (should have committed these a while back)

* Add -no-rules to first simplifier pass

* Move CSE pass

diff --git a/ghc/driver/ghc.lprl b/ghc/driver/ghc.lprl
index 432282d..2b66048 100644 (file)
--- a/ghc/driver/ghc.lprl
+++ b/ghc/driver/ghc.lprl
@@ -570,7 +570,6 @@ Now slurp through the arguments.
 if (  $Status == 0 && $Only_generate_deps ) {
 
     push (@MkDependHS_flags, "-o$Osuffix") if $Osuffix;
-    push (@MkDependHS_flags, "-s$BuildTag") if $BuildTag;
     # They're not (currently) needed, but we need to quote any -#include options
     foreach (@Cmd_opts) {
        s/-#include.*$/'$&'/g;
@@ -720,6 +719,10 @@ sub setupOptimiseFlags {
                                        #  ==> ...(case (case x of I# x# -> fw x#) of ...)...
                                        #  ==> ...(case x of I# x# -> case fw x# of ...)...
                                        # and now the redex (f x) isn't floatable any more
+
+               '-fno-rules',           # Similarly, don't apply any rules until after full laziness
+                                       # Notably, list fusion can prevent floating.
+
                '-fmax-simplifier-iterations2',
          ']',
 
@@ -774,14 +777,23 @@ sub setupOptimiseFlags {
                # No -finline-phase: allow all Ids to be inlined now
          ']',
 
-       '-fcse',        # CSE must immediately follow a simplification pass, because it relies
-                       # on the no-shadowing invariant.  See comments at the top of CSE.lhs
-                
        '-ffull-laziness',      # nofib/spectral/hartel/wang doubles in speed if you
                                # do full laziness late in the day.  It only happens
                                # after fusion and other stuff, so the early pass doesn't
                                # catch it.  For the record, the redex is 
                                #       f_el22 (f_el21 r_midblock)
+
+       # We want CSE to follow the final full-laziness pass, because it may
+       # succeed in commoning up things floated out by full laziness.
+       #
+       # CSE must immediately follow a simplification pass, because it relies
+       # on the no-shadowing invariant.  See comments at the top of CSE.lhs
+       # So it must NOT follow float-inwards, which can give rise to shadowing,
+       # even if its input doesn't have shadows.  Hence putting it between
+       # the two passes.
+       '-fcse',        
+                       
+
        '-ffloat-inwards',
 
 # Case-liberation for -O2.  This should be after
@@ -791,6 +803,8 @@ sub setupOptimiseFlags {
 #        ? ''
 #      : "-fliberate-case -fsimplify [ $Oopt_FB_Support -ffloat-lets-exposing-whnf -ffloat-primops-ok -fcase-of-case -fdo-case-elim -fcase-merge -fdo-lambda-eta-expansion -freuse-con -flet-to-case $Oopt_PedanticBottoms $Oopt_MaxSimplifierIterations $Oopt_ShowSimplifierProgress ]" ),
 
+#      '-fliberate-case',
+
 # Final clean-up simplification:
 
        '-fsimplify',
@@ -3129,6 +3143,9 @@ arg: while($_ = $Args[0]) {
     /^-funfolding-.*$/
                    && do { push(@HsC_flags, $_); next arg };
 
+    /^-fliberate-case-.*$/
+                   && do { push(@HsC_flags, $_); next arg };
+
     /^-funfold-casms-in-hi-file$/
                    && do { push(@HsC_flags, $_); next arg };