From 19f8036efd024ccf19cdf8426853b21e0467d0c5 Mon Sep 17 00:00:00 2001
From: wolfgang <unknown>
Date: Tue, 28 May 2002 09:22:08 +0000
Subject: [PATCH] [project @ 2002-05-28 09:22:08 by wolfgang] Preliminary
 support for GCC 3.1 on MacOS X

---
 ghc/driver/mangler/ghc-asm.lprl |   35 +++++++++++++++++++++--------------
 ghc/includes/TailCalls.h        |   20 +++++++++++++++-----
 2 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/ghc/driver/mangler/ghc-asm.lprl b/ghc/driver/mangler/ghc-asm.lprl
index a3504d3..96e9858 100644
--- a/ghc/driver/mangler/ghc-asm.lprl
+++ b/ghc/driver/mangler/ghc-asm.lprl
@@ -694,30 +694,37 @@ sub mangle_asm {
 		    $p =~ s/^\tsw\t\$28,\d+\(\$sp\)\n//;
 		    $p =~ s/__FRAME__/$FRAME/;
 		} elsif ($TargetPlatform =~ /^powerpc-apple-.*/) {
- 		    $p =~ s/^\tmflr r0\n//;
+		    $pcrel_label = $p;
+		    $pcrel_label =~ s/(.|\n)*^(L\d+\$pb):\n(.|\n)*/$2/ or $pcrel_label = "";
+
+		    $p =~ s/^\tmflr r0\n//;
  		    $p =~ s/^\tbl saveFP # f\d+\n//;
+ 		    $p =~ s/^\tbl saveFP ; save f\d+-f\d+\n//;
+		    $p =~ s/^L\d+\$pb:\n//;
  		    $p =~ s/^\tstmw r\d+,-\d+\(r1\)\n//;
    		    $p =~ s/^\tstfd f\d+,-\d+\(r1\)\n//g;
  		    $p =~ s/^\tstw r0,\d+\(r1\)\n//g;
   		    $p =~ s/^\tstwu r1,-\d+\(r1\)\n//; 
   		    $p =~ s/^\tstw r\d+,-\d+\(r1\)\n//g; 
+  		    $p =~ s/^\tbcl 20,31,L\d+\$pb\n//;
+  		    $p =~ s/^L\d+\$pb:\n//;
+  		    $p =~ s/^\tmflr r31\n//;
 		} else {
 		    print STDERR "$Pgm: unknown prologue mangling? $TargetPlatform\n";
 		}
-
-		if ($TargetPlatform =~ /^powerpc-apple-.*/) {
-			# on PowerPC, we have to keep a part of the prologue
-			# (which loads the current instruction pointer into register r31)
-		    $u_p = $p;	# $u_p is for unexpected prologue
-		    $u_p =~ s/^\tbcl 20,31,L\d+\$pb\n//;
-		    $u_p =~ s/^L\d+\$pb:\n//;
-		    $u_p =~ s/^\tmflr r31\n//;
-		    die "Prologue junk?: $u_p\n" if $u_p =~ /^\t[^\.]/
-		} else {
-		    # HWL HACK: dont die, just print a warning
-		    #print stderr  "HWL: this should die! Prologue junk?: $p\n" if $p =~ /^\t[^\.]/;
-		    die "Prologue junk?: $p\n" if $p =~ /^\t[^\.]/;
+		
+		# HWL HACK: dont die, just print a warning
+		#print stderr  "HWL: this should die! Prologue junk?: $p\n" if $p =~ /^\t[^\.]/;
+		die "Prologue junk?: $p\n" if $p =~ /^\t[^\.]/;
+		
+		if ($TargetPlatform =~ /^powerpc-apple-.*/ && $pcrel_label ne "") {
+		    # on PowerPC, we have to keep a part of the prologue
+		    # (which loads the current instruction pointer into register r31)
+		    $p .= "bcl 20,31,$pcrel_label\n";
+		    $p .= "$pcrel_label:\n";
+		    $p .= "\tmflr r31";
 		}
+		
 		# glue together what's left
 		$c = $p . $r;
 		$c =~ s/\n\t\n/\n/; # junk blank line
diff --git a/ghc/includes/TailCalls.h b/ghc/includes/TailCalls.h
index 92d4f72..2dbd99c 100644
--- a/ghc/includes/TailCalls.h
+++ b/ghc/includes/TailCalls.h
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: TailCalls.h,v 1.8 2002/03/26 10:30:44 simonmar Exp $
+ * $Id: TailCalls.h,v 1.9 2002/05/28 09:22:08 wolfgang Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -161,19 +161,29 @@ but uses $$dyncall if necessary to cope, just in case you aren't.
     { 					\
       void *target;			\
       target = (void *)(cont);    	\
+      __DISCARD__();			\
       goto *target; 	    	    	\
     }
 
 /*
+	The __DISCARD__ is there because Apple's April 2002 Beta of GCC 3.1
+	sometimes generates incorrect code otherwise.
+	It tends to "forget" to update global register variables in the presence
+	of decrement/increment operators:
+	JMP_(*(--Sp)) is wrongly compiled as JMP_(Sp[-1]).
+	Calling __DISCARD__ in between works around this problem.
+*/
+
+/*
 	I would _love_ to use the following instead,
-	but GCC fails to generate code for it if it is called for a casted
-	data pointer - which is exactly what we are going to do...
+	but some versions of Apple's GCC fail to generate code for it
+	if it is called for a casted data pointer - which is exactly what
+	we are going to do...
 
 	#define JMP_(cont)	((F_) (cont))()
 */
 
-
-#endif /* sparc_TARGET_ARCH */
+#endif /* powerpc_TARGET_ARCH */
 
 /* -----------------------------------------------------------------------------
   FUNBEGIN and FUNEND.
-- 
1.7.10.4